Rover goes in tight circles when in Auto and RTL mode. Error Compass Variance Alert.

Posted by Robert Kyamoto on November 13, 2015 at 7:03am

The rover works completely in manual mode, but whenever I switch to auto or RTL the rover just turns in tight circles. I get an error message "Error compass variance". I recalibrated the compass, but that did not do anything. Could I be receiving too much interference from the motor controller? Below are pictures of my build, and various mission planner windows.

IMG_4056.jpg?width=750

ScreenShot20151113at9.32.26AM.png?width=750

ScreenShot20151113at9.32.36AM.png

ScreenShot20151113at9.34.07AM.png?width=750

You need to be a member of diydrones to add comments!

Join diydrones

Tags: ardurover
Email me when people reply –
Follow

Replies

  • Nathan Jones January 25, 2017 at 9:49am

    I've noticed if I let the Pixhawk do the mixing the power is decreased, especially in turns. I remember reading somewhere that it's coded to decrease power by 50% on each side for turns. I haven't found the right combination to make it drive in auto mode with the Pixhawk NOT doing the mixing..

  • t3Man January 24, 2017 at 3:00pm

    Hi All,

    I've been fiddling with a new drone and can't seem to get this figured out either. 

    I have a SaberTooth ESC and have tried mixed and independent modes with various settings and wiring configurations.    The mixed mode is much more responsive than the independent mode, or at least what I have experienced.

     I have a 4 WD chassis with a motor at each wheel.  I've tried skid steering and non skid steering.

    I've managed to get the chassis moving in the right direction using the RC controller in a couple of different configurations.  But when in the auto mode only one configuration allows the chassis to move in a predicitable way, but that configuration has issues with steering at low speed. The chassis moves to the first waypoint and then stops, not sure what is going there yet, Any suggestions?

    But my question is this.

    Is there a reason the pixhawk has to be in the Skid Steer mode?  Can someone explain the control logic and why it is required to have the PH in skid steer mode? 

    Thanks,
    Tim 
     
    Nathan Jones said:

    Did you ever get this figured out? Mine is doing the exact same thing...even the variance error. My Pixhawk and Compass are directly in-line with each other. Should I raise the compass above the Pixhawk? Much like you would have setup in a standard multirotor config?

    Did I mention the Sabertooth's manual drives me nuts when it states "up and down" for the switches instead of "on and off" as it's labled? I plan on changing the mixing to "indpendent" and then skid_steer_out to 1 as mentioned above.....

  • Nathan Jones December 12, 2015 at 7:33pm

    Did you ever get this figured out? Mine is doing the exact same thing...even the variance error. My Pixhawk and Compass are directly in-line with each other. Should I raise the compass above the Pixhawk? Much like you would have setup in a standard multirotor config?

    Did I mention the Sabertooth's manual drives me nuts when it states "up and down" for the switches instead of "on and off" as it's labled? I plan on changing the mixing to "indpendent" and then skid_steer_out to 1 as mentioned above.....

  • Darius Jack November 29, 2015 at 10:25am
    First compass checked
    Secondary compass checked
    Third compass checked

    what's wrong ?

    Just disable all compasses, go outdoor and use GPS generated heading
  • Admin
    Thomas J Coyle III November 28, 2015 at 2:39pm

    @Jake,

    Why do you have APM with External Compass checked if you are using a Pixhawk?

    Also, I would put the 3DR telemetry radio at the rear of the Rover away from the GPS.

    Regards,

    TCIII AVD

  • MR60
    Hugues November 24, 2015 at 12:36pm

    The compass variance comes from thé différent orientation between the Pixhawk and external compass. You seem to have a 180degree difference based on your pictures. You ave to set the orientation parameter right of the external compass.

  • Admin
    Thomas J Coyle III November 19, 2015 at 4:33am

    @Jake,

    You should have always had the Sabertooth in the independent motor configuration and SKID_STEER_OUT set to 1 so that the Pixhawk would do the differential steering mixing.

    Regards,

    TCIII AVD

  • heliboy November 18, 2015 at 4:51pm
    Same problem. Something weird is happening. My bot worked just fine but all we do is do tight circles. Gps lock is fine. No changes made. Sucks. Wife is mad that I am upset at all the time wasted.
  • Darius Jack November 13, 2015 at 7:21am

    Hi,

    what about Battery 0.00v 0.0A ?

This reply was deleted.