Cheerson CX-OF - Flowhold - Whobble

[dreselen]

Today i tested the Cheerson CX-OF sensor in the field.
Loiter and Stabalize work flawless

There is a oscillation (whobble) while hovering in flowhold mode.
It disappears when flying low (<3 ft) or at higher speeds and is very noticable hovering at 5 - 20 ft altitude.

When taking a look at the logfiles, i can see an oscillation

2019-01-10 10-46-58.bin

Looking at the times where GPS.Speed is around 0
and then look at any Flow or accelerometer oscillations

How to finetune this oscillation. Is there a PID mechanism for flowhold?

Frame is 25" spinning 1155 props on 3S LIoN (hence the low voltages at high current)

[dreselen]

For others having the same issue;

I Decreased

FHLD_XY_I to 0,2
and Decreased

FHLD_XY_P to 0,1

Try adjusting these params… Maybe it solves your issues to

[ppoirier]

have you looke at the original blog ?

Cheerson CX-OF low cost optical flow sensor testing

What I described above as a strange behavior: … when I switch from Loiter to FlowHold I see the Copter oscillate quickly in roll and pitch (like if the Roll / Pitch PID was bad tuned), then if I move the quad a little bit around (with RC) the oscillation disappear and the Copter remain stable. should be a normal behavior from what I read in the wiki: Because no Lidar is used in this mode, the optical flow sensor is used both to estimate the vehicle’s height above the surface and the vehicl…

[maroquio (Ricardo Maroquio)]

Hello. Did you got some other better values for these parameters? I’m facing this problem too. Reducing the ?_FILT_HZ to 2 solved partially, because the displacements are higher, i.o.w., the drone position varies a bit more.
Regards!