Guys,
I am puzzled by a very strange behaviour of APM on my SKywalker. The setup was perfectly tuned and I had done several photomapping grids. All settings were fine tuned and the turns were all smooth sharp and with no weaving.
The same setup, one day suddenly gave wierd performance. The airplane went strait to waypoint #1 and then the waypoint 2 was 11km ahead and the plane started weaving . So much so that it made some circles ! I got the plane to FBW control and brought it back. thinkign there was some hardware problem or a control surface issue. But everything on plane was perfect !
I can psot the full log file here, but here are 2 screenshots.
Could it be that if the waypoints are too far apart it can cause in weaving ?
Replies
Hi There,
I believe I've experienced the same thing you've described. My x8 was flying fine for a few passes and all of a sudden it started oscillating in roll coming out of a turn and the oscillation amplitude increased over time until the roll limits were reached. At first I thought perhaps some sort of dutch roll mode caused the control loops to become unstable/marginally stable but the strange thing is as soon as I initiated RTL the plane flew back to home in a straight path. I still don't know what caused the issue as it happened in the middle of the flight. For now I've relaxed my L1 and roll gains a bit to minimize any overshoot that may initiate instability.