Hello all,
A few weeks ago I took my Quad for a "drive".
APM2.5 with 2.9.1b updates.
On one of the runs, everthing was fine, accel was nice (see picture below), everybody (wife, friends, kids) was impressed.
One or two hard landings happened when i handed over the controls to my friends, but nothing more.
Suddenly, while I am flying the copter back towards me/us/the 4yo kids, i see one of the motors simply stop.
The copter loses altitude fast, while doing flips, and i foresee myself urging to the car, with one scalped child on the backseat, on my way to the closest hospital.
See roll In and roll values separate around line 70892 in picture below
I don't know how, miraculously the thing lands flat on its belly, 1m from us, on the grass.
See impact at line 71142 below and the few Gs the copter has suffered!
I do some damage assessment: one broken landing leg!
Yay!
Find below this flight's log for your perusal
2013-05-02 23-41 5 mission 2.log
Lets repair the leg (bits and pieces of the broken leg, linked together with zip ties) and reair the monster!
Another run, where I am testing 50m alt waypoints and POIs.
Everything is nice, but vibration seems a bit higher and increasing while we fly.
"Thats cuz of the crash and the repaired leg"... Yeah!
The flight goes on. Several test missions are executed.
Until,
Mission ends, back to stabilized and I take my eyes two seconds from the quad to waive at friends arriving by car and when I look back up the thing is flipping down from the sky.
Again, see roll in and roll separating around line 23900 of this new mission
and watch the nice sinusoidal of roll, separated from roll In
I also like to watch the subsequent quick drop in altitude from 50m and wonder why it stopped logging before hitting 0.
This time I was flying alone and the quad was pretty far from me.
However, it had less luck than the previous crash: it landed on one arm and tried to bury the motor into 20cm of wet earth/mud.
Damage assessment: one motor ripped out from one deformed arm, another deformed arm, 3 broken props, APM pins bent, battery disconnected, CD case canopy destroyed.
Please find below the log of this flight.
2013-05-03 10-28 4 mission 3.log
And the Google earth of the last 3 modes
Question: Do you guys please have any idea of what happened?
Looks like a bad contact / faulty motor to me. But how do I find a log of motor demand/output?
Replies
Sounds very familiar:
http://diydrones.com/profiles/blogs/flip-and-spiral-death-from-100m...
Wiggle all your connections with the motors spinning (low throttle, held safely overhead or preferably with props off).
Rule two, what you think might have caused your crash might not be correct assumption. So fly carefully, like its going to crash until you feel safe.
Unfortunately I'm not that great at reading logs. Randy is the master.
But from what you said about the first motor stopping, that sounds like either a bad ESC or a bad or loose motor connections. If you had motors enabled you could see that in the logs. The down side to enabling to much logging is that you overload the APM. The APM is trying to do to much with to little. That's why they developed the PX4 flight board.
there is a motors log available, but you have to enable it. i assume you know how since you have raw enabled.
go into the terminal, and type 'log' >enter
then 'enable motors' >enter (iif im remembering right. if you get an error, then its 'enable mot')
another option is to type 'enable all' and it will turn everything on, then you can 'disable [log to disable]' the ones you dont need to save memory.
to my knowledge, you are a little sol on getting those numbers now, i dont think the APM stores that data unless explicitly instructed
as far as your problem goes, im a noob. so im no help. im trying to chase my own 'copter instabilities. so here is a free bump