I’m a newbie on PID tuning, my UAV twitched in stabilized mode and immediately rolled and crashed when switching to POSITION mode.
The logs link here.
What I learned from the log , FD_FAIL_R is the default value 60, in POS mode, the UAV’s rotation angle exceeds this max angle ,so triggered the attitude failsafe . The roll rate controller’s PID settings are rather moderate with:
MC_ROLLRATE_P=0.2
MC_ROLLRATE_I=0.16
MC_ROLLRATE_D=0.005
It seems to me that this pid settings are not the reason it rolled over.
Could someone patiently have a look and give me some advice on the possible reason and how can I improve it.
Thanks for any advice.
There is huge jump in throttle (to zero) just before switching to posision mode.
Which translated to high thrust because of how hover thrust is set. I would guess that following thrust jumps could have caused drone instability and crash.
You should try setting hover thrust to ~0.25 and to center throttle around it.
Also vibration is quite high.
Thanks very much for your help,@coolvision, currently this MPC_THR_HOVER value is the default 0.5, I would try setting it to 0.25 asap ,e.g, after the uav fixed and notify the result. BTW, this uav used to fly well with APM and lately we switch to PX4 without change anything so I am wondering what may cause this high vibration.
