Automatic Control LAB. EngM513 Laboratory User`s manual Version I
Contents
1. and adjustable balance weight Next is the real time controller unit which contains the digital signal processor DSP based real time controller servo actuator interfaces servo amplifier and auxiliary power supplies The DSP is capable of executing control laws at high sampling rates allowing the implementation to be modeled as continuous or discrete time The controller also interprets trajectory commands and supports such functions as data acquisition trajectory generation and system health and safety checks A logic gate array performs encoder pulse decoding Two optional auxiliary digital to analog converters DAC s provide for real time analog signal measurement This controller is representative of modern industrial control implementation The third subsystem is the executive program which runs on a PC under the DOS or Windows operating system This menu driven program is the user s interface to the system and supports controller specification trajectory definition data acquisition plotting system execution commands and more Controllers may assume a broad range of selectable block diagram topologies and dynamic order The interface supports an assortment of features which provide a friendly yet powerful experimental environment EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 13 Aad gent day all Alal giladi asili Bl jy KINGDOM OF SAUDI ARABIA Ministry of Higher Education a JAZAN UNIVERSITY Gls A2. Engineenng Depart FEET PERTEN and Experiment Test No 5 Title Stabilizing Inverted pendulum Experiment Test Description Test Description This experiment steers a horizontal sliding rod in the presence of gravity to balance and control the position of the vertical pendulum rod The mechanism is open loop unstable right half plane pole and non minimum phase right half plane zero As a result feedback control is essential for stability and the structure of the controller must be selected carefully due the non minimum phase characteristics Test Objectives Understanding the stability criteria of the dynamic systems The effect of electrical feedback is demonstrated and the feedback operation is explained Functions of a servo systems Theoretical Background Stability criteria of mechanical systems Lecture Modeling of inverted pendulum system Lecture Modeling of electrical system Lecture Modeling of DC motors Lecture Digital Encoder speed measurement sensors Lecture Modeling and control Servomotors Experiment no 3 Experiment Test Activities Equipment and tools The experimental control system is comprised of the three subsystems shown in the Figure The first of these is the electromechanical plant which consists of the inverted pendulum mechanism its actuator and sensors The design features a DC servo motor high resolution encoders a low friction sliding balance rod
3. application Output variables torque adjustments in angle and displacement Closed control loop status indication of angle or displacement Theoretical Background This Servo system applications are always performed by servomotors with powers ranging from approx 20 W to 20 kW Fields of application Aerospace technology Shipping Robotics Industrial and manufacturing processes wherever positions x y z speeds or angles need to be changed Perquisites Modeling of electrical system Lecture Modeling of DC motors Lecture Tacho generator speed measurement sensors Lecture Experiment Test Activities Equipment and tools Equipment of the experiment Servo set point potentiometer Module 73410 PID controller Module 734061 Power amplifier Module 73413 DC Servo Module 73414 Power supply unit 15V 13A Module 72486 Toggle switch single pole Module 57913 Two channel digital storage oscilloscope HM 205 2 57529 Recommended Extras Multi meters EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 10 Aad geet day all Alal giladi asili 815g EINGDOM OF SAUDI ARABIA Ministry of Higher Education JAZAN UNIVERSITY olla daala College of Engineering Adip il AlS Mechamcal Engmeenng Depart Aasai diall PERTEN Pa Experiment set up Test Procedure 1 Every servo is equipped with a driving machine e g a DC motor with a permanent field or
4. input for external stop 4 mm socket I O simulator EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 18 giladi asili Bal jy EINGDOM OF SAUDI Ministry of Higher Education e 8 stay put spring return switches for input assignment e 1 pushbutton with holding function A ai en eu Di pt A P raS mA Se Kay e 6 4 eS The robot TR5 Training Robot To work with TR 5 you need at least e The TR 5 training robot e The power supply unit with two power leads red black e The RS 232 shorting connector e The LD Rob Software The technical specification of the robot arms mototrs are listed in the following Table EngM513 Automatic Control Engineering Instructor Dr Nada A A Aad gent day all Alal KINGDOM OF SAUDI ARABIA Ministry of Higher Education crilall askili 3 wag College of Enomeenng Asadi il Ais Mechamcal Engmeenng Depart EEA PERTEN a Technical Specifications MECHANICS Position detection absolute potentiometric Working ranges Axis 1 base electric parallel gripper stroke 0 60 mm position and gripping force freely programmable standard version Max payload 250g 256 increments 256 increments 256 increments 256 increments 256 increments 256 increments Max joint speeds Axis 1 46 degrees sec is 2 40 degrees sec 100 degrees sec 174 degrees sec 176 degrees sec Total weight approx
