Rover with Reach RTK and Navio, suggestions about software and settings for Ardupilot


My project is to make an autonomous 4 wheeled robot driving into vineyard and doing some work. It must stay within ±10cm along the line between waypoints and drive at around 1m/s. At the end of each line, it must turn 180° at very low speed and then drive in the next line and so on.

My configuration:

-Robot size and weight: 120cm x 80cm ~150kg
-4 motors, one on each wheel commanded by one servo output
-4 directional wheels commanded by one servo output
-Navio2 + Raspberry Pi board with Reach RTK GPS positioning (we can assume we’ll have FIX status all the time)
-Ardupilot with APM:Rover3.2
-Time to achieve desired angle with steering from straight to full left/right: ~2 seconds
-Turn radius: 60cm

I have been playing with “ATC steering…” settings and find it hard to find good settings for:

  1. Driving straight in the "lines"
  2. Achieve very sharp turns at the end

My question is:

What would you think is the best way to make it work? I don’t want to re-code Ardupilot but rather use it for what it can do good.

I have been thinking of using Mavproxy and/or ROS with python script in Guided mode:

-It would check some parameters, if ok then put it in Guided mode and drive to one waypoint. It would then stop and the “script” would take over setting wheels to full right/left, waiting 2 seconds, driving at low speed until IMU/Compass shows 180° turn. Then check again some parameters, setting Guided mode again to the next waypoint and so on.

Does it seem like a good idea?

PS: I also got very confuse about all Steering settings and Navigation settings in Ardupilot. What basic tuning values would you use?

Thanks for your inputs.

Pretty much in the same situation! Will stay tuned to the topic and describe my problems also

yes, it will work. But the precision and reliability of Reach might be a problem.
Make sure you follow all recommendations for GPS antenna placement and test it. Test it a lot.

Thanks for giving ArduPilot a try.

The tuning instructions are here but if you’re having problems getting it to drive well, the best thing to do is to download a dataflash log and post it here.