Octoquad gets strip

I have an Octoquad seemed to be okay at the Loiter mode (after doing AutoTune) except one thing. It strips - something like losing altitude in the very short time, say, about 5cm at 0.5s. After that, it get stabilized again for some certain of time (about 10s) and it strips again. I can actually here the sound of motors changing speed. By looking at the log file, I could not find the right track to analyze.

Does this symptom sound familiar to you guys? If yes, please share you experience, and even guiding me for the log analyzing (show me where to look at) is very appreciated.

Thanks in advance.

Here is the log files:

Probably you need to tune the altitude controller.

Can you please a little bit specific? Which wiki link I have to follow. Thanks.

google “ardupilot altitude controller”.

  1. This is the first hit: https://ardupilot.org/copter/docs/common-understanding-altitude.html
  2. This is the second google hit: https://ardupilot.org/copter/docs/altholdmode.html
  3. And if you realy want to know how it all works, here is the third google hit: https://ardupilot.org/dev/docs/apmcopter-programming-attitude-control-2.html

You are welcome :wink: