I have the pixhawk installed on a hexacopter frame. I have lots of experience with the APM controller which flies great. However....The Pixhawk has an unpredictable flip. It happens mainly when using GPS functions like loiter, RTL, etc. 90% of the flight its fine without any sign of issues. But all of a sudden it will flip wildly and crash. The problem first presented itself when I tried a RTL. It climbed, moved to its home position and then went wild. Sometimes I hear the beeper (dee dee dee doh). The computer says bad GPS. Sometimes after the beep you will see it heavily glitch and usually a crash. Today it was in loiter mode and a motor shut down causing a light crash. But later that day after placing the GPS/mag on a high mast away from everything, I was flying in Auto mode. Just before it finished its mission it rolled wildly into the ground. No glitching or anything prior to the crash. Is anyone else having these issues?
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Hellos. What are the results of your test with your pixhawk small quadcopter?
thank you
For small frames I'm about to try the naze32 Acro for the first time cc3d it's good too, I tried apm 2.6 in a qav250 but it was too heavy.
The logs I posted are all from that whole day. So I'm assuming its the last... log 27.bin? Now that you mention it about flipping in only one direction, yes it does. It rolls to the right.
I notice the ship make a glitch movement right after the buzzer makes the dee dee dee doh. Usually a crash happens right after that.
The only big crash I had was during a RTL. The ship climbed, moved to home position, hovered, beeped, started glitching a bit, began rocketing into the sky and then flipped (rolled right) continuously till I shut it down to a crash. I posted the log for both crashes below. I hope their the ones.
17 is the big crash
18 is flying manually and crash
27 is flying a mission and crash
18.BIN
17.BIN
27.BIN
Just throwing this out there. I went from APM to Pixhawk and had a crash when I punched the throttle. Turns out I had a sync issue with the motors that was very apparent when I hooked the speed controllers direct to a receiver to test their performance. I only had the signal wires connected to the ESC's, and the fix was to also connect the ground wire. Once I did that the sync problem went away. On your crash log 17 your DesRoll vs Roll looks the same as mine, it tracks fine for a while then diverges before the crash.
Haven't flown it yet (it's been too cold) but I'm sure it has resolved my issue, see the video: https://www.youtube.com/watch?v=H-1j7X_vNw0
for what it's worth, I don't thisnk ground really fixes sync related problems, I think what you see is not only a sync problem, but a ground problem inside the ESC - - anyway, good that it worked for you.
Did you watch the video? It did fix it in my situation. Very repeatable.
Yes, (see comment above) - still, to me this looks like something else than sync only, it looks like a total signal distortion.
I would check ground all over if I saw something like that solve it, you may have some other problems
But again - good to see it solved it for you. :)
Thanks Andre, these are Afro 30a ESC's from hobbyking connected together with a simple distribution board. In the video I was demonstrating how super apparent the problem is you go from 0 to 100% throttle instantly. It's not so obvious if you are smooth on the throttle, which is why my quad did fly until the crash.
Not sure why this fixes the problem but I'm not the only one, this user also was helped by this advice: http://www.rcgroups.com/forums/showpost.php?p=27579271&postcoun...
This is the first time I've had to upload the logs. Any special way to post them?
Got it. Logs are uploaded.
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