So just went for a quick flight LOS in the back yard, cos I was just flying LOS I didn't wait for a GPS fix and just went up there.
About 30 seconds into the flight I see the GPS lights start flashing green and it locks into a banked angle and starts flying towards me. I quickly flicked the RTH button which should have stopped the quad but instead it carried on it's original intecept course and ended up smashing into the side of the house and kept going for 10-15 seconds until the motors stopped.
Not sure I really trust Naza. This is the V2 version and I experience a very similiar thing before with the V1 version where it would just lock into a left hand bank and keep going.
Your not sure you really trust Naza when by your own admission you didn't follow procedure and took off before getting a GPS lock ?
This is almost 100% what happens on every Naza fly away, procedure not followed and then the unit does not perform as expected.
Then you flicked RTH on, knowing that home was not set accurately when you took off ( IE hardly any satellites when you armed it so the home location wasnt even close to where it really was in reality. ) The Naza then tries to return to its thought home position, which was inaccurate and tried to go through a wall because of this.
I don`t think there is anything wrong with your Naza
Pretty sure the manual says you can take off without getting a full GPS lock, you can get a partial lock and take off?
Ian I am having problems with gps lock on my amp 2.5. I have a solid blue light but when I switch to loiter. it is very poor. a massif toilet bowl or it fly's off. I am thinking the heavy cloud cover lately same thing on my x5 would you agree
I still think the best flight controller is the one that I fly and not the on board system!
Tough break, you got to follow checklists!
I was about to fly my APM quad, but I was unsure if I had the switches in Manual, Alt hold or Loiter...
I did not fly, because it's not safe to do so like that!
QuotePretty sure the manual says you can take off without getting a full GPS lock, you can get a partial lock and take off?
Yes you can, but then Home will be totally wrong ( depending on how low a lock you had ) so you can not any longer rely on RTH because home is wrong. It then gets a good lock, doesn't realize home was wrong, so the when RTH is activated it buggers off to totally the wrong place not knowing any better. That`s why it made a bee line for your house.
Quote from: jamiejig on April 07, 2014, 08:50:33 PM
Ian I am having problems with gps lock on my amp 2.5. I have a solid blue light but when I switch to loiter. it is very poor. a massif toilet bowl or it fly's off. I am thinking the heavy cloud cover lately same thing on my x5 would you agree
This is not the correct thread Jamie, if your getting toilet bowl that`s normally the Mag ( compass ) not the GPS.
Without GPS, the quad will just level and land.
With GPS, it will level, wait, ascend to 20ft or something, wait, and then eventually come ambling over to the home location.
In my case, I was flying in ATTI mode, suddenly the quad banked to an angle and started flying towards me, I realised I had no control so as a last resort I flicked the failsafe option. At the very least the quad should level out before initiating FS.
So The Naza definitely not operating as it should have been. Saying this isn't a fly away cos I took off without a full GPS lock is a cop out.
without gps there is no rth option in naza.
Quote from: marcin on April 07, 2014, 09:16:08 PM
without gps there is no rth option in naza.
No but it still has a failsafe. That failsafe returns the naza to level and then reduces power and lands.
I take off in ATTI mode without a GPS lock and then suddenly my quad gets a GPS lock and then starts shifting without me having any control, the Naza is operating totally independently.
Clearly at that point it wasn't operating normally as entering failsafe had no effect, it wasn't trying to return home.
My guess is (and I'm certain I'll be corrected if I'm wrong ;D) is that the RTH doesn't work instantly. I have used it quite a lot and it doesn't react immediately so far as I can see. This would make sense as it must be possible and perhaps quite common for the transmitter signal to be lost for a very short time in which case the UAV would be zooming back home or doing its own thing quite often?
Failsafe works immediately but RTH only happens once the quad has levelled out and has returned to the correct altitude.
I've tested it numerous times in fast forward flight, flick into failsafe and the quad will immediately level out. With GPS, it will pull back to a stop. Without GPS it simply levels out.
In my case, flicking to failsafe and the quad continued to fly in the direction it started.
And still, being in ATTI mode, why would the quad decide to fly off on it's own? I specifically stayed in ATTI mode because I knew I was flying without a GPS lock.
It's all a bit dodgy, if I have some time and method of tying down my quad, I will do some testing to see if I can reproduce.
DJI says: If the connection between the multirotor and the remote control are disconnected during flight, a failsafe system will activate. Provided there was enough GPS signal at the time of the disconnection, the multirotor will fly back to its point of takeoff and land automatically. This feature can also be triggered manually using the One-Key Go-Home function activated using Assistant.
