Roll oscillations, Pixhawk, Twinstar

ArduPlane Plane 3.7
1

I’m having this issue in plane 3.6, .7 and .8 beta and I suppose it´s not version-related so I post it here:

I have an issue with my Twinstar platform. Generally it is super reliable and stable. Recently I tried a few flights in stronger winds (~20-30 km/h) and experienced roll oscillations sporadically. Sometimes they stopped without intervention, sometimes I ewnt to manual for safety reasons.

Roll/DesRoll and PIDS

dUp.jpg815×244 24.2 KB

Short SlowMo video of the issue:

I asked this at various places and got any number of suggestions. I already tried increasing D (no change) a little and reducing P to half the value (sluggish behavior but no more oscillations). The latest suggestion was to kill D because planes in general wouldnt need D at all, just P and a little I. I am looking for more input.

I am especially interested in how planes react to PID settins. There´s a lot of info when it comes to copters - too much P - this happens. Too low D - this happens. Couldnt find that for planes. Any ideas on that besides my little Twinstar problem ?

Oh and I have to say…if winds are not that bad, in the <15km/h range, it flies just great !

2

TSII.txt (5.1 KB)

Here is my TSII parameters. Mine flies great. Maybe this will help you.

Thanks for introducing me to Dashware, very nice!

3

Thx, man ! I see that you fly my current RollP of .85 but lower D. That´s what I was planning to try next. I´ll let you guys know :wink:

PS. Dashware rocks !

4

Putting RollP to .85 and lowering RollD to .02 did help A LOT: