When GPS lost, copter use FS_EKF_ACTION: EKF Failsafe Action and switches to althold mode and starts to accelerate

Yes. Pitch and Roll tune look pretty good. Yaw could use some work. Set INS_LOG_BAT_OPT to 2 and make another hover flight to see how well the Dynamic Notch Filter is working. After disabling the Static Notch.

I do not quite understand how to see that the filter is working

Set the parameter I said, make a short hover flight in Altitude Hold and post a link to the log.

Ok, will try in a few days and will sent!

I couldn’t fly yet because the weather was bad. My friend tried to fly with the drone set up as you wrote and said that the drone also picks up speed when the GPS is lost!
Please watch this video from the simulator, the simulator also shows a problem with a speed increase, described by me, maybe it’s a firmware bug?

video

What else would you expect with no positional data flying in an assisted mode?

altitude retention, and drifting by inertia and wind, definitely not acceleration!

it picks up speed like it’s on full throttle

the copter must stand in alt hold and not roll and pitch!

I have a dji a2 FC, when the gps signal is lost, it simply drift and does not go anywhere at full throttle

We need .bin file and videos. Just videos alone are not enough.

there were logs in the chat, but I already deleted them, there were vibrations along the x-axis in the logs, but vretli can cause this behavior, the simulator itself confirms this! There will be an opportunity I will make one more test flight but I am sure it will be the same even if everything is perfectly tuned!

It’s probably doing what you have configured it to do. Why didn’t it Failsafe to AltHold if that’s what you want?

We will need to see a .bin log of this to know anything further