I built a relatively large quad-copter and started to tune and test it. SW version is 1.10. 1
The initial testing was done indoors with ring safety cable over blocks (not to let it fly away). No reliable GPS was available. Only OpticalFlow was activated in EKF2.
The vehicle was very stable in the stabilized mode. In position mode though the oscillations appeared at take off then vehicle stabilized (while in velocity control) for a while but switching to position control the oscillations diverged leading to a crash. Most of the parameters for the position controller were default as simulations tests (SIH) were ok for the position and the mission flight modes.
Log file url is enclosed.
Thank you for your support and appreciate any ideas,