Discussions

Pixhawk Auto Mode elevator / throttle glitch

Posted by SlipstreamFPV on February 27, 2016 at 9:29pm

The pitch servo and throttle are constantly pulsing very quickly in auto modes:

3691278920?profile=original

I've done a fresh flash whipping all old settings and re-tuned my plane with the same result. Does anyone know what can cause this issue? I'm worried it might be a bug and with enough pulsing the pitch servo or ESC might give up!

There is a log here:

https://www.dropbox.com/s/sfbm41ro714iq8d/4.BIN?dl=0

I'd be very grateful if anyone who can read the logs better than me could have a look and see if anything sticks out. In comparison roll has no issues and is a very clean graph between desired and actual roll. The plane was flown on a relatively calm morning.

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

Join diydrones

Email me when people reply –
Follow

Replies

  • Corrie Venter February 29, 2016 at 10:12am

    Take a read at this post, sounds very similar . . .

    http://diydrones.com/forum/topics/fbwa-servo-jitter-when-gps-has-no...

    • SlipstreamFPV > Corrie Venter February 29, 2016 at 5:58pm
      Interesting. Certainly the graph on the ground looks similar. I have 2 GPSs on the plane. I wonder if that has an effect. The linked threads in that link still don't have the exact same features and there doesn't seem to be a particular fix either. I think THR_MIN is on 0 in this case to allow the autopilot to glide.
  • Moderator
    Graham Dyer February 27, 2016 at 11:36pm

    What are your pitch PID's set to?

    • SlipstreamFPV > Graham Dyer February 29, 2016 at 3:42am
      P 0.65
      I 0.04
      D 0.02

      Roll is the same and behaves well. I did an auto tune and it originally had P a bit higher but I turned it down by .15 to see if that was causing the oscillation or noise on the pitch output.

      Thanks for looking into this!
This reply was deleted.

Activity

Neville Rodrigues liked Neville Rodrigues's profile
Jun 30
Santiago Perez liked Santiago Perez's profile
Jun 21
More…