Example of GPS mode to ATTI to Out of Control Mavic
2344 12 2017-2-1
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Stewie Griffin
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Just wanted to show an example of what happens when the Mavic goes into ATTI mode and has a mind of its own.  

Please excuse my crude way of showing this (directly filming the replay function on my tablet).  I also covered the area where it shows where I live for privacy.  Lastly, its a bit confusing when mentioning directions such as right and left for which way Mavic is going and which direciton inputs I'm giving, but given that you can see which way the Mavic is pointing, it does become clear.  (times refer to the time stamp of the video playback position in youtube)



1.  Just before I hit play, you can see I use the sticks pulled inward to start the motors.

2.  Initial message states interference, but I always have this, and it has never affected me.  Take note of the fact that I have 11 satelites.  I initially apply a bit of left stick after taking off, and the Mavic does go left, but then let go right away.

3.  00:20, you see the Mavic drifting to the right without any stick inputs, all I did was gain a bit of altitude when I noticed it was drifting for safety.  No mention yet of GPS issues for 5 seconds.

4.  00:25, apply some right stick in error, since its obviously already going right.  This is also when you see the satelites drop to 9, and the little bars on top go red.  The blocked out coordinates say Weak GPS Signal.

5.  00:30, starts to now go backwards with no stick input and although the right stick input was still being given, it stopped moving right.

6.  00:34, it has started drifting left, and at this point i give it left in error but only for 2 seconds.

7.  00:37, gain some altitude now to clear trees and such.  Must have been really freaking out right now.  It moves to the left even faster, although there hasn't been any stick input for left or right for a few seconds.  From 00:36 to 00:42 there is no sideways stick input, but you can see how quickly it was moving.

8.  00:38, giving it full forward, and since its pointing toward me, at H, it should be moving forward but isn't.  At the same time, giving it altitude, and that you can see it making it climb.  This is why this ATTI mode is scarry.  You give it full forward to come towards you and its like it has no power to go in your intended direciton.

9.  00:44, finally starts going a bit forward and to the right, without any right stick input.  I am also going down now because even though I went up to clear obstacles, I am having trouble seeing it I need to see it in order to have any hope of bringing it back.  If the wind was first blowing it to the left, while all of a sudden does it now start moving right without any right input?  Its at least going closer to me, but its without stick input.

10.  00:54, finally stats to stabilize and stops drifting, which happens to be a few seconds before GPS is enabled.  I think that it takes a few seconds for the app to register that is has GPS lock.

11.  01:00, even though it has been showing about 11 satellites for a while, at this point, the bars finally turn white and GPS mode is re-established.  You also see me give it a bit of right stick, and it does go right as it should.


Now, before someone thinks that there was interference because of the initial message, keep in mind that my tablet was recording all of this, so how could it know what is happening every second if the controller and drone weren't talking to eachother?  Second, and more importantly, you see at 00:25 when I give it an input to climb, and it does so.  Every time it reacted on up and down inputs, but the left and right, or backwards and forwards inputs were problematic.

So here is the thing.  If this was wind, then why first does it go right, and then go back?  The winds couldn't have been shifting this wilding only a few dozen feet above the ground.  Also, why does it not go in a direction when there is clear 100% stick input?  And why does it go in other directions without any stick input when I assume it can't be just the wind?

Lastly, and this is my biggest question, how does the drone know where it is and able to report to the app so that it can log its precise movement for playback?  If it knows this, why isn't it using this knowledge to stay still?  I would expect that if it in fact losses GPS, and doesn't know where it is, and hence hold steady, or rather, think its holding steady even though its drifting, then why is the drifting so well recorded?  The outline of the route it took matches very well what I remember.  So some parts of the drone must have been keeping a very good record of how it was flying, and why this info couldn't be used to keep it steady without drifting I don't know.




2017-2-1
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SteveDickin
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I had this exact scenario today, except that mine mostly drifted with wind until the GPS bars suddenly went from 1 red to full bars immediately.  Reading on other forums too of people having the exact same things happening last 2 or 3 days.
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madispuk
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I had the same experience. DJI haven't said a word yet. Hopefully they will investigate that issue after holidays.
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DroneFlying
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"Initial message states interference, but I always have this, and it has never affected me."

