Plane always flies to right of waypoints

3691121799?profile=originalDoes anyone know what might cause the plane (Skywalker 2014 with pixhawk, 3dr gps/compass) to always fly to the right of the waypoints?  This results in my planned flight lines being alternately too close, then too far, apart.  This happens every flight, regardless of wind speed or direction; flying crosswind, or parallel. First flight line starts NE corner.

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  • Did you activate the Sideslip controller?
    • Yes. I enabled it, but saw no effect.   Maybe it's poor tuning, but I expect tuning is mostly about how quickly the plane responds and stabilizes -- I would think on a long flight line, it would eventually show an effect if it's going to work, even if my tuning isn't optimal...?

    • Post a screen shot of your basic PIDs.
    • 3702762677?profile=originalServo Yaw Integral was 1.0 when I was testing with side-slip controller enabled-- reset back to 0.0.

  • Paul,

    I've beat the trim issue to death. The log from 17 Jun is about it good as I can get. The plane is still flying side-slipped, even with left rudder trim and lots of right aileron trim.  Any idea (besides trim) as to why?  An experiment I could do? What's keeping the autopilot from moving the plane onto the flight line?

  • Mapper905,
    Did you ever resolve this issue?
    • I've made progress, but there are still issues (see recent posts). I haven't had a chance yet to try suggestions from "Drone-University".

    • Have you tried activating the Sideslip Controller? YAW2SRV_INT and YAW2SRV_SLIP?

      I tried this yesterday and it really helped to get the plane closer to the track, but I'm still noticing a slight left bank.

  • 3702868390?profile=originalIn fact, the rudder is visibly biased to the left.  However, to follow your suggestion, I still added some additional left bias.  In manual mode, the additional left trim is causing the plane to turn left now. However, in stabilize & FBWA it appears to be flying straight.  I re-flew the mission and there is significant improvement over the original.  Picture and log attached.  Interesting though, is that for the W->E lines, the plane is STILL banked left even though the crosswind is from the South.  This can't be right!?  I'm running 2.78b -- have there been changes to the firmware that might affect this?

    2014-06-15 18-56-18.tlog

    • Have you tried to set trim_auto = 1, then fly on manual mode with a perfect trim, then move to stabilize mode and check for improvements ?

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