Crash after autotune in Roll

Good morning all,

I wanted to improve the behavior of the drone by making an autotune in ROLL.

During the flight but after the autotune, the drone flew perfectly. once landed and the values ​​recorded, the drone no longer wanted to take off with the following message “Critical PreArm ACRO_BALL_ROLL / PITCH”
After searching the internet, I lowered the value of ACRO_BALL_ROLL to 0.90 to be below the calculated ATC_ANGLE_ROLL_P value of 0.903658.
Drone agrees to take off but once in the air, it swings permanently from left to right. It is very difficult to stabilize it. I switched from Position hold mode to Alt hold thinking that the problem of having to keep the drone in position. However the drone continued to swing. I know now that the problem is not a position keeping but a stabilization problem.

Here are my Logs:

Voici mes Logs : 12.11.2019 DANGER instabilité en ROLL.param (18.3 KB)

Quelqu’un peut m’aider?

I had this happen on a large hexacopter once. The auto tune returned values that were alarmingly low for ATC_ANG_RLL_P. Same for yaw and pitch. I think the value was 0.8 or 0.08 but on a stable tune it is higher around 5 or 6. I got the same Pre arm warning and similar behavior when airborne. I think the best option here is to revert to the old tune you had and attempt the auto tune again, at least that’s what we did.

Unless someone else can explain why autotune seems to return strange values sometimes, might be something higher level that I am unaware of.

A log file (.bin file from flight controller) of the flight where it crashed would help.

Have you read through the Wiki page on tuning here?

I would suggest you go back to defaults, read the wiki and make appropriate changes as recommended and try again.
Maybe start the autotune with a less aggressive setting and starting from current PID’s

Sorry for the late respons!

Thanks for your help!

mboland : Here are all the file of the flight!

Very greatfull for your answer

The PID values you had setup would not have helped.

You can see the roll oscillating from takeoff.

Go back to default PID’s, make the folder changes and adjustments mentioned in the Tuning wiki and try again.

I did the Tuning wiki and when i do it, the drone can fly but when i do an autotune, there is everytime this oscillating. i tried one more time and i crashed one more time…
I have no idea why…