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1. Firing State Sequence tDetect is Enabled At 11 53 40 A tDetect Enabled but not Fired At 11 53 41 tShout is Enabled At 11 53 40 tShout is Fired At 11 53 42 tDetect is Not_Enabled At 11 53 41 tDetect Enabled but not Fired At 11 53 44 tShout is completed At 11 53 44 n qm tDetect is Enabled amp t 11 53 43 tShout is Enabled At 11 53 43 tDetect is Not Enabled At 11 53 44 tDetect is Fired At 11 53 47 tShout is Fired At 11 53 48 tDetect is Enabled At 11 53 44 tShout is Enabled At 11 53 44 tShout is completed At 11 53 48 I amp haut is Fired At 6550 Fig 75 Sequence of enable and firing There are also other tools on the R T monitor This are again enhanced tools help to control the simulation process The panel that contains this is 102 Commands stop Contine Reset Exit Fig 76 Control panel 0 5 shows the speed interval in second The other buttons were clearly described in chapter 4 Whenever a user click on the stop button the simulation stops until the continue button is pressed or the ok button from the pop up massage box is clicked The message box that informs the user to do so is looks like below Stopped press ok ar click on continue Fig 77 Message box that appears when the stop button clicked The R T monitor also provides a text display on the main display to inform about the total number of place the tran
2. 8 2 1 Systems modelling and simulation ceeccceesscccceesececceececeeescceceeececsueeceeeeuecesseneceeseneeeetas 8 2 2 Discrete events dynamic systems DEDS cccccccccsssecccceeesececeseeesecceeseeeeeeeseeeeeeeeeseegees 10 2 3 Continuous event time SIMUIATION eccixecscksu vere av ERU EXYV ha rer Ee EUR ENV ETE EEUU Eae ea SOY ORE eR GI RAN Ga 12 2 4 uil 12 2A PNAC EDU TMI 13 EUM gues id cc 14 D MEI e 14 2440 Are WEIEN cenre Fives g Ed deam o qeessdeen Genera ursa dnb E furaspE E e pEI UM oPde UPS 15 PESCE Tm E E Hm 15 2 4 6 Mathematical representation of a Petri Net cccccccessccceessececeesececeeeseceeeeeceseeneceeseeeeeetas 15 24 7 Firing Seguence andfiring UME euer eispveS set bus tuer ree aba aas ETI I cEUb Udine ber PER DE La En Scr PCE bue DE 16 2 5 Extended Petri MEt NN EET E T E 16 Zo ped PET NO sud apetece ite oua DUE MED Ede sad iT ade qeicaduR MeEONE UE 17 2 5 2 SCOCMASUC LI Be POCEPINBES cesssesderiviese Euro eER PUn ERU LD NE UR be YE ensuite RU N PI UN PEDE RIVE ES 17 253 COLOUR Crt CEN aos cider t ebore ktuburst aie dusa dior n ertrHi nU uses ES 17 2 6 Cp ETHER 17 20 1 The StHUCEUFEOT GPOHSIIVI cine initam ep eris does item ed teid missi d t
3. Matlab Root Figure pM Uicontrol Axes Uimenu Push button Image File Edit box Line Edit Static text Surfaces Help Uitable Plot Uislider Fig 41 MATLAB GUIDE tool components For working with a large system the best way to work with a gui is a GUIDE Because GUIDE by itself would minimize the mess by creating all call events and gives also a template The three main components for MATLAB gui are a Component or object Objects like Pushbutton listbox uitable textbox and so on Guide provides an easy drag and drop method in order to create a desired GUI component Reset Fig 42 Example of a component 47 b Figures Figures are window forms in MATLAB Any visual studio tool has form designer and in MATLAB these forms are called figures In the normal MATLAB operation figures are created automatically whenever the MATLAB plot function plots a data Empty figures can also be created with the function figure on the command window It can also be used to plot any kind of gui components by adding the function arguments B Operate_GPenSIM Files MSF Filename DocumentsWM ATLABAThesis RT Monitor PDF Filename Documents MATLAB Thesis RT_Monitor TOF file name S MATLAB ThesisiRT_Monitorit1_pre m G
4. 10 set handles edit15 String tem pl set handles edit15 Visible on elseif stremp s infoplcs text73 tem pl sprintf tem pl curr trans Tok num2str tokens to be consumed At num 2str rt clock string From curr Place 10 tem pl sprintf tem pl 10 set handles edit16 String tem pl set handles edit16 Visible on elseif stremp s infoplcs text74 tem pl sprintf tem pl curr trans Tok num2str tokens to be consumed At num 2str rt clock string From curr Place 10 tem pl sprintf tem pl 10 set handles edit17 String tem pl set handles edit17 Visible on end end end 150 end consume_tokens m Note that the blue highlight is the original source code of the GpenSIM consume_tokens m function delta X index OP inherited color set inherited costs consume tokens transition selected toklD global PN Ps PN No of places A PN incidence matrix token removals from input place input_weigths A transition 1 Ps extracting the weight of input arcs disp input_weigths disp input_weigths inherited color set inherited costs 0 Move input tokens into Virtual places as virtual tokens PN X PN X input weigths 96 take tokens from input places PN VX PN VX input weigths and push into Virtual places PN global transitions transition absorbed tokens i
5. end Executes on slider movement function slider2 Callback hObject eventdata handles Hints get hObject Value returns position of slider get hObject Min and get hObject Max to determine range of slider Executes during object creation after setting all properties function slider2 CreateFcn hObject eventdata handles Hint slider controls usually have a light gray background if isequal get hObject BackgroundColor get 0 defaultUicontrolBackgroundColor set hObject BackgroundColor 9 9 9 end function edit10 Callback hObject eventdata handles 96 Executes during object creation after setting all properties function edit10 CreateFcn hObject eventdata handles Hint edit controls usually have a white background on Windows See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit11 Callback hObject eventdata handles Executes during object creation after setting all properties function edit11 CreateFcn hObject eventdata handles Hint edit controls usually have a white background on Windows See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit12 Callback hObject eventdata ha
6. LY 2 tPEDES BEEP 1 tEM Y ON 1 tEM Y OFF 1 allothers 0 1 The firing times of the transitions differ from each other For example the firing time of red tR_ON light is on for five seconds 3 The TDF files COMMON PRE COMMON TDF This common precondition of the transitions checks whether the current enabled transition the enabled transition in gpensim structure PN by using a MATLAB string comparison method and send command to the NXT device to turn on the appropriate light if strcmp transition name tR_ON disp ON RED SwitchLamp global info lightRED on elseif strcmp transition name tRY disp ON RED YELLOW SwitchLamp global info lightRED on SwitchLamp global info lightYELLOW on 93 The above code is the first two if close blocks just added to show how the lights are enabled to be on Similarly in this common precondition file the conditions for a pedestrian are checked and let the NXT beep sound to be triggered Note that the pedestrian is on as the pedestrian crossing button is pressed In this model the touch button is used to do so if strcmp transition name tPEDES BEEP disp ON pedes beep NXT PlayTone 440 500 The pedestrian transition fires for some amount of time then returns to the normal simulation cycle This is done by decrementing the count by 1 as shown below if strcmp transition name tPEDES CYCLE if not globa
7. elseif stremp s text70 set handles text79 String num2str XO source nr elseif stremp s text71 set handles text80 String num2str XO source nr elseif stremp s text72 set handles text81 String num2str XO source nr elseif stremp s text73 set handles text82 String num2str XO source nr elseif stremp s text74 set handles text83 String num2str XO source nr end end 96 end 2696969696End NGT end else 96 sources is a vector imarkings 1 3 00 1 if ne length imarkings Ps error initial marking must be same length as number of places end XO imarkings end end gui painter m function gui painter t1 t btncolr textT str textT colr str global PN global handles global global info s trans find GUI component trans t1 if isempty s trans if stremp s trans text1 set handles text44 String string HH MM SS current time set handles pushbutton1 BackgroundColor t btncolr set handles text47 String textT str set handles text47 ForegroundColor textT colr elseif stremp s trans text2 set handles text45 String string HH MM SS current time set handles pushbutton2 BackgroundColor t btncolr set handles text48 String textT str set handles text48 ForegroundColor textT colr elseif strcemp s trans text21 set handles text46 String string HH MM SS current time set handles pushbutton3 BackgroundColor t btncolr
8. 1 disp At num2str current time PN global transitions t1 name is fired 969696 NGT fire AnimNGT t1 969696End NGT delta X output place inherited color inherited costs consume tokens t1 selected tokens assign any resources reserved by t1 resource usage cost 0 if Rs resource usage cost resource assign t1 end output token cost cost of output token t1 additonal cost resource usage cost inherited costs create new event to be put in Queue new event in Q create new event in O t1 delta X output place if override colorset new color else colorset union new color inherited color end if ischar colorset colorset colorset end new event in Q add color colorset new event in Q add cost output token cost EIP add to events queue new event in Q EIP addto Queue 6 Update list of enabled trans after token removal for j 1 No of enabledTrans check events one by one t2 set of ordered enabledTrans j PN Enabled_Transitions t2 enabled_transition t2 Y recheck end else if firing conditions are NOT satisified NGT START hasnotfired AnimNGT t1 0 148 269696 NGT END cancel any resource reservations by the transition if Rs resource unreserve t1 end end 96 if fcs end if enabled transition end fort 2 1 269696 for non enabled trans dont care2 notenabledTrans find PN Enabled Transitions lt 0
9. 116 Appendix A Install GpenSIM and configure NXT A 1 Install GPenSIM and R T monitor tool 1 Download GPenSIM zipped file from the author s website The web address http www davidrajuh net gpensim Note that the website also provides a handy user manual for building a Petri net model 2 Unzip the file in to the hard drive of the PC 3 To add the newly implemented R T monitor tool it has to be embedded inside a GPenSIM file The tool needs a manual integration l e we need to copy and paste the files one by one The following table shows the files and their associated directory inside GPenSIM The directories can be different it depends on the directory of the unzipped folder location C gpensim 12 timed_pensim Real PTtime select m C goensim 12 timed_pensim gpensim m C gpensim 12 timed_pensim find GUI component places m C gpensim 05 Print_and_Plot token number ngt m C goensim 05 Print_and_Plot markings string m C gpensim 12 timed_pensim fill GUI initial dy m C gpensim 13 firing gui painter m C gpensim 13 firing fire AnimNGT m C gpensim 13 firing fire Complet AnimNGT m C gpensim 13 firing hasnotfired AnimNGT m firing start C gpensim 13 firing firing start m Table 10 How to add the R T monitor to the existing gpensim file find_GUI_component_trans C goensim 13 firing find GUI component trans m The files with directory sign are t
10. 6 In oil and gas industry the mobility can be defined by lambda This A Is defined as the ratio of effective permeability of the fluid to its viscosity For example if there is a fluid i The mobility Ai is defined as A Un A mobility ratio is a ratio of the mobility of the displacing phase to the mobility of the displaced phase 7 The following mathematical modelling shows the mobility ratio of oil in an oil reservoir 20 ko Aw git ee Since one purpose of modelling is to enable the system analyst to predict the effect of behavioural changes to the system A model should be simple and easily understandable A good model should acquire realism and simplicity Even if the system is very large it should always consider a modular approach to the whole system This can be achieved by dividing the whole system into subsystems and sub modules Modular approach also acquires optimization 8 Modelling can be represented mathematically using formulas or symbolically using some figures When we design a model we should always realize the distributed probability function These help the system to have an accurate resemblance of the whole system with some standard error Ne Beyond designing a model we can also add more features to the existing model in order to make it more artificially intelligent and to add features like HCI human machine interface This along with a simulation and modelling would result in a precise contr
11. The associated result on a newly implemented R T monitor would be as follow Transitions A Transition names tAssemble tInPut tProduction lin tProduction lin tProductionline el e2 3 UP Completed Fired Completed Mot m in and Enbl but Hot States d s Fired Current CTE 3A Time 08 34 18 08 34 20 08 34 21 08 34 20 08 34 20 Fig l Sample output of Transitional panel on R T display Also it is possible to display the number of token in every places during the simulation process On the newly implemented R T monitor it would be like the following picture Places Place Names plnout Buff pOutPut1 pOutput2 pOutput3 pOutput B InitiallMark G G tProduction li a Production li a tProduction li a tProduction li a nei Tok 1 C nei Tok 1 neil Tok 1 C3 nel Tok 1 cm At 08 54 10 At 08 34 10 At 08 34 10 At 08 34 10 Fromplnout amp Fromplinout_ Fromplnout B Fromplnout B uff Buff n uff m uff m 4 Fig Il Sample output of place panel on R T display There are also control button that help to control the simulation where the previous version of GpenSIM doesn t provide a method to control the simulation like pause stop continue Commands Simopeed 0 5 Eum O co jim j py Print State Space Fig IIl Control buttons on the new R T monitor The tool also provides a push button to di
12. curr trans is Comleted but not member of R T monitor disp RETURN ON R T_DISPLAY return end str3 curr trans is completed At tempzsprintf temp str3 rt clock string 10 else str3 curr trans is completed At J tempzsprintf temp str3 num2str current time 10 end set handles edit2 String temp gui painter completing tran y Completed y str3 disp At num2str current time curr trans is completed disp hasnotfired AnimNGT m function hasnotfired AnimNGT t1 f global PN global str2 global temp2 global temp global handles global global info curr trans PN global transitions t1 name 9ecurr Place PN global_places i name if PN REAL TIME 146 if ismember curr_trans global_info rt_monitor_trans return end temp2 sprintf temp2 PN global_transitions t1 name is Not_Enabled At rt_clock_string 10 if isempty temp2 set handles edit1 String temp2 end end if f 0 for not fired str2 PN global transitions t1 name Enabled but not Fired At if PN REAL TIME tempzsprintf temp str2 rt clock string 10 else tempzsprintf temp str2 num2str current time 10 end set handles edit2 String temp gui painter t1 c Enbl but Not Fired c str2 else 96 for never fired str2 PN global_transitions t1 name Not enabled and Fired at if PN REAL TIME tempzsprintf temp str2 rt clock s
13. end a at1 end if stremp s infoplcs text68 tem pl sprintf tem pl curr trans Tok num2str tokens to be consumed At num 2str rt clock string From curr Place 10 tem pl sprintf tem pl 10 set handles edit11 String tem pl set handles edit11 Visible on elseif strcemp s infoplcs text69 tem pl sprintf tem pl curr trans Tok num2str tokens to be consumed At num 2str rt clock string From curr Place 10 tem_pl sprintf tem_pl 10 set handles edit12 String tem pl set handles edit12 Visible on elseif stremp s infoplcs text70 tem pl sprintf tem pl curr trans Tok num2str tokens to be consumed At num 2str rt clock string From curr Place 10 tem pl sprintf tem pl 10 set handles edit13 String tem pl set handles edit13 Visible on elseif stremp s infoplcs text71 tem pl sprintf tem pl curr trans Tok num2str tokens to be consumed At num 2str rt clock string From curr Place 10 tem plzsprintf tem pl 10 set handles edit14 String tem pl set handles edit14 Visible on elseif stremp s infoplcs text72 tem pl sprintf tem pl curr trans Tok num2str tokens to be consumed At num 2str rt clock string From curr Place 10 tem pl sprintf tem pl
14. make some delay to reduce the speed for simulated time end From the above code we can clearly see that t1 is the index of the current enabled transitions if and PN Enabled Transitions tl enabled amp notcurrently firing PN Firing Transitions tl Once the condition satisfied i e transition t1 is enabled but not currently firing the next step is to check it on the precondition fcs new color override selected tokens additonal cost firing preconditions t1 p p The variable FCS returns the precondition result from the calling function firing precondion if fcs firing conditions satisfied let the transition fire PN Firing Transitions tl 1 disp At numZstr current time PN global transitions tl name is fired 555 NGT fire AnimNGT t1 The fire AnimNGT m do a similar function to that of the enable AnimNGT but here the code takes t1 as the current firing transition state and is only used to plot red bar on the GUI The current transition can be accessed as follow Curr trans PN global Transitions C1 name The function then called the gui painted in order to plot a red bar on the GUI gui painter tl r Fired r str2 Str2 is a global value Like that of str1 for enabled transitions it records the status of the current firing transition as a string along with the current time str2 PN global transitions tl name is Fired At temp sprintf
15. set handles text2 String global info rt monitor trans 2 name else set handles text2 String global info rt monitor trans 2 end 96 Executes on button press in pushbutton14 function pushbutton3 Callback hObject eventdata handles global global info global PN set handles pushbutton3 Visible on if not PN REAL TIME set handles text21 String global info rt monitor trans 3 name else set handles text21 String global info rt monitor trans 3 end 96 Executes on button press in pushbutton4 function pushbutton4 Callback hObject eventdata handles global global info global PN set handles pushbutton4 Visible on 128 if not PN REAL_TIME set handles text22 String global info rt monitor trans 4 name else set handles text22 String global info rt monitor trans 4 end function pushbutton5 Callback hObject eventdata handles global global info global PN set handles pushbutton5 Visible on if not PN REAL TIME set handles text16 String global info rt monitor trans 5 name else set handles text16 String global info rt monitor trans 5 end 96 Executes on button press in pushbutton18 function pushbutton6_Callback hObject eventdata handles global global info global PN set handles pushbuttono Visible on if not PN REAL TIME set handles text17 String global info rt monitor trans 6 name else set handles text17 String global info rt m
16. 0 Yn O gt R as La 0 1 X4 8 Ya 8 gt 1 An example of a real time simulator is an airplane pilot simulator where the main simulator control unit reads every sensor and actuators data live and compile it using a simulation 23 engine Here we need to mind that one can simulate any type of model which are suitable for discrete event flow using a real time or a simulated time Since GPenSIM is used to simulate and model discrete event systems the focus of the thesis will be only the real time in discrete event dynamic systems Note that GPenSIM runs both in simulation clock and real time clock 3 2 Real Time Simulation using GPenSIM GPenSIM uses two kinds of timing for timing event It uses a real time or simulated time 29 There are different kinds of tools that can be used to model and simulate systems in real time MATLAB provides different kinds of tools like SimEvents and SIMULINK in order to perform simulation Both tools are capable of performing real time control activities and allow incorporation of diverse tools like fuzzy neural net etc and libraries However these two tools are general purpose simulation tools and are not Petri net based 28 The need for Petri net based simulator because of the many benefits of using Petri nets such as possessing simple graphical representation as well as strong linear algebraic representation that allows mathematical analysis both on the structural and on the behavioural
17. 1 pDetect tCheck 1 pGrant tEnter 1 pNot alarm on tEnter 1 tArrive pDoor 1 tDetect pDetect 1 tCheck pGrant 1 tEnter in pInside 1 Alarm control NXT m clear all clc global global info global info REAL TIME 1 This is a Real Time run global info STOP AT current clock 3 0 O 20 stop after 2 mins global info passwords A B C global info resetCMD 1000 init ALARM NXT initialize NXT png petrinetgraph alarm def doorModule def j dyn mO pArrive 1 pEnd 1 pCode 1 dyn ft tDetect 5 allothers 1 pni initialdynamics png dyn 9edisp System is ready sim gpensim pni close Alarm NXT Never forget to clean up after your work plotp sim pStart pDetect pEnd 155 init ALARM NXT m function init ALARM NXT 6 initialize alarm and ultrasonic in NXT global global info 6 initialize global variables global info NORMAL CYCLE false initializ NXT warning off MATLAB RWTHMindstormsNXT noEmbeddedMotorControl COM CloseNXT all hNXT COM OpenNXT bluetooth ini 26 look for USB devices COM SetDefaultNXT hNXT 96 sets global default handle global info NXT handle hNXT global info detect SENSOR 4 global info RESTART BUTTON SENSOR 1 global info OBJECT DISTANCE 20 NXT_PlayTone 440 500 Close_alarm_NXT function close Alarm NXT COM CloseNXT all tDetect pre m f
18. 2 and p2 is 3 are at least as large as the weight of the arcs connecting them to t1 b Fired Transitions As far as the transition is enabled and all the preconditions are fulfilled the transition will fire Literally it means it will take a token from the input place and put it to the output place This also shows that an event has occurred 2 4 3 Arcs Arcs are connections or paths between a place and a transition or vise verse The role of an arc is e Asa Link an arc can act as a link in communication and data transfer modelling Simply itis a connection e Asa bandwidth it can also act as a bandwidth in communication Medias e As a work flow management An arc in a Petri net graph can be used to model the mechanism of workflow in industrial areas 14 2 4 4 Arc Weight The arc weight is the maximum capacity of the arc that can fire number of tokens at the same time For example if the arc weight is 2 the maximum number of tokens that can be fired is less than or equal to 2 2 4 5 Tokens Tokens are input elements Tokens can be fired to show an event has occurred and is passed to the next part The role of a token can also be described as Physical object like a product a part of a system a manufacturing drug a person Information objects for example an email message a signal a report a file a packet a data frame e Collection of objects for example a vehicle that carries products for delivery a wareho
19. NXT intelligent brick 43 This device is the main microcontroller unit and it has a firmware which can be integrated with many platforms open source and can be coded by different programming languages The NXT brick contains ports to take input and output processor unit memory Bluetooth card LCD display Main processor Atmel 32 bit ARM processor AT91SAM7S256 256 KB FLASH 64 KB RAM 48 MHz Bluetooth wireless communication CSR BlueCoreTM 4 v2 0 EDR System USB 2 0 communication Full speed port 12 Mbit s 3l Sensors Four input port three output port 6 wirecables 100 x 64 pixel LCD graphical display Ultrasonic sensor Sound sensor Touch input sensor Light sensor Connecting Cables Building bricks Software USB cable Different kind of Lego building bricks to build the support This are taken from LEGO toys RWTH Mindstrom Fantom driver NeXttool 3 3 2 Door alarm system using NXT A door alarm system can be modeled using NXT intelligent Brick and GPenSIM based on a predesigned Petri net model The following shows a clear image of the model concept Fig 21 A door alarm model using NXT and ultrasonic sensor The real life model of the above picture is shown below 22 Alarm Switch Outside house Fig 22 Model of door alarm system using flowchart To model the system using NXT we required the following equipment 1 NXT brick microcontroller The NXT brick micro
20. Similar to the implementation of Real PTtime select m section 5 1 1 the main function of GUI takes variable arguments and also returns some variable arguments the main function with its input and output arguments is shown below 69 function varargout GUI varargin GUI is a MATLAB code for calling and running GUI fig GUI by itself creates a new GUI or raises the existing Singleton Inorder to run GUI H GUI returns the handle to a new GUI or the handle to the existing singleton GUI CALLBACK hObject eventData handles calls the local function named CALLBACK in GUI M with the given input arguments GUI Property Value creates a new GUI or raises the X of oe dp de dp de dp de op o dP dP l existing sinaleton Startina from the left nronertv value naires are gui Singleton 1 gui State struct gui Name mfilename gui Singleton gui Singleton qui OpeningFcn GUI_ OpeningFcn gui OutputFcn GUI OutputFcn gui LayoutFcn l qui Callback 1 if nargin amp amp ischar varargin 1 gui State gui Callback str2func varargin 1 end if nargout varargout l inargout gui mainfcn gui State varargin else gui mainfcn gui State varargin end This main function is also created by the MATLAB GUIDE tool as a calling function to call the figure file components The comments are written for documentation l e it will be served as a help file As
21. disp s_ trans if strcmp s trans trans info txt set handles trans info txtl String string HH MM SS8 current time set handles gui barl BackgroundColor t btncolr set handles trans info txtll String textT str set handles trans info txtll ForegroundColor textT colr elseif strcmp s trans trans info txt2 set handles trans info txt2 String string HH MM SS current time set handles gui bar2 BackgroundColor t btncolr set handles trans info txt22 String textT str set handles trans info txt22 ForegroundColor textT colr The strings with a single quotation in the above code snippet shows the names of the text boxes in the GUI designer and the gui bar s are the bars designed on the designer of the MATLAB GUIDE to illustrate transitions and plot the color using series of set commands as shown above As it is shown on chapter four the transitions are designed using a push button as a bar and their name on a text box So what actually this function do is that it searches the name of the transition which is denoted by a pushbutton and the name with a text field and plot colors using a set command with the appropriate properties V Display real time activities of places on R T monitor function infoplc plI transition tokens to be consumed This file has a function that do a similar function to that of the one which writes the tokens every places but this one adds features that tell at what time
22. end COMMON_PRE The common precondition is set to be same for some transitions they fire as far as they are enabled This function also has a condition to turn of the ringing alarm if the user entered the correct code elseif strcmp transition name t off disp Off the alarm i input Enter the reset code if eq str2double i global info resetCMD handle COM OpenNXT bluetooth ini NXT StopSoundPlayback handle t now the alarm is off end 92 5 2 4 Implementation of R T City Traffic light system using NXT 39 The implementation for traffic signal has different function Some of them are adapted from the discrete event dynamics system course but with some changes The functions are listed below 1 The PDF file we have three modules thus we have three different kinds of PDF files These are traffic NXT def PDF for Normal cycle pedes def PDF for Pedestrian crossing It contains a PDF file for a pedestrian crossing model emergency def PDF for emergency blinking 2 MSF Similarly the msf file is denoted as traffic NXT The MSF is similar to the above section s main simulation file except the names of some variables Since there are three modules the calling function of the PDF files is Shown below png petrinetgraph pedes def emergency def traffic control NXT def And also the initial dynamics are declared as shown below dyn m0 pR 1 dyn ft tR ON 5 tRY 2 tG 5
23. global info global info global info NAT handle hNXT lightRED MOTOR A lightYELLOW MOTOR B lightGREEN MOTOR C RESTART BUTTON SENSOR 1 PEDES BUTTON SENSOR 2 EMERGENCY BUTTON SENSOR 3 NORMAL CYCLE false PEDES CYCLE false PEDES CYCLE COUNT 5 EMERGENCY CYCLE false function init TL NXT This MATLAB file initialize light sensors touch sensors and the motor ports in the NXT The NXT devise has three inputs and four output ports and one USB port To connect the NXT with the MATLAB we need to install the toolbox for NXT devices called RWTH toolbox 38 This function connects with the PC through a USB port and a Bluetooth port The Bluetooth port is opened using the following function hNXT COM OpenNXT bluetooth ini bluetooth ini has a configuration files for assigning a port as shown below Bluetooth NXT Name NZT NXT MAC 00165302F DD Channel 3 BaudRate 9600 DataBits 8 Stop its 1 SendSendPause 5 SendReceivePause 25 Timeout 2 Then the hNXT port file is set as a default communication port for the brick COM SetDefaultNXT hNXT GPenSIM interacts with the NXT intelligent Brick using global variables Every ports are declared into the global info variable 95 Chapter 6 6 Experimentation and Analysis This chapter show some test result of the implementations in chapter 5 This part includes a test result of simulating mod
24. gp pause gt 0 gp pause gp pause O 1 set handles text75 String num2str gp pause else set handles text75 String num2str gp pause set handles text75 String Max speed gp pause O0 1 end 96 Executes during object creation after setting all properties function text68 CreateFcn hObject eventdata handles 96 Executes during object creation after setting all properties function text69 CreateFcn hObject eventdata handles set handles edit4 BackgroundColor get O DefaultUicontrolBackgroundColor Executes during object creation after setting all properties function text70 CreateFcn hObject eventdata handles Executes during object creation after setting all properties function text71 CreateFcn hObject eventdata handles Executes during object creation after setting all properties function text72 CreateFcn hObject eventdata handles 96 Executes during object creation after setting all properties function text73 CreateFcn hObject eventdata handles Executes during object creation after setting all properties function text74_CreateFcn hObject eventdata handles Executes during object creation after setting all properties function text1 CreateFcn hObject eventdata handles 96 If Enable on executes on mouse press in 5 pixel border Otherwise executes on mouse press in 5 pixel border or over resetbtn function resetbtn_ButtonD
