Quad trembling (Small but fast oscillations) when in loiter mode

ArduCopter Copter 4.5
1

Hi all!

I have a large quadcopter platform (28" props) and am having trouble getting a stable “clean” hover in Loiter mode.
In Stabilize mode the UAV flies perfectly and feels really good, but, when I switch to Loiter, the UAV is controllable but has very fast and small oscillations when hovering.
I tried lowering the PSC_POS and PSC_VELXY, and it looks better, but the UAV does not maintain its position very well.

After some research in the forum, I saw that the cause could be vibrations, but I can’t tell what the acceptable values for vibration are. The wiki says, “Vibration levels below 30m/s/s are normally acceptable,” but in the forum, I saw some comments that 30m/s/s are not really good values and can cause some problems.

Any suggestions on what to do here?

The flight log is attached:

Thank you,

2

I managed to fix the problem by changing the:
PSC_ACCZ_P to MOT_THST_HOVER
and
PSC_ACCZ_I to 2*MOT_THST_HOVER

I forgot to do that in the first place…

3

That would had been automatically correctly done if you had used Correctly configure ArduPilot for your vehicles on your first attempt | MethodicConfigurator to configure your copter.

4

Thank you, I’ll try this tool🙏