5. rotary axes and a parallel gripper giving several application possibilities As the controller is integrated in the base of the robot an easy and fast installation and implementation can be assured A quick access to the programming is enabled by the software LD Rob delivered with the robotTR5 The students are going to use the TR5 robotic arm to feed working pieces into sorting station the student is asked to write a program using the LDrob software and to use the I O signals from both the station and the robot to synchronize the process Test Objectives Understanding single input multi output feedback control system Functions of a servo systems DC motors with potentiometric position transducers Theoretical Background Modeling of DC motors Lecture Potentiometer position measurement sensors Lecture Modeling and control Servomotors Experiment no 3 Introduction to Inverse Kinematic Position Modeling IKPM Experiment Test Activities Equipment and tools The mechanical structure of the TR 5 consists of aluminum parts screwed together Each of the five independent axes is driven by a DC Servo motor At axes no 1 2 and 5 power transmission is assured by toothed gears For power transmission at axes 3 and 4 one toothed belt each is used in addition The absolute positions of all axes are determined by potentiometric position transducers This out standing feature of the TR 5 guarantees that even after the s
6. 0 100 50 66 31 0 SP 5 Start WAIT FOR DI3 0 POS 255 30 50 10 78 0 SP 5 TIME 500 ms POS 255 30 50 10 78255 SP 5 POS 100 100 50 66 31255 SP 5 OUT DOO 1 WAIT FOR DIO 0 OUT DOO 0 POS 20 40 50 250 214 255 SP 5 TIME 500 ms POS 20 40 50250214 O SP 5 TIME 500 ms POS 50 60100 200 70 O SP 5 OUT DO1 1 GOTO Init Comments Initial Position Wait for a WP from the Buffer Go to buffer Wait 0 5 second Close Gripper Go to the initial position Alert Sorting Station for a WP Wait for the sorting station to be ready Move to the beginning of the conveyor Wait 0 5 second Drop the WP on the Conveyor Move away from the conveyor Tell the Sorting to start working Start Again Test Results Regarding the geometry of the automation line the reference values of the motors are calculated and programmed Cable channel Conveyor belt a O O Magazines Operator panel Handling unit Automation Line The robots follow the pre described trajectory because of the feedback control system implemented over its motors Conclusion Servomotots are widely used in the Robotics applications due to the required accuracy and repeatability Comments EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 23
7. 6 kg including controller EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 20 Aad geal day etl Alal giladi asili 815g EINGDOM OF SAUDI ARABIA Ministry of Higher Education College of Enomeenng din aig tl Ais Mechamcal Engmeenng Depart EELE PERTEN a wi Test Procedure Regarding the kinematics problem see the Figure the students should calculate the angles of the motors in the start home point and in the final point The experiment steps Step 1 Installation of the software The installation of the LD Rob Software is started by starting the program setup on the CD delivered with the robot TR5 Please follow the instructions of the installation shield Step 2 Installation of the hardware e Connect the TR 5 to the power supply unit with the two power leads e Turn the power switch to ON press the HALT key on the I O Adaptor Simulator and press the RESET key on the TR 5 Step 3 The LD Rob Software After starting the software you see can the window of the LD Rob software that is shown in the figure below By using this software the robot TR5 can either be programmed or controlled manually Controlling the robot manually can be useful to test the hardware of the robot or to drive the robot for checking a position you want to program The parts of this window will be described in the following You can find a detailed description of the software in the document LDRob he
8. Aad geal day etl Alal KINGDOM OF SAUDI ARABIA Ministry of Higher Education giall asil Blas JAZAN UNIVERSITY lja nala College of Engineering Fadia Als Mechamcal Engmeenng Depart PEREA de dig tl and Automatic Control LAB EngM513 T Laboratory User s manual Version Table of Contents Poemen Te CNO areata teeta E dee tan stecune tone E E E 2 SEN EAE INO A E ENEA EE E EA E A EN EEA E TA 5 Pociman a Te 6 e E E E ae 7 DES A E 5 A T E LE E ET E E ee E T 10 Een a CSU NO S r E E E ones aoe dese eaee iste eet 13 e TE NO ae E EE 18 EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 1 Aad geet day all Alal KINGDOM OF SAUDI ARABIA Ministry of Higher Education clad askili 3 hig JAZAN UNIVERSITY ole Azala College of Engmeenng A aig tl Aalis Mechamcal Engmeenng Depart FLETEEPY PERTEN Anad Experiment Test No 1 Title Automatic flow rate control Steady State Response Test Description Recording the characteristics in open and closed loop operation Test Objectives Adhere to the basic rules for recording static characteristics Theoretical Background Using a static transfer characteristic as the graphic representation of the function y f x the most optimum operating range of the controlled system and its proportional action transfer response can be determined The most important steps are listed as follows Only record the measured value after the transient reactions have disappear
