Crashing during terrain following

Benjamin · September 10, 2021, 6:37pm

Dear all,

Sorry for creating topics back to back.
While I test the terrain following with y6 frame, the drone keeps crashing on the terrain.
Could you help me to resolve this issue?

I run the mission below on SITL, and you can probably reproduce the issue as following steps:

./Tools/autotest/sim_vehicle.py -v ArduCopter -f y6 --console --speedup=10 -L Karuizawa
param set WPNAV_SPEED_UP 50
param set WPNAV_SPEED_DN 50
upload and run the mission

You will see that the drone is stuck in a location.

Testing version: Copter V4.1
Mission and log files: https://drive.google.com/drive/folders/1uzDLGToq8cW46ezA1STPgB9vH5VZRb7-?usp=sharing

rmackay9 · September 11, 2021, 12:18am

@Benjamin,

Thanks for the report. I ran the mission provided with a quadcopter (in SITL) and it flew fine so I think this could be purely a simulator issue caused by changes to the virtual Y6 which has led to an extremely poor tune of the vehicle. Below is a graph of the RCOU message and we see the outputs are bouncing up and down.

We’ve seen this problem on other SITL vehicles but I thought I had corrected all the various vehicle’s tuning… apparently not so I’ll have another look.

Benjamin · September 11, 2021, 12:37am

Thanks for your work!
If I want to tune y6, is it the right way to adjust ATC_RAT_YAW_P and ATC_RAT_YAW_I?
Or, should I tune another parameter?

rmackay9 · September 11, 2021, 4:18am

@Benjamin,

I’ve created a PR (https://github.com/ArduPilot/ardupilot/pull/18642) which greatly improves SITL’s y6 tune and I re-tested with the mission you provided and it seems to complete OK.

Txs for the report!

Benjamin · September 11, 2021, 4:47am

@rmackay9
Thanks for the quick patch!
It looks so stable