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HORN - Hank and OpenDRIVE Road Networks: An editor for

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1. A road typically has a predecessor and a successor and can also have a left and right neighbor These are OpenDRIVE features that easily allow you to define connectivity between roads by entering their IDs EDF does not have this feature but HANK figures out the connectivity automatically Types Types are an optional way of paritioning stretches of a road into various types for example a road could go from a motorway into a town road and end up as a pedestrian road Specifying type of road is optional in Open DRIVE and is ignored when exporting to EDF but might help with orga nizing things Road types may vary along the road and are valid from the given s value until the end of the road or another type with a higher s value overrides it Elevations An elevation uses a cubic polynome to specify how the height of the road varies over distance from the start point s EDF also allows specifying a z value as part of the road s reference line and therefore the a variable of elevation can partially be exported to EDF Elevation might vary along the road and is valid from the given s value until the end of the road or another elevation with a higher s value overrides it Super elevations Super elevation uses a cubic polynome to specify how the road is rolled by rotating it around the S axis The value used in the equation is the distance from the starting point s I am not sure why or when this would be useful outside of designin
2. By this time the 3 months of planned time for the project had run out but it seemed like HORN was nearly complete How hard could it be to make the program draw some data and export the data from OpenDRIVE to EDF and adding undo redo functionality and some other minor things A new goal became to try to be done before 5 months and work on HORN kept on going After all it seemed like the hardest part was already done and HORN would be done soon Adding undo and redo was surprisingly simple by contrast to everything that had previously been done before and mostly went smoothly and in the end the resulting design was as good as it could be QT uses an undo stack where you can push objects that inherit from QUndo These must override the undo and redo methods and that is all there is to it The tree used in the editor is a subclass of a QTreeWidget that overrides the currentItemHasChanged method Qt calls it when a not currently selected node in the tree is selected The function does a number of checks to see what updates need to be done to the underlying objects based on what kind of object the modified text belongs to If it thinks that the action needs an undo action the previous text is stored in a new undo and the node is updated to use the new text When undoing the old value is simply converted back to the variable the datanode refers to and the new value is stored instead A benefit of working with OpenDRIVE is that exporting the data was
3. 5 Reed Figure 2 2 The library editor of HANK Figure 2 3 The map editor of HANK 31 Chapter 3 Closing 3 1 The development process We originally agreed that the editor should work directly with EDF and SDL and it seemed like a nice little project It was unknown at the time how complicated getting spirals and splines and arcs to work well would be had we stuck with HANK only it would probably have been possible to leverage some of the source code for HANK to make the editor WYSIWYG in a pinch The additional requirement of working with the OpenDRIVE standard was added later which seemed reasonable at the time and it still makes sense as a requirement as OpenDrive is a very nice standard with good support Unfortunately the addition of OpenDRIVE turned out to hugely complicate everything by forcing me to implement many mostly useless from the per spective of someone who wants to create HANK scenarios classes for the sake of simply having them available so the OpenDRIVE standard would be implemented As OpenDRIVE is based on XML it is very hierarchical and a tree editor was needed to handle the imposed tree structure of the OpenDRIVE data as opposed to a more user friendly approach I originally had in mind I wanted to use HANK objects and geometry selectable on a map with a properties view for the selected object and a panel where new objects could be selected and be dropped on the map where they were wanted
4. A driving simulator in particular is concerned with recreating the experience of driving a car that handles like a real car for example in a race track or in traffic Driving simulators have many uses for example practising driving in general practising various scenarios or in a university environment seeing how people react to various traffic or driving situations as part of behavioral research or to see how people react to a particular road design To this end there needs to be a simulator that allows scenarios and situations to be created There are many driving simulators and a particular driving simulator used at University of Link ping is HANK HANK was created at University of Iowa to help them in their work with traffic research they were especially interested in setting up experiments to see how participants would react to various situations HANK uses two domain specific languages called EDF Environment Description Frame work and SDL Scenario Description Language to create the logical structure of its world While EDF and EDL are both powerful it is both hard for the uniniti ated to get started in part because there does not seem to be any official documentation and even with a teacher it can take a long time to get up to speed It also gets tiresome to essentially through trial and error enter programming code and firing up the simulator until one obtains the desired results There should be a better way to set up
5. An arc represents a segment of a circle or a semi circle if you will They are generally only used to create a curve in the road and are connected to spirals at each end to create a smooth transition between lines and the curve An arc consists of a start point a curvature a length and a heading I found this representation fascinating as it is possible to derive all the information about a circle from this as described above about curvature They are drawn as follows If the curvature is positive OpenDRIVE wants the drawing to start from 1 2 and if it is negative it should start from 7 2 In practise this means that a positive curvature forms a left turn and negative curvature a right turn as seen from the road the driver came from While it might be a bit counter intuitive this is just how OpenDRIVE is designed The middle point is then calculated by rotating the vector 0 radius or 0 radius if it is a negative angle by the heading and adding the resulting vector to the start point Essentially we are stating that if we are at the bottom of the circle the middle is radius units above or below if it is a negative angle the starting point as it is at the lowest highest point of the circle The rotation is necessary as after rotating the start point by the heading the middle is no longer at 0 radius but at some other point along the circle arc This effect can easily be seen by drawing a circle and a line through the to
6. OpenDRIVE simply does not make much sense in that context as most of the data in OpenDRIVE is not an actual object a user would be able to manipulate graphically from a 2d perspective The first milestone of the project was reading through the OpenDRIVE specification and writing code that could load an OpenDRIVE file As OpenDRIVE is based on XML it made sense to use tinyXML which is a great C library for both loading and saving XML files It was easy to get into and easily let me save and load XML data I warmly recommend it for anyone who has a need to write a program that works with XML To implement the GUI I chose to use Qt which I had heard many good 32 3 1 THE DEVELOPMENT PROCESS CHAPTER 3 CLOSING things about and as a GUI toolkit it is both intuitive and powerful with a lot of useful gems sprinkled all over the place However it suffers from what I feel are some fundamentally bad design decisions that makes it difficult to work with that I will shortly discuss here and I advice to try a different framework or GUI toolkit if you have not used Qt before or do not have a good reason to use it In Qt almost everything derives from the base class QObject which is all good but some classes are not derived from QObject and are antagonistic with it to the point where a subclass may not inherit from both and the non QObject classes are then not valid to pass around to other Qt methods as parameters This would not generally matter but
7. SDL Scenario Description Language is concerned with the rules governing the world The language is designed to easily allow the user to create powerful rules through a C like procedural interpreted scripting language and can as such be modified with immediate results while a simulation is running Notable are constructions like when every aslongas and whenever allowing rapid construction of advanced scenarios based on evaluating con ditions Conditions include boolean expressions timers and intersection tests against lines and polygons which is adequate for setting up advanced functionality with only a few lines of code It is through SDL that HANK shines and becomes more than just a driving simulator with a somewhat convoluted workflow for scenario creation and slightly outdated graphics Within the limits of what the simulator is able of simulating anything is possible with SDL A notable feature of SDL is the ability to query the EDF data during a simulation allowing code to refer to the object of inter est directly rather than clumsily trying to use similar coordinates I have compiled some SDL code samples I have seen in the appendix that I hope might be of interest but most of it is from Willhelmsen 1 who goes into some detail about the workings of SDL and I warmly refer everyone who is interested in more detail there 2 1 3 Road networks I have spoken to some length about road netwoks and while I am sure most
8. South_1000_Block 10 0 1 neg create BicycleRider location sdl locator RDL South_200_Block 120 0 1 pos home sdl locator RDL South_1400_Block 126 9 1 pos The statement exit causes the simulation to exit It is also possible to create objects from EDF as features for example features 1 given an exact location relative to the road coordinates and features may or may not contain a behavior or data list featurel 13 4 10 2 pos feature3 120 4 10 0 none behavior create flagperson p1 23 2 p2 32 feature2 10 2 2 34 both data1 data2 data3 feature4 1 0 1 23 neg data1 data2 data3 behavior create flagperson height 2 2 place 302 electronic_sign 20 0 35 0 2 3 3 0 data list if any behavior create trafficsign sync 23 2 p2 291 0 p3 32 p4 a token 49 a a P svenska Detta dokument halls tillg ngligt p Internet eller dess framtida ers ttare under en l ngre tid fr n publiceringsdatum under f ruts ttning att inga extra ordin ra omst ndigheter uppst r Tillg ng till dokumentet inneb r tillst nd f r var och en att l sa ladda ner skriva ut enstaka kopior f r enskilt bruk och att anv nda det of r ndrat f r ickekommersiell forskning och f r undervisning verf ring av upphovsr tten vid en senare tidpunkt kan inte upph va detta tillst nd All annan anv ndning av dokumentet kr ver upphovsmannens medgi
9. This section will try to explain how to work with them and give a back ground to how they are implemented Before explaining more about them I feel it is important to explain what Curvature is as it is central to many of these geometries 2 4 2 Curvature It is well known that the area of a circle is 7 radius and circumference is 2 m radius Curvature is defined as the slope of a circle for some point along the circumference which turns out to be 1 radius for all points on the edge of the circle that means that the bigger the circle is the lower the curvature is If you draw a small circle you need to turn your hand faster than if you draw a larger circle where the curvature is lower You can think of the curvature of a point as the amount the curve bends in that point In a circle and a line where it is always 0 curvature is constant but in other geometrical figures like spirals splines and polynomes it can vary It also turns out that the curvature and length can be used to measure an angle Recall that the circumference of a circle is 2 x m x radius 2 7 is 360 degrees measured in radians or a full rotation of the circle Curvature is 1 radius so radius is 1 curvature The angle the arc measures is then length radius It is useful to allow negative curvature even though it would be bizarre to have a negative radius The angle is then calculated as above and after obtaining it the radius is negated so it is positive again th