9. a single phase or multi phase AC motor 2 A step down gear unit which slows the motor down to a useful operating speed for a variable resistor 3 The variable resistor can have a circular shape in this case a torque for angular adjustment is applied to its shaft If the variable resistor has a liner shape adjustment must be carried out by means of a spindle The mechanical setting of the wiper determines the displacement setting For both systems the following applies 3 1 Corresponding to the magnitude of the inputs signal for the machine the input voltage or phase difference generated is almost proportional to the speed PT 1 3 2 If the starting voltage is taken into account this results in a dead time PT1 T 3 3 Every rotation of the machine results in a control interval at the potentiometer according to the operating duration the potentiometer sums up the control intervals with respect to time integral system the length of the control intervals dt depends on the input values voltage phase for the machine 4 The output variable is taken from the wiper of the variable resistance used to feed back the position attained and fed to a controller The comparator at the input of the controller compares the feedback variable Ux with a set point value Uw forms the system deviation U Ug U for the purpose of matching i e it counter adjusts Ux until the system deviation is Ug 0 and the machine is no longer suppli
10. aracteristic into the defined operating range 6 Repeat steps 3 and 4 for the case of the closed control loop set the switch to Closed Loop Enter the measured values into the table Test Results Table Steady state characteristics for Open Loop and Closed Loop l Loop Loop Open Closed Rate C row Rate V V 0 3 Q a 2 pn D M1 v o i o 2 o o 4 o os ee oe ooe jz o w Steady state characteristic in the open loop operating mode EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 3 Aad geet day all Alal giladi asili 815g EINGDOM OF SAUDI ARABIA Ministry of Higher Education College of Enomeenng din aig tl Ais Mechamcal Engmeenng Depart PELEA PERTEN a wi Steady state characteristic in closed loop control mode Conclusion The static characteristic in open loop operation is non linear i e it does not have a constant gradient and it has a dead zone from 0 up to approx 4 3 V Because of the internal feedback the characteristic is linearized and the dead zone severely reduced however for low voltages the control loop tends to oscillate and the compensation times become increasingly longer Comments A CASSY interface can used If you have an XY recorder or a CASSY interface at your disposal you can use these to record the characteristics The CASSY system is particularly well suited for evaluation and display of measurement valu
11. are displayed beneath the trackbars When all axis have reached their set position the green LED will light up Speed can be selected independently in the range 1 5 The button Reset sets all set values to 128 and the speed to 5 maximum With Get Robot Position it is possible to read the actual positions back from the robot Robot I O As long as the robot is online the LEDs in this field show the actual states of the digital inputs and outputs of the robot base In order to change the state of a digital output the checkbox beneath the corresponding output LED can be used Robot program In this part of the window you can program the robot TR5 The appropriate entries of the context menu right click or key F10 can be used to add insert or delete an instruction line The instruction set of the robot TR5 consists of the following instructions NOP POS OUT TIME WAIT IF GOTO LOOP HALT EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 22 Aad geal day etl Alal KINGDOM OF SAUDI ARABIA Ministry of Higher Education crlall askili peet JAZAN UNIVERSITY ol Azala College of Engmeenng u aig tl Ais Mechanical Engimeenng Depart Saill PERTEN ani The TR 5 program memory is non volatile and is powered by a long life lithium battery your programs will remain stored in the robot s memory for around 10 years even when the mains power is switched off Labels Instructions Init POS 10
