Add Rover Simulation and sim config

[LorenzMeier]

This adds a full rover simulation for SITL and Gazebo. The physical config will follow this week for a Traxxas Stampede. This is to enable student projects at ETH.

Running it: make posix gazebo_rover

It kind of works already (tested manual and missions), needs further fine-tuning here and there. But I'm confident we can drive this outdoors already.

[mhkabir]

Sexy rover model there ;)

[dagar]

Likely not helpful here, but FYI there'a an old abandoned PR for adding ground firmware here - #6050

[marcozorzi]

I'm trying to test this and having issues. I cloned the pr-rover branches of both Firmware and sitl_gazebo and I get the same errors as above here:
[ 36%] Building C object px4/src/systemcmds/pwm/CMakeFiles/systemcmds__pwm.dir/pwm.c.o
/job/catkin/src/px4/src/systemcmds/pwm/pwm.c: In function 'pwm_main':
/job/catkin/src/px4/src/systemcmds/pwm/pwm.c:637:9: error: ignoring return value of 'read', declared with attribute warn_unused_result [-Werror=unused-result]
read(0, &c, 1);
^
compilation terminated due to -Wfatal-errors.

This can be easily fixed by changing line 637 of src/systemcmds/pwm/pwm.c storing the return in a variable (I used ret as done below).

After that the simulation compiles and runs but I encur in errors saying:

[Err] [gazebo_mavlink_interface.cpp:933] joint_control_type[velocity_kinematic] undefined.

These disappear if the joint type in rover.sdf are changed to velocity instead of velocity_kinematic. In this case, the simulation is not working, I'm still working on a fix.

[LorenzMeier]

@marcozorzi Worth re-trying. I removed the special joint type and added a velocity PID controller (which is also closer to what is around in HW).

[marcozorzi]

@LorenzMeier Yes now it's working perfectly

[Kiwa21]

Interesting pull request here ! It really is beginning to look like ROS/Gazebo simulations :)
I don't have a deep knowledge of the Rover stack. Do we have some kind of Lidar avoidance like we have in Copter with the SF40 ?

[LorenzMeier]

Thanks!

[LorenzMeier]

@Kiwa21 The rover parts right now are mostly for driving the vehicle. High-level navigation should be done in a higher-level software component.

[coveralls]

Coverage increased (+80.4%) to 98.367% when pulling a6a74f5 on pr-rover into 6e64bff on master.

[julianoes]

@coveralls took a while 😄.

[julianoes]

@sarahToonsi please don't necro-bump. Open a new issue an properly describe your issue, thank you.

[sarahToonsi]

@sarahToonsi please don't necro-bump. Open a new issue an properly describe your issue, thank you.

Sorry :)