I never got any further with this - would love to know more!
@proficnc Have you heard anything more about this? Or, @rmackay9 maybe this is something youâve run into?
did you look at this?
https://discuss.ardupilot.org/t/dealing-with-vibrations-and-harmonics-a-competition/13619/17
some good info thereâŚ
do a high rate logging flight, and then the FFT, this will tell you whats going on.
if you have vibrations in the 80Hz range (FFT will tell you) you may need to add a wide base, very soft low frequency isolation under the systemâŚ
ONLY do this is the FFT check says you should.
Per @proficncâs recommendation (and @Charlie_Râs post) I got the attached FFT. There is clearly some nastiness happening in the ~80hz range, which IMUs 1 and 2 pick up but IMU3 doesnât. Clearly theres a tradeoff between the damped and undamped IMUs when noise is either below or above 100hz.
@proficnc one concern I do have is that IMU1 seems to be picking up quite a bit of noise around 180hz. Gyro1 also seems to be getting hit in the same band. Strangely IMU2 doesnât see those problems. Something to be worried about?
-Allan