25. hObject refers to the current component that is doing some activity or event and handle is an event handler of the hObject The function keeps the object for example pushbutton and put it in to the handles structure as an output 67 function Real PTtime select OpeningFcn hObject eventdata handles varargin handles output hObject Update handles structure guidata hObject handles pushbuttonl0 Callback hObject eventdata handles The variable guidata pass the content of the two variables hObject handles This guidata store components like hObject along with their associated events and keep them in a form of structure data type This function is called only once in the R T monitor As mentioned above the main purpose of this gui form is to select some places and transitions for displaying and monitoring b Real PTtime select OutputFcn OutputFcn This function returns the output data to the MATLAB command line interpreter after the opening function returns control and before control returns to the command line t Outputs from this function are returned to the command line function varargout Real PTtime select OutputFcn hObject eventdata handles amp Get default command line output from handles structure pushbuttonlO0 Callback hObject eventdata handles varargout 1 handles output C CreateFcn This function contains an event that is used to create components li
26. set handles text49 String textT str set handles text49 ForegroundColor textT colr elseif strcemp s trans text22 143 set handles text57 String string HH MM SS current time set handles pushbutton4 BackgroundColor t btncolr set handles text50 String textT str set handles text50 ForegroundColor textT colr elseif strcemp s trans text16 set handles text58 String string HH MM SS current time set handles pushbutton5 BackgroundColor t btncolr set handles text51 String textT str set handles text51 ForegroundColor textT colr elseif strcemp s trans text17 set handles text59 String string HH MM SS current time set handles pushbutton6 BackgroundColor t btncolr set handles text52 String textT str set handles text52 ForegroundColor textT colr elseif strcemp s trans text18 set handles text60 String string HH MM SS current time set handles pushbutton7 BackgroundColor t btncolr set handles text53 String textT str set handles text53 ForegroundColor textT colr elseif strcemp s trans text19 set handles text60 String string HH MM SS current time set handles pushbutton8 BackgroundColor t btncolr set handles text54 String textT str set handles text54 ForegroundColor textT colr elseif strcemp s trans text20 set handles text61 String string HH MM SS current time set handles pushbutton9 BackgroundC
27. the Petri net a transition can fall in to two categories These are a transition cannot fire in the current loop and a transition is enabled but is not firing in the current loop This should be observed while we work with real time simulation It s because of the fact that we can see the where about of every token and in the preconditions If a transition fall in this group the color of the rectangle will switch to cyan for enabled but not firing and light purple for never firing Here we need to mind that the two events are alike even if the transition is cannot fire in both cases Fig 52 Never fired transitional event Fig 53 Enabled but not firing transition Firing complete state In GPenSIM after a transition has passed through enabling and firing events it will be considered as a complete event So in the R T monitor it is denoted by a yellow rectangle as shown in the figure below Fig 54 A Firing complete event The Transition panel also contains information under the rectangles like caption for the name of every transitions named as Transition name colored texts based on their status as transition status and the current time which is in real time The need for a color text is that the events of the transition are as fast as a human eye can t even see it especially in sensor networks Thus the good way to keep an eye open is to give extra information about an event and put it to a log file so that the user can r
28. FTI Ee Transition names tRobot l tRobot2 tRobot3 Transition Enabled Enabled States Current Time 234118 23 41 18 234118 Fig 49 Transition panel on R T monitor The information provided by this panel are event display or color based animation associated transition names Transitions status and the current time for real time display The event display displays the status of every transition in the R T monitor Every transition has a display denoted by a rectangle and their status is identified by different colors based on their events i e In a Petri net model a transition has basic four states and these are a Enable or not enabled state In the R T monitor the enabled transitions are denoted by green rectangle i e whenever a transition fulfils the enable criteria in the precedence matrix in the current simulation loop of GPenSIM The display rectangle will switch the color to green Fig 50 a transition of R T monitor on enabled status Enabled transition b Fire or not fired state Similarly for a transition that is currently firing in the current time and current loop the rectangle will be switched to red to inform the current status of the transition and it will stay red until the next event comes 55 C d Fig 51 a transition on firing status Never firing state or dead locked and enable but not firing This transitional event status display is a little bit different From the incidence matrix of
29. Fired At 11 07 09 tR OFF is completed At 11 07 08 tEM BUTTOMNH is Mot Enabled At 11 07 10 tEM BUTTON Enabled but not Fired At 11 07 10 E Fig 85 Enable and Firing sequence for traffic model Note that to get the current status of the simulation the scroll button must be used This stores and displays the results in a text format This helps us to analyze the reachability and other P N analysis The state diagram for the simulation result is shown below GpenSIM stores its result as a dump file and display its result on the MATLAB command window As it is discussed on the statement of problems this dump file to large and not show results live during the simulation process The following shows a state space result of the traffic light system State Diagram T xxmnme T1 13 3 pR pR pR pR State O Initial State pR At start At time 11 13 31 Enabled transitions are tEM BUTTON tPEDES BUTTON tRESTART BUTTON tR ON At time 11 13 31 Firing transitions are tR_ON Time 11 13 40 State 1 Fired Transition tR ON pR OFF pR_OFF Current State pR OFF Virtual tokens no tokens Right after new state 1 At time 11 13 41 Enabled transitions are tEM BUTTON tPEDES BUTTON tRESTART BUTTON tR OFF At time 11 13 41 Firing transitions are tR OFF t r Time 11 1342 055 State 2 Fired Transition tR_OFF pRY pRY pRY Current State pRY Virtual tokens no tokens Ri
30. RESTART BUTTON check for RESTART BUTTON press OpenSwitch res btn switchState GetSwitch res btn CloseSensor res btn if switchState RESTART BUTTON is pressed fire 1 else fire 0 end t start btn post m Ebbene hem es niece ebrei e low josie UE Trete yes ie ie glon le lela info E Sige UNS Eee TINI n NS meos c ICOM Cree Ny o Je TEES E XO Elgus Teu rr IPS sereno Souiquclle en exe vele ane Ley 5 Hardware NXT m 157 function 2 Hardware NXT command str function Hardware NXT command str switch lower command str case f initialize init init TL NXT switches in NXT case close clear close TL NXT Never forget to clean up after your work case nearest disp Method is nearest otherwise disp Unknown method end iV Source code for traffic light model The complete source code for traffic light system is available at 39 158
31. User interfaces design Though GpenSIM can model and simulate any type of Petri net model it lacks a mechanism to have a graphical human machine interface HCI tool This tool is a system that makes the user to have a visual interaction with the background resources GUI tools provide a method or class object called FORMs which has components like textboxes that are visible for humans A user can easily interact with pre designed forms The forms for graphical user interface are designed using MATLAB Here we should mind that we can use another tool to implement the GUI The design of a GUI is very complicated and tricky unless a careful design approach is taken Here in this 45 thesis project i intended to use a MATLAB GUI designer called GUIDE for implementation It is obvious that most developing software platforms provide a tool to implement a graphical user interface This is due to the rapid development of HCI Based on this it has been taken some assessments on using different tools like java and visual studio NET But the better method to design a graphical user interface component for GPenSIM is GUIDE MATLAB provide a tool for designing graphical user interface called GUIDE and the associated file extension is called fig For example GUI fig 32 4 3 1 Graphical user interface gui basics Graphical user interface tools are tools that make a visual and graphical human machine interaction Now a day s most software provides
32. a graphical layout operation The results will also be processed using nargout Like in the above condition for nargin the variable nargout also checks if there are output arguments For example if a push button is clicked and the click has handled an event to do something The result should also be appeared on the graphical user interface The condition that checks this operation is shown below if nargout varargout ltnargoutj e gui marzntfem gui State vearardguniel Else Gus mainicn gu ui State Vareroin gt gt end From the above condition if nargout is true then the main function calls the other MATLAB function gui_mainfcn and passes the struct gui_state and all of its input arguments varargin and returns as an output argument varargout If the there is no output i e nargout is not true then the gui mainfcn will be called but varargout is null ii OpenFcn OutputFcn and CreateFcn a Real PTtime select OpeningFcn As it is mentioned in the previous chapter whenever we create a GUI using GUIDE a MATLAB automatically create different functions with some templates that can be edited 32 The function Real PTtime select OpeningFcn is also a type of function created while designing a Real PTtime select OpeningFcn but has been modified to fulfil the conditions of the R T monitor functionality This function takes three input arguments of hObject handles varargin and eventdata The
33. a matrix structure For example if we have three places the PN global places will be PN global places 1x3 struct and it will return the name of the places the total number of tokens in that places and the token bank a place where tokens are absorbed and stored The 1x3 struct for the above structure give a result in the command window as 1x3 struct array with fields name tokens token bank The next step is to organize the global variables as below before moving towards to plotting Here the GUI accepts both the Real Time and the non real time simulation This condition is checked as 72 f it is not a real time i e if we are using a simulated time the places and transitions are by default extracted from the global PN variable Simply we don t have places and transition that are selected for real time display purpose l e Real PTtime select didn t run in the gpensim The values are gt PN global places gt PN global transitions If itis in real time i e we have places and transition that are selected on run time from the Real PTtime select interface These values are named as global info rt monitor places and global info rt monitor trans if not PN REAL TIME not real time but work anyway disp Not real time set handles text84 String NOT REAL TIME SIMULATED CLOCK No trans PN No of transitions No places EN No of places global info rt monitor places PN global places global inf
34. about the designing a Real Time monitor R T monitors for GPenSIM It describes how the design was done and also describes about a MATLAB GUIDE a tool that the R T monitor were designed and implemented Chapter 5 is about the implementation of the thesis work It deeply describes every steps that were taken to implement the system with some code snippets and flowcharts Chapter 6 is the testing results of the simulation and modeling of systems in chapter 3 and displaying their live real time simulation of on the new implemented R T monitor interface HCI Chapter 7 is discusses about the general methods and approaches that were taken to implement the system also discusses about the drawbacks of the newly implanted system and suggests further improvement about the system Finally this chapter concludes the thesis work in few paragraphs Chapter 2 2 Background 2 1 Systems modelling and simulation Simulation and modelling have been applied in a wide range of areas like applied science social science and engineering ranging from economic forecast up to space shuttle design Modelling and simulation are two symbiotic terms in the computing world where one of them follows the other by a logical coincidence Modelling is a process of creating and presenting a mathematical symbol or formula that resemble the actual real life system by gathering and analysing all the necessary information about how the system behaves without actually testing it
35. contains 89 1 PDF file for each module The implementation was made by using a modular approach of gpensim The modules are Door def m Alarm model def m Key padmodel def m The PDF codes are found in the design section or in the appendix MSF file The main simulation file contains global variables to pass global parameters The following code show the global variables in this model global Xnro oTOP AT current clock 3 a LLL 20 SEOP i121 20 global xnfo passwords A D 5G I global 2mnto deltab 9 global 1info readIn 0 png petrinetgraph i oor der alarn model der key padmodel Her TDF file There are two pre and two post conditions These are COMMON PRE m A common pre condition for some transitions COMMON POST m A common post condition of some transitions tEntry pre A pre condition of an event to arm the alarm tRinging post The post condition to let the alarm ring 5 2 3 Implementation of R T door alarm system using NXT The implementation of this model contains methods The complete code is available on Appendix c 1 PDF The model has two PDF file thus we use a modular approach The pdf of both models were described in the design part section 3 3 1 of the R T door alarm model MSF The main simulation file contains the global variable declarations for example it defines whether the system is in real time or not and the elapsed real time and the passwords B
36. event of the dynamic systems can be modeled using Petri nets and can be simulated on real time using GPenSIM and their simulation status can be displayed on a newly implemented R T monitor It has been successfully developed a user friendly tool that helps to display and control the status of a real time simulation of discrete event dynamic systems The newly implemented tool was also successfully tested as shown in the chapter 6 test results believe this tool can be used in real life applications of GPenSIM 113 References 1 Andrea BOBBIO System modelling with Petri net Istituto Elettrotecnico Nazionale Galileo Ferraris Italy pp 2 Lego Mindstrom Available at http en wikipedia org wiki Lego Mindstorms NXT 3 Bernard P Zeigler Herbert Praehofer Tag Gon Kim Theory of Modeling and Simulation Integrating Discrete Event and Continuous pp iiv 4 Anu Maria Introduction to Modelling and Simulation State University of New York at Binghamton 1997 pp 7 8 5 Law and Kelton Simulation Modeling amp Analysis 3 e 2000 pp 4 6 Turgay Ertekin Basic applied reservoir simulation 2001 pp 1 Available UiS biblotekk braga 7 Nnaemeka Ezekwe Petroleum Reservoir Engineering Practice pp 15 section 15 7 8 Ivan C Mustakerov and Daniela Borissova A Discrete Choice Modeling Approach to Modular Systems Design 2013 pp 117 118 9 Discrete Event Simulation Availa
37. exists simultaneously l e it controls how many gui windows we can open at the same time 32 If gui_singleton 1 then there can be only one copy of the figure layout If gui_singleton 0 then there can be more than one simultaneous duplicate of the GUI figure So in our R T monitor the gui singleton is always 1 l e there is no duplicate of the GUI at the same run time In addition to a gui singleton variable there is also another declared structure variable this struct contain all the declared variables in a struct form These are gui filename gui singleton gui OpeningFcn gui OutputFcn gui LayoutFcn gui Callback This is automatically created by the GUIDE environment The purpose is just to store the GUI state in one structure GUL State dene ci Nemes mirLiemence s PCDI Ss Tuned e e ST aedes OI 46 en Oremus eum c Ciel Jeux Selecrm Ogsusuels Cu s cce Nowa OmnepxbUEIS cm CiNecil PUES Select OUIEEUEIECL sr po hau gorge Mr Loue allpa k EE 66 The other variables nargin It is a MATLAB keyword used to define the number of input arguments for the main function So the condition Me Nargin See a Nar OV SHE Cb iL gul Stace gui Calloack Stieziruine weieeieo iin i end Checks if there are input arguments i e varargin 1 and the inputs are of character array If the conditions are fulfilled then the Callbacks will be populated inside the gui struct and perform
38. flow and Petri nets at a higher level and so on The lack of well structure integrity hierarchy in Automata is a serious shortcoming for modeling large systems since a large and complex system should be decomposed into sub models and systems 10 The state flow is a mechanism used in Simulink MATLAB simulation tools and Simulink can also provide tools to model and simulate DEDS but their intension is not particularly designed 10 to simulate discrete event systems So in every direction the most powerful tool to model DES is Petri Net One of the most fascinating features of Petri net tools are functions for exporting Petri nets to other tools and for importing nets from another tool Besides Petri net provides concurrency parallelism and synchronization 11 DEDS covers all aspects of discrete event flows that include theory and formal models like Petri Nets supervisory control Min Max plus algebra discrete simulations performance analysis optimization and optimal control 12 The basic terms in discrete systems are events loops or cycles Discrete event flows can be modelled using different kinds of mathematical methods some mathematical models that can model the discrete flow are A Markov chain It is one of method that can model a discrete event flow l e it is a series of random values 13 MC is a mathematical method that undergoes transitions from one state to another on a state space It is a random process usually ch
39. front for modelling and simulation of discrete events LabView is another good tool that can be defined as a real time control simulator however LabView is not based on Petri nets either Generally there isn t a single tool that is purposely designed for simulating Petri net based with real time capability and allows an easy integration of diverse tools and techniques in the models of discrete event dynamic system 29 A real time Petri net model consists of RTPN P N SE CE Time P N is used for graphical Petri net model i e Ordinary P N The Extension for system resource It is defined as SE R 0 t X Y R set of system resources R R1 R2 Q set of executable operations Q a1 a2 a3 o the partitioning of the operations into subsets that can be executed by the individual resources o R 2Q t the set of timing that are taken for operations t Rx Q N X Y are input and output components 24 Stands for the Color Extension of a P N model it functions as overloading tokens with some data to differentiate one token from another map transitions to logic functions Time PTime TTime TTime Set of transition time i e firing time it is the time taken by transitions to fire Firing time can deterministic or stochastic PTime The time taken by places to hold a token Holding time can deterministic or stochastic 29 Table 1 Real Time Petri net components Ac
40. function and the file have the same name 33 The file name is Real PTtime select m The function name is function varargout Real PTtime select The main function Real PTtime select takes two arguments like any other figure created by GUIDE These are varargout for output and varargin for input variable arguments Varargout is a cell array for returning output arguments E g varargout 1 handles output Varargin is also a cell array for passing variables as input arguments 65 The main function begins with a series of comments for help documentation about the GUI l e if someone wants to know about the Real PTtime select he can just type gt help Real PTtime select on the command window The following figure shows the main function that is created by GUIDE to start the GUI layouts function varargout Real PTtime select varargin gui Singleton 1 gui State struct gui Name mfilename gui Singleton gui Singleton gui OpeningFcn Real PTtime select OpeningFcn Gul Outputren BREAL PTtime select OutputFcn gui LayoutFcn S gui Callback ine if nargin amp amp ischar varargin 1 gui State gui Callback str2func varargin 1 end if nargout varargout 1l nargout gui mainfcn gui State varargin LSS gui mainfcn gui State varargin end The gui singleton is a variable that is used as a flag to specify if one or more duplicated instances of the gui can
41. in real life i e a model is a representation of the construction and working of some system of interest 4 The following picture shows how to model a system The three basic things that we should consider while we work with simulation and modelling are Fig 1 Relation between System and M amp S System A system is a group of objects that are interconnected in some form of logical interaction to accomplish some purpose Model Constructing a conceptual framework that describes a real system 4 Simulation Perform experiments using computer by different implementation tools of the model Analysis make conclusions from the output that assist in decision making process As it can be seen systems models simulation and analysis have some interaction And their interaction can be categorized in a hierarchical order as show below 5 Experiment with actual system Physical model Experiment with a model of the actual system Mathematical model Analytical solution Simulatoin Fig 2 Hierarchy of modelling and simulating a system An example of modelling is a reservoir model in the oil and gas industry The engineers use a computer program to model the actual system in order to estimate the potential of their reservoir capacity And also they would get accurate performance predictions for hydrocarbon content Besides the risk analyst can also use some simulated data in order to analyses the risk and genuinely manage it
42. is 11 56 33 We can clearly observe the system has detected an object at time tO and so tDetect fire at tO and complete its firing at t1 From the above pic the user doesn t enter the password correctly and hence the NXT trigger the alarm signal and shout at t1 The input password is inserted in the MATLAB command window as shown below Enter codel At 42681 tShout is fired tShout At 42683 tShout is completed Similarly tokens can be displayed on the place panel of the R T monitor The display show the result below 101 Places Place Names pDetect pEnd potart QO Detect Tok a 1 At 11 53 47 FrompStart Initial Mark LL Fig 74 Status of tokens in the selected places The above figure shows the initial marking of the tokens and their status during the simulation process The box shows the place pStart has initial marking at time 11 53 47 and by scrolling down it is possible to see the status of the token gaming on every simulation cycle pStart pDetect pEnd Table 7 Analysis of the tokens and places on the door alarm model using NXT From the above table it can be observed that tokens are removed from pStart as the NXT detected an object and Fired and token are stored in the end place The R T monitor has also a method to display the status of the simulation by denoting it as enable and firing sequences The figure below shows this operation Enable Sequence
43. is the token fired and which transition is responsible for it It gives the output like this on the GUI The MATLAB script file that does this activity is called infoplc m tRobot2 Tok 1 At 23 47 08 FrompsStart tRobot3 Tok 1 vi Start Firing for an enabled transition The function that starts the firing of an enabled transition in GPenSIM is called Firing strat m The next four steps vii viii ix and x introduces a method to plot the status of every transitions by calling the above file gui painter m All of them are called from a gpensim 13 firing firing start m file system folder To describe their functionality we need to discuss about the firing start m file and its functions function EIP firing start EIF 81 This function is called from a gpensim file where the simulation starts the variable EIP is a gpensim system file that is used for creating queue Q for events in progress no that EIP is initially O as there is no events in Q if any PN Enabled Transitions EIP firing start EIP end The firing start is an important gpensim system function it has a lot of operations like resource management of tokens along with firing But for the R T monitor the focus would be limited to only extracting he enabled transitions from the incident array vii enable AnimNGT m The name enable AnimNGT is given after the term animation for an enabled event of a transition from the project view as it perf
44. it can be seen everything in this main function except the function name is similar to the declaration of Real PTtime select m file Initially this function was created as a template i e It is a default gc control function of the MATLAB GUIDE file that creates the basic layouts 33 34 35 Then it has been edited according to out intension ii OpenFcn OutputFcn CreateFcn All of the three functions have a similar structure as that of the previous section This are again initialized by the MATLAB GUIDE tool and edited according to the aim of the R T monitor The Opening function that has been called by the main function is shown below This function is used to import and work event data The keyword guidata accepts variables of the object or components called hObject and the event handler handles The function will invoke another function that is called a start function by passing variables of the input arguments hObject eventdata and handles Those variables will call the function that starts the plotting and painting 70 function GUI OpeningFcen hObject eventdata handles varargin global cnt cnt 0 handles output hObject guidata hObject handles startCode hObject eventdata handles Similarly to the previous one the output function would also be initialized automatically by the GUIDE The main objective to prepare an output argument called varargout that is used by the main function The follo
45. its purpose is to find the place component in the GUI lii Plot the initial markings on the GUI According to chapter 2 the main simulation file of a gpensim contains the initial dynamics of the system modules Thus it would be better to show the initial dynamics also on the real monitor screen Its purpose is to show the comparison of token from their initial state throughout their simulation process Note that the previous one is used to plot the quantity of tokens in every place as the simulation is on progress This would give a big picture l e the user doesn t need to recheck the initial dynamics as on the run time The implemented script file that does this activity is called fill GUI initial dy m 78 function fill GUI initial dy initial dynamics global hn global PN global handles global global info Ps PN No of places XO zeros 1 Ps initially XO is used to put the initial markings in a cell array The function fill GUI initial dy takes the initial dynamics of the gpensim as an input argument and plots it on the main gui by searching their appropriate place name on the gui interface The MATLAB function that searches an object on the gui is shown below imarkings initial dynamics m0 if iscell imarkings sources pi i p2 3 no of sources length imarkings 2 number of places extracting places imarkings returns the initial marking of the MSF Then from the imarkings
46. my list1 PN global places 96 load global places from GPenSIM my_list2 PN global_transitions load global trans from GPenSIM convert to cell array to put into list box for places pics cell1 cell numel my list1 1 for j 1 numel my_list1 for places pics _cell1 j 2 my_list1 j name end put into the list box set handles listbox5 String pics cell1 convert to cell array to put into list box for transitions pics cell2 cell numel my list2 1 for k 1 numel my_list2 pics cell2 k my list2 k name end set handles listbox3 String pics cell2 96 Executes on select transtions to the R T transtions function pushbutton11 Callback hObject eventdata handles global new remove menurTs stor all the ne global newmenu newmenuz currentitems22 get handles listbox4 String list entry cellstr currentltems22 index selected get handles listbox4 value choice Istbox2 list entry index selected curi22get handles listbox3 String new remove menurTs curl2 choice lstbox2 set handles listbox3 String new remove menuTs 125 set handles listbox4 Value newltems currentltems22 newltems index_selected set handles listbox4 String newltems if isempty newltems if length newltems gt 1 set handles listbox4 Value 1 end end GUI m function varargout GUI varargin GUl isa MATLAB code for calling and running GUI fig The GUI is designed an
47. of R T simulation in door security using gpensim esee 89 5 2 3 Implementation of R T door alarm system using NXT c ssscccccssececcessececeeseceseeeceeeeeeeeeees 90 5 2 4 Implementation of R T City Traffic light system using NXT 39 eee 93 CADE Octo m a rpm ru rM I CM TI 96 6 Experimentation and Analysis 5 p cou v Ge e erat sonde cta sient edd 96 iV 6 1 Experimentation for R T simulation in section 5 2 eeccceseccceeececeseceeeesceeenceseeeceseueceeeneeeeees 96 6 1 1 Test results for R T simulation in Industrial application ccceeeccccessececeesececeeeceeeeeeeeeees 96 6 1 2 Test results For NXT door alarm Model serani EE 99 6 1 3 TestresultsTOr traffic light SVSEemm sie ce e bro i Io Ged ab End Utili o edo e evo Ue tuat eb uetus tua du Uus 104 Girls lg e T 111 7 DISCUSSION and CONCIUS ION sa casssavasiuvcsancseag eva abechoncen vated nies EDO beeen nema aes De e 111 7 1 BI co T E nents 111 7 2 F rtherdtmppFOVelTiellbes s eae sot ua does o a a eS Mas Led m I EA due 112 7 3 CONIU Oean RTL TS 113 Reference S oazi n o T PcHUu THE 114 AOD NOKA inen a E E O AN 117 TANG a 0 Ga B orra aare E I Md IM M MM 121 oler aod t PITT 122 P N PN R T DEDS GPenSIM gpensim MSF PDF TDF HCI NXT MATLAB GUIDE GCBO gcf GUI m GUI fig Real PTtime s