10. lane As a container format for a finished network it works very well but it is my personal opinion that it was a poor choise to work directly with the format in hindsight Another issue with OpenDRIVE is that it is only a format for specifying in high detail the layout of the road network It does not contain anything like scenario scripting or graphical information I might come across as 2 1 BACKGROUND CHAPTER 2 BODY being critical of the standard but I do think that it is very good at what it does However I feel that using OpenDRIVE has forced me to make design decisions I am not comfortable with that have negatively impacted the resulting program which could have been a better editor if it was allowed to focus on doing a good job with HANK scenario creation As HORN is heavily centered on OpenDRIVE the standard is implicitly described in the manual in the part about the XML editor a little bit ahead so I will not go into more detail here 2 1 2 HANK Hank 1 consists of a simulator coupled with an interpreter for the two related languages EDF Environment Description Framework and SDL Scenario Description Language The simulator loads these files along with some binaries including 3d graphic files and textures that I am in formed are created in 3d modelling software and lets the user drive around the scenario in a virtual car in a premade scenario of arbitrary complexity HANK even allows on the fly modificatio
11. mostly straightforward It was possible to get a first version going that could handle most of the data that could be exported It was possible to simply walk the tree from the root to the leaves and call every node s export method from its parent node There was the small issue of not actually being able 35 3 1 THE DEVELOPMENT PROCESS CHAPTER 3 CLOSING to write to files that needed to be dealt with which ate up a lot of time and there was also the fact that arcs and spirals were given in a different format with different parameters and splines did not exist at all in OpenDRIVE In light of all this exporting files was put on ice for the time being as more information about these geometrical figures was required to proceed In total it had taken around 5 months to get to this point where most things seemed to be working well enough and the FONLY major thing left was to get the WYSIWYG part to work and add some minor features The main part of this project and the reason it took another 7 months to complete was the WYSIWYG drawing functionality It turned out that drawing little colored lines to represent the various geometries of the roads was anything but easy It seemed obvious from the start that given a large enough scenario the program would become unusable without working culling only drawing visible objects so the first and easiest part of the drawing code was to implement a quad tree where all geometry was stored accord
12. orientation for the spline e num segments How many segments should be used by HANK to create it A spline is a mathematical function that interpolates between two values in a smooth way The term comes from the spline tools engineers used when planning roads and railways in the past they essentially put nails in a board as points a line should go through and dragged a thin metal sheet along the path marked by the nails so it was forced to bend smoothly and make nice curves These could then be copied and magnified and put to use in the real version A spline in HORN consists of a series of cubic bezier spline segments A cubic bezier spline segment has a start point two control points and an end point 10 26 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY EDF uses splines They are not part of the OpenDRIVE standard but only specifies the start and end points as well as several control points in between that the line must pass through A cubic bezier spline segment requires five control points A starting point an ending point and 3 other control points that affect how the line is curved While there are no control points before the first or after the last points there are instead tangents that fill the same purpose As the 3 control points are not defined in the data by the user they are calculated as follows There are three points we need to consider The previous point a the current point b and the next point c
13. readers can immediately understand the meaning I felt it might be in order to explain what the term means before we go on A road network is simply a set of roads that form a network by connecting to other roads in the set The road network can be navigated with for example a car It could intuitively be modeled as a graph with a number of nodes where roads branch off and a number of edges that contain the surface cars drive on with information about the layout of the road Another way of looking at a road network would be as what gets drawn in a road map While the basic idea is simple to grasp there are many variations in different standards about what details can be modified and it is important to choose one that fits the problem one is trying to solve well 2 1 4 Road network editors A road network editor is simply a program that allows its user to edit a road network A common theme for road network editors is the map view where many properties of the road including its physical layout are described graphically While having a WYSIWYG interface to the data being worked on is not a requirement to work with the data it is probably the most important feature a road network editor can have The extent to which the 2 2 PREVIOUS WORK CHAPTER 2 BODY map view can be used to edit data varies between editors but typically some things just have to be manipulated as text While every editor has its own purpose and is tailored to that with spe
14. Each of a b and c has a tangent associated with it a t b t c t To calculate t for all control points but the start and end points of the spline we need a starting point and an ending point The starting point tl is achieved by calculating the mid point for the line ab and the end point t2 is the mid point of the line bc Or to use formulas tl b x a x b y a y 2 t2 c x b x c y b y 2 t t2 tl the points needed are then b b b t 2 c c t 2 Repeating this process starting with b as the second point of the spline and shifting the points so b becomes a c becomes b and a new point becomes c in a new cubic bezier spline until all points have been used we are able to draw a spline that goes through all the spline points accurately To read more about how it works I refer you to 9 While splines are not really required to make a road you can achieve anything with the right combination of lines arcs and spirals splines are a nice addition to the arsenal for when you quickly would like to model some set of continuous curves They are however not a standard part of Open DRIVE but EDF uses them and so I would recommend that they should be used as little as possible to achieve compatibility with other simulators They are however available and working well if you are happy with making an EDF only scenario I chose to make splines an extension of geometry so in addition to all their normal EDF param
15. I also felt that it led to very verbose code littered all over my constructors that did nothing but cause problems and waste space when all I wanted was to be able to pass a function pointer to an object It is possible that there are things slots and signals are good for but I was unable to find any situation where a simple callback had not been better and far less messy and error prone These two issues are responsible for the huge constructors for most of the HORN classes which also ended up being large time sinks Eventually it was possible to get around much of the problems and HORN was able to get a window with a tree editor that loaded OpenDRIVE files and displayed the data in a proper hierarchy The next obvious steps were making the data editable and saveable Originally HORN was going to use an XML saving class written by me with syntax similar to cout which also had methods to convert from basic datatypes to strings something that is shockingly missing in C standard library While there was nothing wrong with the code HORN was for some un known reason unable to write to a file The program code that gets directly compiled into the executable is physically unable to write to files any kind of files both C functions and C methods just fail A lot of time was spent figuring out what was wrong with perfectly fine code before it became necessary to give up on it A second attempt was done using tinyXML and surprisingly it worked ju
16. Qt only allows callbacks on QObjects more on this later and callbacks were required to get things to work with Qt A workaround I discovered by myself after much fuss was to have a sub class that contains an object that derives from QObject that also contains all the data and the non QObject class methods then refers to the data in the QObject subclass object in its overriding methods For example class foo QObject int data J class bar QTreeNode foo myData void doSomethingUseful doSomethingInQt a y is the only construct I came up with that let me work with some parts of Qt The tree nodes in particular were very difficult to work with and took a long time to implement well Initially the idea was for all classes to subclass QObject and contain a text field that they provide custom behavior for It was going to be clean simple and very little room for problems It might have been possible to somehow implement that design maybe something could have been hacked together by using qTreenode subclasses but during the project it never worked out Using Qt was probably a bad idea in hindsight as it s support for tree editing was questionable and not really the focus of the framework Eventually HORN became the current convoluted mess with Hank TreeN ode instead A HankTreeNode is basically a text field in the tree editor with 33 3 1 THE DEVELOPMENT PROCESS CHAPTER 3 CLOSING a void to some va
17. closer at the parts that Chapter 2 Body 2 1 Background 2 1 1 OpenDRIVE OpenDRIVE is an open standard for a file format describing a road network It is very detailed with a lot of relevant properties for various parts of a road network and the details of individual roads It focuses on being a data description language and I feel it does so very well with a broad range of data that can closely define the characteristics of a road network OpenDRIVE is based on XML with a root node called OpenDRIVE which has child nodes like roads crossings and junctions Most nodes have both data and other nodes which in turn may contain further data and nodes This imposes a tree structure on the data that makes it directly harmful for moving various objects around as they are tied to their parents For example a road line is part of a lane which is part of the left lanes which is part of the lanes which is part of the road which is part of the roads but as a road does not necessarily have any left lanes it is not clear what moving a road line from road A to road B should actually do This limitation has somewhat limited the usability of HORN in that it is very reliant on copying things back and forth between the library and the editor rather than just moving physical things around In the above example it would be more intuitive to me to just place a road line where I want it to be rather than positioning it in coordinates relative to the road inside a
18. done implementing OpenDRIVE is sadly wasted as most properties of a road in OpenDRIVE are not used in EDF and it was hard to work in SDL in a good way as OpenDRIVE just does not support any behavioral programming The end result is a mixed bag of good and bad things with plenty of room left for improvements The ideal workflow for HORN would be to design the road network in HORN and try to use a minimum of SDL code trying to focus on the creation of various objects that will be in the scenario that is being worked on Then when the design is done the 3D environment can be created according to the parameters of the scenario Actual SDL code should be worked on in a separate file that can be appended to the object definitions output from HORN and then have HANK load the combined file T hope that in the end HORN will be useful to everyone who is interested in it and that it will see further development now that all the work has been poured into it If there is a serious interest in improving HORN and continuing to use HANK I believe HORN has a bright future as a plugin to a 3D modelling program There are a few conclusions for me to take away from this project The first conclusion is that sometimes it actually is better to give up on an almost done project and cut your losses rather than to fight it out and ending up way over time if it looks like it might take longer than expected Requirement specifications are not necessarily final and can be ren
19. in the scenario They are not part of the OpenDRIVE standard which only works with meters The defaults should be good enough and work as one would expect but EDF also supports the following units e meters em kilometers e km e feet e ft For speed units mph is the only valid entry Header contains some metadata that may or may not be of interest RevMajor and Minor are the version of OpenDRIVE this scenario was made in Name is the scenario name Version is some version number for the scenario Date would be the last time it was worked on and it also contains North South East West which do not seem to have much actual use The vendor tells the user what company made the editor the scenario was created in In HORN the vendor attribute lists everyone who has worked on HORN It is currently only me but I hope that more contributors can be added to the list soon Nothing here gets exported to EDF 2 3 3 Controllers The category Controllers contains a list of controllers They are meant to be used to control traffic lights for example but they only define the what Id Name Sequence priority over other controllers and a number of Controls that have a signal ID and a type The how instructions on how they are meant to operate are however not present so I do not see much use for them when working with HANK Nothing here gets exported to EDF 2 3 4 Roads The main building block of a road network are also the category with
