ArduPilot Mega in-flight problem

after take-off (manual) the APM's behaviour was weird.
switching to AUTO or RTL caused some significant change of course, but not to the expected headings, rather some random direction/turn
also switched to FBW+stabilize, and it all felt a bit "something is not right"
just before 2:00min i switch to manual
probably at this stage APM has already stopped working
and when i switch out of manual some 20 secs. later, i activate a messed up autopilot
at 2:30 engine shuts down, shortely thereafter you can see a small throttle impulse, somewhere before or around this time i completely lost control over the model.
manual, AUTO, RTL, FBW nothing worked
switch off TX and back on, no reaction
i guess the remaining flight was the glider's own performance - there was no wind - or maybe the APM froze up in stabilize mode

Category:

Science & Technology

Tags:

• APM
• ardupilotmega

[MUFONAnalyst]

Did you ever figure out what happened ? Looks like a battery failure to the Ardupilot system. That is the only thing that seems to explain why you lost ALL control.

-Marc

[wowi55]

@MUFONAnalyst

No, I never figured it out.

I noticed that my eneloop battery is providing a higher voltage than the APM is happy with.

This explains eratic servo behaviour on startup. I used to think it was an issue of the sensors having to get used to the outside temperature, but it is not. A fully charged eneloop is too much (5.8V). What I do now is fully charge the receiver battery and drain 100mA, which leaves me with some 5,5V - and this fixes the weird behaviour I had on startup

[wowi55]

@MUFONAnalyst

...but this does not explain the in-flight behaviour in the video...

my suspicion:

the small impulse from the speed controller (at 2:30) produced some interference to APM or the Rx, which resulted in a failsafe situation. My failsafe was (then) to simply STABILIZE.

After that flight I recovered the plane unharmed and did further flights. Since then I have not had another issue, it was just a one-off. BTW, Nowadays I used RTL as failsafe.

[Mazenaounallah]

very amazing work, and smooth flight indeed

[AVKtt]

imho very noisly p.supply

[miginator666]

i'm having probelm too. Probably due to a unreliably power supply. The twitching of the servo's sounds familiar. I use a BEC. If power is interupted you probably go into a restart of the Ardupilot unit causing loss of control.