48. of other transitions this would give a full functionality for the R T monitor in displaying every event in the entire simulation For example in the figure below tRobot3 may be in the in the R T monitor or not but it is a transition in the entire simulation p tRobot3 Enabled but not Fired Fig 63 A small display panel to show the status of all the transitions in the simulation 61 Chapter 5 5 Implementation The R T display system was implemented using MATLAB software As it was mentioned in chapter 4 The R T monitor can be implemented with different kinds of tools like java or other graphical user interface supporting tools like visual studio net Note that MATLAB can support and access the packages of java and other languages But the precise way of implementing this graphics display system or R T monitor for GPenSIM would be using the MATLAB studio This is due to the fact that GPenSIM by itself runs in a MATLAB platform and also the performance of a MATLAB would decrease while working with an imported graphics data especially for simulation The previous chapter shows how the basic interface design of R T monitor is made and what are every single terms in the R T monitor Once the system has been designed the next math is connecting every graphical interface components based on the GPenSIM events During the simulation process they should be handling events and giving the interface a real meaning As discussed above the MATL
49. output hObject Update handles structure guidata hObject handles pushbutton10 Callback hObject eventdata handles Outputs from this function are returned to the command line function varargout Real PTtime select OutputFcn hObject eventdata handles Get default command line output from handles structure pushbutton10 Callback hObject eventdata handles varargout 1 handles output Executes on button press in pushbutton3 function pushbutton3 Callback hObject eventdata handles 96 Executes on selection change in listbox3 function listbox3 Callback hObject eventdata handles 96 Executes during object creation after setting all properties function listbox3 CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end 96 Executes on selection change in listbox4 function listbox4 Callback hObject eventdata handles Executes during object creation after setting all properties function listbox4_CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end 96 Executes on button press in pushbutton4 function pushbutton4 Callback hObject eventdata handles global newmenu Trans currentitems t get handles listbox3 String l
50. sections below All of them passes similar variables but with different kinds of information including the colour types to plot on the GUI This is a way how the R T monitor differentiates the status of every transition The gui painter function is shown below The script file that does this activity is called gui painter m function gui painter tl t btncolr textT str textT colr str global PN global handles global global info The calling function passes the arguments as follow for enable transition gui painter ti g Enabled g strl Where t1 is the index of the current transition from the enabled transitions set g is a property in MATLAB for green color and the function takes five input arguments t1 T1 is an index that selects the current transition from the global t1 cell array t btncolr Color for the current active transition and plotted on the GUI textT str Name of the current active transition and written on the GUI Enabled Fired textT colr Color for the name of the current active transition Str Status in text forms and used to give information in text i e Str1 str2 str3 fired enabled and so on Table 4 Variable that pass arguments to the painter The variable s trans is the current transition that is on processing at real time t then search the transition on the GUI and plot the appropriate info 80 s trans find GUI component trans ti if isempty s trans
51. set handles listbox6 String newltems if isempty newltems if length newltems gt 1 set handles listbox6 Value 1 end end Executes on button press in pushbutton7 function pushbutton7_Callback hObject eventdata handles 124 Executes on ok button pressed function pushbutton8_Callback hObject eventdata handles global newmenu stores the places global newmenu_Trans stores the transtions global global_info stores global variable everywhere global hn global info rt monitor places pStart pBuff2 pBuff1 pBuff3 global info rt monitor trans tRobot1 tRobot2 tRobot3 Istl get handles listbox6 String to check places Ist2 get handles listbox4 String to check transtions if isempty Ist1 amp amp isempty Ist2 global info rt monitor placesznewmenu 6 copy the cell array to global R T places global info rt monitor transeznewmenu Trans 6 copy the cell array to global R T trans set handles text3 String Please wait close Real PTtime select 6 close the window else msgbox please select transtion and places from the left lists end Executes on clear button press in pushbutton9 function pushbutton9 Callback hObject eventdata handles clear items set handles listbox4 String set handles listbox6 String 96 Executes on button press in pushbutton10 function pushbutton10 Callback hObject eventdata handles global PN
52. set of ordered nenabledTrans randomgen notenabledTrans No of nonenabledTrans length notenabledTrans for k 1 No of nonenabledTrans 96 check events one by one t set of ordered nenabledTrans k hasnotfired AnimNGT t 1 end Infoplc m function zinfoplc pll transition tokens to be consumed 9einfoplc i PN global transitions transition name tokens to be consumed global PN global handles global tem pl global global info curr trans PN global transitions transition name curr Place PN global places pll name s infoplcs find GUI component places curr Place if isempty s infoplcs s_infoplcs disp return end if PN REAL TIME if ismember curr_Place global_info rt_monitor_places amp amp ismember curr_trans global_info rt_monitor_trans tem0 for i 1 length global_info rt_monitor_places comp global_info rt_monitor_places i for j 1 length PN global_ places if stremp comp PN global places j name tem0 tem0 PN X j end end end disp a 1 while a lt length global_info rt_monitor_places switch a case 1 set handles text95 String num2str tem0 1 case 2 set handles text89 String num2str tem0 2 case 3 set handles text90 String num2str tem0 3 case 4 set handles text91 String num2str tem0 4 case 5 set handles text92 String num2str tem0 5 case 6 set handles text93 String num2str tem0 6 case 7 set handles text94 String num2str tem0 7 149
53. simulation progress visually The newly implemented R T displaying tool provides GPenSIM to have a tool that serve as an HCI to display the status of the real time simulation and even provides a way to control the status of the running simulation Previously GPenSIM used to store the simulation result in ASCII dump file and print only the states of the simulation using print state space function at the end of the simulation The R T monitor is integrated inside gpensim so that all the gpensim operations can be interpreted in to the R T monitor The R T monitor displays the operation live without showing the background GPenSIM operation In addition to developing R T monitor for displaying the status of a real time simulation it has also been developed different kinds of real life models The models were created to test the R T monitor and to illustrate the real time simulation of DEDS The systems that were modeled are production line on real time and colored P N room security using keypad door alarm using NXT ultrasonic sensor and the traffic light system using NXT These modeled were designed to resemble the actual system and their event to be 111 monitored on real time basis Modeling a system is not an easy task it needs a deep knowledge of the developing tools and real life model Especially working with NXT intelligent Bricks needs a deep understanding of the MATLAB environment and functionality of the NXT microcontroller All the
54. temp str2 num2str current time 10 The value 10 is used to set a margin to record values on a newline The sprintf is the MATLAB keyword used to build string in a formatted way 85 Ix fire Complet AnimNGT m After a transition is fired it would be great to show the firing completion after some firing time t this makes the HCI model more meaning full Since GPenSIM has methods to show that the completion of the firing and store that statistics in its log file recorder In the R T monitor the fire Complete AnimNGT is called from the gpensim file for completing a firing called firing complete the following code shows the calling function for the firing compelte Lf EIP not empty ENIGT sobbed e e e e e e e e e e e e e e e e e e e ee e e e e e e e de de dede deee he e ee LOG colormap EIP number of completions firing complete LOG colormap EIP FTS index SNGT Pee eS ee eS Se ee See eS Se ee Ee Ee eS ES ee ee eS ee ee ee Ee Ee Ee Ee Ee Ee Ee Ee ee a end The firing complete is gpensim built in file and takes all the basic information about a transition along with log file the color map for colored Petri net and the EIP and the FTS index In a single simulation cycle there might be more than transition that has completed firing thus these are identified in gpensim as a top event l e gpensim takes the transition that is on the top of the EIP top event EIP 1 Then the transition that has
55. the code below extracts the number of token at the starting point The place will be searched on the GUI using the find GUI component places function and returns the place id on the GUI Once the searched object matched the one from the global real time places i e the value of s is found in the above code snippet the initial markings would be inserted into on the textbox that is found on the GUI for i 1 no of sources curr source name imarkings 2 1 1 source nr check valid place curr source name initial tokens imarkings 2 1i X0 source nr initial tokens Lf strcmp s place pos nr 1 set handles text77 String num2str XO 0 source nr elseif strcmp s place pos nr 2 set handles text78 String num2str X source nr The above loop iterates for every places whose initial markings are declared in the main simulation file For example suppose we have 5 places and the initial marking is declared as dyn mO p1 10 p2 10 p4 20 where p3 and p5 doesn t have an initial marking the loop skips those places that doesn t have an initial marking even if they are components of the real time simulation 79 iv Color plotter on R T monitor This file contains methods that frequently call the GUI eventdata handlers during the simulation process for plotting the status of the selected transitions This MATLAB file is called from the three files i e v vi vii and viii of the file
56. to control the simulation accordingly This is in other word the statement of our problem is resolved The codes that do this activity i e those that connect the GUI components with the gpensim were roughly described in the table 2 In this section we will try to look them deeply here Plot Number of Tokens on R T monitor As described shortly in table 2 the function token number ngt is used to plot the number of tokens on every selected places during the gpensim runtime The MATLAB file that do this activity is called token number ngt m And the associated function that passes arguments is called token number ngt This file is also embedded inside a gpensim system folder and contains a method to call the gui event handler and plot the number of tokens inside the small circles on the GUI The file is stored in a gpensim folder as C gpensim 05 Print_and_Plot token number ngt m The extracted token numbers will be sent to the GUI on the gui design view it will be displayed as This gpensim calling function of this file is called markings string The use of the marking string in gpensim is to identify the markings with a range of the matrix indices 76 25 This function takes two input arguments these are the markings and the range of the incidence matrix named as range_of_indices function markings str markings string markings range of indices Converts token vectors markings into a display str
57. to have an effective HCI model we need to develop a system that has a user friendly user interface reliable connection or interface a method to integrate with other tools and platforms and provide a method to analyse works that are performed at the background There are different kinds of interfacing techniques the most known one in the recent technologies is using a gui i e graphical user interface Different developing studios provide a graphical user interface tool which has a background call back with a specific programming language It will be well described in the design section As it is discussed above the HCI with a graphical view makes a human being closer to the computing world Especially in areas where there is a need to visualize events that are performing in a real time the need for an HCI tool must be a prior requirement Thus HCl tools for simulation and modelling in real time give a user more accurate and clear information about the simulation and even provides a graphical tool to control the simulation event 4 2 Design R T display system The new implemented tool in this thesis has a graphical user interface R T monitor which Will serve as a display unit for the real time control activities The design method of the R T monitor is designed based on the parameters of GPenSIM l e it is designed based on the formalism of GPenSIM so that it would be embedded inside the structure of GPenSIM The R T monitor system cons
58. to plot or prepare the rectangular bar The string that was built on the above code and called by the eval starts running the following code in order to prepare a bar for the transitions to be plotted on the GUI during the simulation The code runs for every transition in the R T monitor 75 function pushbuttonl Callback hObject eventdata handles global global info global PN set handles pushbuttonl1 Visible on make the bar visible if not PN REAL TIME set handles textl String PN global places 1 name else set handles textl1 String global info rt monitor trans 1 end The above code clearly shows if the simulation is in real time the name will be taken from PN global_places struct variable Every buttons were made invisible at first Whenever Their Callback is called they will be visible and ready for color plotting 5 1 3 Other implementations of R T monitor The above two implementations i e in section 5 1 1 and 5 1 2 are just used to select the Real Time places and transitions and to prepare a graphical user interface to show the whole Simulation process for human or they are used as a front end to communicate the user with the background GPenSIM libraries The main issue is not to design a graphical user interface rather it is to extract the basic information from the Petri net during the simulation process and plot those values graphically and enable the user
59. variables are declared on the top the class 37 in this implementation the global info is used to pass global variables GPenSIM stores every component in a structure called PN This PN contains information about the Petri net model For example for figure 1 in the chapter 2 the PN struct variable contains a structure that is shown in in the next figure 71 name Monitor 0207 global places 1x3 struct No of places 3 global transitions 1x2 struct No of transitions 2 global Vplaces 1x3 struct incidence matrix 2x6 double Inhibited Transitions 0 0 Inhibitors exist 0 inhibitor matrix delta T 1 2500 REAL TIME 1 REAL TIME PREV X 0 0 0 HH MM SS 1 current time 39459 STOP TIME 39483 X S 5 0 VX 0 0 0 token serial numer 10 Set_of Firing Costs Fixed 0 0 Set_of Firing Costs Variable 0 0 Firing Costs Enabled 0 Set of Firing Times 5 5 priority list 0 0 system resources No of system resources O The above figure is a PN structure for a petri net model that has three places and two transitions The structure value contains information like name number of places global places and set of firing times system resources and so on For example the name of the simulation is denoted as PN name it contains the name of the simulation Similarly it contains the global transition and places and these are denoted as PN global transitions and PN global places Note that both of them contain
60. versus real time we can see the flow of the simulation operation From the legend we can see which color shows for which place GPenSIM provides a method to plot the simulation result as shown above 98 Similarly using the control button the simulation can be controlled like it can be stopped and continued and even abort the simulation And also the speed of the simulation can be controlled using the buttons as shown below 6 1 2 Test results For NXT door alarm model As it is mentioned on the implementation section the system uses two sensors i e the ultrasonic sensor to detect an object approaching the door and also a touch sensor to reset the system The picture below shows the live result of the sensor nodes as the gpensim is running with the new R T monitor and display system implemented in this thesis Taba Mnt M Pract 1 Current 000 iH Time End Tu AAA VAARAT EAA S D as w t d i NY ium t zu LU AA Wi Qum ie capt N UB CLR DURUM AMALIA AY WW LLE Fig 70 Picture taken during the process of the ultrasonic door alarm model The above figure was taken during the running time of the door alarm system Similar to the other simulations on this section it starts by running the form to select the real components places and transitions in this thesis sense 99 Selected Modules Select Places gt tShout Select Transitiong Fig 71 Select R T co
61. 2str gp pause end gpensim m if nargin 0 gpensim ver return end global PN global handles global hn global temp global temp2 global IDy store PN pni pniis the global PetriNet structure with ini dyn global global_info global gp_pause global hPT initialize all the variables if PN REAL_TIME hPT Real PTtime select GUI to select real time monitor elements 6 i e places and transitions uiwait hPT end t cputime Ts EIP LOG colormap Enabled Trans SET Firing Trans SET SIM COMPLETE Loop Nr ETS index FTS index gpensim init all NGT Prepare the monitor here GUI disp GUI Start here close findobj type figure name GUI if isempty GUI close GUI end tic hn GUI handles guidata hn 139 count 0 if not PN REAL_ TIME disp Simulation will be paused for 1 sec disp It is not real time please select global places and transitions as real time monitoring end fill GUI initial dy IDy_ store set handles text75 String num2str gp pause if eq str2double gp pause 0 gp pause 1 end 96 End NGT disp 969696969696969696969696969696969696969696969696969696 MAIN LOOP 9696969696969696969696969696969696969696969696969696 pause on while SIM COMPLETE Loop Nr Loop Nr 1 if global info PRINT LOOP NUMBER disp Loop int2str Loop Nr Time num2str PN current time 9696969696 Put loop to gui temp2 sprin
62. 34 11 State 2 Fired Transition tProduction line1 pOutPut1 pOutPut1 pOutPut1 pOutPut1 Current State pOutPut1 Virtual tokens no tokens Right after new state 2 At time 08 34 11 Enabled transitions are tlnPut At time 08 34 11 Firing transitions are tlInPut Virtual tokens no tokens hime 03 34 20 57 State 12 Fired Transition tInPut plnout_Buff plnout Buff 2pOutPut1 plnout Buff 2pOutPut1 plnout Buff 2pOutPut1 plnout Buff 2pOutPut1 pOutput Buffer Current State plnout Buff 2pOutPut1 pOutput Buffer Virtual tokens no tokens Right after new state 12 At time 08 34 20 Enabled transitions are tinPut tProduction line1 tProduction line2 tProductionline3 At time 08 34 20 Firing transitions are tlnPut tProduction line1 Time 08 34 32 State 24 Fired Transition tProduction line2 3pOutPut1 3pOutPut1 2pOutput2 3pOutPut1 2pOutput2 3pOutPut1 2pOutput2 2pOutput_Buffer Current State 3pOutPut1 2pOutput2 2pOutput Buffer Virtual tokens no tokens Right after new state 24 At time 08 34 32 Enabled transitions are tlnPut At time 08 34 32 Firing transitions are tInPut The above text is taken from a large gpensim simulation result as a sample as it is very large text and takes a large area to show on this paper As stated above GPenSIM stores this result as a log file and printed on a MATLAB command window
63. AB guide has objects like push button textboxes axes and list boxes and their event driven callbacks like handles hObject and eventdata to export and import information The implementation has global variables But the following table shows the most important global variables that carries data throughout the system There are also other kinds of global variables and they are added in the appendix part of the report Global Descriptions Examples used variables global hn It is used to search the hObject in the gui Section 5 1 3 components global PN It is a gpesim global struct variable that Section 5 1 2 contains a every information of the Petri net model global It makes the other classes to access the Section 5 1 2 handles gui event handlers throughout the system global This is an important gpensim global Global info in any main global info variable its main functionality is to carry information of different cell arrays throughout the system enpi tenp2 sequences to proton aet montor templ temp2 sequences to plot on R T monitor Table 2 Global variables simulation files 62 5 1 Implementation of R T monitor As it is mentioned in chapter 4 the R T monitor has two main gui interface forms The two forms in the R T monitor are called Real_PTtime_select Fig and GUI fig We should recall that the fig extension is a MATLAB figure file extension which contains the layouts of the gui components Recall tha
64. I component places curr Place 555 To print the number of tokens in each places if ismember curr Place global info rt monitor places if strcmp s text68B set handles text95 String tokens elseif strcmp s text69 set handles text89 String tokens The set command put the tokens of the places in to the gui using the global handles ii find_GUI_component_places m This MATLAB file is used to look after the place where the currently fired token has been taken from l e it displays the source of the current token that has been stored into the virtual token bank This function checks both for real time and non real time components If the simulation is in real time the place is checked from the cell array of the real time from the one that we have selected at the beginning function s find GUI component places curr source name This function takes the current source place and returns its associated GUI member This function is invoked by the fill GUI initial dy m and token number ngt m len length global info rt monitor places if PN REAL TIME for j 1 len if strcmp curr source name global info rt monitor places j curr source name global info rt monitor places j myob findobj hn String global info rt monitor places j if isempty myobj disp cant get it return end myobj2 get myob s myobj2 Tag isspace myobj2 Tag end end The above cone snippet is taken from the MATLAB file and
65. LAB software calls a callback in response to a particular event for a component or for the figure itself 35 The callback s are automatically created as the user selects tools and draws on the design layout tool The callback s in any figure can be accessed by right click on the component on the designer view Note that the method callback is the main connector of the figure and the background program Whenever some event happens the callbacks pass arguments to the three variables 8 Cut Ctrl X Copy Cec CireV Clear Duplicate Cti D Bring to Front Ctri F Send to Back Ctrl B Object Brewser Edrtor View Callbacks Callback Property Inspector 5 dd DeleteFcn ButtonDawnFen KeyPressFcn Fig 45 A MATLAB GUIDE designer view For example a callback function for the above pushbutton is shown below runction pushbuttonl Callback hObject eventdat handles hObject handle to pushbutton3 see GCBO eventdata reserved to be defined in a future version of MATLAB O handles structure with handles and user data see GUIDATA The comments are created by GUIDE as an annotation for the GUI component to inform what the variables are used for These comments are optional and can be removed A MATLAB GUIDE by default creates a main function by passing two different types of variables called varargin and varargout Every _Callback function passes at least three types of variable
66. LBACK in REAL PTTIME SELECT M with the given input arguments 96 REAL PTTIME SELECT Property Value creates a new REAL PTTIME SELECT or raises the existing singleton Starting from the left property value pairs are applied to the GUI before Real PTtime select OpeningFcn gets called An unrecognized property name or invalid value makes property application 96 stop All inputs are passed to Real PTtime select OpeningFcn via varargin 96 96 See GUI Options on GUIDE s Tools menu Choose GUI allows only one instance to run singleton 96 Edit the above text to modify the response to help Real PTtime select Last Modified by GUIDE v2 5 30 May 2014 15 35 08 6 Begin initialization code DO NOT EDIT it might disorder the layouts gui Singleton 1 gui State struct gui Name mfilename gui_ Singleton gui Singleton gui_OpeningFcn Real_ PTtime_select_OpeningFcn gui OutputFcn Real_ PTtime select OutputFocn gui_LayoutFcn gui_Callback if nargin amp amp ischar varargin 1 gui_State gui_Callback str2func varargin 1 end if nargout varargout 1 nargout gui_mainfcn gui_ State varargin else gui mainfcn gui State varargin end End initialization code DO NOT EDIT 96 Executes just before Real PTtime select is made visible function Real PTtime select OpeningFcn hObject eventdata handles varargin 122 handles
67. PN REAL TIME set handles text74 String PN global places 7 name J else set handles text74 String global info rt monitor places 7 end Executes during object creation after setting all properties function edit9_CreateFcn hObject eventdata handles hObject handle to edit9 see GCBO if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end Executes during object deletion before destroying properties function axes1 DeleteFcn hObject eventdata handles ax gca cla ax reset Executes during object deletion before destroying properties function axes7_DeleteFcn hObject eventdata handles ax gca cla ax reset Executes on slider movement function slider1_Callback hObject eventdata handles 134 sliderMin get hObject Min sliderMax get hObject Max dummy get hObject Value s dummy sliderMax sliderMin dummy get handles uipanel30 position frameWidth dummy 3 set handles uipanel30 position 0 1 frameWidth s 0 071 frameWidth 0 78 96 Executes during object creation after setting all properties function slider1 CreateFcn hObject eventdata handles 6 Hint slider controls usually have a light gray background if isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor 9 9 9
68. Place names Initial marking Description status pG A place for red and yellow lights A place for yellow light A pace for red light off Table 9 Analysis of the selected places and tokens of the traffic light model at time t The status of the number of tokens is also displayed inside a small box which is found straight below the small circles on the R T monitor For example for the places tR OFF the series of each token gaming is shown below tR ON takes 1 token from pR at 11 07 07 These are discussed in detail in chapter 4 mm IR ON Tok 1 At 11 07 07 FrompR RLOFF Tok 1 Fig 89 Display to show the token gaming A Like all the simulations the enable and firing sequence can also be displayed on the big boxes on the R T monitor The two panel for the traffic light system gives following result 108 Enable Seguente Firing State Sequence tEM BUTTON is Enabled At 11 07 07 tEM BUTTON Enabled but not Fired At 11 07 07 P tEM BUTTONH is Mot Enabled At 11 07 07 tR ON is Fired At 11 07 07 tEM BUTTONH is Mot Enabled At 11 07 08 tEM BUTTON Enabled but not Fired At 11 07 08 tR_ON is completed At 11 07 08 tEM BUTTON is Mot Enabled At 11 07 09 tEM BUTTON Enabled but not Fired At 11 07 09 tEM BUTTON is Mot Enabled At 11 07 08 tR OFF is Fired At 11 07 08 tEM BUTTON is Mot Enabled At 11 07 10 tEM BUTTON Enabled but not
69. RT DISPLAY return end end If the transition is enabled and found in the real time array then the gui painter will be called with a method gui painter tl g Enabled g strl Str1 is a global variable that records the status of the transition along with the current real time that the transition is in an enabled state 83 viii fire AnimNGT m This function has a method to call the gui painter in order to paint a red bar on the GUI interface to illustrate that the current transition is on a fire state According to a Petri net theory Only an enabled transition can fire 11 and also by adding the GPenSIM TDF formalism i e only a transition that is enabled and fulfils the precondition rule can fire Thus like the enabled plotter this function takes values from the gpensim variable PN and call the gui plotter function in order to plot the red bar on the main interface To call the fire AnimNGT from the firing start m gpesim file we need to pass the index of the current active transition The variable used here is called t and the following two code snippets shows this action tunctlon ELP faring Start BIP Inside the firing start function the next step i e to plot a red bar on the GUI for a fired transition we need get those enabled transitions The method to extract enabled transitions is performed using a MATLAB keyword called find dont care enabledTrans find PN Enabled Tran
70. T University of Stavanger Faculty of Science and Technology MASTER S THESIS Study program Specialization Spring semester 2014 Master of Science in Computer Science Open Restricted access Writer Nigussie Girma Tulu Writer s signature Faculty supervisor Reggie Davidrajuh Thesis title Monitor for displaying the status of Real Time simulation Credits ECTS 30 ECTS Key words Pages 166 Discrete Event Dynamic Systems DEDS Real Time R T enclosure CD Petri net P N GpenSIM MATLAB GUIDE NXT device Stavanger 26 June 2014 Summary This paper presents a design and implementation of a monitor to display the status of real time simulation and modelling for discrete event dynamic systems DEDS The modelling and simulation of DEDS in this thesis are implemented using two kinds tools called Petri net and GpenSIM Petri Nets are tools that are widely used now a day to model and simulate discrete events of concurrent and dynamic systems 1 Petri net has a graphical formalism that is getting popularity in recent years as a tool for representing complex mathematical and analytical interactions like synchronization concurrency atomicity sequential and conflict control among physical components or activities in DEDS 1 Besides a Petri net can be primarily used for analyzing and modeling the dynamic and concurrent behavior of distributed systems where there is a discrete event flow GPenSim wher