20. lines I was getting from QT before switching from draw to drawpath more on this later Emme seems like a fine solution for a different problem than what HORN is trying to solve 2 3 HORN HORN is a solution to the problem of wanting a road network editor for the driving simulator HANK while also wanting to be able to somewhat easily future proof the scenarios created by using OpenDRIVE as the file format Because the two formats are quite different from each other some new attributes and categories needed to be added to OpenDRIVE so I ended up extending the OpenDRIVE standard in HORN Still most of the infor mation in a scenario is still not HANK specific so with just a little work a scenario should easily be ported to pure OpenDRIVE HORN consists of three parts An XML data editor where all the data is represented as a tree a map where lines are drawn that show how the roads will be laid out in the simulator and a library that can store commonly used objects I will attempt to describe them and their working here 2 3 1 Basic terminology OpenDRIVE refers to an XML node as a record Records contain lists of other records and attributes There is no actual naming going on in HORN as we work towards the XML but I refer to a list of records as a category in some of my code comments and in this text for example the Roads list con taining many records of type road would be refered to as the roads category but roads list would not be wro
21. name and a type For bridges type is the material the bridge is made from in tunnels it is a classification of underground tunnel or underpass In addition tunnels have lighting and daylight parameters that both go from 0 to 1 allowing us fine control over the lighting inside the tunnel EDF has no concept of a bridge or tunnel and these are therefore sadly ignored when exporting to EDF but they are there should you want to use them anyway 16 2 3 HORN CHAPTER 2 BODY Surfaces Surfaces consist of curved regular grids CRG 3 CRG seem to be essen tially a height map of the surface of a road A big 2 dimensional array where every element is an equal distance from their neighbors with height values measured for every point So for those who want to use them CRG can be used in OpenDRIVE to add some very fine details to the road and require a file name start and end points on the s axis a surprising orientation parameter surprising as the orientation can be derived from the sStart and sEnd parameters which OpenDRIVE uses for other records a mode attached or genuine and s t z and heading offsets as well as a scale parameter for the height data EDF unfortunately does not support this and it is ignored when export ing but they are still available as part of the OpenDRIVE standard should you want to use them anyway 2 3 5 Junctions In OpenDRIVE a junction is simply a place where a road ends and turns into one or more oth
22. set up a category system for roads that store roads in sub categories like straight curvy roundabout etc Right clicking on many objects gives the option insert object name This option copies the currently selected record in the library to the currently selected record container in the editor Likewise we can copy the currently selected record in the editor to the library by right clicking on a category in the library and selecting Copy object here The libraries currently have the file ending hlib Horn Library 2 3 9 Road map view Finally we have the Road map Please see figure for a picture of the map The road map displays the roads as lines seen from above The lines are drawn according to the layout of the road and are color coded according to their geometry type There is not much more to say about what is on the map so here follows what we can do with it The map can be scrolled with the arrow keys or the wasd keys Holding shift scrolls 10 times faster than normal The current position of the bottom left corner is indicated by X and Y in the bottom left of the window ctrl and gt and ctrl scrolling forward on the mouse zooms in ctrl and lt and ctrl scrolling back on the mouse zooms out Zooming is done in powers of 2 so every zoom level is twice or half as large as the previous The map is centered on the bottom left corner which means that zooming in will produce a l
23. the given s value until the end of the road or another lane width with a higher s value overrides it Lanes may also have road marks lines text etc painted on them EDF does not support this but it is available for anyone who wants to use it 12 2 3 HORN CHAPTER 2 BODY Roads may consist of different materials at different times A material in OpenDRIVE is defined as a starting point s distance from the start of the road a surface a friction and a roughness EDF does not support this but it is available for anyone who wants to use it Lane material may vary along the road and are valid from the given s value until the end of the road or another material with a higher s value overrides it Visibilities describes how far a driver can see in various distances at some point and onwards until another visibility record for the lane overrides it The visibility can vary with the s distance from the start of the road EDF does not support this but it is available for anyone who wants to use it Speed records specify the speed limit from a point along the road until overridden by another speed record OpenDRIVE demands that the speed limit should be given in m s but when exporting to EDF it is treated as the speed unit specified in the Hank settings record EDF only allows speeds specified as mph Speed limits may vary along the road and are valid from a given s distance from the given s value until the end of the road or another spe
24. today with the EDF defining the road network and SDL defining the rules it makes sense to combine them all into one big program as a plugin for a 3d modelling program Being able to work with the 3d models from HORN allows it to 40 3 3 FUTURE WORK PROBLEM AREAS CHAPTER 3 CLOSING be a one stop solution Wishes were expressed to be able to handle textures and models from HORN but as that is not a part of OpenDRIVE EDF or SDL there was not much I could do about it As a plugin to a piece of 3d modelling software I can see it working in tandem with the modelling software allowing quick creation of models by entering parameters for roads while being able to tweak road parameters through the modeller interface while creating the environment 41 Chapter 4 Bibliography 42 Bibliography 1 Peter Jason Willemsen Behavior and scenario modeling for real time virtual environments The university of lowa 2000 2 Marius Dupuis e a OpenDRIVE Format Specification Rev 1 3 VIRES Simulationstechnologie GmbH 2010 last checked 21 february 2012 3 Dr Jochen Rauh Helmut Gimmler Road Simulation CRG curved reg ular grid Road Data Format Overview DAIMLER CHRYSLER 2005 2007 http www vires com opencrg docs CRG Overview pdf last checked 21 february 2012 VIRES Simulationstechnologie GmbH 2006 ROD Road Designer Product Data Sheet http www vires com Docs Rod20060612 pdf last checked 21 february 2012 Steph
25. 2 Previous work a a A A a a a e 7 A A A EN ae eae hs ee ads OP ay men a E 7 DRZ VUEMS ss Ga d r Cec isc de trae te eee ae a By Be at 8 D263 CUBE taaan fe bee WO ds le dete nt ct sce 8 25254 MAME qe ls ae hs AS O Des tote 8 2007 HORN aa a e a ap ape g AIG coy ay Ss ee dl Ai 9 2 3 1 Basic terminology 00 9 23 2 X MIs editor eta Maw ha eek AA oR ae he Ss 9 2 33 Controllers Wat e ee ee eG A eee BO 11 23 4 Roads eves Be Bae eee RE ee e a 11 20500 rd UNCUIONSs da ta S E 17 2 3 6 Global objects s rev sor ge o 17 2 3 7 Hank intersection templates 18 2 3 8 Library gt eh eS ek AN fr da dd eh LR 19 2 3 9 Road Map view e 20 2 4 Geometrical figures in HORN o 21 2 4 1 Geometries 2 0 0 0000 eee ee 21 DAD Curvature s elses ees a dd cde BD 22 24 34 EINS o a E Bley A Pah NALS 22 vil CONTENTS CONTENTS 2 4 4 2 4 5 2 4 6 2 4 7 2 4 8 3 Closing 3 1 The development process 3 2 Conclusion 3 3 Future work problem areas General improvements Usability improvements Editing improvements 3 3 1 3 3 2 3 3 3 3 3 4 4 Bibliography 5 Appendix 5 1 Appendix Examples of SDL code 5 1 1 Chapter 1 Introduction 1 1 Introduction 1 1 1 Background A simulator is a program that attempts to recreate a part of reality in as much detail as possible thus making the experience in the simulator as authentic as it can be
26. Institutionen f r datavetenskap Department of Computer and Information Science Bachelor s Thesis HORN Hank and OpenDRIVE Road Networks An editor for creating HANK scenarios while working with OpenDRIVE by Cim berg LIU IDA LITH EX G 12 011 SE September 24 2012 Link pings universitet Link pings universitet Link pings universitet SE 581 83 Link ping Sweden 581 83 Link ping Link ping university Department of Computer and Information Science Final thesis HORN Hank and OpenDRIVE Road Networks An editor for creating HANK scenarios while working with OpenDRIVE by Cim Oberg LIU IDA LITH EX G 12 011 SE September 24 2012 Supervisor Rita Kovordanyi Examiner Rita Kovordanyi Abstract HORN is a solution to the problem of how to implement scenarios in a more efficient way than was previously possible allowing researchers who wish to create scenarios for HANK the ability to quicker implement larger scenarios than was previously possible OpenDRIVE is an open standard for road networks that is believed to be the way forward and Horn is an attempt at unifying OpenDRIVE scenarios with HANK the driving simulator cur rently in use at Link pings Universitet thus futureproofing all work done to implement scenarios Before HORN HANK scenarios were laboriously constructed with a really bad program or by hand and HORN tries to make the process far less painful This thesis describes how to
27. ane Donikian VUEMS A Virtual Urban Environment Model ing System IEEE Computer Society Washington DC USA 1997 http dl acm org citation cfm id 792846 6 citilabs 2012 http www citilabs com products cube last checked 21 february 2012 7 INRO 2012 http www inro ca en products emme features php last checked 21 february 2012 8 German Aerospace Center Institute of Transportation Systems 2011 http sumo sourceforge net doc current docs userdoc SUMO_User_Documentation html last checked 21 february 2012 9 Dr Ching Kuang Shene publication date unknown http www cs mtu edu shene COURSES cs3621 NOTES spline Bezier bezier sub html 43 BIBLIOGRAPHY BIBLIOGRAPHY last checked 21 february 2012 10 Evgeny Demidov 2004 http www ibiblio org e notes Splines Bezier htm last checked 21 february 2012 11 Wikipedia 2012 http en wikipedia org wiki Cornu spiral last checked 21 february 2012 12 Wikipedia 2012 http en wikipedia org wiki Arc last checked 21 february 2012 13 Math Open Reference 2008 http www mathopenref com arclength html last checked 21 february 2012 44 Chapter 5 Appendix 5 1 Appendix 5 1 1 Examples of SDL code I have not found that much examples of SDL code so here I present a few lines I found while working on the project The following is from Willemsen s thesis 1 and creates a pedestrian with an upset mood at the middle of the sidewalk lane road edf fin
28. arger version of the bottom left part of the map I went with this approach instead of the more intuitive middle is the center approach because I felt that it was more convenient to mentally add units to the bottom left corner rather than adding or subtracting around the middle and this way we also avoid having to somehow indicate where the middle of the map is It is also possible to zoom by pressing enter and entering a zoom per centage 500 would magnify the image 500 for example Ctrl 0 restores the default zoom level At the bottom of the screen scale indicates how many units OpenDRIVE wants us to use meters but as HORN has to work with HANK which allows multiple units that is not possible to enforce and likewise x units per line simply means that there are so many units between the lines that form a regular grid to provide a convenient ruler Additionally there are some light grey lines which simply are drawn for every 4th line I found 4 to be a nice number for quickly measuring with the eyes while providing some granularity 20 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY Right clicking on the map can bring up a context sensitive menu with contents that vary depending on what was selected Currently only roads road geometries and objects support right clicks and can be copied moved rotated and scaled Geometries and roads can also be moved to or rotated in the direction of the cursor 2 4 Geometrical fig
29. ates define an intersection area as a polygon who s edges are formed from a number of points Each point defines a road slot that can be as sociated with a corridor in the corridors category When put together the points form lines and the lines are what the road slots are attached to for example if pl defines the slot r1 then the line plp2 is the edge that we will attach rl to Although only one point is entered it is implicit that the line that is formed between this point and the following in the polygon the last point will draw a line to the first point is what is used to define the corridor Junctors are essentially lanes inside an intersection and the name used here must also be used when creating corridors later The left and right junctors categories just mean that they appear left or right of the expres sion inside the parameter list For example 9 0 14 0 0 0 P1 P2 0 5 R1 P3 P4 is what a geom row might look like in EDF P1 P2 would then be in left junctors and P3 P4 in right junctors While they obviously are used to map between lanes and corridors somehow I have not found any rules for how it works Good luck Intersection corridors As was mentioned previously a corridor is an internal road inside an inter section that goes from a start junctor to an end junctor The junctors are 18 2 3 HORN CHAPTER 2 BODY connected to incoming and outgoing roads in the intersection The corridor has a name that is uni
