Frequent Asked Questions

This are the frequent asked questions about UsarCommander, an open-source environment for mobile robot control. UsarCommander is designed to visualize the world as a robot sees it, which allow the developments of algorithms for operator-assistance when operated in tele-operated mode and navigation strategies when operated in autonomous mode.

Q: Can you give some hints for the Warm-up Assignment? A: Stanford has some very good hints in their FAQ.

Q: What is the location of the svn-server?
A: svn://

Q: I can access the software on the svn-server, but cannot commit any changes!
A: This fall there is access control on the svn-server. You first have to assigned to a group before you can commit any changes. Send an email to with your request.

Q: The software is build succesfully, but VisualStudio shows a dialog that a Class Library cannot started directly!
A: Select in the Solution Explorer UsarCommander, and select it as StartUp Project.

Q: How can I search the whole solution?
A: Add the 'Find in Files'-button from the Customize->Commands->Edit menu.

Q: Why are there so many options during configuration, and so little protection against misconfiguration.
A: The environment is designed for research, where you try to keep all circumstances constant and only change a single parameter. After a short learning-curve, the initial mistakes do not longer occur. And when they occur, the program directly exits, to prevent that you continue with a wrong configuration.

Q: I have to specify the ip-number of my server. How can I find the ip-number of a computer?
A: Run ipconfig on the commandline.

Q: The program crashes in the Constructor of CommAgent.
A: The team configuration is not yet instantiated. Push on the blue ball and complete the dialog.

Q: I spawned the Agent succesfully, but nothing happens.
A1: Check if the radiobutton 'Spawn for Commander' is activated. If not, activate.
A2: Check if one of the visualisation layers is activated. If not, activate for instance the layers 'Agents' and 'Obstacles'.

Q: What is the coordination system used by the robot?
A: The robot is using a right hand coordinate system (see section 6.1 from the USARsim manual).

Q: What are the dimensions of the soccer field?
A: The dimensions can be found in section 1 of the 2003 rules or 2006 rules.

Q: What are the locations of the landmarks around the soccer field?
A: The locations of the landmarks are available in the files landmarks2003.txt and landmarks2006.txt.

Q: How are the signatures defined?
A: There are 4 colors in two combinations used for the landmarks: signature 0 -> green 1 -> magenta/pink 2 -> yellow 3 -> blue/cyan.

Q: Using formula (7.11), the elements of the Jacobian Vt (representing the motion model) become infinite for small omega. Can this be prevented?
A: No quick answer for this question yet. Start experimenting with non-straight motions or derive a separate 1-D motion model for straight motion.

Q: How are the layers rendered?
A: In ManifoldImage:RenderPatch is a loop over all layers.

Q: Currently a Release version is build. How can we build a Debug version (without run)?
A: Add to the standard Visual Studio toolbar the Solution Configurations box, by selecting Tools->Customize->Commands->Build->Solution Configurations.

Q: I have added the Solution Configuration box, but this box is inactive (grey)?
A: Go to Tools -Options, Projects and Solutions, General, and check if "Show advanced build configurations" checked? Otherwise, try as last resort devenv.exe /resetuserdata.

Q: How can I print in G0.25?
A: Select printer P005437. The printer can be found in the back of the room.

Q: The Neodym library does not build.
A: Remove in Solution Explorer the current references to AssemblyInfo.cs en Resources.Designer.cs, and replace them with two files in Third Party\Neodym\Properties.

Q: The reference between the Neodym library and projects Agent and Slam is broken.
A: This problem is partly due to the difference between Debug and Release configurations. Select de properties from the projects Agent and Slam, go to the references tab. Delete the current reference to Neodym.dll and Iridium.dll, and replace them by browsing to a library you just build Third Party\Neodym\obj\Release and Third Party\Iridium\obj\Release.

Solved issues

Q: The program crashes in the BufferedLayer.
A: Your number settings are probably Dutch. Change to US-number system and rebuild your solution.
S: Since rev. 1539, the culture is explicitly set to 'en-US'.

Q: The program crashes in the function TcpConnection.Connect.
A: You used the wrong IP-number for the UsarSim server. Check for instance with ipconfig at a command prompt what the IP-number of your local machine is. Local loopback (IP doesn't work.
S: Since rev. 1982, this exception is handled. On the console an 'Error connect to host' is printed.

Q: How many sonar sensors are mounted on a P2AT, and which direction are they headed?
A: A P2AT has 16 sonar senors. This geometry information is read from UT2004/System/UsarBot.ini. In the default configuration a P2AT has 16 sonar sensors:

This means that F4 and F5 are looking nearly straight forward, and R4 and R5 nearly straight backward.
S: Since rev. 1577 the number of front and rear sonars and their direction can be accessed by the calls: Agent.SonarSensor.FrontYaw.Count, FrontYaw(i), RearYaw.Count and RearYaw(i).