My Pixhawk is unrealible

Archive
1

Seems like every time I fly my Pixhawk something weird happens. I don’t have these problems with my APM’s. This morning I went out and flew a short mission for testing. I repeated the mission a couple times. Everything was working fine then part way through the mission it was like a switch was turned off and the quad fell from the sky. The logs from the flight are attached. If someone can help me figure out what went wrong I would appreciate it.

2

At first glance, one can be fooled to believe Arducopter commanded the throttle to 0, because you see ThrOut go to 0.
But then, the last logged line, 71117 , also say Dalt, Alt, BarAlt, and SAlt all drop to 0 - this is not realistic at all.

It seems to me like something crashed, very badly…
I’ve never seen a software crash in normal releases.
Nor do I see strange NTUNE data or anything else that could explain it.

  • Then you say " Seems like every time I fly my Pixhawk something weird happens" - I do not know that kind weirdness you’ve seen earlier, but unless anyone have a better suggestion, I’d blame it on defective Pixhawk, like a hardware/electronic fault, or cold soldering etc.

You can often detect bad pcb/soldering, by letting it “run” (no props) - then take the case and tap on it, or twist in different directions . - it’s a hard case, but some problems can be detected with just few micrometers of twisting force.

3

Thanks Andre-K,
I’ve had a feeling that it was a defective unit. It’s strange it will fly good then all of a sudden do something crazy.

I posted about another episode (with log files) previously in the “Log files, Tuning, and Analysis of Log files” section of the forum, but got no replies. Seems that the old forum worked a lot better. Here’s that link:
http://ardupilot.com/forum/viewtopic.php?f=80&t=6989

I will contact 3DR and see if they will replace it.

4

Put everything back together flew it a couple times without incidence, then boom, fell like a rock again. Here are the logs from the most recent failure.

5

This time, it rolled over for no apparent reason, your DesRoll is not logged, but the software did some attempts to correct it while tumbling down.
I would guess on a thrust failure on one motor, mechanical or electronic problem.

6

Thanks for the reply Andre-K. I’ll put the Pixhawk on a different quad and see what happens.

7

I put the Pixhawk on a different quad, but between work and windy weather I haven’t had much chance to test it. I’ll post the results when I’ve had a chance to check it out.

8

The wind finally died down enough for me to get a test flight in. Everything went OK. I need to test some more to verify. The other quad also flew good sometimes, then out of the blue it would crash.

9

Been a really windy season here. Hard to get much flight time in, but I did manage to get one more flight in. It was a good flight with no issues. It’s looking like the problem is related to something on the other air frame.