Autotune problem of DJI S900 frame

ArduCopter Copter 3.4
1

Hi everyone, I’m a beginner, I have some questions of autotune, hope you can help me to figure out, I’ll appreciate with your kindly help.
The following is my equipment:
Aircraft hardware configuration
DJI S900

Motor DJI 4114 400KV

Paddle DJI 1552

3DR PixHawk

firmware Copter 3.4.1

Here’s the question, I use two version, “firmware Copter 3.3.3 autotune” and “firmware Copter 3.4.1 autotune” to adjust Rate Roll、 Rate Pitch and Rate Yaw, why thery have so much difference? Is that normal phenomenon? Will that be able to resis instand gusts? ( please see the attached pics)

3.3.3 autotune

autotune 3.3.3.jpg743×348 45.3 KB

3.4.1 autotune

autotune 3.4.1.jpg741×351 47.2 KB

yes, the point is that I use the same aircraft but difference firmware versions, the values vary widely, will that be the problem?

Looking forward to hearing from you.
Thank you very much.
Oscar

2

Hi,

there was a large refactoring of that area between 3.3.x and 3.4.x versions. For those that choose to migrate the firmware should handle the conversion of the old settings to the new settings. As a rule of thumb that I use I always redo the calibrations when flashing new versions.

3

It’s hard to be sure but the rate gains look far too high especially for the AC3.4.1 autotune.

I guess you followed the instructions on the AutoTune wiki page? http://ardupilot.org/copter/docs/autotune.html

In particular I think it would be good to reduce the AUTOTUNE_AGGR parameter to 0.05 (http://ardupilot.org/copter/docs/parameters.html#autotune-aggr). All the other advice on that page is also important though like:

  1. remove the gimbal and any other bits of the vehicle that can flop around
  2. ensure the axis being tuned is twitching perpendicular to the wind
  3. maybe reduce ATC_RAT_RLL_FILT and ATC_RAT_PIT_FILT to 10 (http://ardupilot.org/copter/docs/parameters.html#atc-rat-rll-filt)

Hope that helps, thanks for using ardupilot!