Discussions

Short:

Quad has been flying beautifully for months. Updated firmware, had issues, went back to older versions, still have issues. Have logs but not able to diagnose. 

Long: (What I see as important details are bolded.)

I have a fairly stock 3dr quad which has been working well without much maintenance since late March. I took it on a road trip and upon returning, upgraded Mission Planner and the firmware. After one successful ~6 minute flight with the new firmware, I had my first issue. I was flying low to the ground and within a minute the quad started drifting backwards. I compensated by pushing forwards, without seeing much pitch. It continued moving, so I kept pitching until I realized I was at full pitch input. Since I was still moving backwards (and visibly around zero pitch) I dropped throttle and took a 1.5 m hard landing (no notable damage).

I then tried moving to an older firmware (2.9.1b), thinking it might have been a compass issue with 3.01. After moving I did a full recalibration and check over the components. During my first test flight the copter did a similar thing to what it did before, except moving to its right instead of backwards. I was ready and managed to land softer, but still had to bring it down quickly. After bringing it down I noticed that my gimbal was jumping all over the place, as though the accelerometers were reading radically different orientations.

I then reinstalled mission planner, restarted the computer, reinstalled firmware and recalibrated. During the test flight after this it started well, though it felt a bit different (maybe sluggish?) from normal, and I had to hold a higher throttle position for neutral than I was used to. 3-4 minutes into a ~6 minute battery life, the quad started losing power, and I somehow managed to land softly with full throttle input. After disarming I checked the batteries to see plenty of voltage. I them re-armed to check, and the motors spun up normally. The logs from this are the first from the two attached. Despite my lack of practice reading logs, I think there is a pretty evident throttle issue near the end of the flight (6070), but that's all I've been able to gleam from it.

I then tried an older firmware (2.9.1) (while cursing myself for not noting what I was running before upgrading). I then recalibrated, and took another tentative test flight. First ~3 minutes were fine, with a little drift to the right. Then as I was going the rightward drift became more pronounced. I was more prepared for it than I was previously, and managed to hold a level hover as the drift increased, by increasing my roll input. The logs from this flight are the second ones attached. Again, I can't read into them much, though it seems that the quad is registering a large roll in, AND a large roll angle. Since I was holding it in a hover, I suspect this roll angle isn't reading correctly. Of additional note, the gimbal was freaking out in a similar manner to that which I mentioned earlier. This second log also has the IMU readings, if that's of interest.

Based on what I've seen I feel like it might be an accelerometer issue, but one that's starting during flight, and inconsistent. I don't know what else I can do to narrow this down, or what steps I might be able to take to correct it. I would love any advice or direction that I might be able to get. Thank you very much, and I'm sorry for the long write-up, I figured completeness might be of service in case there are some thing which I'm not putting together!

2013-07-26 11-38 2 (Throttle 6070).log

2013-07-26 12-17 2 (Large Roll).log