I am afraid my first message in this forum is a not so happy one.
After about one month building, programming and testing a custom DJI F450 with Pixhawk, I went to a nearby park to fly it.
It took off ok and I started flying it, and decided to test the RTL failsafe.
It didn’t go so well: ss soon as I hit the switch, the quad flew away from me, at great speed, never to be seen again. I spent around 2 hours looking for it in the vicinity of the park, bu without success.
I am sure I followed every recommendation: I set all the failsafes, I let it acquire GPS satellites before I armed and flew it, I did everything…
@benny_lx,
With telemetry enabled you might have been able to find it as the telemetry would have shown you where it was headed.
Telemetry is cheap when compared to the cost of a full blown multicopter.
Regards,
TCIII GM
imo, if it ran away under RTL, either you didn’t have GPS lock before arming (but you say you did) or, the EMI (electromagnetic interference) from your particular setup was so high that the GPS was confused about where it was, and therefore headed in the wrong direction.
Spend some time looking into ways of reducing emi for your GPS unit in the future.
without logs it’s impossible to help you.
Arducopter don’t just run away for no reason, I would guess you did not test navigation and poshold very much, you should have switched it to Stabilize once it flew in unexpected direction.
[quote=“Andre-K”]without logs it’s impossible to help you.
Arducopter don’t just run away for no reason, I would guess you did not test navigation and poshold very much, you should have switched it to Stabilize once it flew in unexpected direction.[/quote]
Unfortunately, I agree with Andre. They may not “run away for no reason”, but the majority of the time, the reason is user error. We can’t tell that without seeing a tlog though.
Not trying to kick you when you’re down and I’m sorry for the loss. The steep learning curve of Ardupilot almost had the same result for me when I started. I hope you’re able to find it eventually.
Thank you all for your comments, suggestions and kind words.
Actually, and looking back, I can only blame EM interference on the GPS, although it was mounted on one of those elevated poles, and well fixed, too…
As a matter of fact, it had a GPS lock. It would not even arm if it did not, as I did not disable any of the pre-arm checks.
One more thing I have been wondering: could there have been a conflict between Copter failsafes and the radio (FrSky Taranis) failsafe? I did not set any specific failsafe on the radio, but I don’t know if it assumes anything by default…
About the FAA number, I don’t have nor can’t have one, as I don’t live in the US, but in Portugal.
Anyway, after I recover from all this (emotionally and financially), I surely will learn from this lesson and will not give up on Copter.
Regarding cause, unfortunately it’s a lot of speculations until you maybe one day are lucky to get it back.
The RC radio failsafe could absolutely be involved somehow, many/most modern RC radios can configure a “hold servo position” , “set preset servo position” or “off” per RC channel.
Many discovered the hard way that letting the radio handle failsafe can lead to disaster.
the video cannot tell even is the external magnetometer was dead, not calibrated, or not connected.
Do some screenshots and posters, maybe somebody will return it to you.
I had a similar fly-away that I recovered, just barely. It is hard to remember exactly what I fixed, but what I did was try to get it to loiter perfectly. After the fly away, it would not loiter reliably, and would usually change altitude rapidly or move around. I spent a lot of time fixing the powering: disconnecting all BEC inputs from the ESCs, checking grounds. I also had an issue with barometer accuracy, which I found through logs. I also checked logs from all test flights and tried to track down any error messages, like GPS errors, and see if I could fix them with adjustments to the build or parameters. I also consistently checked and turned off all failsafes and fences, as they seemed to turn themselves on at random (?) and did not really help me.
Once I had it loitering perfectly along with stabilize mode, I could execute programmed flights and RTL 100%.
since I’m going to test the same setup on a hexa over the next days, please correct me if I’m wrong thinking that with the telemetry linked to my Mac and APM Planner, if I can see the take-off position on the map and it is correct, in case of failsafe the copter cannot fly away but come back home.
It depends on the version your running. Home is set once a good GPS lock is obtained with more than 6 satellites. I think in Tower an Icon shows a house with an H in it after takeoff.
Sorry for the loss of your drone, I know how it feels as I have done the same thing with my fist drone a few years back. What I can tell you is that it is a mistake to fly without telemetry especially for your first flight. It is a little bit like starting a car you have just build without the gauges under the eyes : you do not know what is the status bad or good of your vehicle before taking off. What happened most probably is that you took off without having a GPS lock (can take long minutes sometimes befoire take off); then when you triggered RTL the copter went to the (wrong) home position.
Next time, NEVER NEVER fly your drone with some form of telemetry (be it a tablet or a PC or even OSD on your video downlink), so that you can check the preflight conditions.
I think I have learned my lesson. The next time I take a shot at this I won’t pass having telemetry and some kind of GPS tracker.
Anyway, the more I think of it, the more I am convinced that I set up the failsafes wrongly. I have since been fiddling with my Taranis (after all, it was the only part that stayed…) and think I am prepared to set it up correctly now.