12. at the pressure at the floor of the reservoir is the product composed of the pressure of the liquid column and the atmospheric pressure a differential pressure transducer is used whose first input recetves the pressure from the tank floor and whose second input receives the atmospheric pressure Experiment Test Activities Equipment and tools Equipment of the experiment Liquid controlled system Module 734 262 Power supply unit 15V 3A Module 726 86 Analog multimeter Reference variable generator Module 734 02 Profi CASSY Module 524 10 11 19 WinFACT Software Immersion tube Module 734 876 Differential pressure transducer Module 734 81 Recommended Extras Universal data acquisition PID controller Experiment set up immersion tube differential pressure transducer EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 7 Aad geet day all Alal giladi asili 815g EINGDOM OF SAUDI ARABIA Ministry of Higher Education College of Enomeenng din aig tl Ais Mechamcal Engmeenng Depart ELA PERTEN B Test Procedure The system features can be manipulated using the valves V1 V2 and the reference variable generator MI The inlet flow Qin is caused by MI and V1 and the outlet flow Qou by V2 If V2 is closed completely for example the system demonstrates integration behavior and then constitutes a system without compensation only overflow restricts the liquid level and serves as a li
13. c characteristic the controller parameters are obtained according to good reference response no overshoot Comments It is the aim of each automatic control to reach the set point or desired value as fast as possible with either no or very little control deviation A comparison of control characteristics can be carried out by investigating the various transient responses EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 6 Aad geal A all Alal gall aili Salg EINGDOM OF SAUDI ARABIA Ministry of Higher Education JAZAN UNIVERSITY Clip daala College of Engineering Adip Asis Mechanical Engpmeenng Depart FELT frail PERTEN ani Experiment Test No 3 Title Automatic liquid level control Experiment Test Description Test Description To perform automatic liquid level control upon single capacitance dynamic system Test Objectives Training upon controlling the liquid level system is carried out The effect of pneumatic feedback is demonstrated and the measures needed for the head level are explained Closed control loop is implemented by adjusting the proportional gain Theoretical Background Liquid level measurement in order to control the liquid level it must be converted into an electrical signal As the pressure exerted on the floor of the tank is proportional to the height of the liquid level pressure measurement is a suitable procedure to determine the liquid level Due to the fact th
14. d to the Control Box there is a potential for uncontrolled motion of the pendulum Step 5 Now turn off the power to your PC Step 6 Now enter the Setup menu and choose Setup Control Algorithm option You should see the sampling time Ts 0 00884 seconds Time control and the General Form button selected Now select Setup Algorithm and you should see the following gains T0 2 5 S0 24 61 S1 24 00 H0 1 0 10 1 8427 I1 1 76 E0 0 35 and G1 0 5 This controller was designed using the linear quadratic regulator technique with all error weighting on encoder 1 the pendulum angle encoder In addition a low pass filter was included G1 coefficient to reduce quantization noise Step 7 Exit this dialog box and with the pendulum in the vertical position and the sliding rod in its middle T position select Implement Algorithm The control law is now downloaded to the real time Controller Very gently push the pendulum rod with the ruler to verify that control action is in effect If you do not notice any motor power use the ruler to move it back to the vertical position and then click on the Implement Algorithm button again until you notice the servo loop closed Now select Upload Algorithm then General Form and Setup Algorithm You should see the same coefficients uploaded back from the real time controller to the Executive program Note that the general form algorithm is the only structure that actually runs in real time All other structures e
15. e pairs Ml and Uj into a chart and draw the characteristic Determine the gradient proportional action coefficient Ks of the characteristic in the operating range of interest Dynamic system response reference variable step change Determining the system parameters of an open liquid level control loop 5 Use the automatic control technology software WinFACT to record the step response for operating instructions refer to the WinFACT user manual Reference variable step change to MI 5 V Set the switch to Closed Loop valve setting V2 from sub point 2 EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 8 Aad geet day all Alal KINGDOM OF SAUDI ARABIA Ministry of Higher Education crilall askili 3 hig JAZAN UNIVERSITY ole Azala College of Engmeenng u aig tl Ais Mechamcal Engmeenng Depart EEA PERTEN Pa Test Results The block diagram of the system can be illustrated as shown in the following Figure Block circuit diagram o the automatic liquid level control with cascade flow rate control 1 Cascade flow rate control 2 Flow rate controlled system pump valve VI hose to TANK1 1 0 ne a aiaa aan aaa BF 0 9 Tals Step response of the open liquid level control loop Reference variable step change to M1 5 V Conclusion From the step response the time delay Tu and the compensation time T can be determined The proportional action coefficient K is determined from the
