Yesterday I launched my drone as usual, aiming to fly around and get some nice footage. Prior to flying away I did all checks - it was holding position, and also it was showed correctly on the map via telemetry.
However, suddenly telemetry reported lost gps lock. So I switched into stabilise mode and tried to land the drone. It was rather hard, due to the lay of ground. So when telemetry reported that gps lock was recovered, I switched consequently into PosHold (didn't actually hold position despite HDOP 0.8) and then RTL. When it got to RTL, the drone just started to fly straight away. The last command it DID get was LAND (confirmed by telemetry). But it continued flying away straight into the sky.
The last reported position was waaaay away from me and absolutely not in the direction it was flying to.
Search failed, so as a result I lost it together with my camera and gimbal. Apart from being somewhat very sad I'm puzzled: how come it happened?
It was using tested settings on Copter 3.3.3, I had the system (and GPS) working flawlessly for half a year (checking telemetry after each flight). None of failsafe triggers worked (I had fence, radio and battery enabled and working before). Now what I guess here is that it all might have failed cause it was set to RTL - and the drone might somehow got my home position jinxed. However, it doesn't explain why it didn't LAND when receiving such command.
Also, telemetry link died at the same time with radio link, which is very strange, cause radio has a way better range
Does it mean that pixhawk is no better then the old DJI NAZA? I've been a fan of 3DR for almost three years, but this flyaway saddens me greatly. Also, that's lost money.
Indeed, I did have flight plans loaded, but that area is in an opposite direction to the one the drone started flying. The last obtained GPS position is also in the other direction, so drone wasn't flying there. And previous arming position is also in another direction. However, there's US embassy in the direction where it was flying. Maybe, the drone wanted to get home?
Jokes apart, that's the first time it consequently lost GPS and control......
In fact, that's the second time I lose a drone due to (allegedly) GPS fail. The first crash happened on APM + M8N GPS but it resulted only in hard landing. After I checked logs I saw that there was a strong GPS glitch and, as I had no voiceover at the moment, i didn't know about lost GPS lock.. The drone started unconcrollable landing. The solution to this, as I see it now, was changing flight mode for a COUPLE of times, and not just one - cause in logs I was still "flying" in Poshold when it hit the land.
This time it didn't help at all and probably I indeed had an IMU lockup after GPS total fail.
Justin H. said:
Mhm, how can I get these logs from Tower? Are they saved automaticly or one needs to check something?
Besides, with drone soaring high up in the sky and flying to the city centre.....I guess I have a very limited possibility to get it back. But yeah thanks for the advice, I'd try this option if I manage to find it.
Also, probably u'r right about IMU lockup - it was, indeed, unresposive to any command after RTL
Also that's very true remark - currently I see no replacement on the market. I also loved it - actually, it never even crashed/had a hard landing. Next to flawless behaviour for half a year.....and then goodbye.
Sorry to hear about the loss. Did you have any flight plans loaded? Maybe plot a line from your incident to the home coordinates of your last arming or flight plan and look about 2 miles out for the Iris...
Losing GPS in flight is definitely weird. I've had my GPS scrambled by metal roofs and made the mistake of arming too close to heavy steel objects, both of which caused big problems, but never had GPS just drop out in over 300 flights. Just the thought of the consequences eventually made me put on a secondary mast-mounted GPS. I may be a cautious flyer, but any irregularity with the GPS and Pixhawk is a huge red flag and, for me, requires immediate landing and thorough troubleshooting.