Intertial Nav with Wheel encoders

ArduRover Rover 3.5
1

I’ve got an indoor rover and I’m not able to get it to to into Auto mode. Looking a the logs, I’m getting a “EKF Failsafe” when arming.

I’ve got:

  • Pixhawk 1 (w/ builtin IMU + compass)
  • Wheel encoders
  • No GPS

My inital thought was the the EKF requires an absolute position (ie GPS, or other system) reference. I’d previously tried setting the EKF origin in Mission Planner, but got the same issue.

Is it the case that I do require a position reference (GPS, Video Odometry, etc) before the EKF is happy?

[My initial hope was that the wheel encoders + compass would give enough data for the EKF to plot a reasonable intertial position]

2

@stephendade,

Wheel encoders should be enough but I have heard there is an issue with them in 3.5. I’m afraid I haven’t found the time to properly investigate it yet. I think older versions (3.4.x) will work. Sorry, I should have sorted this out but I’m trying to focus on object avoidance for 3.6

3

Ok, I’ll try that.

Just a note that the firmware.ardupilot.org appears to have the incorrect firmware versions.

Looking at:
http://firmware.ardupilot.org/Rover/stable-3.4.2/
http://firmware.ardupilot.org/Rover/stable-3.5.0/

Both have the 3.5.0 firmware in them. Exact same git versions and files.

I’m thing the build server must have hiccuped at some point and put the 3.5.0 firmware in the 3.4.2 folder…

4

@stephendade, how very annoying. I’ve created an issue.