So i have been flying my quad manually for the past week and had the PIDS tuned out and the gps and external compass placed in different corners everything was working fine i even had the previous flight where the loiter worked like a charm stayed in a 1 meter cubic space at all times. but today i was going to run an endurance test so i took it up in the air and 4 minutes go by and all of a sudden it just jerks to one side and smashes into the ground ripping out my motor and dissabling it to the point is just the whole thing is in dents. so i was wondering what might have caused that. I was running 3drs 2.6 ardupilot on a 500mm frame mith 6m ublox gps and a honney well compass. all was vibrations protected.
i would post the log if i knew how.
Replies
http://youtu.be/gKoeQ78li-4
I had a recent crash from loiter mode similar to what you describe. The drone lurched forward, in my case, nose pointed almost at the ground, before recovering and levelling out. It was about 20-30m up at the time, and was unable to maintain altitude even at 100% throttle. It descended into a tree and crashed.
I have two theories, but I can't be sure if either is correct:
1. motor failure - I noticed some strange things about my motor after the flight ( http://diydrones.com/forum/topics/possible-to-fix-a-failed-motor?xg... )
2. loose prop - it's possible that a prop wasn't fully tightened and came lose, essentially depriving the drone of any lift from one of the motors, just like a motor failure would.
After the crash, I had both loose props and a broken motor, so I probably won't ever know which it was.
Maybe these give you some theories to work with. I had an FPV recording of the whole thing, with OSD showing me the throttle, which helped me rule out most types of software bug, since it showed the drone trying to do the right thing and maintain altitude with 100% throttle, but descending anyway. Logs from APM can also help, but I've never successfully retrieved them with APM Planner.
Nick
here is a video of my loiter working