30. ave tried to copy the relevant parts from the OpenDRIVE standard and have also added my own comments where it made sense to do so and while I have tried to get everything right I make no guarantees that everything is 100 correct In case of any inaccuracies or uncertainties I refer the reader to the definitions of EDF 1 or 2 OpenDRIVE The root node is OpenDRIVE and it contains a number of child nodes that in turn contain a number of child nodes etc I call these containers categories The basic idea is that you right click a category and add new records These contain properties and possibly more categories that can be added to As you go on adding new records to the categories and fill them with data you create your scenario If a record is no longer needed or unwanted it can be deleted by right clicking it and selecting remove Another option that appears when right clicking a category is insert Insert will copy the currently selected record from the library to the selected container if it is of the right type for the record This is covered in more detail later on The tree can be scrolled up and down with the mouse wheel For more information about OpenDRIVE I refer the reader to the Open DRIVE standard 2 The top level containers are e Hank settings e Header e Controllers e Roads e Junctions e Global records e Hank Intersection templates 10 2 3 HORN CHAPTER 2 BODY Hank settings contain the units to be used
31. cial data they all use line segments spiral segments and arc segments to build the majority of the road structure The road segments are connected to each other to form a road and the roads are connected to eachother through intersections forming a network While the details vary another common theme with road network editors is allowing the specification of road lanes for example what traffic is allowed on them how wide they are and to what lanes they might connect to in an intersection Whether these are shown graphically or shown only as text varies between implementations Now that we have explained what they have in common let us look at a few road network editors 2 2 Previous work There are many road network editors out there all with their own purpose and standards The following non exhaustive list of road network editors gives some examples that all look very good but unlike HORN none of them can output EDF data for HANK to use Although they are not solutions to the exact problem I was given they are still interesting as other ways of looking at the problem of how to edit a road network 2 2 1 ROD ROD 4 Road Designer is the OpenDRIVE editor produced by VIRES who co created the OpenDRIVE standard ROD lets the user create an OpenDRIVE scenario through the use of various tools and allows editing of the scenario through 2d or 3d modes that accurately depict what it will look like 2d gives a top down view where on top
32. crosses is triggered when an object crosses a line The example given for it in 1 is event crosses v cartesian_line x1 y1 x2 y2 triggers crossesLineEvent The example given for the syntax of enters is event enters v isect geometry triggers IsectEntranceEvent A special event type is timer which creates a timer that fires after the specified duration is up like event timer null 30 0 triggers Timer30Sec Armed with knowledge about triggers we can now look at examples of every loc sdl locator rdl road 10 3 180 event continuous_timer null 4 5 triggers CREATE EVENT every CREATE EVENT create vehicle place loc and when event crosses null curvilinear_line road distance triggers Stop_Event when Stop_Event send Stop_Event instigator stop 47 5 1 APPENDIX CHAPTER 5 APPENDIX Monitors may also be mixed like aslongas vehicle road_type FOUR_LANE_ROAD whenever vehicle speed lt threshold send vehicle increase_speed 0 10 1 gives many more examples in his text about the intricacies about how to best use monitors that will not be listed here before getting to the last part of sdl Scenarios Scenarios are similar to the concept of classes in C and Java The syntax to define one is defscenario scenarioName pO pl pn SDL code gt and instances of them objects can be created with the create acti
33. curvature the spiral has at the end point In HORN as well as in both EDF and OpenDRIVE a spiral refers to an Euler spiral also known as a Clothoid There are many kinds of spirals with various properties but what separates a clothoid from other spirals is that it has a linearly changing curvature Put another way the curvature can be described with the equation K dK x S m same as the equation for a line but typically m is 0 and in the standard clothoid dK is 1 Let us call the curvature K then the derivata dk dS is a constant value While a circle has a constant curvature the curvature of a spiral increases linearly with the distance S traveled along it so that curvature S dK x S where dK is calculated as the difference in curvature between the start and end curvature of the spiral divided by the length of the spiral or dK endCurvature startCurvature length Remember that increas ing curvature means decreasing radius so the distinct look of a spiral is a continuous line that spins around forming ever smaller circles much like the shape of water draining from a bathtup From this we can see that if the difference between start and end is large relative to the length of the spiral then it will make a smaller circle than if the difference in curvature is small relative to the length of the spiral A spiral smoothly interpolates between two curvatures where one of them is typically 0 and are often seen used in roads and railway
34. dRoad Main Street loc sdl locator rdl road road length 2 0 3 180 0 p create pedestrian mood upset place loc To destroy the pedestrian we could type destroy p SDL sends objects messages that modify their behavior and also allows for if else statements For example if carl speed gt 20 0 send carl stop else send carl increase_speed 20 0 Furthermore it is possible to iterate over all items in a set with a con struction like forall v in vehicle_set 45 5 1 APPENDIX CHAPTER 5 APPENDIX Which would cause all vehicles in vehicle_set to change to the left lane It is also possible to do a normal for loop like offset 2 5 for distance 0 distance lt 1000 distance distance 100 send v change lane left 1 locator rdo road_ref distance offset 180 0 create vehicle place 1 Which would would create a vehicle every 100 units along the road 2 5 units from the middle of the road SDL can be extended with user defined functions like randval math random return lo hi lo randval It would then be accessible through the sdl object like rval sdl randomValGenerator 12 92 In the short SDL description I mentioned the 4 monitors when event SDL block every event SDL block aslongas cond SDL block when ever cond SDL block These create independent threads that monitor for the predicate in their definition t
35. e angle will then be a negative angle and will imply a rotation in the other direction When working with curvature it is important to remember that curvature 1 radius so a curvature of 0 means no radius a straight line and a curvature of 0 001 means a radius of 1000 units whereas a curvature of 10 means a radius of 0 1 units 2 4 3 Line Lines are used to represent straight road segments as part of the geometry of the road I am sure we are all familiar with lines they are drawn between a start point and an end point The start point is given as x y the end point is given in polar coordinates a heading measured in radians and a length To be precise the end point is at x cos hdg x length y sin hdg x length Another way to think about it is to imagine a line that gets drawn from x y to x length y and then gets rotated by the heading When designing a road network lines will probably be frequently used as most roads are straight for long stretches so it is important to be com fortable with them It is common for long lines to connect to spirals which 22 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY then connects to an arc to form a curve which then connects to another spiral and ends with another long line Using this composition it is possible to recreate every shape of a road 2 4 4 Arc Arcs are used to represent turns in a road with a constant curvature as part of the geometry of the road
36. ed limit with a higher s value Lanes also have Access records that are used to further restrict what traffic may be in the lane For example pedestrians only motor traffic only etc The valid options are given in the help section EDF does not support this but it is available for anyone who wants to use it Lastly lanes may have height records that specify the height of the inner and outer sides of a lane which for example allows us to create race tracks that slope sideways slightly or specify that pavements are above the car road EDF has a single height parameter for a lane while OpenDRIVE has two I chose to use outer as the height value that gets exported For identical behavior between HANK and OpenDRIVE inner and outer should both be set to the same value Lane heights may vary along the road and are valid from the given s value until the end of the road or another lane height with a higher s value overrides it Objects Objects are things that might be found in the world of the scenario for example cars pedestrians signs road blocks etc They all have a type name and unique id that OpenDRIVE wants us to fill in Every object has s and t coordinates that are essentially x and y coordinates relative to the road s reference line s would be distance traveled along the line and t would be the distance relative to the middle of the road to where the object is zOffset is how high above the road the object is valid length decides h
37. egotiated despite the air of finality they have I have also learnt that it is very important to do proper research before accepting a set of requirements as some things while they may sound sim ple just are not that simple to implement and get working well drawing anything mathematical should be a big warning sign and require special attention when estimating time required Finally and perhaps most importantly it is best to never assume that the client knows what they want best and that it is important to fight back when a requirement might not be in the best interests of the client after first doing previously mentioned research before accepting a requirements document In general it is better to take some time to research and reflect 38 3 3 FUTURE WORK PROBLEM AREAS CHAPTER 3 CLOSING on requirements before accepting them instead of trying to get started as soon as possible regardless of time constraints It is also important to know about the rules governing the project before starting and to have a good communication with the client throughout the project I was stuck getting the WYSIWYG part of HORN working for a very long time and only found out after I was done that I was allowed to renegotiate the requirements document With better communication we would probably have been able to cut a few features and made the project go a lot less over time Following these four simple rules could have saved much grief for me and I stro
38. er roads They contain lists of connections to other roads priorities for deciding right of road and controllers used to manage the junction as well as a name and Id I have extended it to be used with EDF s intersections by adding the parameters template and x y and z When exporting the intersection will be created as an instance of the intersection template and be translated to X y Z Related to junctions are of course also roads Roads may belong to a junction and if they do then OpenDRIVE refers to them as paths and they are then analogous to the corridors of EDF We make a road a path by setting the road s junction parameter as a non default value Connections are bound to road slots in the template through the Incom ing road slot and Outgoing road slot attributes in the Connection record I found it very surprising that EDF has a far more fine grained control for how intersections are implemented compared to what OpenDRIVE has to offer While my solution is a bit ugly it should work somewhat smoothly with a minimum of extending OpenDRIVE Just remember that files mak ing heavy use of this extension will not work if there is a move from Hank to OpenDRIVE To recap Bind a junction to a template by adding the template name bind roads to template slots place it in the world using the x y z variables 2 3 6 Global objects Global objects are not part of OpenDRIVE but are a part of EDF Global here refers to the fact that they are