16. ed Always change only one parameter at a time keep the other parameters constant Experiment Test Activities Equipment and tools Equipment of the experiment Liquid controlled system Module 734 262 Power supply unit 15V 3A Module 726 86 Analog multimeter Reference variable generator Module 734 02 Profi CASSY Module 524019 WinFACT Software Recommended Extras Universal data acquisition PID controller most a YQ PSs ee a ee ey eee ETT iki ae 2 OE Oe F E aa iim T a Experiment set up for the recording of the steady state characteristic of the liquid controlled system EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 2 Aad geal Ay etl Alal giladi asili 815g EINGDOM OF SAUDI ARABIA Ministry of Higher Education JAZAN UNIVERSITY olla daala College of Engineering Adip il AlS Mechanical Engimeenng Depart Aasa frail PERTEN ani Test Procedure Steady state system response recording the static characteristic 1 Assemble the experiment set up in accordance with Figure 2 Open the valve V1 completely 3 Set the reference variable generator to the values specified in the table and wait until a constant value for the flow rate is produced Make a note of the Criow Rate value in the Table 4 Plot the value pairs by connecting up the measured values you obtain 5 Determine the value or values of Ks from the Note characteristic gradient of the ch
17. ed with a manipulated variable via the control element machine comes to a stop In this experimental set up the DC servo in the control loop is handled as follows with a P controller dependency of the system deviation on Kp controlled oscillations with a PlI controller removal of the system deviation overshoot with a PID controller removal of the system deviation overshoot attenuation removal of controlled oscillations EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 11 Aad geet day all Alal KINGDOM OF SAUDI ARABIA Ministry of Higher Education crilall askili 3 hig JAZAN UNIVERSITY Olga deala College of Enomeenng din aig tl Ais Mechamcal Engmeenng Depart shi Siall PERTEN Pa Test Results A servo system is used for transferring conditions e g angles displacements or positions applying at location A to location B as accurately as possible Such accurate transfers require a closed control loop with feedback from location B closed loop control In simpler cases only adjustment is required at location B this involves an open control loop without feedback Kp 1 0 Ty 05s SIGNALPARAMETER CH1_ _VOLTS7DIV 4Y TIMEBASE SEC DI 55 PRINTERPARAMETER ZOOMRANGE CH1 6 9 EYALUATION CH1i REMARKS Ap 240 Thy OSS Uts IJS oV HAME GCG Instruments i Servo Controller to DC motor If the feedback variable is fed to the input summing unit with the nega
18. er the Setup menu Select PC bus at address 528 and click on the test button If the real time Controller is still not found try increasing the timeout in 20 ms increments up to a maximum of 300 ms If this doesn t correct the problem switch off power to your PC and then take its cover off With the cover removed check again for the proper insertion of the Controller card Switch the power on again and observe the two LED lights on the Controller card If the green LED comes on all is well if the red LED is illuminated you should contact ECP for further instructions If the green LED comes on turn off power to your PC replace the cover and turn the power back on again Now go back to the ECP program and you should see the positions change as you gently move the pendulum rod Step 4 Make sure that you can rotate the pendulum rod and move the sliding rod freely Now connect the power cord to the Control Box and press the black ON button to turn on the power to the Control Box You should notice the EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 14 Aad geal day etl ASLaall collet asili 815g KINGDOM OF SAUDI ARABIA Ministry of Higher Education JAZAN UNIVERSITY olla daala College of Engineering Adip il AlS Mechanical Engimeenng Depart Aasa frail PERTEN ani green power indicator LED lit but the motor should remain in a disabled state Do not touch the apparatus any more remember whenever power is applie
19. es because of its many setting options these to record the characteristics The CASSY system is particularly well suited for evaluation and display of measurement values because of its many setting options EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 4 Aad gent day all Alal aladi asili Bl jy KINGDOM OF SAUDI ARABIA Ministry of Higher Education JAZAN UNIVERSITY Clip daala College of Engineering Adip il Asis Mechanical Engimeenng Depart FELT frail PERTEN ani Experiment Test No 2 Title Automatic flow rate control Dynamic System Response Test Description Dynamic system response of flow rate control recording of the step response reference or set point step change Test Objectives Emphasis to reach the set point or desired value of the control system as fast as possible with either no or very little control deviation Theoretical Background Solution of the first order system Lecture S shape response Lecture Open loop control Lecture Closed loop control Lecture Experiment Test Activities Equipment and tools Equipment of the experiment Liquid controlled system Module 734 262 Power supply unit 15V 3A Module 726 86 Analog multimeter Reference variable generator Module 734 02 Profi CASSY Module 524 10 11 19 WinF ACT Software Recommended Extras Universal data acquisition PID controller Experiment set up for the recording of the stead
