Yes my quad copter flue away a couple of week ago. I have contacted one of developer in the arducopter team, he gave me a mail address to send the flightlog file to so he could have a look at it, but now almost 4 week gone by without any answer, and I don’t know way they don’t respond. So I thought I poste here to see if any of you guys have any idea of what could have happen. I poste a link to YouTube of a video I made from the flightlog file in mission planner so you can see what happened.
For the record this post isn’t to complain on the arducopter team or anything like that, I just want to know what happen. I don’t dare to test auto mission again until I know what went wrong. Link to video on YouTube.
https://www.youtube.com/watch?v=kpe2dupIdXM
Some comments of what happen in the video.
So is there a software glitch/bug in arducopter 3,01? Look at the video and judge for you self.
The mission was just setup to follow the street you see in front of my house. Just a short trip over 8 waypoints at a speed of 3m/s. And at a height of 30 meters.
0,15: Start the copter up I tried loiter for I wile to see if everything seem to be working fin, and it did, a lite wobbly because it was lite gusty out but nothing major.
0,44: Switch to auto.
0,55: the copter reached waypoint 1 ok, and went of to waypoint 2.
1,03: Here I Starts to go south, the copter start roll heavy to the right and took off in very high speed well over 3m/s (21 m/s according to telemetry as you can see). I admittedly switch to RTL (as you can see), but nothing happens. And as you can see I have lost GPS 3D fix, and that’s was propyl what starts all of this. But should the copter just stand still if it lost GPS signal? It isn’t supposed to just fly away, right?
1,15: I then switch to AltHold. And try to fly it back but it did response to any stick command from the radio at all.
1,35: It got GPS 3D fix again, and I just took off in high speed again, no control of it at all. Note the mode was set to AltHold, not any GPS mode (Loiter or Auto etc.). So way did I take off when it was in AltHold mode? It sudden have matter that it got GPS signal when it wasn’t in any GPS mode??? And way in so high speed? And again it didn’t responded to any stick command from the radio, the only thing it seems to respond to was when I switch flight mode on the radio.
2,15: In some desperation I switch off the radio, I have set failsafe to RTL. And I have tried it before and it worked fine. At this point I didn’t know what else to do. And as you can see it went into failsafe mode and flight mode switch to RTL. Way didn’t it RTL?
3,10: And here it stayed hover, I have set no WP or nothing like that here. And you see the flight mode is in RTL.
5, 15: You can fast-forward to this point, I have zoomed out just to let you see that I knows where “home” is, and it also have an accurate distance to home. And the flight mode was RTL and it hade GPS 3D fix. Way didn’t it RTL????? Way did it just stay at that point???
6,22: I suddenly lost telemetry data and you could just barely see it visually. So I took off in a hurry by car to the outer side of the river to get telemetry to work again but I never did. So the copter had already crashed when I arrived or it had took off again. I never found it unfortunately.
The only explanation I can come up with is there some software glitch/bug….Hope to see some comments from you guys to hear what you think….
The copter was a quad copter with APM 2.5 and arducopter v3,01. And I use Futaba FAAST 2.4 GHz for radio and receiver (futaba original).
Sorry for bad English.
Replies
As I read you comment again I see you guys probably thinking that the flight mode was still in auto
(or loiter, RTL or anything that use GPS). And then it all should of make sense, at least more sense but the thing is it wasn’t, it was in AltHold and then it doesn’t make sense at all it jump to GPS positions, right? It shouldn’t have done anything even thou it regain GPS Fix.
Tank you guys for replaying.
There were nearly no wind at all, a bit of gust wind but that’s it. This was at about 23.30 (11.30 PM) at night so where calm. I have flue this copter I much higher wind in auto mission without any problem.
But even if there have been strong wind can explain what happen, I thing anyway. I have no control of the copter at all, it didn’t response to any stick command at all, and it was real scary.
If you look at the video at 1, 20 it just stay hover nearly at the same spot for 15 seconds, and it was in AltHold (according to the HUD), no GPS flight mode. And it’s clear that the second it got GPS 3D fix (at 1,35)it took off in high speed, I could hear the motors when it pass by and I bet I was full throttle. It was like it where heading to a waypoint, but there was no waypoint where it was heading, AND the most important thing here the flight mode was AltHold, it shouldn’t have bothered with the GPS at all, right? Or is there something I missed here. AltHold = No GPS or so it shouldn’t have took off when it got GPS again? That’s way I suspect software glitch. And in the end of the video it’s clear at RTL but it doesn’t.
And as I said before I have no control what so ever of it, but it’s clear the radio have contact because it switch flight mode accordantly but it didn’t obeyed them at all.
Yes I really hope we can share some light on this because I does dare to fly my hex with APM until I know what happen, like you say the copter aren’t cheap and don’t want to lose another. And I have flown other flight controllers but none where I basically was a spectator and could only see it fly away.
Is here any developers reading this? Some comments would be nice from someone who knows theoretical possibilities for the problem. Have you Jesper heard anything outside of this forum?
I looked video twice and I think wind can't be only reason because it fly so fast to north - west and then south - east. Final drift was so slow that it seemed to be caused by wind from north.
I don't have clue what happens inside APM but I have seen very strange behaviour with first or second generation GPS mobile phones (Nokia E52). I got twice an error that it started to guide around the globe. This happened when gps lock was lost and came back later. Also same time I got mean speed around 15000km/h. This happened when I walked from balcony to window at the other side of building. For some reason navigator decided that I just walked around the globe in few seconds and started to guide me back using same path around the globe.
Does APM have mean speed in log and is this mobile phone like behaviour possible with APM even in theory?
I'm very motivated to get knowledge how possible these flyaways are. My copter will cost few thousands with camera gears and flyaways just can't be possible.
Just from looking at it real quick, what was the wind like? It looks to me like there was a lot of wind pushing it around. Right after you regain GPS lock and switch to alt hold mode, the ATT indicator shows the quad in very stable, flat flight. There is no roll or pitch and it is almost perfectly level but still moving, that indicates to me that wind was pushing it.
To further back this up once it crosses the river and failsafe engages it to RTL mode, it is fighting hard to try to RTL but all that it can do is hover. It's pointed to the southwest and rolling hard to the right, in the direction that it knows home is. For whatever reason it would not roll more to the right (not sure on max roll angle while in auto/RTL), but it was hovering between 20-30% roll towards the direction of home and not going anywhere. Again, not sure how the algorithm for max speed is calculated, but if it's based off some kind of max roll, it could be that it needed to roll more to move towards home but the max speed was limiting it.
Anyway, just some incite from outside eyes looking in, sucks that you lost your quad. I just lost a multiwii that I had exactly 3 minutes of flight time on, tested it and it flew beautifully in stabilize, hadn't done any work on it yet as far as mag and vibration dampening.. the receiver antenna broke off and it lost connection with my TX, engaged RTL, and flew away into oblivion without anything I could do. It sucks, it's sad, and hopefully you find your quad. From an altitude of 218, and assuming it stayed at that point until it lost battery (pretty reasonable to assume since that's all it was doing in RTL), and with possible winds like it was at, I'd suspect that it could have fallen anywhere in a 300m radius.. so basically any of those trees.
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