What happens if multicopter gets up side down?

ArduCopter Copter 4.0
1

I have always had a multicopter (450-size quad) for testing of a lot of different controllers and other hardware.

A few years ago I tested very aggressive in Stabilize-mode flying in 5-6 m/s winds on higher altitude trying to se if it flips when changing directions, stopping fast and other insane moves without my own reactions to keep it level. I got it to flip a few times and every time it went stable… up side down. I rolled it back quickly because it didnt try to get it back by it self. Well, last time i planted it upside down in the dirt with a modest thump.
It was on an APM 2.6 (when Pixhawk just came out) and the version of APM:Copter I dont remember.
How does this work today? What happens? Does it get that “I am upside down and have to rotate back”?

I am wondering what happens if the wind is too strong with the 7+ kgs Vulcans (Pixhawk 2.1) I build novadays. They fly very well in 10 m/s, sometimes more, but the motors works a lot (Autotuned setup). But what happens if the motors cant keep it suddenly in a gust?

2

AP has a good separation between the “body frame” rate controllers and the “earth frame” attitude controllers so there’s not really much need for special handling for when the vehicle is upside down. If the vehicle gets upside down somehow it will just try very hard to get itself right side up and it should try and take the shortest path around the sphere to do that.

3

Thanks for the answer. It feels safely.

I remember one more occasion, but that was also with an APM 2.6 some years ago.
A 3DR X8 flying in mildly gusty winds in automisson. Flew well both along and against the wind but suddenly it went over forwards when flying against the wind and just dived from 130 meters straight to the mud. Stable all the way. :slight_smile: