Servers by jDrones

Slow Roll Rates in FBWA

(Charles Young) #1

I’ve successfully maidened my 1st Wing Wing Z-84 running Ardupilot (Chibios, Matek F405-Wing) and I’m very very happy with it – super impressed with how locked in it feels. I’ve ran an autotune (at level 7) and increased roll and pitch limits to 60deg (parameters LIM_ROLL_CD and LIM_PITCH_MAX, _MIN).

I’m looking for some help with Roll rates (and less so with Pitch rates ) in FBWA mode – the plane feels a lot less snappy than I would like (well, when compared to my Eagle Tree Vector planes).

Current Roll PIDs at 0.678 / 0.065 / 0.054 and Pitch PIDs at 1.126 / 0.112 / 0.090.

Is the parameter that I need to change RLL2SRV_TCONST / PTCH2SRV_TCONST? It’s currently at 0.4s. Does STALL_PREVENTION affect this as well?

@hurzburg has suggested looking at the _RMAX parameters. Any further insights?

Cheers and thanks,

My Wing Wing Z-84 (and some other planes too!) Efficiency Comparison Spreadsheet @googlesheets
My YouTube Channel

(Graham D) #2

Change your roll P to 1.000 and I to 0.100 and it will feel much better, or put the autotune level on 8 or 9 and do autotune again

(Charles Young) #3

Thanks for the suggestion Graham! List of things to test so so far:

  • PID tuning wiki - reduce PTCH2SRV_TCONST and ROLL2SRV_TCONST [http://ardupilot.org/plane/docs/roll…roller-tuning]
  • Atx_heli @ rcgroups - “lower/zero RLL2SRV_RMAX and PTCH2SRV_RMAX” [tooltip suggest it’s for ACRO mode only?]
  • Graham_dyer @discuss.ardupiloit- “Change your roll P to 1.000 and I to 0.100; or run autotune at level on 8 or 9”
  • mike_o @rcgroups - "reduce L1 turn control to 12-13 [tooltip suggests it’s for AUTO mode only?]

Weather’s poor atm, so no testing soon. Please let me know of any other ideas/suggestions!

Cheers