39. erating on OpenDRIVE data its primary function is as a road network editor for HANK 1 1 4 Method The method I chose to implement this project was to do some light research into road network editors and coding to the requirements document I was given near the start of the project I used an agile methodology where I developed a feature at a time with a top down design and verified that it was working well and had not broken any other feature before moving on to the development of the next feature checking off features on the requirements document as I got them done and maintained a hierarchical todo list over things that needed to be done to check off a requirement When the program was determined to be working satisfactorily I began writing this thesis with the aim of providing a manual for HORN and to show my findings about road networks 1 1 5 Boundaries Unfortunately HANK has a number of undocumented binary file formats it uses for various things for example graphics As they are undocumented I have not been able to implement any support for them in HORN and therefore creating a 3d model of the scenario is still something that needs to be done separately 1 1 6 Structure This thesis seeks to describe HORN and act as a user manual as well as describe my experiences implementing it and some of the fascinating rules for how to draw some exotic two dimensional geometries I found out about as I worked on HORN We will start by looking
40. eters they also have a heading and a start and end position that work as one would expect Just like geometry they can be scaled moved and rotated 27 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY When exporting to EDF the extra parameters modify the spline data creating the desired EDF definition so when it is run in HANK it should look just like in the editor 2 4 8 Hank Spiral Hank spirals are used to represent a spiral as part of the road They have the following attributes Starting point x y The start point of the spiral in absolute coordi nates This gets added to whichever Heading The heading of the spiral as measured in Radians By default the spiral is rotated by 0 degrees but changing this rotates ev erything by the entered amount This rotation is added to the rotation from the tangent vector straight end x y z The coordinates of the straight end Only one end is needed curved end x y z The coordinates of the curved end Only one end is needed mid point x y z The middle point of the spiral it appears to be superfluous as everything can be derived from the other parameters but it might be necessary to specify to appease HANK straight end tangent x y z The tangent of the straight end given as a vector When using straight ToCurved the spiral is rotated by this vector curved end tangent x y z The tangent of the curved end given as a vector When using curvedToStraight
41. f the next tangent and that was what I had to settle for in the end As I was working on various drawing methods and things started to come together I was very bothered by the very jagged lines QT was drawing for me Qt provides the class QPainter which has many methods for drawing things on the screen all of them except for drawPath create horrible aliasing when you try to do anything fancy as they truncate any positions to inte gers I stupidly assumed that there should be no difference between using drawing operations and using a path with a single drawing operation but the difference is huge so for anyone reading this and thinking of using Qt to draw things I strongly suggest that drawPath should be used exclusively 37 3 2 CONCLUSION CHAPTER 3 CLOSING 3 2 Conclusion After much hard work I finally managed to implement all of the requirements document that was possible to do I feel like HORN had to implement the major foundation for a 2d CAD program to get the WYSIWYG functional ity but in the end it all came together I personally do not think that OpenDRIVE was a good fit for creating HANK scenarios as EDF and OpenDRIVE are so different While they are both good solutions for designing driving scenarios they are also intersecting but far from identical sets and I have been forced to hammer the round peg that is OpenDRIVE into the square hole that is EDF and SDL and in the end mostly succeeded in doing so Most of the work
42. fering to them as property for example zOffset would be replaced with the zOffset of the record I added this so that objects could be used as templates and have the same SDL code and only require the OpenDRIVE properties to be changed There are no restrictions on what values can be assigned to the OpenDRIVE properties while exporting to SDL code so they can essentially be treated as variables if we so desire but I recommend to try to keep the same meaning allowing for easy porting in the future Features Features are simply a string that is treated as a feature in EDF Features are special SDL code embedded in the EDF code Features are not part of the OpenDRIVE standard An example of the usage of a feature is listed at the end of the appendix for those who are interested Every feature is treated as a separate row in the EDF code Range attributes Range attributes are simply a string that is treated as a range attribute in EDF Range attributes are special SDL code embedded in the EDF code Range attributes are not part of the OpenDRIVE standard The only ex ample of range attribute I have seen in EDF was to specify a speed limit i e range_attributes speedlimit 35 0 mph Every range attribute is treated as a separate row in the EDF code Again I have only seen speed limits of mph used but it is possible that other units might work 14 2 3 HORN CHAPTER 2 BODY Predecessor Successor Left neighbor Right neighbor
43. g a rollercoaster but it is part of the OpenDRIVE standard and there if you want it It is not a part of EDF and is ignored when exporting to EDF a is given as radians Super elevation may vary along the road and are valid from the given s value until the end of the road or another super elevation with a higher s value overrides it Crossfalls While Super elevation rotates the road around the s axis crossfall rotates the road around the t axis The value used in the equation is the distance from the starting point s I am not sure why or when this would be useful but it is part of the OpenDRIVE standard It is not a part of EDF and is ignored when exporting to EDF a is given as radians Crossfall may vary along the road and is valid from the given s value until the end of the road or another crossfall with a higher s value overrides it 15 2 3 HORN CHAPTER 2 BODY Lane offsets Lane offsets use a cubic polynome to describe a lateral shift of a lane relative to the reference line and can be useful for modeling some special roads for example the 2 1 road They have no counterpart in EDF and are ignored when exporting to EDF Lane offsets may vary along the road and are valid from the given s value until the end of the road or another lane offset with a higher s value overrides it Signals Signal records contain information about some sort of traffic signal including where it is at relative to the road s and t c
44. ing to their start and end points Where a binary tree splits an area between in half with a horizontal or vertical line a quad tree creates 4 squares each square 1 4 of the parent s area if every object is stored in the largest square where it is contained it is possible to only draw visible objects by rendering all partially visible child nodes The quad tree used the simple rule If the start and end points are in different quadrants for the node they belong in the node otherwise they belong in one of the children which works fine for culling There was some trouble getting it to work quite right mostly because getting the end point of some geometric objects is complicated and easy to get wrong when doing it blindly While the quad tree was done fast some of the last bugs in the project turned out to be lurking in some naive assumptions made while creating the quad tree Of all the geometries only lines were easy to both draw and export I quickly got them working A polynome could easily be plotted by drawing short lines between the calculated values of x and then increasing it by small steps until it reached the end but as they are not part of EDF they could not be exported Getting arcs spirals and splines working well turned out to be a real challenge Information on them turned out to be hard to obtain and the information that was available was not related to drawing them While Qt provides functions for drawing splines and arcs
45. ional information about the Link ping University Electronic Press and its procedures for publication and for assurance of document integrity please refer to its WWW home page http www ep liu se O Cim berg
46. map or when zoomed in a lot on various online map services CUBE focuses heavily on including routes and behaviors in the scenarios and allows for hierarchical scenarios base scenarios can have various sub scenarios who in turn may have further sub scenarios allowing for easy construction of many scenarios 2 24 Emme Emme 7 is a powerful road netwrok editor that ties in with software for transportation planning by INRO Emme defines its network in terms of nodes links and transits Transits seem to be similar to geometry in Open Drive as they connect nodes on a road and nodes can be connected to other nodes through a transit On top of the road network a very notable feature is the ability to import GIS Geo Information System data basically a map with global coordinates that can be overlayed by the road network The roads then get their correct global coordinates and it becomes easy to 2 3 HORN CHAPTER 2 BODY model an accurate version of an existing road network Another interest ing feature is the ability to use a query language to manipulate all objects matching some criteria at the same time The GUI consists of multiple small windows inside a main window Each window lets the user work with some properties of the scenario The map view looks much like a zoomed in city map would look in google maps and lets the user select many objects in an area to modify at the same time It seems like Emme is suffering from the aliased
47. ng either The various geometrical figures that are combined to create the skeleton of a road are called geometries which is a naming convention 1 adopted from the OpenDRIVE standard 2 3 2 XML editor XML is a standardized file format that uses a tree structure of nodes that contain data and more nodes It looks similar to HTML which is used to create web pages HORN is a road network editor This means that we use it to edit and create road networks and therefore the most important part of HORN is 2 3 HORN CHAPTER 2 BODY the data editor The data editor is essentially an XML tree editor with a 1 1 mapping with the underlying XML Please see figure 2 1 for a picture of the XML editor First let us take a quick look at the menus there should not be many surprises there We have file and edit edit only contains undo and redo Menu contains new open save save as export which exports data to Hank s EDF format and exit I take for granted that everyone who reads this text has some experience with what these actions do from working with previous programs and all I would like to add is that they work just as one would expect them to At the bottom of the window a panel is dedicated to a context sensitive help text that changes with the currently selected record I am the first to admit that the help text could be better but it should hopefully provide some idea of what values parameters should have I h
48. ngly recommend that anyone reading this tries to remember it when they embark on a large weakly defined project 3 3 Future work problem areas While I am proud of what I have accomplished and feel that HORN can be used productively to create scenarios for HANK I feel that there is plenty of room for improvements I have listed the things I would have kept on working on myself if it was actually my job to develop HORN further 3 3 1 General improvements HORN currently mostly implements OpenDRIVE It does not attempt to read custom user data which is against the standard and importing scenarios with user data other than what HORN uses might lead to data loss when saving I do not think HORN will be used for more than creating HANK scenarios that can later on be exported with little effort though so it should not be much of a problem For working with data from other editors with custom user data I recommend making a copy of the original file before getting started Some of the custom user data also breaks the OpenDRIVE standard which wants the data to be in a name value pair whereas some times a name node pair is used as entire nodes had to be added as custom data After fixing these two issues HORN will be 100 compatible with OpenDRIVE which would be a good thing The program is also leaking memory or more correctly nothing that is created is ever deleted so after a very it does not use much memory long session of adding and rem
