Fixed wing autotune question

ArduPlane Plane 4.5
1

The autotune level just changes the rates? Or does it increase how aggressive the pids are tuned?

2

You set the desired rates with AUTOTUNE_LEVEL
https://ardupilot.org/plane/docs/automatic-tuning-with-autotune.html#autotune-level-settings

It does change FF, P, I, D on all axes that you have specified in bitmask.
https://ardupilot.org/plane/docs/parameters.html#autotune-axes-autotune-axis-bitmask

Afterwards, check that the I-Gain for Pitch does not cause 1Hz Oscillations during Level Flight.

3

Would it make sense to use different levels for roll and pitch. My plane can do a full roll rotatarion in 1 second. That would be level 11?. Pitch is aroud ,level 7.

4

Could i use aurotune level 0 and set my max rates? I know what the plane can do. 240° sec roll 90° sec pitch. Im just not sure where i should put those rates. Or am i better off just using a level?

5

Just autotune in level 8 and set your desired rates in ACRO.

https://ardupilot.org/plane/docs/parameters.html#acro-roll-rate

6

I use different value of autotune on my flying wing.
Not sure about tuning at level 11 anyway. I never tried so hard

7

I assume ACRO is what Squirrel5 wants. There is a wiki section for it.
https://ardupilot.org/plane/docs/common-aerobatics-tuning.html#verifying-the-rate-capabilities

8

Im talking about regular fbwa autotune. I wasnt sure if i should use the correct level to match the planes rate capabilities. 90°/s pitch 240°/s roll.

9

You can theoretically select autotune level 7 and only the bit for pitch, then autotune pitch.
then the same with level 11 and only the bit for roll selected.

But honestly I don’t think it makes sense if you only fly FBWA with limited roll angle. You have to think about inertia and that you may have not enough time to start the roll, roll with your intended rate and stop the roll before overshoot.
People who tune rates manually do a full roll because it’s easier to tune.

1 Like
10

I fly acro too. The plane is experiencing excessive wind disturbance. I was hoping if i tuned at the ful rate it could react a little better to the wind

11

I haven’t done it myself, but I believe that would be phase margin and d-term at work, i.e. you would need digital servos for a faster control loop to reduce time to correction and d-term to fight short term errors induced by wind.

Means you’re back at

https://ardupilot.org/plane/docs/automatic-tuning-with-autotune.html#tuning-light-agile-aircraft

EDIT:
IMO that’s all wasted effort, you can only fight wind with mass and power, i.e. cruise speed.
I own a ZOHD Drift and experienced the scenario when wind exceeds cruise speed.
I just don’t fly that plane if there is wind and cut auto missions short if I see wind coming up.

12

Oh ok. The plane weight is around 1900g with a 1080mm wing span. It just feels to twitchy in fbwa compared to manual flight