Field Robot Event 2014 – Result

In good old traditon of beeing late to pronounce the result of this years field robot event, the best way to describe it is: “WE DID IT! Team Floribot scored rank 4!”

Field Robot Event 2014 results (.PDF)

But first things first. Last year we identified some major issues with our concept of navigation and the setup of our robot. In the team meeting after the event we decided to use the year of preperation and apply some major changes. One problem of the setup was, that the tank kinematic had it’s issues with to much wheelspin. This way it was impossible to use odometry to determine the correct position of the robot at the end of a lane. Also the wheelspin interfered with a smooth turn to the next lane. So we changed the kinematic setup from the tank kinematic to a differential kinematic with an additional castor wheel. This way we only had three, instead of the former four, contact points and reduced the wheelspin to a minimum. Furthermore this change allowed us, to drive nearly perfect circles.

The second major change was with the concept of our navigation. Last year we used the ROS internal navigation and had quite some issues to adjust it to the contest field properties. So we decided to change our workflow and create our own navigation algorithm. This way it would be much easier to adjust the navigation to the contest rules. Also instead of inserting C/C++ code into the ROS system ourselves, we now generate the C/C++ code with Matlab/Simulink and are able to simulate the code, before we even need to push it on the real system.

Moreover we did a lot of minor chages, too. For example we now have an alternative way to manually control the robot with a Java application, instead of the Wii controller. Besides the team organization improved, thanks to a specific time mangement.

Overall the changes paid off and we scored in our third participation rank 4 of 23 competitors. This fantastic result even attracted some attention to the VDI news. If you like to read the article, just klick on the following link:

VDI news of the Field Robot Event 2014 (German article)

At the end I like to thank all my teammates for the great work they’ve done, in order to get everything ready in time. I know last year was quite exhausting, but in my opinion the effort was totally worth it ;-) .

Start the ROS stage simulation with a MATLAB/Simulink project

This guide is about how to get the ROS stage simulation going combined with our current MATLAB/Simulink project. As usual terminal commands are printed blue.

Note: This guide is not about how MATLAB and ROS stage do communicate with each other. It’s a manual for team member.

Step 1:

Source the “setup.bash” in the “floribot_ws/devel/” directory and execute the launch script “launch_stage1.sh” in the “floribot_ws/src/” directory. The roscore and the stage simulation should be started automatically.

source floribot_ws/devel/setup.bash

./floribot_ws/src/launch_stage1.sh

Step 2:

Open MATLAB and add all folder and subfolder of the directory “floribot_ws” to the MATLAB path (Add to Path -> Selected Folders and Subfolders). After that open with MATLAB the project “floribot_simulink.prj” that is inside of the “floribot_ws/src/” directory.

Step 3

Now open “simulink/robot1_MIL.slx” and start the rosnode connection with the function “start_rosnode” that is accessible at the “project shortcuts” tab. Otherwise execute “start_rosnode” inside the MATLAB command window.

Step 4

If no error occures, open the subsystem “wiimote” inside the Simulink model “robot1_MIL” and start the simulation with the “Run” button. The robot inside the ROS stage window still does not move. First it has to be set to automatic mode with the switch “button_2″ inside the “wiimote” subsystem. After a simple flip of the switch the only thing the robot still needs is the information where it should turn after the end of the first lane. In order to provide this information simply flip the switch “button_left” for a turn to the left or “button_right” for a turn to the right, after the first lane. With this final flip the robot should start moving inside the ROS stage simulation. If you like to cancel the movement of the robot, just stop the Simulink simulation with the “Stop” button.

Field Robot Event 2013 Result

Well it passed quite some time since the Field Robot Event 2013 in Prague, but we are proud to announce that our “Floribot” made it to the 12 th place out of 18 participants.

Results Field Robot Event 2013

Now after this years contest, I like to share some of my impressions that I collected while beeing part of the team “Floribot”. For the most of our team members, including myself,  this was the first experience of an event like this. We arrived at Prague on the 26 th June at the late evening and got the keys to our rooms for the next four days. The rooms were simple student appartments with unfortunatelly no access to the internet. After that we saved us a spot at the working area, where we and all the other teams used to work on our robots. Later we decided to take off the rest of the evening and visit central Prague. I only can say Prague at night is quite impressive, even though the local food prices are quite expensive.

Working AreaOn the first day of the event the field was open for the teams to test their robots under real circumstances. We did a lot of prepartion before the event in order to test our robot under as authentic conditions as possible, but nothing can be compared to reality. Even the paper plants, that our “Project Managing Group” provided us to test, were completly different compared to the real plants.

We worked until late at night on our programs, that did a good job on the simulation, but had quite some difficulties with the measures of the real plants on the field.

On the next day the test field was closed at 12:30 p.m. and the contest began half an hour later. We did our best on this short period of time to adjust our programs to the field conditions although we had quite a lack of sleep. In the end we were able to do a solid performance on all three tasks although not everything worked as intended.

At the end of this day we had the chance to unite with the team “Helios” for the cooperative task. We shared our experiences and worked together quite well. Furthermore our moods were still positive thanks to the self brewed beer that the Prague university provided us at this evening for free ;-) .

At the last day of the field robot event we finished our programs for the cooperative task and managed it to get on the 4 th place. After that we packed our tools and drove back to Heilbronn.

As conclusion I can say, that even though the trip to Prague was quite exhausting, we did a lot of work in a short periode of time and still had fun doing it. We learned a lot from other teams that participated more often than we did and we were able to identify some problems in order to improve ourselfs. For myself, I’m happy to be a part of this great team and I’m eager for the next Field Robot Event, because of all that experiences we made we have a good chance to score even better the next time.

 

Task 1 World

One of the first tasks for the Floribot project is the creation of a new worldmap for the virtual environment ROS stage. The map follows the rules of the Task 1 2013.

You can get a quick overview from the following picture:

The major changes are:

  • Improved load speed (no use of .png files anymore)
  • The floribot now starts at position [0 0]
  • All boarders are now closed
  • Use of “ranger” instead of “laser”

You can launch the world with the following command:

rosrun stage stageros task1_2013.world