49. not owned by any particular road and could for example be a tree a house or a boat in the distance EDF and SDL 17 2 3 HORN CHAPTER 2 BODY do not make any difference on where an object is created or if it is associated with a road or not so global objects is added more as a convenience and help in organizing scenarios logically than a strict requirement and should you prefer to do so all objects can be listed on the object list of a single road with coordinates relative to the road and it should still work out in the end One difference between global and road objects is that road which is replaced with the name of the exported road is not valid for a global object as they do not belong to a road Just like local objects HORN provides a convenient move dialogue for global objects 2 3 7 Hank intersection templates As the name implies Hank intersection templates are intersection templates from EDF and are not part of OpenDRIVE In EDF templates are used heavily for both roads and intersections but intersections require a template to work well For the purpose of exporting to EDF junctions that were discussed above are instantiations of these templates and refer to them for their geometry through the name parameter I have been unable to find any documentation about this and have reverse engineered the format myself There may be inaccuracies from this in my implementation but I am unaware of any Intersection geometries Templ
50. ns through its SDL interpreter As this project has been all about generating EDF and SDL code from OpenDRIVE code I will discuss them shortly here For a more thorough discussion I suggest reading Willhelmsen s thesis 1 Unfortunately it seems like HANK also uses many binary file formats that I have not found any documentation about like path ive net rdb scn and sci so I can not discuss them here EDF Environment Description Framework is a data definition language used to define what exists in the world Its purpose is to build a database that HANK can use to run its simulations in It mostly covers roads intersec tions how many lanes and their properties there are in a road as well as any object definitions that should exist when the scenario starts It is a structured language with a somewhat weird syntax but once learned it allows the user to use templates that can be translated and rotated to quickly create a road network by combining premade roads as building blocks OpenDRIVE and EDF are intersecting but not subsets of each other OpenDRIVE in general provides more detail on the road networks than EDF but lacks a scripting language I was able to export part of the data to EDF but HORN also had to have OpenDrive extended with some EDF specific constructs that OpenDrive does not have such as intersection templates and units of speed and distance intersections and embedded SDL code 2 1 BACKGROUND CHAPTER 2 BODY
51. o become true and if so their body is exe cuted Here is an example of aslongas being used doc v queryCurvilinearCoordinate aslongas v queryLeader doc speed lt threshold send v pass lead Which would cause cars in traffic to overtake a leader if it drives too slowly Here is an example of whenever Obtain access to the human driven vehicle subject edf ownship whenever subject distanceToLeaderInLane lt threshold send subject leader change_lane gt As ownship is the human driven vehicle in SDL this would make the leader in the lane the human is in change lane when the human driver is within a certain distance from them 46 5 1 APPENDIX CHAPTER 5 APPENDIX SDL also lets us use event which have the syntax event event type object reference region or threshold triggers event_name It is possible to replace object_reference with a set of objects which will cause the event to trigger on any of the objects It can also be null in which case all objects affect it Events contain the variables type instigator threshold and timestamp they can all be accessed inside a monitor as event_name variableName A shortcut for events on single variables is to type variable gt gt value like vehicle speed gt gt 30 0 They can only be used in when and every monitors Some possible events are crosses enters and exits which are triggered when an object crosses region lines
52. of the roads lanes lines and junctions are indicated along with the layout of the scenario 3d mode gives a detailed WYSIWYG preview of the world being created Through various tools an authentic looking urban environment can be created for use in VIRES driving simulator In the end ROD outputs xodr xodr is the OpenDRIVE file format for the road network data and flt files for the graphical data 3d models and textures for example that VIRES claim can be used by many different modelling tools and simulators While ROD has very impressive editing capabilities it is however not at all concerned with any kind of scenario rules These are instead created separately in VIRES program Instructor station ROD along with Instructor station offers an elegant solution and might be a logical upgrade path from HORN when HANK is no longer desired but as it obviously lacks support for HANK it would not be very useful for creating scenarios for HANK today 2 2 PREVIOUS WORK CHAPTER 2 BODY 2 2 2 VUEMS VUEMS 5 Virtual Urban Envirnoment Modelling System is a road network editor that was developed as part of the Praxitele project which had as its purpose to create autonomous electrical cars that could drive in traffic and needed a realistic environment to be developed in and experimented with As it focuses on real world behavior the editor is focused on making it easy to make something that maps to reality as much as possible by re
53. omplicated format to achieve an inferior spiral One end HAS to be straight whereas for a OpenDRIVE spiral it can be straight and it comes with many useless parameters Regardless of which spiral you choose to use you still have to conform to one end being straight or there will be problems in HANK later I chose to make HANK spirals an additional specialization of geometry so in addition to all their normal EDF parameters they also have a heading and a start position that work as one would expect Just like geometry they can be scaled moved and rotated and when exporting the extra parameters modify the result so when it is run in HANK it should look just like in the editor 29 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY m HORN Data Editor Nasqeuladuice W React Piw W Amt Piw W Amt Piw iW React Piw W React Piw W React Bella A rowel i cormta of Gust midir onssas of gorras ari brews ore batty rra wh eros Tr hiss sore operator susse to it to renee rotate ant scale parar Currenthy undo Por this is irlanda ae undo tor every mirdad verable geting up sored sure het he prat a dy rl pou vert Road Meade Record The rast header rected datinas te bed parejas ot an indus mad Ii roca remate y by ote records de rang peoretry and bycd propertea of tre oael Daina rasis chast Figure 2 1 The XML editor of HANK 30 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY 1 B
54. on of arcs where positive degrees are a left turn and negative degrees are a right turn as seen from a car going in the direction of the road This was confusing as it supposes that 90 degrees are added or removed from the start angle of the arc depending on if it s a positive or negative angle Splines required a couple of days to get right after I knew about how to calculate the control points and after learning all about arcs I was able to figure out how to get them just right one issue at a time Spirals turned out to be woefully undocumented and all I was able to find was some calculus defining various variables and how great they are in rollercoasters but nothing about how a spiral could be drawn and so it was necessary to keep trying various ideas for how arcs splines and spirals might be supposed to be drawn until they started to line up with each other in the sample OpenDRIVE scenarios that were available OpenDRIVE has a library that is used for calculating points of a spiral which works great and using that I was able to get spirals that go from 0 to n curvature but I have been permanently unable to get it to work from n to 0 as it simply does not seem to be built to do that Eventually HORN could not use the library because of this but there was a part of the code that calculated the tangent of a point in the spiral and using that HORN can draw the spiral with many small lines that go from the previous end point in the direction o
55. oordinates zOffset Signals may have a name and a unique ID they may be dynamic yes no they may face either direction of the road orientation and a number of parameters used to describe what kind of signal it is country type subtype Signals may also have some arbitrary value that I suppose is specific to various simulators as well as a list of lanes they affect validities Signals are not exported to EDF at the moment but perhaps there could be some support added later by someone who better understands what kind of objects are valid in both standards and is able to map between them Object and Signal references References are used to avoid multiple definitions of the same thing The idea is that one road owns an object or a signal and then other roads that are affected by them use a reference to them The reference must specify where they are relative to the road the id being refered to the lanes being affected and the direction of the road being affected In addition to the previous attributes object references also have a valid length attribute that specifies the stretch of road s length affected by the object References are currently ignored when exporting as EDF treats objects as global things and lacks the concept of references Tunnels Bridges Tunnels and bridges are well tunnels and bridges They define a stretch of road as a tunnel or a bridge through a start s value and a s length They have an id and a
56. oving nodes the user might run out of ram It also seems that the program will randomly crash after running for a few days which should not be a problem for normal work but is probably related to the leaks and it might be a good idea to plug the leaks so it can go on and idle forever The leaks should obviously be fixed at some point by adding proper destructors for all classes and making sure that there is some maximum undo length and also having all following redos be cut off and deleted along with possible associated nodes when the user takes some action after having used undo 39 3 3 FUTURE WORK PROBLEM AREAS CHAPTER 3 CLOSING While not really an issue some classes ended up having methods that work on data that belongs to other objects which is a bit dirty and it might be a good idea to clean that up going forward Maybe someone should try to find out how a spiral can actually be drawn using the OpenDRIVE library Another thing is that currently rendering is done in software and is not that fast While tolerable it is not nice and it might be a very good idea to try to port the rendering code to use Qt s OpenGL mode to receive a significant speed boost Improving documentation and perhaps naming variables better could improve HORN a little bit too Fixing all of this could be the major part of a bachelor thesis 3 3 2 Usability improvements Another area with easy improvement is usability the program works and allows the use
57. ow long the object may be Orientation if it is facing towards or against the direction of the road Length and width can be used to describe object if it is rectangular and radius can be used if it is more oval Only one should be defined however Height determines the height of the object we also have rotations in all axises hdg heading pitch and roll Heading is the direction the object is facing relative to the road s direction rotates around 13 2 3 HORN CHAPTER 2 BODY the z axis Pitch points the object up or down rotates around the t axis and roll makes the object lean to the sides rotates around the s axis It is possible to make an object repeat by adding a repeat to the repeats category This can be useful for saying for example that there should be a streetlight every 10 meters It is possible to create an outline polygon to more precisely specify the shape of the object The polygon can either use coordinates relative to the object or the road Just like lanes objects may also have a material which also has a surface friction and roughness Just like lanes objects also have a validities category The validity records in it specify valid lanes for the object Finally there is the SDL parameter which was added on especially for HANK scenarios and is not a valid OpenDRIVE construct The SDL lets the user enter SDL code that can create an object It has the ability to use all the object parameters directly by re
58. p to the bottom of it and then rotating the paper It is the absolute coordinates of this line that needs to be calculated when rotating the start point After knowing the middle point the end point is easily obtained by mul tiplying the radius with the cos sine values of the angle and then rotating the resulting vector by the heading Or more concisely Start Point xStart yStart x y Middlepoint x Middle yMiddle xStart yStart rotate heading 0 radius Endpoint xEnd yEnd axMiddle yMiddle rotate heading cos angle x radius sin angle x radius where rotate rotates with heading the x and y values given to it Wikipedia 12 and mathopenref 13 covers most of this 23 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY 2 4 5 Spiral Spirals are used to represent a spiral segment that connects a line segment with a curve segment or possibly another spiral segment as part of the geometry of the road It has the following properties e Starting point x y The start point of the spiral in absolute coordi nates e Length The S length of the spiral If the spiral is very long compared to the curvature it interpolates it and draws ever smaller circles e Heading The heading of the spiral as measured in Radians By default the spiral is rotated by 0 degrees but changing this rotates everything by the entered amount e Start curvature The curvature the spiral has at Starting point e End curvature The
59. que in the intersection We decide what traffic is allowed on the corridor using the same types as roads in EDF Corridors have a stop line end and an end from which traffic flows These are called stopline junctor and flow percentage junctor and should have the same name as the corresponding start and end junctors The stop line has an associated distance from the junctor and the flow percentage junctor has an associated flow percentage A special type of intersection is a pedestrian crossing For these we may have a curb junctor and an associated curb distance How high the pave ment is above the road There is also the somewhat mysterious parameter num_segments which controls how many control points are used when cre ating the corridor For a normal intersection a value between 5 20 should work well Associated with a corridor are dependencies and points It seems that dependencies are used for creating a chain of conditions that must apply before people may pass for example there could be dependencies such that a traffic light must be green and all other traffic lights must be red before cars are allowed to drive through Points are available but I was never able to figure out for what In the examples I have had available points and dependencies were never used but they are there for you should you need them I should mention that although corridors are very similar in concept to OpenDRIVE paths corridors seem to be created to automa
60. r to edit all attributes but I feel that there is plenty of room to improve the workflow and make the map view display more than just road geometry For example crossings objects number of lanes and their width lane types height info etc Allowing the user to use the map more for editing data would also be good Things like drag and drop to move objects between owners copy paste for selected objects etc would probably improve productivity at least a bit The XML editor is a bit clunky and could probably be implemented better and I am generally unhappy with how the interaction with the tem plate library works right now I added only the largest ones to avoid a giant menu when creating new things in the library but I am sure it can be better integrated somehow 3 3 3 Editing improvements It would also be nice if HORN could be made to include a proper SDL editor with syntax highlighting and information about errors in the code and maybe the possibility of an EDF view with syntax highlighting based on the OpenDRIVE export output where edits made would affect the OpenDRIVE data would be a nice addition too bonus points if it can be made editable so scenarios can be exported back and forth While I do not know about the binary file formats maybe HORN could become an editor for those as well 3 3 4 3d modelling Currently HORN does not handle models or texturing at all As the sce narios are currently hand crafted in 3d modelling software
61. riable an editableObject to the owner of the variable and an enum describing the type of the variable Custom behavior is obviously not possible this way and a large part of HORN s code became constructors creating the HankTreeNodes Another problem with Qt was that it is a GUI toolkit without callbacks Instead of callbacks some obnoxious macros need to be run through a pre processor it was never clear when the preprocessor needed to be run but it was usually a good idea to clean the build and run the preprocessor and then perform a full build to see if mysterious problems that often occured would go away Instead of callbacks the macros use slots and signals The idea is that objects emit signals and other objects can be bound to listen to signals from a certain object and have a certain method called when the signal is received The methods are called slots and must have the same parameters as the signal method This construction is very error prone as Qt will happily let you call a method that does not exist as the macro overrides any compiler error checking and then nothing happens when the program tries to call it Slots and signals also appeared both restrictive and confusing as seem ingly obvious things like binding a slot from another object in the code inside the current object to the signal from a third object which was a surprisingly common situation for me and something I was forced to design my way out of by moving things around
62. s as the optimal transition between an arc and a line as the centripetal force is minized Spirals can also be found in many places in nature for example in sea shells and bird feathers l as I accidentally discovered when I got my rendering code wrong and it ended up drawing pictures of them 24 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY The tangent of a point in a spiral is easily obtained with the simple formula tangent dK 5 2 which is the primitive function of the line formula There should be some way of easily obtaining the x y coordinates of a point in a line using integrals but I was never able to work it out for cases where the curvature does not start at 0 Luckily it is also possible to obtain good approximations of the x y values by starting with S startCurvature and then successively calculating the tangent of the spiral for S and multiplying it by some small stepsize to obtain a line that can be drawn from the end of the previous line The stepsize is also added to the S value and we can repeat this process until the entire spiral length has been stepped through This inherently leads to two problems a A small error is introduced from taking discrete steps From my experience it gets wrong around the 10th to 12th decimal and b as drawing a spiral consists of taking many small steps having a huge spiral is impractical so entering some unrealisti cally large spiral could slow down the drawing speed
63. so it becomes easy to see that the road elements are indeed connected The goal of my project was originally to make something that would let people use a graphical interface to create HANK driving scenarios Another concern was portability as HANK is getting somewhat old and it would be nice to be able to run scenarios on the road networks in a different simulator with as little effort as possible OpenDRIVE is an open standard that is supported in for example SUMO 8 and ROD 4 There are many other road network standards about one for every simulator that has any reason to have road networks but most of them are proprietary and the nice thing about OpenDrive is that it is in fact open and should there be a need to make it work with a particular simulator that at least uses a similar format importing scenarios should be at worst a matter of writing another export functionality for that simulator similar to the exporter in HORN Because of OpenDRIVE being the future it seemed like an obvious choise we agreed to try to make the user do as much work as possible in OpenDrive to make their scenarios future proof I chose to name the resulting program HORN Hank and OpenDRIVE Road Networks HORN lets the user create scenarios in an extended version of OpenDRIVE It is extended as HANK mixes data and behavior in its files whereas OpenDRIVE is only concerned about data and even 1 1 INTRODUCTION CHAPTER 1 INTRODUCTION though HORN is op
64. st fine While it still makes no sense it became clear then that something very wrong was stopping file 34 3 1 THE DEVELOPMENT PROCESS CHAPTER 3 CLOSING output that was compiled as part of HORN from working but if the exact same code was compiled separately as a library and linked in it worked just fine Later on when HORN was supposed to write EDF files the same problem came back but tinyXML was not useful for creating text files Much later on when the priority of the project became exporting files to EDF I reasoned that tinyXML did not fail to write although everything else I tried did and tinyXML is a separately compiled library so a library that is just a wrapper around file operations was created in the hopes that it would work around the problem I was experiencing and it worked very well The wrapper worked much like what was originally the plan and therefore replacing the exporting code only required some tedious manual replacing of function calls in the right places and no rewrites To this date the program is unable to use fwrite and fstream to save data if the code is not from a library This may be related to Qt or the version of GCC Qt Creator ships with but it is definitely something to look out for After a lot of struggling with the above problems HORN could load edit and save OpenDRIVE data with many obscure bugs and a very large body of classes that needed to be implemented along with a forcibly complicated design
65. t in HORN and OpenDRIVE e Length Values in the range 0 Length is used to calculate y values 25 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY e Starting point x y The start point of the polynome in absolute coordinates This point is treated as 0 0 for graphing purposes e Heading The heading of the polynome as measured in Radians By default the polynome is rotated by 0 degrees but changing this rotates it by the entered amount A polynome is a part of the OpenDRIVE standard but not EDF As such they are valid in OpenDRIVE but useless for working with HANK They are used to make the graph for f x a bx a cxra dxrada road segment It does not follow the usual standard that Length is the arc length of the segment instead it just tells us how long the range of x values used in the graph should be 2 4 7 Spline Splines are used to represent a spline segment as part of the road They have the following attributes e Starting point x y The start point of the spline in absolute coordi nates e Heading The heading of the spline as measured in Radians By default the spline is rotated by 0 but changing this rotates it by the entered amount e Start tangent The tangent for the first point e End tangent The tangent for the end point e Points A list of points With 2 points a line is drawn between them with 3 or more points pretty curves are drawn e orientation positive or negative
66. the most data and probably where you as a user of HORN will spend most of the time working Most important are geometries that define the layout of the road and lanes that define what lanes exist along the road I shall start with the most useful categories and cover the others later 11 2 3 HORN CHAPTER 2 BODY Geometries Geometries are central to a road They form the reference line that the road follows and are the only thing that currently gets drawn in the map view Geometries are covered in detail in Geometrical figures in HORN and individual differences will not be covered here Common for all geometries is that they can be moved rotated and scaled Right clicking on a geometry will give a list of available options If a geometry is selected some additional options will also be made available by right clicking on the map view move here rotate here Move here moves the record to the coordinates where the cursor was when the right click occured Rotate here changes the heading of the record so that it points towards the coordinates where the cursor was when the right click occured It should also be noted that roads work just like geometry Right clicking gives the options to move rotate and scale it and right clicking the map view lets the road be moved or rotated to a point Performing an action on the road means performing it on all geometries that are part of the road and it can therefore be thought of as a shortcut
67. the simulation environment and that is where HORN comes in 1 1 INTRODUCTION CHAPTER 1 INTRODUCTION 1 1 2 Similar work There does not appear to have been anything made before that does what HORN does HORN is unique in converting OpenDRIVE files to something that Hank can run Before HORN there was a commercial editor available that uses it s own proprietary format to export to Hank It was hard to use and required much training to laboriously construct road networks through a horrible user interface It s users hate it and feel that anything would be an improvement I was unfortunately only shown it once and did not catch the name but HORN will be replacing it I will be briefly discussing other road network editors that are in no way related to Hank later in this document 1 1 3 Purpose The way things worked was unsatisfactory and I was asked to create a pro gram that allows the user to create scenarios for HANK as well as look into road networks in general By not having to work directly with EDF and SDL in a text editor and just focusing on the data users can save much time and effort that would otherwise be spent learning these domain specific languages and finding syntax errors Another advantage over having a well functioning editor over editing text files is the instant feedback that becomes possible by having a WYSIWYG What you see is what you get screen that shows how the different elements of the road line up