71. TIM ps Enable Sequence 7 p Fiing State Sequence TRON is Fired At 112424 uL 8 ON is completed At 11 24 o E RLOFF is Fred At 11 5 Fig 80 A picture taken during the simulation process of the traffic light model Again this simulation runs by letting the user to select the real time components When the simulation starts at MSF A graphical display will appear and the user can select the places and transitions to be displayed on the R T display The R T monitor skips the rest of places and transitions that are not selected and inform it on the command window as shown below At 11 13 40 tPEDES_BUTTON is Enaled but not member of R T monitor RETURN ON R T_DISPLAY ON RED At 40411 tR_ON is fired At 11 13 40 tR_ON is Fired but not member of R T monitor The form that is used to select places and transition for the traffic light system is shown below This has also been clearly described in chapter 4 105 Bl Real PTtime select RT Places RT Transitions tR OFF tR_ON tEM Y OFF tPEDES BEEP tPEDES BUTTON tPEDES CYCLE tPEDES QUIT tPEDES START tHORMAL CYCLE FEN iut Fig 81 Select R T components for Traffic model The ASCII dump files of the gpensim results are shown below For comparison it is displayed below The selected transitions and places from the above form will be displayed on the R T monitor The transitions panel on the monitor is shown be
72. able AnimNGT file from the gpensim main file i e gpensim To do so the following functions calls this variable if any PN Enabled Transitions enable AnimNGT EIP firing start EIF end From the above code the condition checks whether there are any enabled transitions in the current simulation cycle And if so all the enabled transitions will be plotted green at the same time on the GUI until one of them fires l e the one that fired automatically be turned to red by the fire animator We have discussed that in the cell array values that are numbered one are enabled and what the enableAnim function do is that it takes the index of those values that have one in the cell array and check if they are selected on the R T monitor at the beginning After checking those values it will call the gui painter m The steps are shown below It gets the index of values that are one in the cell array E g 10 1 1 1 This is the enabled transitions enbl trans PN Enabled Transitions 0 1 1 for i l length enbl trans if eq enbl trans i 1 curr trans PN global transitions 1 name tl i Checks whether the transition exists in the cell array and if it is not a member it returns to the normal simulation system Xr PN REAL TIME if ismember curr trans global info rt monitor trans disp At rt clock strinq PN global transitions tl name is Enaled but not member of RT monitor disp RETURN ON
73. abled At 12 45 39 Firing State Sequence zt oop Nr 1 tinPut is Fired At 12 45 39 tProduction line2 Enabled but not Fired At 12 45 39 tProduction line1 Enabled but not Fired At 12 45 39 tProductionline3 Enabled but not Fired At 12 45 39 t amp ssemble Not enabled and Fired at12 45 39 opp Nr 2 t amp ssemble is Mot Enabled At 12 45 38 tProduction line2 Enabled but not Fired At Fig 68 Test result of enable and firing sequence of the production line in R T monitor The above two windows shows the enabling and the firing sequence of the model in ASCII code This gives extra information about the simulation process Similar along with the graphical display the result can also be analyzed using graphical plotting as it is done on the normal gpensim output The plot result of the above system gives the following result plnaut uff pOutPut1 pQOutput2 pOutput3 pOutput uffer BEL BI I I I I I I I I T I I I I I I I I i I I I I I I I I I T I I I I I I I I Number of tokens ys zh IE T l l2 2 2c4Q 2 2 2 2 2gp 4 Rp 2 4Q4 X 0 14 335 14 34 14 345 14 35 Time in HOURS Fig 69 Number of tokens vs time plot result 14 355 14 36 14 365 From the above plot Number of tokens
74. ack hObject eventdata handles global newmenu store the values in cellarray string currentitems get handles listbox5 String Accuse from the right side list list entry cellstr currentltems index selected get handles listbox5 value get the list index choice listbox5 list entry index selected newmenu newmenu choice listbox5 build the R T places cell array set handles listbox6 String newmenu put on the right side list box selected items set handles listbox5 Value remove the selected item from the left listbox newltems currentltems newltems index selected a MATLAB method to remove a cell array item set handles listbox5 String newltems if isempty newltems if length newltems gt 1 set handles listbox5 Value 1 always put at the top to eliminate duplicate end end Executes on button press to remove unwanted selected places from the right listbox function pushbutton6_Callback hObject eventdata handles global new_remove_menu global newmenu newmenuz currentitems2 get handles listbox6 String list entry cellstr currentltems2 index selected get handles listbox6 value choice Istbox2 list entry index selected curi22get handles listbox5 String new remove menu curl2 choice Istbox2 set handles listbox5 String new remove menu set handles listbox6 Value newltems currentitems2 newltems index_selected
75. allback functions Both of them take the selected item from the listed places and transitions from the left side list boxes and store them in to the right side list boxes respectively At the same time the call back functions in a and c above build a string array that will be the global_info rt_palces and global_info rt_transitions The other function b and d are used to remove unwanted items The ok button returns to the main GUI display 5 1 2 Implementation of graphical Display for Real Time Monitor The declaration and initialization parts of the GUI fig are similar to that of the previous section Real PTtime select with some extra codes Similarly this class contains both the layout figure file and the associated MATLAB script file These both files are embedded inside a GPenSIM system folder i e the guide layout file with all the graphical user interfaces components C gpensim timed pensimNGUI fig and also the background script MATLAB file C gpensim timed_pensim GUI m The GUI m has also different kinds of functions that plot constantly each event to the gui interface display GUI fig In the GUI figure of the R T monitor The file name is called GUI m The main function is called GUI V It takes and passes an input argument varargin and return an output argument varargout The prefix name var is associated with the different types of variables in a MATLAB struct cell array form i The main function
76. an computer interaction hci html 31 Jeffrey W Herrmann and Edward Lin Petri Nets Tutorial and Applications The 32th Annual Symposium of the Washington Operations Research Management Science Council 1997 pp 5 32 MATLAB GUI Available at http www mathworks se discovery matlab gui html 33 Meghan Stephens Creating GUI s in MATLAB 2007 pp 1 3 34 The Math Works Building GUIs with MATLAB R V 5 1996 pp 9 2 3 35 MATLAB R the Math works Creating Graphical user interface R2014a p50 2 26 Available at http www mathworks com help pdf doc MATLAB buildgui pdf 115 36 MATLAB GUI Aide Scilab available at https help scilab org docs 5 3 3 fr_FR gcbo html 37 MATWORK MATLAB R the Mathworks V 5 2013 pp 179 4 27 Available at www mathwork com 38 RWTH Mindstorms NXT Toolbox User Manual v4 04 2010 List of functions 39 Traffic Signal Model Complete Code for LEGO Minstorms NXT experiment 2012 Available at http davidrajuh net gpensim 2012 IJSSST traffic signal example LEGO NXT 40 TimedPetrinet Available at http redwood cs ttu edu andersen cs5355 lecture5 pdf 41 Door alarm problem Available at http www cs hmc edu keller courses cs156 s98 slides 368 html 42 Jeffrey W Herrmann Edward Lin Petri Nets Tutorial and Applications University of Maryland 43 NXT intelligent Brick Available at http shop lego com en US NXT Intelligent Brick 9841
77. an efficient graphical tool to make the user more comfortable Every GUI tools provide a method or class object called FORMS l e A form is a class that its member functions are accessible throughout the class All controls in the function are objects In java and visual studio tools a graphical user interface is called form jForm or Form But in MATLAB it is called figure The figures in MATLAB GUIDE are usually denoted as gcf Forms area graphical user interface tools through whicha user interacts with the background source code To make the system more useful and user friendly the interface should have suitable controls for getting input data from the user A MATLAB gui form is called figure As it is know that all MATLAB plots are named as figure1 figure2 and so on This will be explained on the next section A well designed gui should fulfil the following three criteria 33 Simplicity should have unity elegance and clarity Consistency should have a good alignment integrity with the back code and harmony Familiarity It should be user friendly and charm 4 3 2 MATLAB GUIDE A MATLAB gui is called GUIDE It is an event driven programming tool developed by MATLAB in order to provide the users with a graphical user interface GUI development environment 34 The GUI should behave in an understandable and predictable manner so that a user knows what to expect when he or she performs an action For example
78. an use time P N to define the behavior of the above model the basic sub modules for the above are Entrance door model For a simple door model it can be started by designing a model without a condition to check if the door was already opened It is because of the fact that the door might be opened and it should be rechecked the existing door Fig 15 Simple door model using Petri net 28 The above model checks only the status of the door Weather it is opened or not to make it more intelligent The door model can be redesigned as shown below by adding a feature to check if the door is already opened or not Fig 16 Door condition model with previously opened door status The Petri net definition file for a door model will be Alarm model The alarm model consists of three places and four transitions After opening the door if the person didn t enter the correct code within a given range of time At the alarm will Start ringing This is only if the alarm is set to Armed If the alarm is not set or disarmed it will be off or needs to be armed otherwise anybody can enter to the house tRinging PRing Fig 17 Alarm model using P N The Petri net definition file using GPenSIM for the above model is shown below 29 Keypad model The keypad has two transitions each of them with two transitions to fire from an idle token event that has been stored inside the pBuffer place The tExit generates a
79. analysis They added different features to control the simulation in real time i e they do the simulation in real time A good example is a workflow modelling of CNC machine using Petri net A workflow model can be simulated using a Petri net We can consider an example of a machine control from CNC and feeds to different robots The actual model is Production Line Outputs 2 Z Overall Output Outputs 3 Fig 11 Real life model of Production line From the above real life model we can induce a P N model of the production facility is shown below pOutPut1 tProduction line1 plnout Butt tAssemble pOutput Buffer tinPut tProductionline3 pOutput3 Fig 12 P N model for production line 26 As we can see on the above Petri net model the system has three production lines where all of them have the same input source The three transitions tProduction line1 tProduction line2 and tProduction line3 have different methods to choose color tokens from the input Based on the preconditions of the production line every production line uses different kinds of rules to fire an input token Assume a color P N to identify the tokens to each production line The tokens are denoted by different colors say A B C or D and are used rotationally and the tlnPut generates those tokens and stored in olnput_Buff The implementation part will be clearly des
80. ansitional definition file as user defined module The main simulation file consists of dynamic details like initial markings firing times global variables and so on of the P N model GPenSIM uses a modular approach to model a Petri net graph The Petri net definition file consists of the Petri net properties like set of places set of transitions and set of arcs 26 The Architecture of the GPenSIM is shown below in figure 12 It shows how GPenSIM is integrated with the MATLAB tool boxes Other MATLA Tools like systems Fuzzy logic MATLAB Engine Fig 8 General Structure of GpenSIM 25 Simulasjon results A new tool has been under construction in order to develop a graphical user interface for GPenSIM The new project will have a visual interface tool as shown below 18 GPenSIM operational files The following figure shows how GpenSIM operates to model and simulate P N models Transitional definition files pre and post files Pre and post Petri net definition File PDF Main Simulation File Consists of dynamic details MSF Matlab Engine Fig 9 Basic GpenSIM Operations 2 6 2 The main simulation file MSF file The main simulation file consists of dynamic codes like the initial dynamics the initial token states and functions to display and control Petri net properties on the command window The different files main simulation file MSF Petri net
81. aracterized as memory less We can also use binomial distribution to simulate the random discrete flow E g the following figure shows a discrete flow of a simulated random numbers in some specific time n y t a 9 ean A binomial distribution function is a good explanation of discrete event flows The result for tasted t values is shown below 35 Fig 3 Discrete event vs time simulation The potential of a discrete event model is described by its 14 e Ability to compress time expand time e Ability to control sources of variation 1 Y x x e Where x is each score x is mean e Avoids errors in measurement SD value for n terms e Ability to stop and review e Ability to restore system state e Facilitates replication e The modeler can easily control level of the details 2 3 Continuous event time simulation It is one kind of modelling and simulation technique used in modelling an object whose behavior is continuous A good example for continuous simulation is a life time simulation of studying spontaneous flow of a liquid state The exponential distribution function gives continues time results of events for a given period of time This can be denoted by y t e tz 0 0 001 1 y is constant rate t is continuous time Fig 4 Continues time simulation result 2 4 Petri Net Petri Net is one of the widely used tools to model a discrete time event systems A Petri Net is a flexible tool that ca
82. asily evaluated The simulation results in GpenSIM are displayed in a text format The main advantage of a GpenSIM is its reduction in resource managements The ordinary Petri net model shows all the detail information in the frontline But in GPenSIM the resource are pushed to the back ground so that one can see a clear image of the model GpenSIM can model and analyses any type of Petri net file Its integration with a MATLAB environment makes it more flexible and powerful to analyze the properties of a Petri net model 25 To install a GPenSIM one must download the zipped file from the owner s web site The website also provides a handy manual that makes anyone to learn fast how to use GPenSIM Since GPenSIM works in MATLAB platform it must be unzipped in to the MATLAB 17 folder or the user should set the root path inside the MATLAB file menu to GPenSIM The installation step is available in appendix section of this paper After installing the GPenSIM the program can be tested by writing GPenSIM in the MATLAB command window gt gt GPenSIM GPenSIM version 8 0 Last update August 2013 C Reggie Davidrajuh uis no http www davidrajuh net gpensim 2 6 1 The Structure of GPenSIM GPenSIM as discussed above is a tool to model and simulate a Petri net graph The tool consists of two main modules and one user defined module The two main modules are the main simulation file MSF and the Petri net definition files PDF and the tr
83. ble from www cs wm edu esmirni Teaching cs526 DESAFC 1 1 ppt 10 Reggie Davidrajuh 2009 GPenSIM A new Petri net simulator section2 pp 25 Available at http cdn intechopen com pdfs wm 9199 pdf 11 James L Peterson Petri net Theory and the Modelling of Systems Englewood Cliffs Nj Prentice Hall Inc 1981 ISBN 0 13 661983 5 pp 2 3 12 Xi Ren Cao 2012 discrete event dynamic systems Theory and applications Vol 23 number 4 ISSN 0924 5703 pp 1 3 Available at http www springer com mathematics applications journal 10626 13 Markov Chain Available at http en wikipedia org wiki Markov chain 14 G Fishman 2001 Discrete Event Simulation Modeling Programming and Analysis pp 26 27 15 Jin Shyan Lee and Pau Lo Hsu Applications of Petri net to Human in the Loop Control for Discrete Automation Systems pp 170 16 Reggie Davidrajuh 2009 Modeling and Simulation of Discrete Event Systems with Petri Nets pp 1 7 17 James L Peterson Petri net Theory and the Modelling of Systems Englewood Cliffs Nj Prentice Hall Inc 1981 ISBN 0 13 661983 5 pp 19 18 Cassandras G and Lafortune S Introduction to Discrete Event Systems Springer 2007 114 19 James L Peterson Petri net Theory and the Modelling of Systems Englewood Cliffs Nj Prentice Hall Inc ISBN 0 13 661983 5 1981 pp 6 17 20 Tao Hong and Mo Yuen Chow Timed Petri Nets Modelling for Fault Study Advanced Diagnos
84. ce sim plotp sim plnout Buff pOutPut1 pOutput2 pOutput3 pOutput Buffer grid on production def m function png production def png PN name A Simple Petri Net definition png set of Ps plnout Buff pOutput Buffer pOutPut1 pOutput2 pOutput3 png set of Ts tAssemble tInPut tProduction line1 tProduction line2 tProductionline3 png set of As plnout Buff tProduction line1 1 plnout Buff tProduction line2 1 plnout Buff tProductionline3 1 pOutPut1 tAssemble 1 pOutput2 tAssemble 1 pOutput3 tAssemble 1 tAssemble pOutput Buffer 1 tlnPut pInout Buff 1 tProduction line1 pOutPut1 1 tProduction line2 pOutput2 1 tProductionline3 pOutput3 1 tinout pre m function fire transition tlnPut pre transition global global info if strcmp transition name tInPut index mod global info cr index 4 1 global info cr index global info cr index 1 transition new color global info cr index fire 1 return end tAssembly pre m function fire transition tAssemble pre transition if stremp transition name tAssemble fire 1 152 else disp Wait until other lines finish their task fire 0 end COMMON_PRE m function fire transition COMMON PRE transition if stremp transition name tProduction line toklD1 select token with colors plnout Bu
85. communication network routers switches and so on It can also act as a buffer for example in a hard disk conveyor belt depot queue or a post bin and so on 13 e To denote geographical location like a place in a warehouse office or hospital e To denote the state or the state condition for example the location of an elevator is or the condition that a specialist is available for a particular moment 2 4 2 Transition Transitions are event driven conditions where events are actions which take place in the system In a petri net the occurrence of an event is controlled and managed by the current state of the system Similarly the transition has some common roles in DES A transition can fire only if it is enabled A transition is enabled if the number of tokens in the input place is greater than or equal to the arc weight 17 A transition can be used as e An event for example a transaction a database search activity starting an operation the death of a patient the switching system of a traffic light e Transformation of an object to another form like accepting a product updating a database record or updating a document file e Transportation of objects like transporting goods or sending a file a Enabled Transitions A transition t T in a Petri net is said to be enabled 18 If x pj w pi tj for allp I t The transition t1 in figure 2 is enabled since the numbers of tokens in the input places p1 is
86. completed firing is returned as completing tran top event event The function that calls the R T plotter is shown below while and EIP not empty time to fire top event EIP 1 time to fire le top event completion time PN current time if time to fire log record colormap record firing complete one top event FTS index 55 NGT completing tran top event event fire Complet AnimNGT completing tran 5 End NGT LOG LOG log record recording of events for tracing back colormap colormap colormap record EIP EIP 2 end no of completions no of completions 1 end EIP not empty isempty EIP end The fire Complete AnimNGT perform similar function to that of the fire AnimNGT but here the transition is not extracted from the global PN Rather it is the transition which is on the top of the event queue that is taken for plotting on the R T monitor As mentioned in chapter 4 on the gui the bar that tells the status of the current completed transition is denoted by a yellow color Thus the painter is called by 86 gui painter completing tran y Completed y str3 EB P Jg Y E Y Str3 is an array of strings that records those transitions that has completed firing str3 curr trans is completed At ie temp sprintf temp str3 num2str current time 10 X hasnotfired AnimNGT m Referring chapter 4 section 4 3 2 and this function takes two event of a transition the
87. controller has port to interface to PC and also ports to interface the touch input sensor and the ultrasonic sensor The main purpose of the NXT intelligent Brick is that is takes input from the PC and detects the passing by object based on the pre defined Petri net model 2 NXT ultrasonic sensor The ultrasonic sensor in NXT is used to sense any object and also capable of calculating the distance of the object from the sensor node The ultrasonic sensor is used in this code as a sensing node of an object who intended to cross the door The ultrasonic sensor Measures the distance between the NXT Ultrasonic Sensor and the nearest object in front of the sensor The sensor can detect objects from approximately 5 to 255 centimeters away Fig 23 NXT Ultrasonic sensor The sensor detects objects that are in some angle It is possible to calibrate the ultrasonic measuring degree 33 Fig 24 Angular range of ultrasonic sensor detection 3 Touch input sensor This input button is used to reset the alarm It restarts the operation of the alarm system The NXT touch input sensor works when a user presses the orange button The NXT brick has four input ports and read this sensor input and makes an output i Fig 25 Reset button NXT touch input sensor The flowchart for the alarm system is shown below 34 Object Person Door No Yes Alarm on off Ente
88. cording to GPenSIM formalism the design issue of a real time in GPenSIM considers three main design approaches These are Realizing token game in gpensim structure by a method like as soon as possible ASAP firing delayed firing or by aging Realize a way to model events Consider the options either events by places or event by transitions Analyze a way to interact with the external environment of the model Is it either thorough places or by transition A token game in GpenSIM is defined as consumption of input tokens and creation of output tokens within a specific range of firing time The following figure shows firing time t n for a token game firing time n P1 Iu t 0 Osten t gt n Fig 10 Token gaming The above figure shows that at time t 0 tO is enabled as the input place has enough tokens to be consumed and ready to fire Between the given firing time n the amount of token that are equal to the arc weight bandwidth will be fired in to the output place p1 Token gaming simply shows the condition of disappearance and reemerging of tokens by the transition 25 3 2 1 Real Time simulation in Industrial application The demand of real time modelling and simulation in industrial are steadily increasing Different companies prefer to have a model and simulate it before starting to plant a machine Even more companies prefer to do more than just modelling simulating and
89. creation after setting all properties function axes7 CreateFcn hObject eventdata handles radius 2 centerX 5 centerY 7 rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor w axis equal 96 Executes during object creation after setting all properties function axes15 CreateFcn hObject eventdata handles radius 2 centerX 5 centerY 7 rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor w axis equal 96 Executes during object creation after setting all properties function uipanel1 CreateFcn hObject eventdata handles Executes during object creation after setting all properties function text3 CreateFcn hObject eventdata handles 138 Executes during object creation after setting all properties function text4_CreateFcn hObject eventdata handles Executes during object creation after setting all properties function text5_CreateFcn hObject eventdata handles Executes during object creation after setting all properties function text6_CreateFcn hObject eventdata handles Executes on button press in pushbutton19 function pushbutton19 Callback hObject eventdata handles global gp pause if gp pause gt 0 gp pause gp pause 0O 1 set handles text75 String num2str gp pause else gp pause O0 1 set handles text75 String num
90. cribed on chapter 5 Section 5 2 1 3 2 2 Real Time simulation in room security As it is mentioned above we can simulate any kind of discrete event flow using Petri net hence GPenSIM In this part modelling for the usual entrance gate security system will also emphasize the concept of real time modelling using GPenSIM The model for such system is available at 41 Fig 13 Entrance handle with keypad The real life model of an alarm system using three modules is shown below Fig 14 Actual model of a house alarm system with keypad 24 The following algorithm will give a brief steps about the working principle of an alarm system The algorithm e Ifthe alarm is on and ready to detect o Check if the entrance is ready and closed When opened read and save the current time Q4 e Enter the combination password within 120 second 2 min If the entry code is not entered within the current real time 61 2min or if the entered code mismatches with the stored codes after three trials e Trigger the alarm signal fcodeis correct keep on the cycle e To disarm the alarm and stop the ringing tone o Enter the combination code in the keypad o Else continue ringing e Totrigger the alarm again store the next time 62 o Enter the exist combination code The entrance alarm will be armed after some delay at time 62 so that the new time will be the current time The time interval with every firing will be Ad 6 We c
91. d control of the model In this thesis timed P N are used 2 5 2 Stochastic Timed Petri Nets Stochastic time delays with transitions A stochastic Petri net SP N is a Petri net where each transition is associated with an exponentially distributed random variable that expresses the delay from the enabling to the firing of the transition 22 2 5 3 Color Petri net CPN CPN is representing of tokens with different types of colors CPN is a well organized and suited modelling approach for systems that consists of a number of quite different tokens or processes that interact and synchronize Good examples of CPN application areas are communications automated production control systems distributed systems work flow management analysis 20 2 6 GPenSIM GpenSIM is a tool for modeling and simulating the discrete event systems DEDS GpenSIM is integrated inside a MATLAB platform and thus have access to the built in MATLAB functions GpenSIM defines the Petri net graph in the Petri net definition files The results of a simulation are shown in a MATLAB file In GpenSIM systems can be divided into modules These are static part and dynamic parts The static part contains a Petri net Definition file If we have different modules the pdf can be divided in two different types of Petri net definition files Similarly the main simulation file contains a dynamic part of a GpenSIM In this approach a complex systems become more transparent and can be e
92. d created by Nigussie Girma as realtime display and monitor for GPenSIM The GUi is embedded inside a GPenSIM A GPenSIM is a general petrinet simulator Vio Sat etait Cat SIS oe GUI by itself creates a new GUI or raises the existing singleton In order to run GUI H GUl returns the handle to a new GUI or the handle to the existing singleton 96 GUI CALLBACK hObject eventdata handles calls the local function named CALLBACK in GUI M with the given input arguments 96 GUI Property Value creates a new GUI or raises the existing singleton Starting from the left property value pairs are applied to the GUI before GUI OpeningFcn gets called An unrecognized property name or invalid value makes property application stop All inputs are passed to GUI OpeningFcn via varargin 96 See GUI Options on GUIDE s Tools menu Choose GUI allows only one instance to run singleton To use this tool one should have a knowledge of Petri net and GPenSIM in addition to Matlab GUIDE See also GUIDE GUIDATA GUIHANDLES gpensim Petrinet 6 Last Modified by GUIDE v2 5 13 Apr 2014 17 55 59 6 Begin initialization code CAUTION DO NOT EDIT The code before reading the readme file p isdaeeecte IS gui_Singleton 1 gui State struct gui Name mfilename gui Singleton gui Singleton gui OpeningFcn GUI OpeningFcn gui Ou
93. definition files PDFs and transition definition files TDFs can access and exchange global data using global variable called global info 26 The global info can also be used to control the condition of a TDF by semaphore The global info variable can be accessed by the Petri net definition file main simulation file and transitional definition files 2 6 3 The Petri net definition file PDF file The PDF in GPenSIM consists of the set of places the set of transitions and the set of arcs It has also a set of Inhibitor arcs The good thing with GPenSIM is it supports an inhibitor arc The PDF file in GPenSIM is denoted by def where the user can write the PDF name by adding the def file where it is saved as a MATLAB file 22 26 2 6 4 The transitional definition file The transitional definition file consists of two files these are called pre and post files The pre condition consists of a user defined functions that shows an event which happens before a firing state of the transition In this part we can infer different kind of rules that controls the control activities of the simulation Similarly the post condition consists of a user defined functions that shows a post events which happens after a firing state of the transition An example of a pre and post file for the above is shown below 19 function fire transition COMMON PRE transition global global info if strcmp tranaition name processNewMsc fire eq g