20. g PID etc are translated to the general form by the Executive prior to implementation Default Step Response Angle Encoder l l ee f S L a l ee pot Q wt tt tt pii ee o B 1 2 3 4 5 6 7 8 g Time seconds Commanded Position counts Encoder 1 Position counts Step Response at Angle Encoder 1 Closed Loop Step a a a a DN D S S a S Ar a S TT ed S S a T E S a 0 1 4 Time seconds Encoder 2 Position counts Step Response at Sliding Rod Encoder 2 EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 15 Aad geet day all Alal giladi asili 815g EINGDOM OF SAUDI ARABIA Mimistry of Higher Education JAZAN UNIVERSITY lJa Asal College of Enomeenng din aig tl Ais Mechamcal Engmeenng Depart ELA PERTEN B Step 8 Enter the Command menu and select Trajectory In this box select Step and then Setup You should see step size 300 counts dwell time 4000 ms and no of repetitions 1 If not change the values to this parameter set Exit this box and go to the Command menu This time select Execute and with the Sample Data box checked run the trajectory You should have noticed a step move of 300 counts a dwell of 4 second and a return step move Wait for the data to be uploaded from the real time Controller to the Executive program running on the PC Now enter the Plotting menu and choose Setup Plot Select Encoder 1 and Commanded Position for
21. g rod travel the actual sliding rod travels approximately 0 24 meter The encoders are all optical type whose principle of operation is depicted A low power light source is used to generate two 90 degrees out of phase sinusoidal signals on the detectors as the moving plate rotates with respect to the stationary plate These signals are then squared up and amplified in order to generate quadrate logic level signals suitable for input to the programmable gate array on the real time Controller The gate array uses the A and B channel phasing to decode direction and detects the rising and falling edge of each to generate 4x resolution Hence the effective encoder resolution is 16 000 counts rev and 50200 counts m for the respective pendulum and balance rod measurements The pulses are accumulated continuously within 24 bit counters hardware registers The contents of the counters are read by the DSP once every servo or commutation cycle time and extended to 48 bit word length for high precision numerical processing EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 17 Aad geal day all Alal giladi asili Bl jy KINGDOM OF SAUDI ARABIA Ministry of Higher Education el College of Engineering Aadil Aal Mechanical Engmeenng Depart Agiliti Aadil ani Experiment Test No 6 Title Robot Control Position control of DC servos Experiment Test Description Test Description This training articulated arm robot has 5
22. lp pdf In the left bottom corner you can see if the robot in online i e if there is a communication between the robot and the computer If the robot is offline click on Robot gt Init EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 21 Aid geet day etl Alal giladi asili 8 lig KINGDOM OF SAUDI ARABIA Ministry of Higher Education JAZAN UNIVERSITY olla daala College of Engineering Adip il AlS Mechamcal Engmeenng Depart Aasai Sail PERTEN Pa Boro T T Fie Robct Options E Sh gt 8 Robot program Position and Speed Cortrol Robot 0 Asis Change Pos Set Act Digtal 0 255 Inputs Outputs Al Bocy 9 f _ J 1a 0 e er A2 Skeulde 128 0 e ores A3Elba e ll g 0 rs Ad Hand peoia 0 e lor A5 Wiis e 128 0 r3 AS Gree 128 1 re2 Reset Speed 5 m E ri __Get Robot Fos e era ofie 5 TR5 software Step 8 write the program as follows Position and Speed Control The six axis of the robot arm are A1 Body A2 Shoulder A3 Elbow A4 Hand A5 Wrist and A6 Gripper In manual mode no robot program is running they can be manually controlled by the six track bars in this field The track bars change the set value of the corresponding axis If the robot is online it will follow this set point by activating the appropriate drive Set and actual values
23. miting facility As the outflow or drain off Qow is a function of the level height h the outflow rises with increasing level height a steady state level h settles in where inlet and outlet flows are in equilibrium The Figure illustrates this relationship qualitatively V2 1 Valve V2 completely opened V2 0 Valve V2 completely closed If Qou is too low or Qin is too high hs lies above the overflow edge In this case h cannot be reached Qualitative representation of the drain or outlet flow as a function of the liquid level height a overflow For h 0 there exists a value of Qou other than zero because the outlet opening permits a certain amount of drain or outlet flow dependent on V2 The maximum liquid level achievable by the automatic control as a function of the valve setting V2 is obtained by the steady state level at an MI setting of 10 V maximum manipulated variable of the liquid level controller Steady state system response Setting of valve V2 1 Set up the experiment in accordance with Figure 2 For M1 5 V set the valve V2 in such a fashion that a steady state level hs of approx 80 90 mm sets in 3 Using the valve setting for V2from sub point 2 the steady state level hs is recorded as a function of the input variable M1 For this set the values of M1 specified in a Table 5 1 and note down the values of h which settle in careful slow compensation processes 4 Plot the valu
