GPS, hpos and vpos errors whie simulating rover on sonoma_raceway

Hi there,

I’m having a lot of difficulty, with no success, trying to simply have a successful “drive” around Sonoma Raceway world with the rover.

I have checked out the v1.12.0 PX4 tag and have set up my environment. I can build PX4 no problem.

Here are the steps and some observations:

  1. build PX4: make px4_sitl_default gazebo_rover__sonoma_raceway
  2. In QGC: Set up way points around the track using the “relative to terrain”
  • Note here that I get errors saying “waypoint below home” and no matter what I do I cannot resolve these. I have no idea if these are the root cause of the issue.
  1. Try to start the mission
  • this is often unsuccessful and I have to just click around on Arm, and start, etc and eventually it starts. It often says that the vehicle rejected arming but there is no output on PX4 that says anything.
  1. Mission starts and eventually the vehicle appears to loose GPS and the watchdog sets hpos, and vpos error bits.

I have yet to just simply have the rover drive anywhere and not have some sort of catastrophic failure.

I don’t have any failure injections enabled.

Is this expected? Why is the gps loosing signal in a simulation? Is the EKF just not able to cope with the vibrations of the vehicle? Or is something else happening here? I was expecting to be able to simply set waypoints and have the vehicle drive through them and only when I introduce errors would things go wrong. That doesn’t appear to be the case.

In the flight log you can see the “glitch” at about 50 seconds in. In this particular run the rover is somehow able to recover and continue driving but that is not typically the result.

Here is my flight log:

Should I I be posting on gazebo’s support forums?

After more investigation I noticed that right before the GPS failure I see this message in px4:
INFO [commander] Takeoff detected

Wondering why that is…