94. e The Petrinetgraph is a gpensim build in command to road the pdf file from the drive Note that we use this file in main simulation file 20 gt gt png petrinetgraph mypdf def png name A simple PN model global places 1x2 struct No of places 2 global transitions 1x1 struct No of transitions 1 global Vplaces 1x2 struct incidence matrix 2 1 0 1 Inhibited Transitions 0 Inhibitors exist 0 inhibitor matrix gt gt Note that mypdf_def refers to the Petri net definition file Step2 Create the transitional definition files i e pre and post files Step3 Create the main simulation files Identify the global variables i e make some policies Load the pdf file Using the above command gt gt png petrinetgraph mypdf def The png returns the set of places set of arcs and set of transitions If there are more than one pdf files i e modular approach The calling will we as below P pngspetrrinetgraph imypoLl oer mypdr2 der mypdf2 def Declare the initial dynamics The initial marking and firing times of the simulation Usually the dynamic systems are denoted as dyn in gpensim The initial dynamics are declared as Seo V DNO Ol GU Oe Gb pu Oja Here the mO denotes the initial marking or the number of tokens at the starting point Here note that we don t need to declare for every place in the model l e we can declare this only for places that have tokens at the begin
95. e this thesis will rely on is a general purpose Petri net simulation tool used to model and simulate systems of discrete events that are designed using a Petri Net tool In this thesis a human computer interaction HCI tool for GpenSIM is also introduced This is because of the fact that GPenSIM doesn t provide a method to display the simulation process on a graphical display unit The newly implemented HCI tool is used for displaying the status of the running GpenSIM file on a monitor screen it has also an enhanced tool that helps the user to easily control the Real Time simulation process To illustrate the application of Real Time simulation and modelling using Petri net and to test the newly developed HCI tool for GpenSIM it has also been implemented different kind of real life models in some application areas like industry traffic light signal and door alarm In this thesis NXT intelligent brick with sensors have been used to show how GpenSIM works for modelling the real life system run on Real Time and also to illustrate the modelling power of a Petri net by testing the newly implemented display tool The NXT Intelligent brick is a simple robotic device that is built for educational purpose 2 The device is used to get a Real Time data from different sensor nodes on Real Time Acknowledgment First of all would like to thank God for making me stronger and giving me the power to pursue my thesis work Next would like to thank my Sup
96. elect m Real PTtime select fig FCS 0 0 y B a O tl gui singleton Callback GUI gui Notations Petri net Structure data type in GPenSIM Real Time Discrete event Dynamic Systems General Purpose Petri net simulator GPenSIM system file Main simulation file Petri net Definition file transitional definition file Human computer interaction LEGO Mindstrom microcontroller device A MATLAB graphical user interface layout designer tool a MATLAB variable automatically created each time a callback is executed and returns the handle of the object A MATLAB command creates an empty figure Background MATLAB script file for R T monitor display MATLAB designer layout file for R T monitor display Background MATLAB script file to select places and transitions MATLAB designer layout file for Real PTtime select m firing condition satisfied Measuring parameters Symbols that denote Events Symbols that denote time frame GUIDE command to control the number of opened gui windows The background event handling function in MATLAB GUIDE The Main display in the new implemented R T monitor graphical user interface vi Vil Chapter 1 1 Introduction The field of Simulation and modelling is one of the rapidly developing area in computer science 3 Different scientific areas introduce the need for modelling and simulation according to their basic necessities It is well known that computers have changed the way we used
97. els in chapter 3 using R T monitor This would give a brief explanation about the objective of the project 6 1 Experimentation for R T simulation in section 5 2 6 1 1 Test results for R T simulation in Industrial application The model for this section was deeply described on the implementation section 5 2 1 As it was described on the design section the first step before the simulation starts were to select the real time components i e selected places and transitions The screen shot of the operation below shows the progress of selection of places and transitions that is intended to be displayed on the R T monitor E Real PTtime select a RT Places Selected Modules pOutput Buffer pOutputs RT Transitions tProduction line Fig 65 Test result picture of the R T component select window Until the user select places and transitions the gpensim wait for a response of the ok button Once the ok button is clicked the simulation will resume by displaying the R T monitor Since there are few places and transition the whole components can be selected and are displayed as shown below 96 Transitions se Transition names tinPut tProduction lin tAssemble tProduction lin tProductionline el e 3 Transition Fired Completed Enbl but Not Enbl but Not Enbl but Not States Fired Fired Fired Current um m Time 12 46 02 12 46 02 12 46 02 12 46 02 12 46 02 Fig 66 Test result of status of transitions in t
98. empty temp2 set handles edit1 String temp2 end disp At num2str current time PN global transitions t1 name is enabled str1 PN global transitions t1 name is enabled gui painter t1 g Enabled gstr1 prev trans curr trans end end fire AnimNGT m function fire AnimNGT t1 global PN global str2 global temp global handles global global info curr trans PN global transitions t1 name 9ecurr Place PN global_places i name if PN REAL TIME if ismember curr trans global info rt monitor trans disp At rt clock string PN global transitions t1 name is Fired but not member of R T monitor disp RETURN ON R T DISPLAY return end end if PN REAL TIME str2 PN global transitions t1 name is Fired At tempzsprintf temp str2 rt clock string 10 145 temp temp isspace temp if isempty temp set handles edit2 String temp end else str2 PN global transitions t1 name is Fired At tempzsprintf temp str2 num2str current time 10 set handles edit2 String temp end 96969696 Call painter here gui painter t1 r Fired r str2 fire Complet AnimNGT m function fire Complet AnimNGT completing tran global PN global temp global handles global global info curr_trans PN global_transitions completing tran name if PN REAL TIME if ismember curr trans global info rt monitor trans disp At rt clock string
99. ent kinds of components The detail will be explained in the implementation part To illustrate the interface design as shown in the following figures 53 MOPUIM UIEW JOWUOW J Y 8t si4 aui pasdeg E 0 0LFEZ dv PRIQEUZ JON si 30902 SOB JO ON O0L2Ftz Jv paget s zjoqoui 0 L ZP EZIE pad PUB paiqgus jon 4090H Ol LF Ee v Pepggu s zjoqoui pesdsuis JWEN 60 J FEZ Ty Paull si cjoqogn 60 iF Ee Ty paget s cjoqou voyeurs z amp 0 2F Cz Jv Pally st zyoqaog H 60 F E2 PY pageta si gogog SPUBWWO7 ois a Dy s2uenbss ajgeug 4 k a 40 6 099q JIL Tv38 Cache eisdoz ungdop ue dui E 60 2F z v p OL 270904 je pall4 oz 0 0 o pue pejqeua Joy poqoy HJE genu oz o 0L4 Z aun pug ueisd eungd zungd ngd Nd 8Ll Hr EZ awl els S3JEld LFE 8L LE EZ SLL PES aui yuana pat SOEs payqeuq pajqeuy pue pajqeua Joy uon sug L cyogoy coqos 10q041 sStleu uomrgsusgl 4 k Agjdsi jua43 SUOnIsugl ino Im The components of the R T monitor are grouped in different panels This gives clear information about the status of R T elements and can easily be controlled As shown on fig there are seven panels These are i Transition panel As the name implies this panel consists of the selected elements of the real time P N model transitions It contains detail information of every single transition Here we need to remember that the panel consists of only the selected transitions Transitions
100. ervisor prof Reggie Davidrajuh for his endless support starting from day one up to my final submission He was always encouraging me to create new ideas would like also to thank Stale Freie for borrowing me all the necessary lab equipment and also for letting me to use the lab at any time want At Last but not least would like to thank my lovely fianc Arsema Takele and my lovely daughter Atnasia Nigussie for understanding and giving me more energy throughout my study couldn t be at this stage if it wasn t for them would like also to thank my whole family specially my sister Alemtsehay Girma for encouraging me to work harder would like also to thank all of my friends and my classmates for having wonderful times together ii Contents DTA dem moo i PRC INOW MON aera E oct cede cn te esr es oe Mum Edi reU UNTEN Edd ii OS a sare ries eet ec gpm temi tumida emen ene nae oe Maca MEME E Misc UNE iii Mes E vi CRP er Aa M HS 1 1 IME GNC Th O n prm 1 1 1 MOYON E E E E E E E 1 1 2 GOWO CTIE IS a iiam imme UvPI UN mU NU MN UI PIUD M DIR UR DHUE 2 1 3 AAOC ON EE nee EE E aU MEINEM ee ME 6 1 4 Chsptere OO asec poete E mu dua aM ird pep a der S pU i rh 6 Giclee E 8 2 BAC 1 9 Ug o cee anc NR
101. es function edit6_CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit7_Callback hObject eventdata handles global global info global PN set handles uipanel27 Visible on if not PN REAL TIME set handles text72 String PN global places 5 name J else 133 set handles text72 String global info rt monitor places 5 end 96 Executes during object creation after setting all properties function edit7 CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit8 Callback hObject eventdata handles global global info global PN set handles uipanel28 Visible on if not PN REAL TIME set handles text73 String PN global places 6 name J else set handles text73 String global info rt monitor places 6 end Executes during object creation after setting all properties function edit8 CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit9 Callback hObject eventdata handles global global info global PN set handles uipanel29 Visible on if not
102. esides the init_Alarm_NXT initializes the NXT intelligent Brick The firing time of the detection transition is set to be 5 and the rests are 1 90 clear all clc global global info global info REAL TIME 1 This is a Real Time run global info STOP AT current clock 3 0 0 20 stop after 2 global info passwords A B C global info resetCMD 1000 init ALARM NXT initialize NXT png petrinetgraph alarm def doorModule def dyn m0 pArrive 1 pEnd 1 pCode 1 dyn ft tDetect 5 allothers 1 pni initialdynamics png dyn disp System is ready sim gpensim pni close Alarm NXT Never forget to clean up after your work It is advisable to close all the NXT ports and setting after the simulation is completes this helps the MATLAB to save more memory by removing the catches init Alarm NXT This part contains the basic initializations of the NXT and the sensor nodes by connecting the NXT with the Bluetooth port of the PC function init TL NXT initialize traffic lights and switches in NXT global global info initialize global variables global info NORMAL CYCLE false initializ NXT warning off MATLAB RWTHMindstormsNXT noEmbeddedMotorControl COM CloseNXT all hNXT COM OpenNXT bluetooth ini look for USB devices COM SetDefaultNXT hNXT sets global default handle Then also assign the ports as shown below g
103. evise it at any time 56 Event Display Ta 5 Transition names tRobot tRobot iRobot E Enbl but Hot Completed Enabled States Fired Current x Time 12 51 23 12 51 23 12 51 23 Fig 55 Transition names event status and Current time display ii Places panel A place panel contains a similar to above section i transition panel and gives information about the status of the selected real time places of R T monitor Like transitions denoted by a rectangle in Transition panel places are also denoted by small circles in this panel this is also to give extra visibility for places The following figure shows the place panels in the R T monitor Places Place Names pBuffl pBuffz pBuff3 potart InitialMark 10 at D QO tRobot2 Tok 1 4 At 23 47 08 FrompStart a 0 Joa neee tRobot3 Tok 1 Fig 56 R T monitor places This panel also provides information about the quantity of the tokens starting from the initial markings up to the final token absorption in every place When every time a transition fires a token the R T monitor also displays the number of tokens mobilized in every places inside the circle It has also a textbox to display which transition has taken the token and at what time Displaying such information is quite feasible especially while we work with some real time simulation controlling the movement of tokens gives extra information for the controller For example while modelling and si
104. f the two events In this chapter we will see different types of R T models on different application areas 3 1 Real Time simulation and modelling Real Time simulation and modelling exists on different application areas It is one type of simulation and modelling technique that is applied for different kinds of control activities in addition to simulating systems in real time It can be used in both discrete and continuous event simulations A simulation can be modelled using a stochastic and simulated time in order to predict some imaginary system however when we think of Real Time applications the feasibility of a real time simulation is unquestionable In real time simulation time is everything For instance we may be interested in guaranteeing that the nt occurrence of some event y takes place before a deadline time T Hence the simulation time can be denoted as 27 Tan STO The performance measurement is denoted by P Tyn lt I y Similarly for discrete event time it can be expressed as Let Xn 0 denote a time interval between two events of a given type For example Xn 0 denotes nth lifetime of event a defined as the interval from the instance when a is activated until the time it occurs and the first subsequent occurrence of another event p Similarly we can define another event Y 0 Both event X and Y depends on the parameter 0 Finally Il can be some random value We can develop a method to calculate their probability for Xn
105. ff 1 1 toklD2 select token with colors plnout Buff 1 2 transition selected tokens toklD1 tokID2 fire any transition selected tokens elseif strcemp transition name tProduction line2 toklD1 select token with colors plnout Buff 1 2 toklD2 select token with colors plnout Buff 1 3 transition selected tokens toklD1 tokID2 fire any transition selected tokens elseif strcemp transition name tProductionline3 toklD1 select token with colors plnout Buff 1 4 transition selected tokens toklD1 fire toklD1 else fire 1 end ii Source code for room security model Door def m S door model of the alarm system function png 2door def png PN namez Door alarm model png set of Ps pDoor Close pDoor OPen pDoor was Opened k png set of Ts tClose tOpen t Check open tWO tWC png set of As pDoor Close tOpen 1 pDoor Open t Check open 1 pDoor was Opened tWC 1 pDoor OPen tClose 1 tOpen pDoor Open 1 tClose pDoor Close 1 t Check open pDoor was Opened 1 tWO pDoor Open 1 tWC pDoor Close 1 Alarm model def m An alarm model function png alarm model def 96 Alarm system model png PN name z Alarm system model png set of Ps pDisarmed pArmed pRing png set of Ts tDetect t a off tOff tRinging png set of As pDisarmed tDetect 1 pArmed tRinging 1 pRing tOff 1 tDetect pArmed 1 tRinging
106. firez1 end else fire 0 end end end COMMON_POST m i gae COMMON ISOS iE ie eens iL ie ei JE SIE COmo CE eee Tie mCi nane yee Oi ej SERCH Ebaiohtlon mane em beep off end tEntry_pre m function fire transition tEntry_pre transition global global_info ereadIn if ismember global info readIn global info passwords firezglobal info deltaT lt 60 disarm the alarm end 154 tRinging post m function tRinging post transition Trigger the alarm beep on iii Source code door alarm model alarm def m function png alarm def png PN name LEGO Robot alarm png set of Ps pStart pRestart pAlarm pDetect pEnd pCodes pNotMatch pRinging pEnd png set of Ts t Start btn tOn tDetect tCheck tShout tOff png set_of_As pStart t Start btn 1 t Start btn pRestart 1 pRestart tOn 1 tOn pAlarm 1 pAlarm tDetect 1 tDetect pDetect 1 pDetect tCheck 1 pCodes tCheck 1 tCheck pNotMatch 1 pNotMatch tShout 1 tShout pRinging 1 pRinging tOff 1 tOff pEnd 1 ipEnds to Start bth Tr doorModule_def m function png doorModule_def png PN_name Door_alrm_model png set of Ps pArrive pDoor pDetect pGrant pInside pNot alarm on png set of Ts tArrive tNo alarm set tEnter in tEnter tCheck tDetect png set of As pArrive tArrive 1 pDoor tNo alarm set 1 pDoor tDetect
107. gent Brick 38 The model consists of three sub models where each of them has different interaction with the NXT ports The sub modules are 1 Normal cycle This presents a normal cycle of a traffic signal in a junction The standard cycles of a traffic signal is fig 33 Traffic lighting cycle These are the status when the lights bubs that turns on at the same time t The ordinary P N model for the above steps is shown below tRed 2 RedYellow tYellow 2 S xix y pYellow tRedYellow 2 Green tGreen 2 Yellow Fig 34 P N model for traffic light cycle The module can be redesigned as shown below 39 tRS B pNOR CY tR Oi pR Off Fig 35 Module for normal cycle 2 Pedestrian interrupt If a pedestrian want to cross the road he presses the PEDESTRIAN CROSSING button on the traffic pole which is the NXT touch sensor 2 in the NXT model tPE CY pPE START tPE START pPFE DEC amp pBEEP tHEEP tPE QUIT Fig 36 P N model for pedestrian module 3 Emergency blink The emergency blink frequently displays yellow light The transition tEM START fires when the user touches the input touch sensor for emergency blink The cycle that is shown in the model below perform this operation The cycle operates until the loop finishes then it return to the normal cycle 40 pEM_START tEM B pR OF 1 1 tEM_ START pEM Y ON tEM Y ON pEM Y OFF tEM CY tEM Y OFF pEM
108. ght after new state 2 At time 11 13 43 Enabled transitions are tEM BUTTON tPEDES BUTTON tRESTART BUTTON tRY At time 11 13 43 Firing transitions are tRY Time 11 13 45 109 State 3 Fired Transition tRY pG pG pG pG pG pG pG pG pG Current State pG Virtual tokens no tokens Right after new state 3 At time 11 13 45 Enabled transitions are tEM BUTTON tG tPEDES BUTTON tRESTART BUTTON At time 11 13 45 Firing transitions are tG Right after new state 25 At time 11 14 58 Enabled transitions are tEM BUTTON tPEDES BUTTON tRESTART BUTTON tR ON At time 11 14 58 Firing transitions are The above code continues until the 25 state space diagrams 25 Here only some lines are displayed due to the lengthiness of the result The plot result is for the above code is shown below The plot using gpensim is shown below From the plot it is possible to analyze the simulation result pNORMAL YCLE j pR PR gF F 1 pRY pG Number of tokens 0 11 11 11 115 11 12 11 125 11 13 11 135 11 14 Time in HOURS Fig 86 Plot result of the simulation for traffic light model Since we have only one token in the initial mark from the plotting it can be noticed that the number of tokens falls between O and 1 As the simulation time goes the number of token in every places shows a onetime up and down 110 Chapter 7 7 Discussion and conc
109. he next step is getting into another cycle Conventionally the traffic light after green light is the yellow light to tell caution about the red light for the traffic flow in that direction The tG releases its resource to tY This can be illustrated on the R T monitor as shown below Transitions sd eM xg Transition names tG tEM BUTTON tY iRY tR_ON tR_OFF Transition Completed Enbl but Not Fired Enabled Completed Completed Completed States S Current Time E 11 08 03 11 08 03 11 08 03 11 07 53 11 07 59 11 08 00 Fig 83 Transitional display panel Green light is one yellow is enabled It can be observed that tY is immediately enabled after tG has completed firing at the current time which is 11 08 03 N B This plotting process continues for every cycle until the simulation is terminated Similarly here it is possible to see the status of the number of tokens in every place on the same monitor as discussed in chapter 4 The place panel that does this is shown below 107 Places Place Names pG pR pRY pY pR OFF InitialMark 1 6 0 C C C t ON Tok 1 4 tR ONTok 1 a tR ON Tok 1 tR ON Tok 1 a tR ON Tok 1 At 11 07 07 At 11 07 07 At 11 07 07 At 11 07 07 At 11 07 07 FrompR FrompR FrompR FrompR FrompR tR OFF Tok 1 MR OFFTok1 IR DFFTok 1 IR OFFTok 4 tR_OFFTok1 Fig 84 Status of number of token on a selected places To illustrate this see the following table Current total tokens
110. he original files of gpensim files where the R T monitor files are integrated in i e there are calling methods inside these files 117 4 Open MATLAB in administrator mode and set the path as shown below gt Go to File gt set path Tm PY EX I LL S rnLALGau a File Edit Debug Parallel Desktop W New b pen Ctrl O Close Command Window Ctrl VW Import Data Save Workspace As Ctrl S Set Path Preferences Page Setup Print Ctrl P 5 On the new pop up dialog window click add with sub folders A Set Path All changes take effect immediately MATLAB search path n CAUserskNigguDocumentsyVMATLAB di C gpensim di CAgpensim 00 444232 Main Simulation Functions i CAgpensim 01 petrinetgraph m C gpensim 02 cotree di C gpensim 03 print_statespace di C gpensim Od plotp di C gpensim 05 Print_and_Plot di C gpensim 06 cycle n CAgpensim07 Performance Metrics di C gpensim 08 invariants i CAgpensim09 siphons and traps di C gpensim 10 reachtree di C gpensim 11 442224 Internal Functions n C gpensim 11 preprocessor Move to To p hd owe U p Move to Bottom di C gpensim 12 timed_pensim di C gpensim 12 timed_pensim html di CAgpensim13 firing A new browser window will pop up then browse the unzipped gpensim file and select the file and save it and close the window Or using a MATLAB Command Addpath home user MATLAB unzipped gpensim file And pres
111. he running simulation of production line model As we can see from the above figure i e the transition panel the event of the transitions is clearly described using a color plotting Whenever the tInput of the P N model fires the event handler let the associated name tlnput handler to be red Similarly the plotting continues for all of the selected transitions As it is in real time the time that the event takes place is also displayed using hh mm ss format Similarly for the selected places the place panel gives the following figure at some timet Places Place Names plnout Buff pOutput Bul pOutput3 pOutput2 pOutPut1 o0 O tProduction li a ne1 Tok 1 At 12 45 41 Fromplnout E InitiallMark utt F Fig 67 Test result of status of places in the running simulation of production line model Suppose that we have initial marking of 30 in a place plnput Buff for the production feeder The event handlers plot this value under the place name As the simulation processes and token are moved from one place to another the plotter will put the number of token under the plotter to the associated places 97 Enable Sequence t oop Nr 1 tinPut is Enabled At 12 45 38 tProduction line1 is Enabled At 12 45 38 tProduction line2 is Enabled At 12 45 38 tProductionline3 is Enabled At 12 45 39 tProduction line2 is Mot Enabled At 12 45 39 tProduction line1 is Mot Enabled At 12 45 39 tProductionline3 is Not En
112. ical to control and watch the overall activities of a large Petri net model within a single monitor In this R T monitor the maximum number of places is set to be 7 and the maximum number of transitions is set to be 10 B Real_PTtime_select kon a RT_Transitions Fig 46 Real Time components selector Real PTtime select The R T component selector has a graphical user interface with different push buttons and list boxes In the figure above the graphical interface has three separated panels The first panel is called RT Places the second panel is called RT transitions and the third one is called a command Each of the first two panels consists of two push buttons named as select places or transitions and remove buttons and two list boxes The following figure shows the RT Places panel The design is the same for RT Transitions RT Places Selected Modules Fig 47 R T places panel 52 The first side left side list boxes automatically load all places and transitions from the global GPenSIM variables and by using the middle buttons we can choose a selective places and transitions that we wanted to observe visually throughout the real time simulation process This has also been designed to have a remove button so that we can remove the unwanted but selected items so that the simulation won t be interrupted The last command panel has two buttons ok and clear The ok button saves the selected items fr
113. idea of HCI has emerged from the broad project of cognitive engineering in the cognitive science 30 One part of the cognitive science was the development of some scientific and well informative applications known as cognitive engineering HCI was one of the results of cognitive engineering In order to communicate with a machine there must be some sort of communication or connection mechanism These are either by making some physical contact or some kind of sense contact For example keyboard is one kind of physical contact and eye sensor and RF technology are some kind of sense contact At the background of the physical contacts HCI provides tools that program the machine to do what a user has requested This is literally called software l e software is a background series of commands that interacts the user with the machine The following figure shows how the cognitive engineering categorizes HCI with other science 43 Computer Science Technical Communication Ergonomics Himan Content Factor HCI Strategy Qualitv Software User Experience Usability testing ZN Analytic Information Interaction Architecture Design Market Library science Software Research Design Fig 39 Human machine interaction There are different kinds of HCI methods We need to mind that designing only a good graphical user interface doesn t mean we have a good HCI tool In order
114. imilar to the steps in appendix section A 1 Open MATLAB in administrator mode and go to the file menu Under file menu point to set path button gt File gt set path In a similar way to that of section A 1 a window will pop up Click on add with subfolder and browse the RWTH toolbox save and close the window When the above steps are done the NXT toolbox environment should be added to the MATLAB toolbox directory A 4 How to connect the NXT device with the windows 7 The primary connection of the NXT device is to connect it using the USB cable This is used to setup the device and let is to prepare for a Bluetooth connection The steps to setup the NXT with USB and Bluetooth follow the following instruction 1 Download the Fantom Driver from the web at http www lego com en us mindstorms downloads software ddsoftwaredownload 119 Note that there are different kinds of Fantom Driver for different platforms so it must be downloaded to the appropriate one In this set up it has been downloaded for Windows 7 64 bit Extract the zipped folder Then open the folder with two options one for Mac devices and one for windows Since the setup of this project is done on windows open for windows Follow the instruction to install the driver Finally the NXT device is successfully integrated with PC After the driver is installed the next step is to update the NXT firmware Because the NXT device firmware should always be
115. in to the input buffer so that the three transitions can access the color tokens The code snippet shows the function that does this activity function fire transition tlInPut PRE transition global global info if strcmp transition name tInPut index mod global info cr index 4 1 global info cr index global info cr index 1 transition new color global info cr index fire 1 return end The function produces new colors at the transition is enabled and ready to fire COMMON PRE This function is used as common pre condition for the threetransitions tProduction_line1 tProduction_line2 and tProductionline3 Production line 1 takes input raw material colored by 1 2 and 4 and use all of them Similarly production line 2 takes input raw material colored by 2 and 3 and use one of them as an input at time t and the last one uses only input colored by 3 tAssemble pre This transition fires as long as all the above three transitions fire and the output places are not empty 5 2 2 Implementation of R T simulation in door security using gpensim The implementation includes three PDF file one MSF and common pre condition for transitions This section has a similar implementation to that of the section 5 2 3 door alarm model with NXT Except that there is no NXT device in this section Only the source code will be provided in the appendix section But roughly it
116. ing e g 0 1 O 3 becomes p2 3p4 if tokens if eq tokens 1 tokens nr str no need to print i before else tokens nr str int2str tokens end markings str markings str tokens nr str PN global places i name end if tokens The above condition checks if there are tokens in the gpenism matrix if there are any it will build the string markings_ str which contains the number of tokens in every places at time t Now one the tokens are extracted the next step is to display those tokens on the graphical interface This is done by the token_numner_ngt m file and it is invoked by passing variable as shown below StSsaNGT if PN REAL TIME token number ngt curr Place int2str tokens markings str end tttLNGI end for 1 1 Bs In the above code the curr Place is the place that is currently holding the current tokens Tokens are the current tokens in every places and the marking str is the string that has a format to display on the command window p1 p2 3p4 for Matrix 1 1 O 3 The function token number ngt takes those variables and start putting the number of tokens in every place i e circles in the GUI The first step is to find the current place on the GUI by calling the function find GUI component places and then it starts putting those values TI function token number ngt curr Place tokens markings str global handles global global info s find GU
117. ing GPenSIM instruction 2 Anew window will appear if GpenSIM is running on real time The window requests the user to select the places and transitions from the overall transitions and places It is the file with name Real PTtime select m in this newly implemented R T tool The tools also provide a button to remove the unwanted but selected items Seched Modules a Select Pisces ifi Selec Tren ie iR 3 After selecting places and transition click on the ok button to start the simulation or clear to clear the selected fields If there are no selected items Commands Ok Clear 4 Nowthe real components are selected the R T window will appear The R T monitor integrates with the running GPenSIM and starts plotting the status of the simulation 5 The R T monitor has also tools to control the simulation This includes controlling the simulation speed stop the simulation and continue the simulation 121 Appendix C C 1 Source codes for R T monitor Real PTtime select m function varargout Real PTtime select varargin REAL PTTIME SELECT MATLAB code for Real PTtime select fig 96 REAL PTTIME SELECT by itself creates a new REAL PTTIME SELECT or raises the existing singleton H REAL_PTTIME_SELECT returns the handle to a new REAL PTTIME SELECT or the handle to the existing singleton 96 REAL PTTIME SELECT CALLBACK hObject eventData handles calls the local function named CAL