"Now, before someone thinks that there was interference because of the initial message, keep in mind that my tablet was recording all of this, so how could it know what is happening every second if the controller and drone weren't talking to eachother?"


In my experience it's not normal to get the interference message at takeoff. I've gotten that message many times while flying, but only when the Mavic was pretty far away and even then only while it was in certain locations (presumably where there really is strong interference).

You seem to be under the impression that the interference message means that the "controller and drone [aren't] talking to each other" at all, but that's not how it works: if they aren't communicating at all you'll get a "disconnected" message.
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Jason Lane
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DroneFlying Posted at 2017-2-1 09:44
"Initial message states interference, but I always have this, and it has never affected me."

"Now, before someone thinks that there was interference because of the initial message, keep in mind that my tablet was recording all of this, so how could it know what is happening every second if the controller and drone weren't talking to eachother?"

I've seen the interference warning at the start of about 60% or more of my flights. It flashes up on the screen just as I initiate takeoff. The first few times it happened I got a bit worried and I checked all the signal indicators on my screen, also went into the menus to check the sensors states. Everything looked perfect with full signal bars, etc. Eventually it stopped bothering me, and I just always do a quick check that my signal bars all look good before takeoff. The interference warning never reappears at any other stage of those flights, only at takeoff.
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hallmark007
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Im only surmising here, but to me it looks like this might be a compass problem, because it looks to me that compass heading and gps don't seem to be agreeing, and if that's the case then it's a problem with compass, have you calibrated your compass lately or the area you were flying might have some interference.

Because I've seen a similar on other threads, it also could be a firmware issue.

You might just sync your flight to dji cloud and maybe one of the mods here can  have a look and let us know if this is something we should be concerned with.
Good luck
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Stewie Griffin
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hallmark007 Posted at 2017-2-1 11:36
Im only surmising here, but to me it looks like this might be a compass problem, because it looks to me that compass heading and gps don't seem to be agreeing, and if that's the case then it's a problem with compass, have you calibrated your compass lately or the area you were flying might have some interference.

Because I've seen a similar on other threads, it also could be a firmware issue.

I haven't calibrated anything because I haven't been asked to by the app.  Besides, none of this would explain why the Mavic doesn't accept any inputs from the sticks for direction (it seems to go up and down just fine).  This is what people are saying over and over again.  I had a full forward stick with the Mavic pointing towards me for at least 5 seconds and got no reaction.  I've seen so many videos of people flying around things and think its only a matter of time until they all crash.  When you lose GPS, it cannot be controlled, so if you aren't high enough to avoid everything, it more than likely won't end well.
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Stewie Griffin
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Jason Lane Posted at 2017-2-1 10:32
I've seen the interference warning at the start of about 60% or more of my flights. It flashes up on the screen just as I initiate takeoff. The first few times it happened I got a bit worried and I checked all the signal indicators on my screen, also went into the menus to check the sensors states. Everything looked perfect with full signal bars, etc. Eventually it stopped bothering me, and I just always do a quick check that my signal bars all look good before takeoff. The interference warning never reappears at any other stage of those flights, only at takeoff.

Agreed.  As you can see, I had no other interference messages for this very short flight.
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hallmark007
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Stewie Griffin Posted at 2017-2-1 12:17
I haven't calibrated anything because I haven't been asked to by the app.  Besides, none of this would explain why the Mavic doesn't accept any inputs from the sticks for direction (it seems to go up and down just fine).  This is what people are saying over and over again.  I had a full forward stick with the Mavic pointing towards me for at least 5 seconds and got no reaction.  I've seen so many videos of people flying around things and think its only a matter of time until they all crash.  When you lose GPS, it cannot be controlled, so if you aren't high enough to avoid everything, it more than likely won't end well.

When you loose gps your AC will go into Atti , if this happens then your aircraft will move with the wind , this didn't seem to be happening with your aircraft, so I was thinking you still had enough gps or sats, but your aircraft was not responding properly to your stick commands, leading me to come to the conclusion that compass and gps were not agreeing on the heading.