24. nala College of Engmeenng Aiding il Aal Mechamcal Engmeenng Depart ERA i adigil wud Experimental control system Test Procedure The student must ensure the followings a The ECP Executive program has been successfully installed on the PC s hard disk b The actual DSP printed circuit board the real time Controller has been correctly inserted into an empty slot of the PC s extension ISA bus this applies to the PC bus version only c The supplied 60 pin flat cable is connected between the J11 connector the 60 pin connector of the real time Controller and the JMACH connector of the Control Box d The other two supplied cables are connected between the Control Box and the Inverted Pendulum apparatus e The Inverted Pendulum apparatus has the adjustable weight at the default height shipped from the factory The experiment steps Step 1 Switch off power to both the PC and the Control Box Step 2 With power still switched off to the Control Box switch the PC power on Enter the ECP program by double clicking on its icon or type gt ECP in the appropriate directory under DOS You should see the Background Screen see Section 2 1 3 Gently rotate the pendulum rod and later the top sliding rod by hand You should observe some following errors and changes in encoder counts Step 3 If the ECP program cannot find the real time Controller a pop up message will notify you if this is the case try the Communication dialog box und
25. plotting left axis and select Plot Data A plot similar to the one shown in previous Figure is generated Replace Encoder 1 with 2 via the Setup Plot box and then plot data A similar plot to the one shown in Figures should be seen Notice the initial reverse motion which is a characteristic of a non minimum phase plant This phenomenon is explained from basic laws of dynamics Test Results With the control system of an inverted pendulum as shown in the Figure it can be concluded that Motor drive dynamics Servo Amplifier Voltage propor Controller tional to desired Motor admittance Torque Voltage propor tional to motor current Mechanism Drive Block Diagram Servo loop closure involves computing the control algorithm at the sampling time The real time Controller executes the General Form equation of the control law at each sample period Ts This period can be as short as 0 000884 seconds approx 1 1 KHz or any multiple of this number The Executive program s Setup Control Algorithm dialog box allows the user to alter the sampling period All forms of control laws are automatically translated by the Executive program to the General Form prior to downloading implementing to the Controller The General Form uses 96 bit real number 48 bit integer and 48 bit fractional arithmetic for the computation of the control effort The control effort is saturated in software at 16384 to represent 5 volts on the 16 bit DACs who
26. se range is 10 volts The 5 volt limitation is due to the actuator s amplifier input voltage scaling Conclusion The control designs given here are in no sense optimized but rather are designed to demonstrate several fundamental principles of control The student can implement other designs or invent other approaches such a Feed forward design for improved tracking performance is readily implemented through the Setup Feed forward box under Setup Control Algorithm b Trajectories may be optimized for characteristics such as rapid response minimum tracking error or minimum peak control effort The user may select from the library of geometric trajectories or develop and implement custom shapes via User Defined in the Trajectory Configuration dialog box EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 16 Aad geet day all Alal giladi asili 815g EINGDOM OF SAUDI ARABIA Ministry of Higher Education el College of Engineering Pugh ois Mechamcal Engmeenng Depart Aalia Aadi il and Comments There are two incremental rotary shaft encoders used in the inverted pendulum These are used to sense the position and velocity of the pendulum rod and the sliding rod The pendulum angle encoder has a resolution of 4000 counts per revolution The sliding rod encoder connected to the motor has a resolution of 500 counts per revolution which is equivalent to approximately 12500 counts per meter of the slidin