118. ion edit4 Callback hObject eventdata handles global global info global PN 132 set handles uipanel24 Visible on if not PN REAL TIME set handles text69 String PN global places 2 name else set handles text69 String global info rt monitor places 2 end Executes during object creation after setting all properties function edit4 CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit5 Callback hObject eventdata handles global global_info global PN set handles uipanel25 Visible on if not PN REAL TIME set handles text70 String PN global places 3 name J else set handles text70 String global info rt monitor places 3 end 96 Executes during object creation after setting all properties function editb CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edite Callback hObject eventdata handles global global info global PN set handles uipanel26 Visible on if not PN REAL TIME set handles text71 String PN global places 4 name else set handles text71 String global info rt monitor places 4 end 96 Executes during object creation after setting all properti
119. ion of gpensim code for the real time models This implementation section describes short descriptions about the implementation of the real time DEDS using a gpensim for model that are designed on chapter 3 5 2 1 Implementation of R T simulation in Industrial application As discussed in chapter3 one application of real time simulation is in industrial area For the example discussed above the gpensim code for a model that uses areal time is given below 1 PDF The PDF file define the static Petri net structure or graph of a module The png return the basic structural information about the PN model function png production def png PN name A Simple Petri Net definition png set of Ps plnout Buff pOutput Buffer pOutPutli pOutput2 poutput3 png set of Ts tAssemble tInPut tProduction linel tProduction line2 tProductionline3 png set of As pInout_Buff tProduction linel 1 pInout Buff tProduction line2 1 pInout Buff tProductionline3 1 r poutPutl tAssemble 1 pOutputZ tAssemble 1 poOutput3 tAssemble 1 tAssemble pOutput Buffer 1 tinPut prinout Buff rl tProduction linel pOutPutl 1 tProduction line2 pOutput2 1 tProductionline3 poutput3 1 As the name shows the model is about a simple workshop machine that takes input from the Input area and puts in different buffer locations 2 MSF The main simulation file con
120. is Automation and Control Lab pp 1 2 21 James L Peterson Petri net Theory and the Modelling of Systems Englewood Cliffs Nj Prentice Hall Inc ISBN 0 13 661983 5 1981 pp 80 90 22 Tadao Murata Petri Nets Properties Analysis and Applications Proceedings of the IEEE vol 77 No 4 April 1989 pp 5 6 23 S ren Christensen Niels Damgaard Hansen Colored Petri Nets extended with Place capacities Test Arcs and inhibitors Aarhus university pp 88 92 24 Reggie Davidrajuh Extended P N models Discrete Simulation and Performance Analysis available from class notes of DAT530 at UiS 2013 25 Reggie Davidrajuh GPenSIM A new Petri Net simulator 2010 Available from http www davidrajuh net gpensim 26 Reggie Davidrajuh A Tool for Modeling and Simulation of Discrete Event Systems 2010 pp 8 11 27 Christos G Cassandras and Stephane Lafortune Introduction to Discrete event Systems pp 744 28 MATLAB Matlab simulation tool Available at http www mathworks com 29 Reggie Davidrajuh Developing a Petri Nets based Real Time Control Simulator ISSN 147 36 3 804x IJSSST Vol 13 No 2 pp 28 30 30 Carroll John M Human Computer Interaction brief intro In Soegaard Mads and Dam Rikke Friis eds The Encyclopedia of Human Computer Interaction 2nd Ed Aarhus Denmark The Interaction Design Foundation 2013 Available online at http www interaction design org encyclopedia hum
121. ist entryT cellstr currentltems t index selected t get handles listbox3 value choice listbox3 list entryT index selected t listitems get handles listbox4 String newmenu Trans listitems choice listbox3 set handles listbox4 String newmenu Trans set handles listbox3 Value newltems t currentltems t newltems t index selected t set handles listbox3 String newltems t if isempty newltems t if length newltems t gt 1 set handles listbox3 Value 1 end end Executes on selection change in listbox5 function listbox5 Callback hObject eventdata handles Executes during object creation after setting all properties function listbox5 CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end 123 Executes on selection change in listbox6 function listbox6_Callback hObject eventdata handles Executes during object creation after setting all properties function listbox6 CreateFcn hObject eventdata handles 6 Hint listbox controls usually have a white background on Windows See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end Executes on button press to select R T places function pushbutton5 Callb
122. ists of two graphical user interfaces these are 44 The main form GUI m to control and display the ongoing visual display unit called GUI this also serve as a control unit for the real simulation system The GUI gives all the necessary information about the status of selected transition and places As it is mentioned on the statement of problems it would be very practical if we are able to watch the transition of every live event This gives GPenSIM a full HCI tool A window to select the desired transitions and places select R T monitor m from the overall ongoing simulation components i e places and transitions On the monitor the reason that a user need to select some specific transitions and places is that when we work will a large systems it is impractical to control all the conditions of the transitions and places simultaneously GPenSIM is well known by its efficiency in modelling discrete systems that use a Petri net tool Or simply it is a general purpose Petri net tool AS it is mentioned above the R T monitor source code is embedded inside GPenSIM The algorithm of an extended GPenSIM is shown below The over view of the GUI in the system is Transitional definition files pre and post files Pre and post Matlab HCI Main Petri net Using Simulation File definition MATLAB and Consists of dynamic File PDF MATLAB details MSF GUIDE GpenSIM Structure Fig 40 The over view of R T monitor 4 3
123. itor places j 9ecurr source namezglobal info rt monitor places j myobj findobj hn String global info rt monitor places j if isempty myobj disp cant get it return end myobj2 2get myobj s myobj2 Tag isspace myobj2 Tag end end else disp Not R T for j 1 len if stremp curr source name global info rt monitor places j name 9ecurr source namezglobal info rt monitor places j name myobj findobj hn String global info rt monitor places j name if isempty myobj disp cant get it return end myobj2 2get myobj s myobj2 Tag isspace myobj2 Tag end end end token_number_ngt m function token_number_ngt curr_Place tokens markings str global handles global global_info s find GUI component places curr Place if isempty s 26969696 To print the number of tokens in each places if ismember curr Place global info rt monitor places if stremp s text68 set handles text95 String tokens elseif stremp s text69 set handles text89 String tokens elseif stremp s text70 set handles text90 String tokens elseif stremp s text71 set handles text91 String tokens elseif stremp s text72 141 set handles text92 String tokens elseif stremp s text73 set handles text93 String tokens elseif stremp s text74 set handles text94 String tokens end end set handles print state space String markings str end markings string m fori start pi
124. juh GPenSIM in Real Time 1 1 Motivation The task of designing evaluating developing a discrete event dynamics systems DEDS in a Real Time systems requires a deep knowledge of modelling and decision making rules for an intelligent system One might get it very difficult to design a DEDS unless a proper tool is used But using the available tools like Petri net and the simulation software gpensim it can be simplified even can one develop a system that is more dynamic and intelligent The Petri net model for Fuzzy Adaptive and Expert System Controller integrated into the GPenSIM Simulation Tool Kit has greatly facilitated this task Usually the proving of validity of models is an interesting task because even if an excellent simulator is running on an excellent hardware the simulation results of inaccurate model will never be valid Especially for real time simulation the data of R T simulation are large and needs a proper management to achieve validity For a DEDS one of the ways that we can improve the performance of a simulation and modelling is that if it is possible to watch the movement of every tokens and the status of each event during a simulation process Even it would be very easy to control the process by putting the unwanted redundant information into the background and making only the valuable units visible for the user 1 2 Goal of the thesis The main objective of the thesis was roughly discussed in the summery sectio
125. ke push button dropdown menu and so on For example a function to create components for listbox1 is named as listbox3 CreateFcn This built in MATLAB function automatically creates the edit1 textbox t Executes during object creation after setting all properties function listbox3 CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get 0 defaultUicontrolBackgroundC set hObject BackgroundColor white end The hObject in the above function is used as the newly created event handling object And the eventdata are reserved to the future MATLAB versions The variable handles contains a structure with event handles and used to pass the newly created object s event The GUIDE always creates components with templates For example in the above list box the default is created to be the window s default background color iii The callback functions The above functions are just used to make layouts of the gui design These functions are created by the GUIDE with some templates To make the layout work the selection their 68 callback function need to be added Since there are six buttons in the gui interface there are six different callback function for each of the buttons The buttons are a Select Places button b Remove places button c Select transitions buttons d Remove transitions button e ok f Clear Both a and c have similar c
126. l info PEDES CYCLE COUNT fire 0 return else global info PEDES CYCLE COUNT global info PEDES CYCLE COUNT 1 end COMMON POST COMMON TDF The common post condition release the resources after transitions fires in this case the post condition turns off the lights on the NXT devices if strcmp transition name tkR OFF disp OFF RED SwitchLamp global info lightRED off elseif strcmp transition name tRY disp OFF RED YELLOW SwitchLamp global info lightRED off SwitchLamp global info lightYELLOW off tEM BUTTON Specific TDF The emergency blinking turns continuously the yellow light on and off for a given cycle This button runs whenever the emergency button is pressed EM BUTTON global info EMERGENCY BUTTON OpenSwitch EM BUTTON switchState GetSwitch EM BUTTON CloseSensor EM BUTTON if switchState RESTART BUTTON not pressed fire 1 global info EMERGENCY CYCLE true global info NORMAL CYCLE false 94 The other function is the restart button it is not included in the implementation to reduce redundancy It is used to restart the normal cycle It is a reset button done by using a touch sensor 4 NXT functions that are used to interact the NXT intelligent Brick device with GPenSIM are init TL NXT Special file for NXT functions global info global info global info global info global info global info global info global info
127. lobal info NXT handle hNXT global info detect SENSOR 4 global info RESTART BUTTON SENSOR 1 global info OBJECT DISTANCE 20 From the above code snippet it can be shown as the sensor port 4 is used to connect the ultrasonic sensor Similarly the sensor port 1 is used for restart button that is used to switch of the ringing signal Similarly the objects can be detected at a distance of 20 cm the distance is small due to the sensing capability of the ultrasonic sensor of the NXT device TDF tDetect pre This pre file has a method to read the ultrasonic value and set fire if the object is detected 9 function fire transition tDetect pre transition global global info OpenUltrasonic global info detect distance GetUltrasonic SENSOR 4 if distance lt global info OBJECT DISTANCE fire 1 else fire 0 end From the above code the OpenUltrasonic function detects the object from the sensor 4 which is the source port for the ultrasonic sensor node If the object is detected in a given interval then it will fire tDetect post The post condition function lets the alarm to be triggered if the person doesn t enter the appropriate code within a given time if stremp transition name tDetect read keypad input Enter code if ismember read keypad global info passwords disp detected DETECT OBJECT for n 1 10 500 beep NXT PlayTone 440 500 end end
128. lobal info semafor 1 else fire eg global info semafor 0 end We use a COMMON PRE file if we have transitions that have a common pre event of a transition On the above code the Common pre file accepts a transition and fires according to their sequence Note that pre and post conditions are user defined function Similarly for a post condition we use a common post file function fire transition COMMON POST transition global global info if strcmp tranaition name proceassNewMSG global info semafor 0 else global info semafor 1 end GPenSIM also provides different kinds of Petri net analysis tools like colored Petri net resource management project scheduling internal clock Coverability tree prioritizing transitions measuring activation time stochastic timing modular modelling approach and many different optional tools to analyze and control the performance of the given Petri net model Generally GPenSIM can serve from modelling and simulating up to analyzing a discrete event system The steps used in designing a GPenSIM code are shown below Step1 Create the Petri net definition files PDF or modules Identify and write the basic elements of a Petri net graph the places Identify the basic elements of a Petri net graph the transitions and Connecting the elements with arcs l e connect the places and transition based on the P N rule The following picture shows the structure of the pdf fil
129. low Transitions Event Display 4 Transition names tG tEM BUTTON tRY tY tR_ON tR_OFF Transition Fired Enbl but Not Fired Completed Completed Completed Completed States EE 11 08 02 11 08 03 11 08 02 11 07 53 11 07 59 11 08 00 Fig 82 Transitional panel that shows the Green light is on on the Traffic light model From the above figure it can be seen the status of every selected transition during the simulation process As mentioned in the design section the rectangles along with the texts below frequently change based on the simulation status The table below clearly shows the status of the simulation during one cycle 106 Transition Transition Current Time Event Display Description names Status t Red display 11 08 02 Green light is on at t Enabled but not Emergency button tEM BUTTON Cyan 11 08 02 firing ready to fire at t Red to yellow has Completed 11 08 02 completed at t Yellow light has Yellow Completed 11 07 53 completed t delta t Red light on status finished tR OFF Completed 11 08 00 Red light is off Table 8 Analysis of the selected transitions of the traffic light model at time t Yellow Completed 11 07 59 Once after the one cycle has finished its operation t
130. lusion 7 1 Discussion The need for simulation and modelling is unquestionable Different areas apply simulation and modelling for different purposes For example some companies prefer to use simulation and modelling in order to keep the quality of their products at a small cost They model and simulate every single unit before performing the real physical implementation As it is mentioned in chapter two systems can either be static or dynamic Dynamic systems with a discrete event flow has become an easy way to model systems This ensures more concurrency and optimization Since Petri nets provides concurrency parallelism and synchronization 11 they became more popular tool to model DEDS Having both the DEDS and P N any kind of system can be modeled Once we have the model the next step is to simulate it The simulation in DEDS is performed based on their events Events are key terms in DEDS every single action is encountered as an event Especially monitoring those events in a real time needs more caution It is very important to pay more attention for a real time simulation In a non real time simulation the analysis can be performed at the end of the simulation But in real time simulation it is impractical to analyze the simulation at the end of simulation as we can t get back the already passed time GPenSIM can perfectly simulate the DEDS that are modeled using a Petri net tool But GPenSIM doesn t provide a way to display and control the
131. m centerY 7 m cnt cnt 1 rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor randcolor LineWidth 1 96 Executes during object creation after setting all properties function axes1 CreateFcn hObject eventdata handles global y global n global j radius 2 centerX 5 centerY 7 j hObject rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor w axis equal circle2 Executes during object creation after setting all properties function axes2_CreateFcn hObject eventdata handles global PN radius 2 centerX 5 centerY 7 rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor w 131 axis equal Executes during object creation after setting all properties function edit1_Callback hObject eventdata handles Hints get hObject String returns contents of edit1 as text str2double get hObject String returns contents of edit1 as a double Executes during object creation after setting all properties function edit1_CreateFcn hObject eventdata handles See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit2 Callback hObject e
132. models were created based on the real life dynamic systems whose events rely on real time The models are constructed to examine the behavior of real life systems using a Petri net theory and to test the R T monitor The models are not designed to be too large so that anyone can easily understand them Simulation of a large Petri net model is intrinsically a difficult task partly because of the fact that many elements have to be processed in large number of cycles The best way to simulate those large models is that the models should be designed in a modular approach by dividing the large model in to smaller sub models Some drawbacks The newly implemented tool can display the status of any kind of P N model developed by gpensim Even if it can do so it has also some drawback and needs further improvements Some of the drawbacks are Speed of plotting even though developing a gui using MATLAB is a prior option for gpensim Due to some cons of the MATLAB GUIDE the result shows some small delay in plotting but which is not significant for small models This is because of the fact that MATLAB GUIDE is developed for some simple GUI application not for working with simulation and modelling of larger systems In simulation and modelling large amount of data can be processed at a small time interval For example if we work with 12 transitions and the firing time of each is very small the GUIDE findobj searches for all of the transition in one c
133. mponents for Door alarm model After selecting the components the next step is plotting on R T The transition panel for two selected transition is shown below Transitiong __D9 _ _ ____ CS Event Display AZ Transition names tDetect tShout Transition Fired En pe States Ire Current Time 11 55 45 11 55 45 Fig 72 Transitional panel of the R T monitor for door alarm shows the Sensor detects The analysis can be shown in the following table Transition Event Display Transition status Current time name hh mm ss Enabled but not fired 11 55 45 Table 5 Analysis of the transition tDetect on the door alarm model using NXT After some time t and different cycle the transition states are changed to different terms and this can be shown as 100 Transitiama Event Display OOOO Transition names tDetect tShout Transition Completed Fired States Current E Time 11 56 33 11 56 33 Fig 73 The alarm is triggered as the input code mismatches The status described as Transition Event Display Transition status Current time name hh mm ss Yellow display Complete 11 56 33 Table 6 Analysis of the transition tShout on the door alarm model using NXT From the above table the R T monitor status completely changed in to different status The previous time was 11 55 45 and the current time
134. mulating a building with full of distributed sensor networks controlling only the events might not be enough l e there might be a need to visualize the movement of every single token in every place 57 potart 20 20 Robot Tok 1 At 23 47 08 Frompstart Lm tRobot3 Tok 1 Fig 57 A Single place and full info for R T monitor iii Enable sequence log This GUI panel contains a wide textbox to display the status of the enabled transitions in the entire simulation loop in a sequence fashion It can also serve as a text log file and it can be exported to another use Note that this log stores not only the selected R T monitor transitions but also all the global transitions of the simulation This helps to give a clear image of the sequence Enable Sequence tRobot2 is Enabled At 12 54 40 tRobot3 is Enabled At 12 54 40 tRobot is Enabled At 12 54 41 tRobot3 is Enabled At 12 54 41 tRobotl is Hot Enabled At 12 54 41 tRobotZ is Enabled At 12 54 41 tRobot1 is Mot Enabled At 12 54 41 tRobot3 is Enabled At 12 54 42 tRobotz is Enabled At 12 54 42 tRobot3 is Enabled At 12 54 42 Ce ee eed f u FE 4 dc Fig 58 Enable sequence on R T monitor screen iv Firing sequence log Similar to the enable sequence log there is also a method called firing sequence log for firing transitions This again stores the entire firing sequence of the transitions 58 Firing State Sequence tRobot is Fi
135. n above The current version of GPenSIM doesn t have a method to display the Real Time simulation process of DEDS on a visual interaction unit HCI tool l e it doesn t have a mechanism to graphically display the status of every transition and their associated input output places and the number of tokens in every place during every simulation cycle Besides GPenSIM lacks a method to control the speed and process of the simulation The current version of GPenSIM stores the simulation results in some form of ASCII dump file log file and the result is displayed using a MATLAB command window Similarly the status of the simulation is displayed using the normal MATLAB disp function This is quite infeasible when we think of Real Time systems where the actual progress of the simulation is running on a Real Time If we consider a system with a lot of sensors and actuators which are running on real time It would be better to have a method to capture the ongoing process rather than going back and evaluating the damped ASCII code files A good example is simulation in industrial application where there are different production line and the status of the lines are represented as Petri net transitions It would be tedious and impractical if we let the simulation file to be stored as a dump log file and retrieve it for analysis thus the best way would be designing a visual aid tool to interact with the background system and to see the actual ongoing progre
136. n be used to model any type of real life system It is identified as a bipartite directed graph denoted by three types of objects 15 These objects are called places transitions and directed arcs connecting places and transitions The places are denoted by circles transitions are denoted by bars and directed arcs denoted by an arrow that connects the places and transitions 31 G V E Where V are graph vertices and E are edges or arcs in Petri net model V PU T And PNT Where P is a finite set of places and T is a finite set of transitions 12 Token p din Transition T 2 Place P Arc E Arc Weight Fig 5 Asimple Petri Net model with a dot token marking Number of tokens in a petri net model can also be represented by number The numbers inside a small circle places show the total number of tokens in those places Here note that the numbers would be changed as a transition fires i e as the event is altered P4 P2 Ti P3 Fig 6 A Petri net model with number of tokens denoted by number 2 4 1 Places A place in a petri net model is used as an input or output area to the model It can represent a buffer area or a passive element It is used to initialize or accept tokens The role of a place varied in different types of activities Some roles of a place are list below 16 In communication systems a place can act as a type of communication medium like a telephone line middleman or a
137. nderline score is the name of the figure and the suffix after the underscore is a built in function name for guide The rest of the string OutputFcn is a reserved word to export the event data Componentname Create This function is created for every created component by gui For example if we create a pushbutton using a GUIDE The GUIDE will automatically create a source code for the component to be created Changing this function will make the component unresponsive 4 4 R T monitor user interfaces The Real Time display interface consists of three forms each of the interfaces are invoked by GPenSIM according to their usage A MATLAB provides a method to exchange GUI data in an object format 4 4 1 Design of an interface to select a Real Time places and transitions The name Real PTtime select which refers to Real Places and Transitions select and is given because this graphical user interface is used to select real time component here in our case places and transitions of the Petri net definition files This is to mean that we can specifically select the places and transitions from over all components of the real time Petri net model The need to minimize the number of places and transitions is that when we work with large systems and while there are plenty number of places and transitions in the model we need to limit our focus only with some places and transitions at the same time 51 Literally it is to mean that it is impract
138. ndles Executes during object creation after setting all properties function edit12 CreateFcn hObject eventdata handles 6 Hint edit controls usually have a white background on Windows 135 See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit17 Callback hObject eventdata handles Executes during object creation after setting all properties function edit17 CreateFcn hObject eventdata handles Hint edit controls usually have a white background on Windows See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit16 Callback hObject eventdata handles Executes during object creation after setting all properties function edit16 CreateFcn hObject eventdata handles Hint edit controls usually have a white background on Windows See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit15 Callback hObject eventdata handles Executes during object creation after setting all properties function edit15 CreateFcn hObject eventdata handles Hint edit controls usually have a white backgr
139. nging pEnd png set of Ts t_Start_btn ton tDetect tCcheck tShout tOff I png set of As pStart t Start btn 1 t Start btn pRestart 1 pRestart ton 1 tOn pAlarm 1 pAlarm tDetect 1 tDetect pDetect 1 oDetect tCheck 1 pCodes tCheck 1 tCheck pNotMatch 1 pNotMatch tShout l tShout pRinging l pRinging tOff l tOff pEnd 1 l pEnd t Start btn 1 36 3 3 3 Traffic light system modeled using NXT intelligent Brick Fig 28 A Traffic light system The traffic light system model designed using an NXT is shown in the following picture 4uW gt nxt IDE1141 Fig 29 Traffic light model using NXT The following model shows a traffic light system designed using NXT and Matlab It is the resemblance of the above model The model was taken from the work of Norwegian traffic light system from UiS 29 39 37 Desktop Environment MS Windows 7 GPenSIM Real Time Control Simulator LEG has Die Fig 30 Integration of Traffic signal system with GpenSIM The model uses different kind s components NXT components The components that are used in the model are list below NXT brick the main microcontroller unit A usb 2 0 cable to connect the device with a PC Two NXT touch input sensor Three output light cables Fig 31 NXT Touch button sensor Fig 32 A cable to connect light displays to the NXT intelli
140. ning Similarly the initial dynamics contains firing time of a transition For example if we want the transition to fire for 6 seconds we can write declare the firing time as gt gt aAyns it D DI Or allothers 1 allothers refer to the rest of transition It serves as a default firing time After declaring the two cell arrays the next step is packing them into the initial dynamics pack This is denoted as gt gt pni initialdynamics png dyn Zl Call the gpensim file Using a gpensim command by passing the pni and dyn struct variables gt gt sim gpensim pni Then the gpensim will compile the inputs and process the simulation file by calling the tdf files and gives an output The output file can be represented either using a plot or print state space to print out the simulation result in ASCII code 22 Chapter 3 3 Overview of Real time simulation and some application Time event and cycle loop are key terms in simulation and modelling Some events occurred for a specific period of time interval and some events may occur as a cyclic event Thus to simulate a model we need to define the time interval in which one event has happened The two types of time in simulation are simulated time and real time Based on these we can simulate any kind of model weather it is discrete or continuous When we consider a type of simulation and modelling we intended to calculate the overwhelmed time venture o
141. nput weigths for i 1 Ps tokens to be consumed input_weigths i disp tokens to be consumed disp tokens to be consumed if tokens to be consumed 96 96969696969696 NGT 96969696969696 display the following transiton transiton place i number of tokens tokens to be consumed time PN current time 96 96969696969696 NGT 96969696969696 inherited color from pi inherited costs pi selected toklD consume token in place i i tokens to be consumed selected toklD inherit colors and costs from different places inherited color set union inherited color set inherited color from pi inherited costs inherited costs inherited costs pi 9edisp inherited costs disp inherited costs NGT infoplc m called here infoplc i transitionitokens to be consumed end end C 2 gpensim codes for the R T system models i Source code for production line 151 MSF m the main file to run simulation clear all clc global global info global info PRINT LOOP NUMBER 1 global info STOP AT current clock 3 0 O 30 global info REAL TIME 1 global info cr 1 2 3 4 96 color rotation global info cr index 0 init rotation index O png petrinetgraph production def dyn mO pOutPut1 1 pOutput2 1 96 pOutput3 1 dyn ft tInPut 2 allothers 1 pni initialdynamics png dyn print system info pni sim gpensim pni print statespa
