Hi I got an xls sheet from Shawn, where some filtering frequencies as re-calculated according prop size.
I found something strange:

All ACC_RAT_XXX_FLTT and FLTD parameters moves together (e.g. for 22" prop it is 11Hz, for 10" size prop they are 21Hz, except for one which is the ATC_RAT_YAW_FLTD which is 0.
in ardupilot it is standard 0 too, but in the remark a 5…50Hz rate is defined.

So my question: should it be 0 or 11?
What is the difference in behaviour?

Ps. Today i made a test flight with the rebuilt x4 (22" props), where the above mentioned parameter was set to 11Hz.

I found a strange behaviour:
In loiter mode moving into one direction (e.g. to right) not to fast and stop in one position (again not really suddenly - almost softly) and the drone made a tilt movement into the other direction - in that case left. Which could be normal - to be able to stop, but somehow the altitude seemed too high 20-30 degrees.
Is it normal? Can it be because of this param?
If not what else?


FLTT is a way of removing noise in the control loops coming from the EKF and RC input. If you set it too low you will remove some of the responsiveness of the craft, but too high and you will get a little more notchiness from these sources. For example on my 3" quad I have FLTD set to 100Hz and FLTT set to 30Hz. If I set FLTD to 30 the copter would be unflyable, but keeping FLTD high and lowering FLTT makes for a smooth locked in feel.

On yaw things are a little different because the response is based on the movement of the motor bells. Typically FLTE is tuned instead of FLTD. I do not tend to set FLTT on yaw

Let’s see a .bin log, it sound like you’ve got classic yaw issues that changing the filter values won’t fix.

I checled the today logs ans the vibe values were high. (I was shocked ) closed to 30-40.
Im checking all the props/motor balance. And will flight a new soon hopefully with smaller vibe and will upload that one. Im curious if the strange yaw behaviour will remain. Coming back soon.