68. the spiral is rotated by this vector bearing left or right left is the default value and right simply mirrors it I am not aware of a way to mirror an OpenDRIVE spiral so this might be a positive feature for EDF direction straightToCurved or curvedToStraight This affects which of curved end and straight end is used as the start point of the spiral as well as the direction of the spiral increasing or decreasing curvature spiral length The s length of the spiral This is the same as length for an OpenDRIVE spiral spiral radius The radius of the spiral at the curved end which is the same as 1 end curvature for an OpenDRIVE spiral 28 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY e num segments How many segments should be used by HANK to create it e super elevation While EDF does not seem to support super elevation in general it does allow super elevation in spirals This is a single value which makes the entire road lean to the left or right Hank Spirals are used just like Spirals and equivalent spirals will look the same In HORN HANK spirals are internally converted to spirals before they are drawn They are not part of the OpenDRIVE standard and are provided because they are part of the EDF standard As such they are not recommended to use for scenarios that should be portable but they are available if you want to use them The main difference is that it uses a different more c
69. they expected different data than what was available from the OpenDRIVE data or the EDF data and so the new milestone became to research the rules governing the drawing of these geometries so HORN could map them to what Qt wanted After much searching little nuggets about how to perform some operation on one of them were found here and there for example calculating arc length or mid point of an arc and this wonderful page that explained how to calculate control points for a cubic spline when the spline is only given as the points it must pass through 11 36 3 1 THE DEVELOPMENT PROCESS CHAPTER 3 CLOSING After spending all my waking time for weeks hunting for information about this I was completely burned out from all the stress and having worked 3 months longer than I was supposed to and still not being anywhere near done I found myself being unable to do any kind of work for a couple of months but slowly got back to it during the spring and was able to get arcs working somewhat well I still thought I would be done soon and kept fighting with the code every day More courses had to be missed as I was struggling to get done with the project Over the course of months from various online resources the rules gov erning splines and arcs became clear and it was possible to eventually make them connect with the lines in various sample OpenDRIVE scenarios A pitfall that was encountered with arcs was that OpenDRIVE uses a special definiti
70. tically form a line between its two junctors so there is no good way to convert paths to corridors Intersection traffic control objects A traffic control object is essentially a wrapper around the line instance_name object_type parameterl parameterN and as such you simply fill it in with the desired name of the object in instance name the type of the object in object type and the parameters it should have as a comma separated string in parameters 2 3 8 Library The library is meant to be used to store commonly used objects and tem plates While it could use some polish it does just that Please see figure 2 3 for a picture of the library The library has its own set of menus that mirror the editor s menus apart from export which is not a valid operation on a library The main part of the library has an XML editor that works exactly like the one in the data editor with the only difference being that it has a different root node with different available operations 19 2 3 HORN CHAPTER 2 BODY While the editor has an OpenDRIVE root the library does not actually have a root instead it works with categories that can be created by right clicking on the background or on a category and selecting Add Category Categories are just containers that can contain other categories as well as objects While they start with no name categories can be given any name by double clicking on them and typing in a name For example we could
71. to a crawl In practise it works great though and using the suggested spiral endpoints in the pro gram makes them line up nicely with the ones from sample OpenDRIVE scenarios I found spirals to be poorly explained in the few texts I have found about them and most of what I know has come from essentially researching spirals by myself The above might not be a complete mathematical background and might sound confusing but should be sufficient to get you started exper imenting with spirals in HORN They are amazing things of beauty that are found throughout nature and our roads could not be built without them The correct way to use them is to attach one end with curvature 0 to a line and another non 0 end to an arc then attach another spiral from the arc to a line EDF requires one end to be 0 but if exporting to EDF is not important it is possible in OpenDRIVE to make an S shaped curve by using negative to positive curvature or to make a spiral that interpolates from one arc to another Wikipedia 11 has a writeup that was fairly useless to me but which might be interesting for those who want to know more about the math relating to spirals 2 4 6 Polynome OpenDRIVE refers to cubic polynomes as polynomes They are used to represent a cubic polynome segment as part of the road They have the following attributes e The polynome itself A cubic polynome is given by the formula y atb x c x2 d x3 a b c d are parameters we can edi
72. to repeating the same action for all geometries manually Lanes Another important part of a road are the lanes Lanes flesh out the reference curve of the geometry with driving fields Under Lane sections there are left lanes center lanes and right lanes Left lanes are left of the middle of the road right lanes are right of the middle It is also possible to have a special center lane in the middle of the road The center lane is supposed to have some special conditions forced on itself which are currently not enforced but basically it may only be a single flat lane While center lane is optional there should only be one as there is only one center of the road there can be any number of left and right lanes Lanes may have successors and predecessors just like roads for merg ing for example Center lanes are special in that they may not have any successors or predecessors All lanes have a certain lane type for example some lanes may be side walks car lanes or have special restrictions on who may drive there The type argument specifies this Lanes also have a width and at least one width must be specified for every lane EDF only handles a fixed width per lane whereas OpenDRIVE uses a polynome to describe the width of a lane For exporting to EDF having a single width record with the parameter a set to the desired width should give the same result in both OpenDRIVE and HANK Lane width might vary along the road and are valid from
73. ures in HORN 2 4 1 Geometries First of all we need to have a quick refresher on radians because OpenDRIVE works in radians and as HORN tries to follow OpenDRIVE as literally as possible angles are entered as radians in HORN As everyone surely is familiar with 180 7 so radians desiredangleindegrees x 7 180 and degrees desiredangleinradians x 180 7 Geometry in HORN is used to describe the layout of the road Common to all geometries are the attributes e Start point x y The absolute x y coordinates in world space where the geometry starts e Length How many units long the geometry is When talking about length it is refered to as S in formulas Heading The rotation of the geometry measured in radians End point x y The absolute x y coordinates in world space where the geometry ends Using this as a start point for following geometry is a good idea e End heading The tangent of the direction the geometry is pointing in at its end point Using this as the heading for following geometry is a good idea I have chosen to expand a little on these for some geometries where there is more to say In OpenDRIVE geometries are implemented as a geometry record fol lowed by a record that describes what kind of geometry it is There are 6 different geometrical figures in HORN These are e Line e Arc e Spiral e Polynome 21 2 4 GEOMETRICAL FIGURES IN HORN CHAPTER 2 BODY e Hank Spiral e Spline
74. using maps with road sign information and real estate data The road information can then be modified by editing the sample data or adding to it but the general idea is to let the user create a scenario from real world data with a minimum of fuss and much of the effort is used on adding data that was not available from the original data for example height and direction of houses VUEMS is only concerned with creating a physical world whereas the simulator gets Al and scenario rules from elsewhere 2 2 3 CUBE CUBE 6 produced by Citilabs is a large framework consisting of many different programs for working with and analyzing traffic and other kinds of urban phenomena of various kinds in detail While they do not provide any driving simulators they provide solutions that visualize what the results of a particular simulation might be and is therefore well suited for traffic and city planners who want to see how their designs and policies will work and have access to preliminary statistics about their solutions before they are implemented There are many CUBE solutions for analyzing for example logistics public transits traffic etc At the heart of it is an editor similar to HORN but with more detailed options relating to the simulation packages being used and better maps The base package is extended through various plugins that add features to it The map view has been designed with a distinct car map feel as one might expect to find in a road
75. vande F r att garantera ktheten s kerheten och tillg ngligheten finns det l sningar av teknisk och administrativ art Upphovsmannens ideella r tt innefattar r tt att bli n mnd som upphovsman i den omfattning som god sed kr ver vid anv ndning av dokumentet p ovan beskrivna s tt samt skydd mot att dokumentet ndras eller presenteras i s dan form eller i s dant sammanhang som r kr nkande f r upphovsmannens litter ra eller konstn rliga anseende eller egenart F r ytterligare information om Link ping University Electronic Press se f rlagets hemsida http www ep liu se In English The publishers will keep this document online on the Internet or its possible replacement for a considerable time from the date of publication barring exceptional circumstances The online availability of the document implies a permanent permission for anyone to read to download to print out single copies for your own use and to use it unchanged for any non commercial research and educational purpose Subsequent transfers of copyright cannot revoke this permission All other uses of the document are conditional on the consent of the copyright owner The publisher has taken technical and administrative measures to assure authenticity security and accessibility According to intellectual property law the author has the right to be mentioned when his her work is accessed as described above and to be protected against infringement For addit
76. vity statement Although the syntax for this is never given I would assume it is create activity scenarioName p0 pl pn It seems like SDL does not want parameters passed to the scenario to be named variables The sample code given for a scenario is as follows defscenario LightSequencer vehicle Obtain a reference to the vehicle s current road road vehicle queryRoad Locate the intersection towards which the vehicle is approaching on it s current road isect vehicle queryNextIntersection Determine the traffic light controlling the next intersection towards which the vehicle is heading traffic light isect queryTrafficControlDevice sync_point TRANSITION_TO_RED aslongas vehicle queryDistanceToNextIntersection gt 0 0 eta vehicle queryDistanceToNextIntersection vehicle speed send traffic_light sync sync_point eta event exit vehicle isect geometry 48 5 1 APPENDIX CHAPTER 5 APPENDIX triggers EXIT_EVENT when EXIT_EVENT create LightSequencer EXIT_EVENT instigator Here are some more samples used to create various things in sdl these are from a biketown sdl file by Linus Volter create Sink radius 30 0 location sdl locator RDL South 100 Block 10 0 1 pos create TwinSource speed 25 0 proximity 30000 0 location sdl locator RDL South_200_Block 10 0 1 pos alt_location sdl locator RDL
77. work with the Road Network Editor program HORN Hank and OpenDRIVE Road Net works that was developed for working with HANK s scenarios as well as my experience implementing it and some of the fascinating rules for how to draw some exotic two dimensional geometries I found out about as I worked on HORN 111 Acknowledgements This work would not have been possible to accomplish without the help of my parents and my beloved Ingrid and my thanks go out to them for helping me and standing by me through it all My thanks also go out to my advisor Rita Kovordanyi for allowing me to take the time needed to finish everything and giving me goals to work towards and my opponent Jens Christensen who helped me improve this document in many small ways 1 would also like to thank my study councilor Siv S derlund for helping me to get through the education Contents 1 Introduction 1 LL Imtro ducto s s E A O A A A Arn 1 GIL Background O Be aS 1 1152 Similar work 2 3 gcse a va ser a ek ede oh ae d 2 TL YPurpose 2 ju wine Pa BE PALS a ak oe ee ee 2 ELA Method os dnt eek be Je eM lite ee etc hte ce Sh 3 141 5 Boundaries sc so oz aa ee ee ee eS len ER ra 3 MEME ASTTUCLULS in A cette ais A eS 2S 3 2 Body 4 21 Background y oy ad Qed be ae Byes a 4 2 1 1 OpenDRIVE o lg dl ALS 4 212 HANK 5 o a e ie ad SAR rr 5 2 1 3 Road networks o o 6 2 1 4 Road network editors 6 2

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