142. nsitions that have completed firing with the associated firing time t 64 hasnotfired AnimNGT m This method calls similarly the gui painter file by passing the current transitions and a flag The flag is used to differentiate the two states of firing of transitions l e We know that a transition might be enabled but not fired at time t and also there can be a condition where a transition is not enabled and note fired at the current time t infoplc m This file has function to plot the status of the token flowing l e it will write on the GUI the starting of the token to where the token is absorbed Table 3 Implementation file names of R T monitor 5 1 1 Implementation of a user interface to select places and transitions This section is about an implementation of a figure file Real PTtime_select fig in chapter 4 This figure file along with the MATLAB script file is embedded inside a GPenSIM system directory i e the guide layout file with all the graphical user interfaces components C NN NgpensimMimed pensimWReal PTtime select fig and also the background script MATLAB file C gpensim timed pensim Real PTtime select m The use and functionality of this MATLAB figure file were clearly described in the previous chapter The main function of the GUI is i The main function In MATLAB working environment the main function name and the file name use the same name For example in Real_PTtime_select the main
143. o Ge Go Gee Fig 43 GPenSIM file Operation figure Created for illustration c Property inspector The MATLAB GUIDE provides a property inspector tool From where we can inspect properties like background colour component name and handle events Almost every GUI providing software studios have a property inspector The MATLAB GUIDE property inspector is shown below Gs Roe Ex ES Inspector uipanel uipanell Files BackgroundColor C S BeingDeleted off BorderType etchedin E BorderWidth 1 F BusyAction queue Z ButtonDownFen E Clipping off CreateFcn E PE DeleteFcn E F Font ngle normal i FontName MS Sans Serif Pd Fontsize 10 666666666666666 FontUnits pixels n FontWeight normal Hu l ForegroundColor E BE HandleVisibility on HighlightColor EX Co HitTest on x Interruptible on g Position 0 018 0 211 0 722 0 732 n cor Goh Fig 44 MATLAB GUI designer property window 48 d Callbacks Finally there must be some way to perform an action if a user clicks a mouse on a button or types information on a keyboard A mouse click or a key press is an event and the MATLAB program must respond to each event if the program is to perform its function Every callback function has a variable called handles to handle each operation since the guide is an event driven program Generally callback function controls the behaviour of the gui figure and of individual components MAT
144. o rt monitor trans PN global transitions else if it is in realtime take the global variable from the Real PTselect set handles text84 String REAL TIME if isempty global info rt monitor places amp amp isempty global info rt monitor trans No trans length global info rt monitor trans No places length global info rt monitor places else disp There is not places and transitions selected for the realtime please select return there is nothing selected so return to the gpensim normal end end After calling the global values and check whether they are the member of the real time or not The next step is to pass each of those values to the MATLAB gui plotter to plot the circles and bars a To display the status of places For the places the plotting is done as in the following code snippet It shows the calling of the MATLAB axes and Edit gui components for every places in that cell array The axes which are MATLAB gui components are used to plot small circles to illustrate the places and the edit boxes are used to put the name of the associated place that we need to plot Remember that the names are extracted from the global places 73 The function uses a MATLAB built in function called eval in order to invoke the callback for the edit and CreateFcn for axes The eval is an easy and fast MATLAB built in function used to run a given value for j 1 No places t
145. odels the specification of process synchronization asynchronous events concurrent operations and conflict or resource sharing for a variety of manufacturing automated systems at a discrete events level 20 2 4 7 Firing Sequence and firing time The firing sequence of a transition depends on different techniques In GPenSIM When there are more than one enabled transitions the firing sequence is made by the transitional definition file Step 1 TO is enabled and can fire Step 2 T1 is enabled and can fire Step 3 TO is enabled again after t1 fires Fig 7 Firing sequence The firing time of a P N denotes for how long the transition can fire For example if it is 3 the transition will fire for 3 seconds 2 5 Extended Petri net A pure or an ordinary Petri net the one that has been explained so far can be expanded to other types of Petri net to increase the modelling performance As mentioned above P Ns can be used to model a wide variety of systems However there may be systems which cannot be properly modeled as P Ns meaning there may be limits on the modeling power of P Ns 24 some of the extended Petri net are 16 2 5 1 Timed Petri Nets The basic Petri net models don t have any mechanism to deal with the duration of system activities 21 24 40 But adding timing parameter to the Petri net model addresses this issue A deterministic times are created with transitions This is used to achieve a better sequence an
146. ol system that has all round features Systems can be analyzed based on the following criteria and can be decided in what way a system can be modelled 9 Deterministic or Stochastic It is always important to analyze whether the model contain stochastic elements or not If the system contains a discrete flow we can add random variables Randomness is always easy to add to discrete event systems DES Static or Dynamic We should also analyze the behaviors of the system Whether it is dynamic or Static Continuous or Discrete Does the system state evolve continuously or only at discrete points in time Continuous Continues event dynamic system simulation Uses classical mechanics Discrete queuing inventory machine shop models discrete event dynamic system simulation 9 Real Time or simulated time Based on their event time systems can be differentiated as Real Time and simulated time 2 2 Discrete events dynamic systems DEDS DEDS are one kind of systems that under goes a discrete event property Usually they are used to model and optimize systems with complex processes and distributed systems where there is a discrete data flow This can also provide capabilities for analyzing and optimizing event driven communication using hybrid system models agent based models state charts and process flows There are several tools that can be used to model and simulate discrete event systems Some of the tools that can be used are Automata State
147. olor t btncolr set handles text55 String textT str set handles text55 ForegroundColor textT colr elseif strcemp s trans text23 set handles text62 String string HH MM SS current time set handles pushbutton10 BackgroundColor t btncolr set handles text56 String textT str set handles text56 ForegroundColor textT colr end set handles uipanel1 BackgroundColor t btncolr for the small window set handles text13 String str pause 0 2 end enable_AnimNGT m function zenable AnimNGT global PN global str1 global temp2 global handles global global info global prev trans enbl transzPN Enabled Transitions 6 O 1 1 for iz1 length enbl trans 144 if eq enbl trans i 1 curr_trans PN global_transitions i name t1zi disp curr trans a current time if PN REAL TIME if ismember curr trans global info rt monitor trans disp At rt clock string PN global transitions t1 name is Enaled but not member of R T monitor disp RETURN ON R T DISPLAY return end end if eq a current time amp amp strcmp curr trans prev trans disp curr trans prev trans are equal return end if PN REAL TIME temp2 sprintf temp2 PN global transitions t1 name is Enabled At rt clock string 10 96 else temp2 sprintf temp2 PN global transitions t1 name is Enabled At jnum2str current time 10 6 end if is
148. om both panels R T places and R T Transitions right sided list boxes to set of real time components and return to the simulation process This user interface is implemented in aiming the user can easily select the real time components easily from every modules without any ambiguity The interface is embedded inside the GPenSIM tool and run whenever we start running a main simulation file 4 4 2 Design of a graphical display system for Real Time Monitor GUI main This HCI form is the heart of the R T monitor display After we select the real time component using Real PTtime select form this graphical display form appears and starts displaying the background process of the GPenSIM simulation process The display unit is designed to acquire all the necessary information of the real time component As it is mentioned in the statement of problems the main objective is to provide GPenSIM with Real Time display unit that would show the simulation of the Petri net model The GUI is embedded inside GPenSIM When a main simulation file runs it will also start running after we select the necessary R T monitor elements We know that GPenSIM runs in two modes i e either in real time or simulated time So the GUI is designed to run in both modes i e It runs both in the real time and the non real time simulation modelling but it gives an information in what mode is the simulation running The following figure shows the whole GUI display unit It has differ
149. onitor trans 6 end 96 Executes on button press in pushbutton7 function pushbutton7_Callback hObject eventdata handles global global info global PN set handles pushbutton7 Visible on if not PN REAL TIME set handles text18 String global info rt monitor trans 7 name else set handles text18 String global info rt monitor trans 7 end 96 Executes on button press in pushbuttons function pushbutton8 Callback hObject eventdata handles global global info global PN set handles pushbutton8 Visible on if not PN REAL TIME set handles text19 String global info rt monitor trans 8 name else set handles text19 String global info rt monitor trans 8 end 96 Executes on button press in pushbutton9 function pushbutton9 Callback hObject eventdata handles global global info global PN set handles pushbutton9 Visible on if not PN REAL TIME set handles text20 String global info rt monitor trans 9 name 129 else set handles text20 String global info rt monitor trans 9 end 96 Executes on button press in pushbutton10 function pushbutton10 Callback hObject eventdata handles global global info global PN set handles pushbutton10 Visible on if not PN REAL TIME set handles text23 String global info rt monitor trans 10 name else set handles text23 String global info rt monitor trans 10 end function pushbutton15 Callback hObjec
150. opmmi Ip Ee tU P MUR b IMS 18 2 6 2 The main simulation file MSF file eeeessseeeeeeeeeennnneenn nennen 19 2 6 3 THE Petri met definition file PDF file iuis os eeste cea RU e Prix ten et Door Ra Co Rpa ub Ud rbrbu est saa Dh Eoo bic 19 iii 2 6 4 The transitional definition file eee cece eccececcececcecsccecsceecsceccscecececeecsceecscesesceescesaecusaecess 19 CRATERS eode pis idet brin uta a a au auto naen 23 3 Overview of Real time simulation and some APPliCAatiON cccccseeccccsseccceeseceeceeseceeeeneces 23 3 1 Real Time simulation and modelling ssassn a nnne 23 3 2 Real Time Simulation using GPENSIM ccecccccsssccccesscccceesececseeceeeeecceeeuseceseuaecessegeceeseges 24 3 2 1 Real Time simulation in Industrial application 00 0 eeeccccesseccceesececeeesececeeececeeeeceeseeeeeenes 26 3 2 2 Real Time simulation in room security eessen a nennen nnns 27 3 3 Real Time simulation and modelling using NXT machine eese 31 3 9 E TUCI MIBOSUEOIICIGUICE csileattcs parat cete udalsc aa ulcu ttam D tse obses to a udrd 31 3 3 2 Door alarm system using NXT i s rrr dee end ni pco pa UTE TRUE ALU Red E aT RRB 32 3 3 3 Traffic light system modeled using NXT intelligent Brick ccccccccsssececesececeeseceeeeeeeeeees 37 MODEA E MI M MM MM MM MEE 43 4 Designing R T monitor Tor GPensS Mass ics oes EE HUE o EFE bec Hee epu s EC Udo testo Ve hse ese D E Ep 43 4 1 Human Comp
151. orms the color plotting as a kind of animator If there are any enabled transitions at time t then it changes the color of the rectangular bars on the GUI to a green color by calling the function of gui painter In a Petri net model there can be more than one enabled transition at a time t during a simulation process and gpensim puts all those enabled transition into a one dimensional Matrix Array For example if we have four transition t1 t2 t3 and t4 in the model Then gpensim puts all those values in an incidence matrix form as shown below PN Enabled Transitions O 1 1 0 1 Enable i e p2 and p3 are enabled at timet 0 Not enabled i e p1 and p4 are not enabled at timet From the above say the current time t is at 13 35 25 or 48917 then it can be described as At 13 35 25 or 4891 7 48917 O 1 1 O As the simulation goes i e at At the sequences of the enabled transition will be stored in a cell array and it will also been putted on the text box on the GUI The value will be at 13 35 25 or 48917 suppose the firing time is 1 second Zo O 1 1 9 48918 O 1 1 1 A8919 1 1 9 l PN is a global structure as it was described in section 5 1 2 in gpensim that carries all the information about the Petri net model and the status and information of the Petri net model will be stored in a structure that contains matrix array and values are stored inside the PN structure 82 In the same simulation cycle the gpensim will call the en
152. ound on Windows See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit14 Callback hObject eventdata handles Hints get hObject String returns contents of edit14 as text 96 str2double get hObject String returns contents of edit14 as a double Executes during object creation after setting all properties function edit14 CreateFcn hObject eventdata handles Hint edit controls usually have a white background on Windows See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end function edit13 Callback hObject eventdata handles Hints get hObject String returns contents of edit13 as text str2double get hObject String returns contents of edit13 as a double Executes during object creation after setting all properties 136 function edit13 CreateFcn hObject eventdata handles Hint edit controls usually have a white background on Windows See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end 96 Executes on button press in pushbutton20 function pushbutton20 Callback hObject eventdata handles global gp pause if
153. ownFcn hObject eventdata handles Executes during object creation after setting all properties function axes3 CreateFcn hObject eventdata handles radius 2 centerX 5 centerY 7 rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor w axis equal 6 circle Executes during object creation after setting all properties 137 function axes4_CreateFcn hObject eventdata handles radius 2 centerX 5 centerY 7 rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor w axis equal 6 Hint place code in OpeningFcn to populate axes4 96 Executes during object creation after setting all properties function axes5 CreateFcn hObject eventdata handles radius 2 centerX 5 centerY 7 rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor w axis equal 6 Hint place code in OpeningFcn to populate axes5 96 Executes during object creation after setting all properties function axes6 CreateFcn hObject eventdata handles radius 2 centerX 5 centerY 7 rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor w axis equal Hint place code in OpeningFcn to populate axes6 96 Executes during object
154. pRing 1 tOff pDisarmed 1 t a off pDisarmed 1 Key padmodel def m a Key pad model for key combination function png key padmodel def A PN model for key pad png PN_name a PN model for key pad 153 png set of Ps pBuffer pEntry entered pExit entered png set of Ts tEntry tExit png set of As pBuffer tEntry 1 pBuffer tExit 1 tEntry pEntry entered 1 tExit pExit entered 1 Room sec MSF m clear all clc global global info global info REAL TIME 21 This is a Real Time run global info STOP AT current clock 3 1 1 20 6 stop 1 1 20 global info passwords A B C global info deltaT O global info readInzO png petrinetgraph door def alarm model def key padmodel def dyn mO pDoor Close 5 pBuffer 5 pDisarmed 1 dyn ft tDetect 5 allothers 1 pni initialdynamics png dyn disp System is ready sim gpensim pni plotp sim pStart pDetect pEnd COMMON PRE m function fire transition COMMON PhRE transition global global info if stremp transition name tOpen amp amp strcmp transition name tExit if stremp transition name tDetect 96 tDetect is enabled since there Y are tokens in pDisarmed and pExit entered deltat1 current_time readIn zinput Enter the combination code deltat2 current_time deltaT deltat2 deltat1 if deltaT lt 60 if ismember readIn global info passwords
155. pecs Y tEM QUIT Fig 37 P N model for emergency blink 4 The overall model is The system uses a modular approach All the above sub system models combines to make a complete traffic light model The P N model that shows the overall system is shown below 4 Model Pedistrian tPE_CY ao pPE START tPE START d a pEM_S5TART pBEEP BEEP Y __ tEM START At pEM DECS Model Normal Cycle E T tE M QUIT Model Emergency Fig 38 A complete model of a traffic light system The traffic light signal model consists of NXT equipment To interface the NXT to a MATLAB we need to install different kinds of drivers and set up the Bluetooth connection of the main working station with the NXT device 42 Chapter 4 4 Designing R T monitor for GPenSIM 4 1 Human Computer Interactions HCl A human machine interaction HCI is a method of building a bridge between a human being and a computing machine In recent times after the introduction of personal computers operating systems and text editors the HCI tools become a rapidly developing tool In these days everything is getting more computerized Human being becomes more potential user of computers As the technology got more advanced and computers get to be more available there becomes some sort of need to shape the human interaction with computer The cognitive science introduces a method to simplify the interaction between human and computer Thus the
156. r Code Yes i on alarm off 4 trigger alarm Enter NXT Fig 26 Flow chart of Door alarm system using NXT e And the Petri net model for the above flow chart will be as shown below Fig 27 A Petri net model of door alarm system 35 The whole system can be divided in to two modules and each of them will be called in the main simulation file The first module is to model the door and the second one is to model the NXT sensor The static P N of the door alarm model is shown below function png doorModule def t ok lt DEFNU gt door alarmodel png PN name door alarm model png set of Ps pArrive pDoor pDetect pGrant pInside pNot alarm on png set of Ts tArrive tNo alarm set tEnter in tEnter tCheck tDetect png set of As pArrive tArrive l pDoor tNo alarm set r l pDoor tDetect 1 pDetect tCheck 1 pGrant tEnter l pNot alarm on tEnter in 1 pNot alarm on tEnter in yi tArrive pDoor 1 tDetect pDetect 1 tCheck pGrant l tEnter in pInside 1 Similarly the static P N of the NXT ultrasonic sensor is shown below The main simulation file and the transitional definition files are described in the implementation section function png alarm def png PN name LEGO Robot alarm png set of Ps pStart pRestart pAlarm pDetect pEnd pcCodes pNotMatch pRi
157. ratic plot object For example we can set its fore ground colour property as Set h Color red We can also specify the properties when we call the plotting function in another M script file h plot x y Color red We can also get the object property by using a get function And it will return the object and its possible values as numerical value which is an id for that component and its property A get gcf Color where gcf returns the current figure and it stands for get current figure Will return ans 0 2 0 20 1 This value is the combination of one of the MATLAB colour RGB 50 e In addition to the Callback function a MATLAB GUIDE also creates four types of functions with some templates These are Guiname This is main function and created with some templates like struct It will be discussed in detail in the implementation part The main functions with two variables look like this function varargout guiname varargin Guiname OpenFcn The prefix guiname before the underline score is the name of the figure and the suffix after the underscore is a built in function name for opening the figure file on run time The function is used to open the figure just after the main function is run and it fills the handles output with proper arguments and a starting event The function takes four arguments i e hObject eventdata handles and varargin Guiname Output Similarly the prefix guiname before the u
158. red At 12 54 40 tRobot3 is Fired At 12 54 40 tRobot1 Mot enabled and Fired at12 54 41 tRobot1 Mot enabled and Fired at12 54 41 tRobot 2 is completed At 12 54 41 tRobotZ is Fired At 12 54 42 tRobot1 Enabled but not Fired At 12 54 42 tRobot1 Enabled but not Fired At 12 54 43 LDinhbntlEnablad hit nnt Fired At 17 54 43 Fig 59 a Firing sequence on the R T monitor The space shows the loop interval and the active transition in every loop In the GPenSIM main simulation file if the global info PRINT LOOP NUMBER 1 the spaces would be replaced with a string with loop number to show the loop interval as shown below Firing State Sequence oop Nr 1 n t1 is Fired At 15 10 56 t2 Hot enabled and Fired at15 10 56 t1 Not enabled and Fired at15 10 56 opp Nr 2 t1i amp completed At 15 10 57 t opp Nr 3 m Fig 59 b Firing sequence with loop number v Basicinfo This GUI panel shows a basic info about the total number of places transitions simulation name and total elapsed time Simulation Name Mo of places No of Transitions Total Elapsed time Fig 60 Basic info about the Model simulation vi Commands This is also another panel that contains some commands to control the simulation this gives the R T monitor extra capability in controlling the simulation besides displaying the events For example while we simulate a robot that takes f
159. rom the CNC machine and put 59 to the buffer if the user needs some diagnosis the simulation can be stopped so that the working machines also paused Commands Stop Continue Rese ext Print State Space Fig 61 Control buttons on R T monitor While the simulation is pause there is some added time to the overall elapsed time this should be handled otherwise in real time simulation delay has a significant factor Let s denote a delay between two event a and b ast Even a Event b Event b Fig 62 Event diagram with time Event b was supposed to happen at t but due to the delay At it ended at t The overall elapsed time would be t t and the delay is At t t From this we can conclude that pausing the simulation for longer time will make the t to be high This can lead the system to be less accurate Similarly the command panel contains a method to control the speed of the simulation In GpenSIM while working with real time we can also speed up or delay the firing without losing the real time but just only adding some delay time 9 Ad 0 Oo where f is final time o is initial time The difference between this and the above pause is that the delay time is very small the maximum 0 25 in speed control so that it won t affect the real time 60 vii Sequence display of global transition status The R T monitor has also an extra display to show the status of the rest
160. ry res strcat axes num2str CreateFcn hObject eventdata handles res2 strcat edit num2str j42 Callback hObject eventdata handles eval res eval res2 catch err disp err break end end The MATLAB string builder produces the two strings for example for the first iteration in the loop the strcat yields axes num2str GCreateFeninObj ecr eventdata handles Gives axesl CreateFon hObjecrt eventdata handles edi num2str jt2 CalibeackihOb ecl eventdara handles 7 Gives edit3 Callback hObject eventdata handles Hence the eval evaluates the above two strings which has a meaning in the MATLAB GUIDE After evaluating the strings or calling the callbacks the MATLAB gui starts running the string The functions that plot a small circle using axes are shown below MATLAB has different techniques to plot circles The usual approach is using a rectangle command by changing the curve as 1 1 which the MATLAB compiler knows this is a circle CenterX CenterY is the center of the axes function axesl CreateFcn hObject eventdata handles radius 2 centerx b centerY 7 t To draw a circle using rectangle in matlab rectangle Position centerxX radius centerY radius radius 2 radius 2 Curvature 1 1 Facecolor w axis equal make the axis same as the given dimention 74 The function that writes place named jus
161. s A developer can choose which one is comfortable for his code Note 49 that each of them have different purposes These are hObject eventdata and handles If each of them is not used in the callback function the guide will put an underline warning sign on each of them hObject This variable handles the event of current operating object or component which creates a getcallbackobject called GCBO In MATLAB the GCBO are dynamically created each time when a callback is executed Their functionality is to get handle to current callback object OBJECT FIGURE GCBO and returns the handle of the object whose callback is currently executing and also the figure containing that object 36 eventdata The event data in MATLAB take event handlings data and pass throughout the platform These are reserved for future version of MATLAB handles This method is the basic for MATLAB GUI events When MATLAB creates a graphics object or component it assigns an identifier to the object 37 This identifier is called handle and sometimes denoted as h One can use the handle identifier variable to access the hObject properties with two built in functions called set and get functions For example the following quadratic statements create a graph and return an event data to a plot result object in a form of h x 0 0 1 1 y 2x Fa h plot x y We can use the handle event handler h to set and get the properties of the quad
162. s enter 5 To check whether the path is set or not type gpensim on the Matlab command window and enter A 2 Operation in GPenSIM 118 The author s website of GpenSIM provides an instruction how to develop a Petri Net model using GPenSIM The instructions were clearly discussed on the GPenSIM part The simple way to use GpenSIM 1 Open new MATLAB script file 2 Start by creating Petri net Definition file PDF Then save the file with suffix _def at the end of the file name For example production def m 3 After creating the PDF file open new MATLAB script file and start creating the transitional definition file for the intended transition The transitional definition files contain the post and pre conditions If two or more transitions have same pre and post event create a common TDF file by the name COMMON PRE and COMMON POST 4 After Creating the TDF files the next step is creating a main simulation file MSF Da A 3 How to set up the NXT device The NXT device doesn t usually work on windows 7 service pack1 but in this thesis it has been used service pack 2 and works fine To install the NXT device we need to download and install the RWTH Toolbox in the MATLAB Environment The steps to do so are Download the version of the toolbox v4 08 JUN 2013 is used in this setup Extract the zipped file in to the hard drive Preferred into MATLAB toolbox folder inside the MATLAB installed folder Now s
163. se are Atransition is enabled but not fired Atransition is not enabled and not fired Both plotting are taken place in this file They are identified using a flag i e 1 and O If O it is the first condition and the color would be cyan and if it is 1 the color would be light purple The function is called from a start firing m which similar to the plotting for a firing condition in Section viii To check the two conditions For a transition not enabled but not fired if and PN Enabled Transitions tl PN Firing Transitions t1 hasnotfired AnimNGT ti 1 end The above condition checks the status of the PN and if both conditions are not satisfied the plotter function hasnotfired AnimNGT with a flag value of 1 will be called Fora transition enabled and not fired This function is a continuation of the if condition of the fire AnimNGT As it is mentioned on section x above considering an enabled transition and the preconditions the precondition checker function returns the firing condition satisfied FCS value If this condition is satisfied the firing AnimNGT is called Otherwise the hasnotfired AnimNGT will be called with a flag value O to tell the plotter that the event is enabled but can t fire i e it will plot a cyan color hasnotfired AnimNGT ti 0 This function also calls a gui painter in order to paint the cyan color on the R T monitor display 87 5 2 Implementat
164. se set handles text84 String REAL TIME if isempty global info rt monitor places amp amp isempty global info rt monitor trans No trans length global info rt monitor trans 6PN No of transitions No places length global info rt monitor places 6PN No of places else disp Please choose the display places and trans in The main simulatio file return end end set handles text75 String num2str gp pause set handles text40 String No places set handles text41 String No trans if No places 7 No places 7 end for j 1 No places 127 try res strcat axes num2str j CreateFcn hObject eventdata handles res2 strcat edit num2str j 2 Callback hObject eventdata handles eval res eval res2 catch err disp err break end end if No trans 10 No trans 10 end for i 1 No trans try mzstrcat pushbutton num 2str i Callback hObject eventdata handles eval m catch err disp err break end end 26969696969696 button transition handlers function pushbutton1 Callback hObject eventdata handles global global info global PN set handles pushbutton1 Visible on if not PN REAL TIME set handles text1 String global info rt monitor trans 1 name else set handles text1 String global info rt monitor trans 1 end function pushbutton2 Callback hObject eventdata handles global global info 9 6 global PN set handles pushbutton2 Visible on if not PN REAL TIME