If you really want to see this working try flying your aircraft down on top of a steel roof, the conflict with gps compass and stick movements will show a very similar pattern to what you have shown on your video.

But I would try to get a moderator to have a look at this. Good luck
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hallmark007
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Stewie Griffin Posted at 2017-2-1 12:17
I haven't calibrated anything because I haven't been asked to by the app.  Besides, none of this would explain why the Mavic doesn't accept any inputs from the sticks for direction (it seems to go up and down just fine).  This is what people are saying over and over again.  I had a full forward stick with the Mavic pointing towards me for at least 5 seconds and got no reaction.  I've seen so many videos of people flying around things and think its only a matter of time until they all crash.  When you lose GPS, it cannot be controlled, so if you aren't high enough to avoid everything, it more than likely won't end well.

When you loose gps your AC will go into Atti , if this happens then your aircraft will move with the wind , this didn't seem to be happening with your aircraft, so I was thinking you still had enough gps or sats, but your aircraft was not responding properly to your stick commands, leading me to come to the conclusion that compass and gps were not agreeing on the heading.

If you really want to see this working try flying your aircraft down on top of a steel roof, the conflict with gps compass and stick movements will show a very similar pattern to what you have shown on your video.

But I would try to get a moderator to have a look at this. Good luck
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Stewie Griffin
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hallmark007 Posted at 2017-2-1 12:33
When you loose gps your AC will go into Atti , if this happens then your aircraft will move with the wind , this didn't seem to be happening with your aircraft, so I was thinking you still had enough gps or sats, but your aircraft was not responding properly to your stick commands, leading me to come to the conclusion that compass and gps were not agreeing on the heading.

If you really want to see this working try flying your aircraft down on top of a steel roof, the conflict with gps compass and stick movements will show a very similar pattern to what you have shown on your video.

The area I was on did have lots of concrete, hence metal inside, and also a metal statue I believe, so what you say is very possible.  I don't doubt that the metal will interfere with the compass,but I don't see why it would interfere with the stick movements.  It clearly has no trouble going up or down.  It should also know how to go forward.  It may not be able to calculate exactly what the speed of each motor should be to fly a certain speed since it might not know how strong the wind is and all that jazz, but I still figure if you hit full throttle forward, it should give you something in that direction.

Thanks for wishing me good luck.  I didn't even put in a ticket because I do think its rare, and I do think its a software thing that needs to be worked on, and not that my drone needs to be sent back.  Its been a while since there was a new firmware, but hopefully the new one will have lots of improvements.

The least DJI could do is talk about the ATTI mode and what can be expected and how it works for the Mavic.
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hallmark007
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Stewie Griffin Posted at 2017-2-1 15:51
The area I was on did have lots of concrete, hence metal inside, and also a metal statue I believe, so what you say is very possible.  I don't doubt that the metal will interfere with the compass,but I don't see why it would interfere with the stick movements.  It clearly has no trouble going up or down.  It should also know how to go forward.  It may not be able to calculate exactly what the speed of each motor should be to fly a certain speed since it might not know how strong the wind is and all that jazz, but I still figure if you hit full throttle forward, it should give you something in that direction.

Thanks for wishing me good luck.  I didn't even put in a ticket because I do think its rare, and I do think its a software thing that needs to be worked on, and not that my drone needs to be sent back.  Its been a while since there was a new firmware, but hopefully the new one will have lots of improvements.

I would go to another area grass field, just start up your AC take it up 8ft or so just check forward,backward yaw right yaw  left up 1ft down 1ft , and just make sure when you stop each movement that AC levels out , if there are no free movements in a circle motion or strange curve movement when you fly it straight. If that works out ok then your IMU and compass are fine.

With regard to dji getting involved your right, there reaction is p##s poor, if this is not a real problem then they should say it, if it is or might be , then they should post a warning to others who may have a problem..
Good luck
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The Rev
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I have also had this problem and this is looking like a common problem and I think its dangerous and im really carfull that I fly in open space so I can just bring it down.
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