Hello and thank you for taking the time to have a look at this.
The log I have is from a very short set of three flights, lasting no more than a couple of minutes collectively.
I have tried to analyze the problem myself and have been unable to figure out why the system behaved as it did.
Specs: Pixhawk and Ublox gps/compass module sold by 3dr, running Autopilot 3.1.5. The copter we have is a fairly standard 800mm hexacopter, the only difference being this copter is much more top heavy than most due to a large heavy sensor array mounted on a tower on top of the drone.
It was a fairly windy day but not as bad as many days that the system has been flown on before. The copter flew perfectly in stabilize, no wobbling or incorrect movements whatsoever. As soon as loiter mode is engaged during the first two flights the system began swinging back and forth violently before i switched the system back to stabilize. On the second flight I tried reducing the loiter p value because I couldn’t think of anything else that could cause this behavior in loiter mode exclusively (Loiter had worked fine on previous flights with the same tuning). The problem persisted so I set the value back for the third flight and the system loitered fine for a short time then promptly flipped over and flew straight into the ground.
Here is an example of the roll position/des. roll to illustrate:
[attachment=0]Roll.jpg[/attachment]
Any help with this problem would be appreciated,
Gage