165. sition names and total elapsed time This is shown in a black box Simulation Name No of places No of Transitions Total Elapsed time Fig 78 General information about the simulation The simulation name is retrieved from the PN name and also the number of places from PN No of places and PN No of transtions The total elapsed time show the total simulation time 103 The plot analysis from gpensim gives a result as shown below This also gives extra information about the status of the simulation pDetect pEn d Number of tokens i gt 11 921511 92211 9225 11 92311 9235 11 92411 924511 92511 9255 11 926 11 9765 Time in HOURS Fig 79 plot result for Door alarm model From the above plot and the legends we can see that the token from pStart declined as they are fired by the transition tDetect The tokens in tDetect are fired only once in the given time and it goes up and stop at time t And finally the number of tokens in the pEnd increase as the token gaming stores the tokens inside this place 6 1 3 Test results for traffic light system The traffic light model uses three light outputs and three input touch sensors for NXT model The following picture was taken during operation 104 LIRE T poe WW N po NS MA NN NK W li N S NN S m MYON ay WW Y MN M Ki NAM A V At DN Start Time End Time Ne MN Y is Fired Af REAL
166. sitions 0 enabled transitions to be fired based on a PRIORITY or RANDOMLY priority exist any PN priority list if priority exist set of ordered enabledTrans priority enabled trans enabledTrans else set of ordered enabledTrans randomgen enabledTrans end No of enabledTrans length enabledTrans From the above code the find function returns all the items from the above Matrix PN Enabled Transtions with a value of 1 We should note that the find looks only for the transitions in current loop Hence only one dimension is checked at time t Based on their priority i e t1 t2 t3 t4 or randomly the transitions The transitions would be sorted according to their priority or randomness GPenSIM provides sorting mechanism using two functions called priority enabled trans and randomgen The first function sorts out enabled transitions in descending order of their priority And the other tool is used to order the enabled transitions randomly using a function called randomgen 25 All of the transitions that are enabled are now sorted in a single cell array known as set of ordered enabledTrans Then the next step is letting the transition that fulfils the 84 pre conditions to fire and on the other hand plotting calling the plotter to make the associated bar on the GUI red for i 1 No of enabledTrans check events one by one ti set of ordered enabledTrans 1i if not PN REAL TIME pause l1
167. splay the result of the dump file The following picture shows how the newly R T monitor system help to display and control the status of the Real Time simulation of a traffic light signal on a single monitor Fig IV Sample picture of the newly implemented R T monitor system 1 3 Adaptations The source code for the R T monitor are embedded inside a GPenSIM system hence some part of GPenSIM source code are added to this paper with proper citations Also for testing the R T system the idea of modelling traffic light signal using NXT are taken from the course discrete simulation and performance analysis with some slight modifications 1 4 Chapters review Chapter 1 is about the introduction of the thesis work motivation adaptation and the statement of problems Chapter 2 is about the background of the project work idea l e it briefly describe the definition and types of simulation and modelling with some examples and also the need to use them in modern life It also discusses about modelling a discrete event dynamic systems basic Petri net theory and GPenSIM Chapter 3 is about the Real Time simulation and modelling of Real Time system It describes about different kinds of petri net modelling in R T GPenSIM This chapter also has example of modelling real time P N model l e Petri net in industrial application in house security door alarm using NXT and Traffic signal system using NXT intelligent Brick Chapter 4 is
168. ss The newly implemented tool acquires GPenSIM to have an enhanced tool to work with the simulation operation of the P N model i e there is a control button on the interface unit which would help the user to control the ongoing system with time by watching the progress on a single display Generally since time is a key value in Real Time simulation it can be very difficult to overview the results of a simulation that are only presented in a text log file especially for larger models it can be more complicated The following figures show the difference between the two results i e the result of the current GPenSIM simulation and the newly implemented tool For the example mentioned above suppose we have three production lines that read input from a source input and put the result on a buffer The ASCII dump file is State Diagram Time 08 34 03 State 0 Initial State no tokens At start At time 08 34 03 Enabled transitions are tlnPut At time 08 34 03 Firing transitions are tInPut Time 08 34 09 State 1 Fired Transition tInPut plnout Buff plnout Buff plnout Buff plnout Buff plnout Buff Current State plnout Buff Virtual tokens no tokens Right after new state 1 At time 08 34 10 Enabled transitions are tInPut tProduction line1 tProduction line2 tProductionline3 At time 08 34 10 Firing transitions are tlnPut tProduction line1 Time 08
169. stop pi tokens markings i curr Place PN global places i name if tokens if eq tokens 1 tokens nr str no need to print 1 before else tokens nr str int2str tokens end markings str markings str tokens nr str PN global places i name end 96 if tokens disp markings str set handles print state space String markings str 26969696NGT if PN REAL TIME token number ngt curr Place int2str tokens markings str end 969696969NGT end 96 for i 1 Ps fill GUI initial dy m function fill GUI initial dy initial dynamics global hn global PN global handles global global info Ps PN No of places XO zeros 1 Ps initially if not isfield initial dynamics mO initial markings warning initial markings NOT given disp else imarkings initial dynamics mO if iscell imarkings 96 sources p1 1 p2 3 no_of_sources length imarkings 2 number of places extracting places for i 1 no_of_sources curr source name imarkings 2 i 1 source nr check valid place curr source name initial tokens imarkings 2 i XO source nr initial tokens 26969696 NGT 142 if ismember curr_source_name global_info rt_monitor_places s find GUI component_places curr_source_name if isempty s if stremp s text68 set handles text77 String num2str XO source nr elseif stremp s text69 set handles text78 String num2str XO source nr
170. t eventdata handles For stop button global h2 h2 msgbox Stopped press ok or click on continue uiwait h2 96 Executes on button press in resetbtn function resetbtn Callback hObject eventdata handles global gp pause if gp pause gt 0 gp pause gp pause 0 1 set handles text75 String num2str gp pause else gp pause 0 2 set handles text75 String num2str gp pause set handles text75 String Min speed end 96 Executes on button press in pushbutton18 function pushbutton18 Callback hObject eventdata handles close GUI clear all clc Executes on button press in pushbutton7 function pushbutton11 Callback hObject eventdata handles global h2 uiresume GUI close h2 function circle2 to add tokens we should be able to draw some small circles let use a small dots radius 0 25 centerX 3 5 centerY 7 rectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 1 1 FaceColor k function del circles global y global n 130 global j clear j radius 0 25 centerX 5 y centerY 7 n jerectangle Position centerX radius centerY radius radius 2 radius 2 Curvature 0 0 FaceColor w LineWidth 0 00001 function circle global y global n global cnt randcolor rand 1 rand 1 rand 1 On i l 2 radius 0 3 x rand 1 y X centerX 5 x m rand 1 rand 1 n
171. t below the circles is shown below Function edit3 Callback handles global global info global PN set handles uipanel20 Visible on if not PN REAL TIME set handles text68 String PN global places 1 name else set handles text68 String global info rt monitor places 1 end Since we have two kinds of simulation this check whether the simulation is in real time or not The main purpose of this function is to plot place names The command set handles Visible on makes the initially invisible components visible during the run time This is because of the fact that when the R T monitor was designed using the designer tool GUIDE the components were made to be invisible and let the simulation makes them visible whenever they are needed b Todisplay the status of transitions Similarly for the transition a pushbutton is used to serve as a bar to represent the selected transitions Again here the eval function is used to run the built string using strcat with the associated place For example if we want to plot the first place p1 the for loop produces a string as pusbbuttonl Callback hObject eventdata handles The eval will run this callback by passing the three basic variables lFor 1 1 No trans try m strcat pushbutton num2str i Callback hObject eventdata handles eval m catch err disp err break end end The eval runs the string and calls the callback function
172. t both figure files were designed using a MATLAB GUIDE tool Every figure file in a MATLAB has a background MATLAB file m Thus MATLAB keeps two separate files for every MATLAB gui file names with same name but different file extensions For example for Real PTtime select name there are two kinds of files called Real PTtime select m and the layout Real PTtime select fig Note that the two files can be kept on separate directories but it would be better to keep both of them inside the same directory A MATLAB file path can detect it wherever the other files This has been one pro about MATLAB Both GUI and Real PTtime Select runs before the simulation starts Their main purposes are to prepare a rough sketch i e HCI tool to display the simulation status The flow chart of R T system The flow chart and the algorithm of R T monitor are shown below The general overview of the design was shown in the design section MSF Select Ps and Ts Inform Not Realtime Call HCI and Continue with gpensim cycle Start Simulasjon Fig 64 The flow chart of R T monitor HCl 63 In the above flow chart the HCI tool contains all the gui components and script files of the GUI m The rest of the flow is a normal GPenSIM operation In addition to the two GUI files the system has also different classes that help handling the GPenSIM and filling out the information on the GUI The functions and classes of the R T moni
173. tains declaration of the simulation and color PN components Assume we have color distribution as shown below global info PRINT LOOP NUMBER 1 global info STOP AT current clock 3 inf inf inf global info REAL TIME 1 global info cr 1 2 3 4 color rotation T is for raw material one for the production line 2 is for raw material two for the production line 3 is for raw material three for the production line 4 is for raw material four for the production line Now every transition will select the color combination and put to the assembler These are done by the TDF files The simulation will run a life time But every detail runs under real time notion global info cr index 0 init rotation index 0 88 The variable cr_index is used for color rotation among tokens The index makes the colors to rotate so that the input buffer makes a random choice of tokens 3 TDF It has been designed a three kinds of transitional definition files to let the system has a preconditions before firing From the definition of gpensim when a transition fire it inherits colors of all input tokens thus new tokens deposited into output places would have all the colors inherited from the input tokens To prevent inheritance of tokens gpensim provides a method called overriding The three pre conditions in this model are tinPut pre This TDF file has a method to rotate colors and put them
174. terJnteractlohns HCL aste etie t a d b bet up e ME ebbe D 43 4 2 Desieh R display Syste om 44 4 3 User INLET FACES deSen annn cress accseetasrecsmtutag tee socaciara renee waaueeaa aac see een 45 4 3 1 Graphical user interface Sul DasiCs ico teaeeeedexcteloai Nets edcieatees 46 4 32 JWIATEAB GUIDE crie a MPs dinD Me RM uet Save t E Ed rM e eR uin 46 4 4 ReT Haonitor MISST Titel Tat OS eevnmietos bue tr vob ate PN tE Ep NN UeR FOX VE FER ND OUR EI EM PU EU Y T UR RE eMUR 51 4 4 1 Design of an interface to select a Real Time places and transitions 51 4 4 2 Design of a graphical display system for Real Time Monitor GUI main 53 CADE een re ne ee ene oe ar renee CP ne eS RO ee ee eRe eer en Pe ee een eee ae en ee ee ee 62 5 implemen aoaea mer vert disstade bue temet iste tue Meu I Sree eta oci Muta lE 62 5 1 Iriplemientation of R T mohltof ood RE E onda eee bd onl 63 5 1 1 Implementation of a user interface to select places and transitions 65 5 1 2 Implementation of graphical Display for Real Time Monitor een 69 5 1 3 Other Implementations OF RT MONITO usce seo uet Ne OE CPUR Ea eae Ue Qe uA S O 76 5 2 Implementation of gpensim code for the real time models eeeeeeee 88 5 2 1 Implementation of R T simulation in Industrial application eeeeeseeeeee 88 5 2 2 Implementation
175. tf temp2 Loop Nr int2str Loop_Nr 10 if isempty temp2 set handles edit1 String temp2 end tempzsprintf temp loop Nr int2str Loop Nr 10 if isempty temp set handles edit2 String temp end else if isempty temp2 temp2 sprintf temp2 10 set handles edit1 String temp2 end if isempty temp tempzsprintf temp 10 set handles edit2 String temp end end for i 1 Ts PN Enabled Transitions i enabled transition i end start NGT KK K K K K K K CE K CE K K K K K K K K CE K K K K CK K K CE K CE K K K K K K CE K CE K K CE K K K K K K KK 2 if isempty PN name set handles text39 String PN name end len length PN Enabled_ Transitions count count 1 if any PN Enabled_Transitions enable AnimNGT EIP firing start EIP end end while SIM COMPLETE Finally pack results pack sim results Enabled Trans SET Firing Trans SET LOG colormap sim results PN 9696969NGT distime rt clock string set handles text67 String distime e cputime t toc 140 set handles text42 String num2str toc 6 elapsed time find GUI component places m function s find GUI component places curr source name global global info global hn global PN if ismember curr source name global info rt monitor places s disp return end len length global_info rt_monitor_places if PN REAL_TIME for j 1 len if stremp curr source name global info rt mon
176. to live not only by assisting on the day to day activities but also by letting to model the actual system and enable us to predict about the future work The technique of modelling real life activities is called simulation and modelling It is obvious that most part of our day to day activities starting from counting time notion are more or less related to mathematics Since mathematical formulations have powerful tools to represent the actual system and our day to day activities that are associated with Real Time systems can be modeled using mathematical tools based on a Real Time The terms modeling and simulation are often used interchangeably Thus this thesis discusses about the basic method of modellings and simulation using the appropriate tools in Real Time The implementations were carried out on a MATLAB studio using a MATLAB language It has also been used an NXT Mindstrom microcontroller with different types of sensors to get a Real Time data input from some sensor nodes The simulations were designed and implemented using a GPenSIM and Petri net tools The current version of GPenSIM runs in two modes these are using either 1 Simulated clock 2 Real time clock When the real time clock is used the simulation is actually performing real time control activity like reading sensor input data making control policy and then feeding the actuators outputs with control output data The idea was adapted from the work of prof Davidra
177. token that armed the alarm tEntry pEntry entered tExit pExit entered Fig 18 Model of keypad The Petri net model for the above system is shown below The overall model The combined system model will look like as follow There are three modules and in the picture below the blue highlighted border color show the sub models of the whole system Module 1 ae Ta x Module 2 Fig 19 The overall alarm system model 30 Now the above model is a simple model to make it more intelligent we can add a sensor instead of the combination and wait time Section 3 3 2 introduces a method by adding a sensor and NXT device 3 3 Real Time simulation and modelling using NXT machine 3 3 1 NXT Mindstrom device The NXT Mindstrom is a multipurpose microcontroller device that has multi functionality The device can be used to model robots traffic lights material sorting and different types of sensor based systems The NXT device components can be bought in a form of a pack The packs contain different types of equipment that are used for educational purpose In addition to the main microcontroller unit NXT brick there are different cables building Lego bricks different sensors like ultrasonic light sensor sound sensor tough input sensor light lamps and small tires if someone wants to build a simple robot or vehicle and so on 38 The main components are a Hardware NXT intelligent brick microcontroller Fig 20
178. tor i e the GUI components and other files are added in to the GPenSIM background source code and these are identified by some comments from the original gpensim file The MATLAB scripts files that are implemented in the R T display are eT Real PTtime select m See Chapter 4 find GUI component places To search a current source place name where a token has been removed from GUI components find GUI component trans To search a current active transition name from the GUI components token number ngt m This MATLAB file plots the real time token during the runtime fill GUI initial dy m This file plots the initial marking of the real time places at the beginning of the simulation gui painter m This MATLAB file has global variables like handles which can directly access the GUI m and GUI fig in Order to paint the coloured bars according to the status of the transitions in the current cycle enable AnimNGT m This file invokes the file gui painter m with associated transition name current time and type of colour in order to paint a green bar which is dedicated for enabled states in the R T monitor fire AnimNGT m Similarly this file has a function to invoke the file gui painter with variables like the transition name current firing time t and colour type in order to plot a red bar for firing transitions fire Complet AnimNGT m This file has also a similar function like the above two Its purpose is to plot yellow bars for the tra
179. tputFcn GUI_ OutputFcn gui_LayoutFcn gui_Callback if nargin amp amp ischar varargin 1 gui State gui Callback str2func varargin 1 end 126 if nargout varargout 1 nargout gui_mainfcn gui_ State varargin else gui mainfcn gui State varargin end End initialization code DO NOT EDIT 96 Executes just before GUI is made visible function GUI OpeningFcn hObject eventdata handles varargin global cnt cnt 0 global global info user data handles output hObject guidata hObject handles set gcf Units normalized Position O 0 1 1 get gcf Position gt gt 001 00 9154 pushbutton14 Callback hObject eventdata handles function varargout GUI OutputFcn hObject eventdata handles varargout 1 handles output varargout 2 handles uipanel11 969696969696969696969696969696969696969696969696969696969696969696 Vlain Start969696969696969696969696969696969696969696 function Start button Callback hObject eventdata handles function pushbutton14 Callback hObject eventdata handles global PN global global info 6 global gp pause gp pause 0 5 if not PN REAL TIME disp Not real time set handles text84 String NOT REAL TIME STOCHASTIC TIME No trans PN No of transitions No placeszPN No of places global info rt monitor places PN global places global info rt monitor trans PN global transitions el
180. tring 10 else tempzsprintf temp str2 num2str current time 10 end set handles edit2 String temp gui painter t1 0 8 0 55 0 7 Not enabled and fired 0 8 0 55 0 7 str2 end firing start function EIP firing start EIP 06 GPenSIM firing start m global PN Rs PN No of system resources dont care enabledTrans find PN Enabled Transitions gt 0 enabled transitions to be fired based on a PRIORITY or RANDOMLY priority exist any PN priority list if priority exist set of ordered enabledTrans priority enabled trans enabledTrans else set of ordered enabledTrans randomgen enabledTrans end No of enabledTrans length enabledTrans 9696969696969696NGT end continue 147 for i 1 No of enabledTrans check events one by one t1 2set of ordered enabledTrans i if not PN REAL TIME pause 1 make some delay to reduce the speed for simulated time disp Sim paused disp not Real Time end disp if and PN Enabled_Transitions t1 not enabled amp firing PN Firing Transitions t1 hasnotfired AnimNGT t1 1 end 9696969696969696969696969696969096969690 if and PN Enabled Transitions t1 enabled amp notcurrently firing PN Firing Transitions t1 fcs new color override selected tokens additonal cost firing preconditions t1 if fcs firing conditions satisfied let the transition fire PN Firing Transitions t1
181. unction fire transition tDetect pre transition global global info OpenUltrasonic global info detect distance GetUltrasonic SENSOR 4 if distance lt global info OBJECT DISTANCE fire 1 else fire 0 end CloseSensor SENSOR 4 tDetect post m function tDetect post transition disp Object detected COMMON PRE m function fire transition COMMON PhRE transition global global info if stremp transition name tNo alarm set disp No Alarm the entrance if free elseif strcemp transition name tEnter in disp Inside house elseif strcemp transition name tEnter disp The Person is clear the alarm and check line elseif strcemp transition name t off disp Off the alarm 156 i input Enter the reset code if eq str2double i global info resetCMD handle COM OpenNXT bluetooth ini NXT_StopSoundPlayback handle now the alarm is off end else disp the alarm is set continue end fire 1 tCheck pre m function fire transition tCheck pre transition global global info 6 pause 1 read keypad input Enter code if ismember read keypad global info passwords disp detected DETECT OBJECT for n 1 10 500 beep NXT_PlayTone 440 500 NXT PlaySoundFile Woops rso 0 end fire O else firez1 end t Start btn pre m function fire transition 2 t Start btn pre transition global global info res btn global info
182. updated before a Bluetooth connection is setup To update the firmware O O O O Turn on the NXT by holding the on off orange Button Press the left arrow button until the setting icon on the NXT display is shown Then select this setting icon with the orange button Again push the left arrow until the NXT version is shown Select this icon by using the orange button Now the version will be shown The newer firmware version can be downloaded from the http www lego com en us mindstorms downloads software nxt firmware Again download the utility tool NeXT Tools to access the NXT device from a PC It can be downloading from the website http bricxcc sourceforge net utilities html Now connect the NXT with the PC using a usb 2 0 cable Open the NeXT tools and a small window with port option will appear Select usb from a dropdown menu and press ok Choose Download firmware from the menu Wait for some minutes until the firmware is updated Now turn on the NXT brick and browse to the setting using the left arrow button Inside that setting there is a Bluetooth icon open the icon and press the orange button to connect to the PC N B the PC s Bluetooth device should be visible so that the NXT can locate the Bluetooth signal 120 Appendix B User manual for the R T monitor To use the R T monitor read chapter 4 well or follow the following instructions steps 1 Run MSF The one that has been created us
183. use with stored parts or an address of a file e An indicator of a state for example the indicator of the traffic signal or the state of an object A token indicates whether a certain condition is fulfilled or not l e if the place contains a token then we can conclude that the next firing state is that place by seeing the token 2 4 6 Mathematical representation of a Petri Net A Petri net can also be described mathematically as follow 19 N P T I O Where P is the finite set of places P p1 p2 p3 p4 p where L gt O T is the finite set of transitions T ft1 t2 t3 tn wherem O0 PMT 76 the place and transitions are disjoint properties or objects l e P A is always O N c PxT U TxP is flow relationship the Union of the relation between places and transitions l e itis the Petri net model of the set P XT gt N Isan input function that defines a set of directed arcs from P to T Where N 0 1 2 3 4 O T x P gt N is an output function that defines a set of directed arcs from T to P A marked Petri net is denoted by N Mo where N is the Petri net model and Mo is the initial marking The initial marking is the number of token at the start of the model before entering to a firing state Marking u is an assignment of tokens to the places of Petri net at 19 15 u u1 p2 u3 un For example Mo 2 3 3 is an initial mark for Figure 6 A Petri Net was designed to give m
184. ventdata handles Executes during object creation after setting all properties function edit2 CreateFcn hObject eventdata handles 6 Hint edit controls usually have a white background on Windows See ISPC and COMPUTER if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end Executes during object creation after setting all properties function uipanel14 CreateFcn hObject eventdata handles Executes during object creation after setting all properties function uipanel15 CreateFcn hObject eventdata handles Executes during object creation after setting all properties function text13 CreateFcn hObject eventdata handles 96 Executes when user attempts to close figure1 function figure1 CloseRequestFcn hObject eventdata handles delete hObject function edit3 Callback hObject eventdata handles global global info global PN set handles uipanel20 Visible on if not PN REAL TIME set handles text68 String PN global places 1 name J else set handles text68 String global info rt monitor places 1 end Executes during object creation after setting all properties function edit3 CreateFcn hObject eventdata handles if ispc amp amp isequal get hObject BackgroundColor get O defaultUicontrolBackgroundColor set hObject BackgroundColor white end funct
185. when a mouse click occurs on a pushbutton the GUI should initiate the action described on the label of the button A MATLAB Guide has a lot of similarities with java applet But MATLAB is a bit terrible The advantage of using MATLAB guide over using java is that it contains libraries that perform functions needed for scientific computing This is unquestionable Most engineering and scientific areas prefer to use MATLAB languages this is due to their 46 flexibility and integrity with other MATLAB libraries But still MATLAB has some weaknesses like it is only useable in math Works environment It is like it has pros and cons The other con is that MATLAB is very expensive software these has been a headache for most of developers 32 e There are two ways of developing a graphical user interface in MATLAB These are a Using a MATLAB command UiControl The MATLAB Uicontrol creates a user interface and returns a handle of the user interface component For example if we want to create a pushbutton with its callback function pushbutton1 Callback we can the command using Uicontrol as below h uicontrol Sryle pushburLtron Callback V pushbuttonl Callback h can be used to return the result so that it can be used with another function b Using a toolbox called GUIDE A MATLAB GUIDE is a MATLAB toolbox used to create a graphical user interface based on a MATLAB script file A guide has a structure as shown below
186. wing code snippet shows the GUI OutputFcn Note that GUI is the name of the R T monitor in the thesis function varargout GUI OutputFcn hObject eventdata handles global global info global hn global a Varargout i handles output The varargout 1 refers to the number of event handles that would be returned as an output argument The createFcn as mentioned in the previous section is a function that creates the entire layout for every gui component lii Start The graphical user interface and plot the basic layouts The function GUI OpeningFcn from the above section invokes a function called startCode which starts plotting a small circle for places and a bar for transition Here not that the places and transitions are the selected places and transition from the overall places and transitions for a Real Time displaying purpose The function to do such condition is shown below function startCode hObject eventdata handles global PN to acces the PN structure and informations from the Gpensim global global info is used to pass and acces the global variables global gp pause is used to pause the whole system to create a delay gp pause 0 5 initilize to 0 5 second In the above code snippet the global variables are used as a bridge to import a gpensim run time components Note that In MATLAB GUIDE the global variables should be declared inside every function unlike other programming language where global
187. ycle and on the gpensim might start the next cycle before the gui components are finished searched for plotting Thus the system shows some slowdowns This happens due to the object searcher tool Delay time to select transitions and places while we select places and transitions we might spend a lot of time where the NXT sensors might not tolerate 7 2 Further Improvement The System can be further extended Anyone who is interested can extend the system to be more intelligent and even can add more control features It is possible to implement a monitor that not only displaying the status of the transition and places but also can work as a decision maker tool and can even add some conditions like supervisory control and fuzzy logics For example in distributed sensor network it is possible to implement a method 112 that makes decision based on the gpensim formalism The system can also be implemented to be integrated with other tools Even it is possible to implement a tool that can run on mobiles and the user can easily control the simulation on mobile devices Also the drawbacks can be corrected and the system can be re implemented to be a fault tolerant system 7 3 Conclusion GPenSIM is a power full tool to model any kind of DEDS By adding tools like an HCI system a gpensim can be extended to perform more excellent tasks like displaying the status of the simulation Generally in this thesis it has been seen that the discrete

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