Technically it did Return To Home .. maybe it needs a subroutine written so that it rings the doorbell and asks to be let in rather than smashing through the wall :D
Quote from: Heliotrope on April 08, 2014, 11:12:06 PM
DJI says: If the connection between the multirotor and the remote control are disconnected during flight, a failsafe system will activate. Provided there was enough GPS signal at the time of the disconnection, the multirotor will fly back to its point of takeoff and land automatically. This feature can also be triggered manually using the One-Key Go-Home function activated using Assistant.
Yep that is what happens.
Quad enters failsafe, quad levels out, quad waits, if quad has GPS it goes to 20 meters, waits, and then starts returning home.
If you have a naza you should try it sometime, it doesn't just keep flying. It stops what it's doing before returning home.
This would be a lot clearer if it wasn't for the fact that you took-off before a full GPS signal was made. Although you were flying in ATTI, the fact that a partial GPS signal was there - I don't believe means that it fails over to the "there's no GPS" mode and simply lands in a failsafe. Clearly it shouldn't go bonkers either and fly into a wall either.
However, this may fall into the case of flying in an unknown or at least "inbetween" condition, and hence got unsupported/unpredictable results.
I'm not saying that's how it should be, but probably how DJI might view it. There's certainly a lot to be said for open source FC firmware when you have this sort of situation - it's impossible for us to debug, so we have to speculate, the trust in the FC ebbs away.
Quote from: CurryKitten on April 09, 2014, 10:02:45 AM
There's certainly a lot to be said for open source FC firmware when you have this sort of situation - it's impossible for us to debug, so we have to speculate, the trust in the FC ebbs away.
I'm very glad it's not open source, the number of people with the ability to play around with it properly would be tiny and many who think they could probably couldn't.
I'm sure that DJI have their issues but when you have the massive volumes of kit out there being flown by all sorts of people in countries all over the world any faults are usually identified and DJI have the resources to fix them (as they did last year with Wookong I believe). If Joe Bloggs enters the market and sells 100 units what are the chances of a failure showing up compared to someone selling 100,000 units.
Maybe I'm being short sighted but I can't see too many really useful major developments that we actually need with FC firmware. If what we have now works properly then personally I don't see the need for much more. Yes, I could let my imagination run riot, but the only big change I see coming is the use of Galileo in a few years as opposed to GPS.
Quote
I'm very glad it's not open source, the number of people with the ability to play around with it properly would be tiny and many who think they could probably couldn't.
Something being open source doesn't mean the codebase is a free-for-all, people can submit changes/add-ons/features to the cows come home, but whether any of them make it in is determined by the committers on the project.
What it would allow is people to poke around if there is a perceived problem and look for any possible holes in the code that could cause the issue people are seeing. There wouldn't be a huge number of people that would have the skill, or indeed the motivation to do this... but there doesn't have to be really - just one or two. See KaptainKuk and the few guys doing branches of the official KK2 code.
Quote
I'm sure that DJI have their issues but when you have the massive volumes of kit out there being flown by all sorts of people in countries all over the world any faults are usually identified and DJI have the resources to fix them (as they did last year with Wookong I believe). If Joe Bloggs enters the market and sells 100 units what are the chances of a failure showing up compared to someone selling 100,000 units.
Sure - it's pretty obvious that the higher number of units = higher number of failures. However, I don't see DJI doing anything about this. I'm very much on the fence on this one, I've not had any issues on my Naza V1 FC, and I haven't really seen documented flyaways in which all the setup was followed rigorously. So, perhaps the reports are hyped up, but they are certainly enough to put people off Naza, and so deserves some comment from DJI
KK- I didn't appreciate that that's how it would work - just shows how little I know which is why I'm happy to rely on DJI, for better or worse!
Quote from: CurryKitten on April 09, 2014, 10:02:45 AM
Although you were flying in ATTI, the fact that a partial GPS signal was there - I don't believe means that it fails over to the "there's no GPS" mode and simply lands in a failsafe. Clearly it shouldn't go bonkers either and fly into a wall either.
I've read the Naza manual front to back and the only warning about flying without a full GPS lock is that you might encounter some drift.
That being said, flying in Atti mode, the GPS shouldn't come into play whatsoever yet is has done and shifted me into the wall.
Im gonna e-mail DJI anyway and see what they think.
I dont think its got anything to do with gps tbh. There are accounts of exactly the same thing happening to Naza's which are not even equipped with gps. If it was a gps issue then flying in Atti mode shouldn't be affected. The most plausible explanation I've read is the Gyro/Acclerometer unit gets its knickers in a twist and and doesn't know when the quad is level anymore.
Its my belief that most fly-aways are caused by one or more of the following:
1) Not allowing the GPS to get a fix before take-off.
2) Compass rotating on the stalk before or during flight.
3) Compass not being mounted high enough on the air-frame.