27. steady state characteristic Comments If you want to avoid non linearities overflow or non filling in the system then the initial step is to set the outlet valve V so that a suitable steady state can set in In addition a manipulated variable is set for MI and the valve V2 is set so that a desired steady state level hs is reached EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 9 Aad geal day etl Alal cpllall asili 815g KINGDOM OF SAUDI ARABIA Mimustry of Higher Education gs JAZAN UNIVERSITY Cl jhe inla College of Engineering Aadil Asis Mechanical Engineernng Depart FEAET PERTEN and Experiment Test No 4 Title Servo control of DC motor Experiment Test Description Test Description An experiment which provides an introduction to servo technology its purposes functional modules and machines The DC servo with tacho generator is investigated as is the influence of Kp and tacho feedback in terms of accuracy and correction time Furthermore in a further section of the experiment the mass inertia ratios are altered by attaching an additional weight Test Objectives Training upon operating controlling the DC servos is carried out The potentiometer is treated as well as the requirements for a rapid and accurate control operation The effect of electrical feedback is demonstrated and the measures needed for problem free operation are explained Functions of a servo Examples of
28. tive sign it is subtracted from the reference variable set point value The system deviation Xa w x is formed The system deviation forms the manipulated variable in the controller and the control element This variable adjusts the machine until the system deviation is X4 0 If the feedback loop is removed the control loop is opened and the machine operates as long as a manipulated variable is applied open control loop Conclusion Strong positive overshoot followed by overshoots of decreasing magnitude Following a standstill or reversal in direction compensation only takes Place once the integrator component in Uy has reached the starting voltage Comments Depending on the results of these comparisons the controlled variable X is adjusted to correspond with the reference variable W In other words a controller must 1 measure register evaluate 2 compare 3 adjust The controller registers the actual value of the controlled variable at the output of the system by means of a sensor and compares it with the set point value The difference is processed such that it causes a change in the manipulated variable which counteracts the deviation of the controlled variable from the set point value EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 12 Aad geal day etl Alal cpllall asili 815g KINGDOM OF SAUDI ARABIA Ministry of Higher Education ge College of Engineering Aadil Aal Mechanical
29. witch on of the unit the robot controller knows the exact current position of each single axis Thus tiresome reference runs are no longer necessary The controller is integrated in the base of the robot An 8031 processor is the heart of the controller In the PtP point to point mode movements of single axes or even of more axes at the same time can be realised User programmes can be stored in a battery backed up RAM Memory capacity is 8 KB this corresponds to approximately 1000 program steps In addition the robot can be connected with a PC via an RS 232 interface 8 digital TTL compatible inputs and outputs are at the user s disposal through a parallel port connector The gripper is powered by a DC Servo motor via a spring mounted cable Thanks to this structure the gripper position as well as the gripping force are freely programmable In addition the extremely wide stroke of 60 mm permits the handling of a wide variety of pieces without making modifications at the gripper fingers necessary I1 O Adaptor Simulator For communication with the robot TR5 the I O Adaptor Simulator 728110 can be used This O Adaptor Simulator can be used to send or receive binary signals for example start or stop commands to the robot TR5 The I O Adaptor Simulator has the following features e 8 digital inputs 4 mm sockets TTL compatible overvoltage proof up to 30 V e 8 digital outputs 4 mm sockets 5 V TTL 24 V PLC with LED display e 1
30. y state characteristic of the liquid controlled system EngM513 Automatic Control Engineering Instructor Dr Nada A A Page 5 Aad geet day all Alal giladi asili 815g EINGDOM OF SAUDI ARABIA Ministry of Higher Education JAZAN UNIVERSITY olla daala College of Engineering Adip il AlS Mechamcal Engmeenng Depart Aasai Sail PERTEN Pa Test Procedure Determining the system parameters on the open control loop 1 Assemble the experiment set up in accordance to the Figure 2 Use the automatic control software WinFACT for the recording of the step response Set the reference variable to MI 10 V set the switch to Open Loop 3 Determine the time delay and compensation time Ti and Tg of the system 4 Modify the experiment set up by integrating an external controller CASSY or the PID controller into the experiment set up Set the selection switch to Open Loop 5 Experiment with different controller types P PI PID and controller settings and observe their effects on the step response 6 Remove the external controller Set the selection switch to Closed Loop and record the system s step response 7 Compare the control response during internal and external automatic control operation Test Results With the system parameters Ks from the steady state characteristic Ks 2 0 Tu 0 3s T 0 4 s Reference step response open control loop Conclusion With the system parameters K from the stati
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