Need help. DJI won't cover flyaway crash. Ignores flight data.

[Faceplant]

How do you avoid this? If your drone starts doing weird things in the sky is that it?

 

[sinxa]

How do you avoid this? If your drone starts doing weird things in the sky is that it?

ATTI mode.

Because its only use barometer for keeping its heights and ignore GPS+compass into calculation.

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[Deleted member 62848]

DJI Phantom 3 Flyaway crash:

Once the phantom has compass malfunction on the air, the firmware logic calculates the wrong result. Even just for hovering (with no input command), it will drive it to wrong dirrection. That's what causing "toilet bowl effect".

The dangerous thing is, the phantom didn't even realize that its compass is malfunctioning, so it won't show any error message and keep calculating wrong values of trajectory over and over.

How to avoid this is make sure your actual heading is match with the heading on the map. Maybe only your self who can confirm the situation on that location, between the onboard video vs the flightlog video on your 1'st post. Make sore it is perfectly match the orientation (N,E,S,W) not only the rotation movement on the map.

And this youtube video i post here is one example, that phantom didnot realize its compass malfunction, so it won't show any error message. The worst thing is the pilot also didnot aware about it.

I believe this is exactly match your case, i can see it from the same "toilet bowl" trajectory.

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Yeh i try not to let sit hovering to long in one spot then i get the toilet bowl going,,in nz here we get a good bowl effect goin,,can throw u out the sky,,ha,, come on dj fix the drone

 

[sinxa]

Watch this example carefully.
1. The onboard video showing that the phantom heading along with the bridge.
2. The red arrow on the map, heading to 90 degre left of the bridge.
3. Phantom didnot realize its compass was incorectly reporting heading data, so no error message showed.
4. Neither pilot aware on this condition.

If you insist to fly on this condition especialy with P-GPS mode, it's fatal.
What you need to do when this happen is calibrate compass before flight.

Compass miscalibration is happening a lot on every device even on our cellphones. sometime we open the map application and found it's dirrection is not match with the actual heading we're facing, even the map display is rotating somehow along with our movement. On this condition we need to calibrate our cellphone by move it as the "8" number path for a couple times until we find it prefectly match our actual heading. And this "8" number path adopted by "DJI dance" for the same purpose.

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[With The Birds]

DJI Phantom 3 Flyaway crash:

Once the phantom has compass malfunction on the air, the firmware logic calculates the wrong result. Even just for hovering (with no input command), it will drive it to wrong dirrection. That's what causing "toilet bowl effect".

The dangerous thing is, the phantom didn't even realize that its compass is malfunctioning, so it won't show any error message and keep calculating wrong values of trajectory over and over.

How to avoid this is make sure your actual heading is match with the heading on the map. Maybe only your self who can confirm the situation on that location, between the onboard video vs the flightlog video on your 1'st post. Make sure it is perfectly match the orientation (N,E,S,W) not only the rotation movement on the map.

And this youtube video i post here is one example, that phantom didnot realize its compass malfunction, so it won't show any error message. The worst thing is the pilot also didnot aware about it.

I believe this is exactly match your case, i can see it from the same "toilet bowl" trajectory.

Sent from my D5503 using PhantomPilots mobile app

That's is precisely my earlier point and has been my experience (unfortunately). When I stupidly flew from a metal structure I had no compass issues reported in the app or logged but the heading indicator was almost completely reversed and I had to fudge the control inputs to bring the AC home. I'm convinced a RTH command at that point would have ended badly.

 

[jason]

Hey Everyone!

I'm sorry if this isn't the correct area for this post. If it isn't just let me know. This post will be kind of long....

So I've been wanting to get into this hobby for ages now. I finally saved enough and was persuaded by my wife enough to finally buy a drone (P4). I flew it three times before it flew away on it's own and crashed into a river....

Here is the flight data:

Here's the video of the crash:

The following is the complaint I eventually sent in to the BBB. It describes the incident in detail:



So that's the nuts and bolts of what happened. I originally got the following from DJI: Imgur: The most awesome images on the Internet

After my BBB complaint I got the following response:



Again, they ignored everything that happened before the RTH....

So here I am... What do I do now?

Thanks!!

Well you seem to have some of the brightest engineers here an with all that knowledge someone will have the correct answer as to why it took the plunge.

 

[With The Birds]

I'm not sure the heading direction on the app is accurate though. When I turned the map on my app The Heading also turned with my map orientation. See these screenshots Imgur: The most awesome images on the Internet

But if the compass was acting incorrectly, why would the aircraft accelerate in the way that it did? Why didn't it stop moving when I pressed the RTH function? Why didn't it ascend to the preset height? And why did it descend into the water when it was a 165 feet from the home point? The AC clearly knew it wasn't over the home point. I'm not trying to call you out here, I'm just genuinely curious. I really appreciate your feedback.

And what really makes me suspicious, is that DJI continually refuses to acknowledge the events before the RTH function. Even when I call them out on it. Over the phone or through the complaint process they just act like I didn't even mention the events prior to the RTH. Makes me think they know it was a malfunction... but maybe I'm reading too much into it

Ok, so I have just opened a log in GO, no matter how I move the devic the depicted AC heading doesn't change and it agrees with the camera orientation in my video....

 

[IIIDaemon]

Also, here what DJI sent me after the first call. It's a copy of their logs:Imgur: The most awesome images on the Internet

.
...MiltonDave, is that the Only image of their analysis they sent you..? if not, would you Please send them to me at the following email address:
VaData (at) Yahoo (dot) com , Thanks
.
IIIDaemon
www.GasRecovery.net

 

[Meta4]

I live right down the road from that bridge. I was thinking of buying the same unit and using it on my boat out in the river while sturgeon fishing. I'm worried about having a malfunction because of my aluminum boat.

Relax ... if your boat was made of steel it might have some effect but aluminium doesn't affect compasses

 

[sinxa]

This part i picked for the estimated time when the drone was exactly above the edge of the river.
We can see from the onboard video shows the drone is heading to the land (away from the water).
But the red arrow of the map heading oposite...

When this happened in GPS mode, it wouldn't need pilot input to crash it self, since it calculates wrong trajectory for the whole time over and over but it will never reach the desired point it should be.
It just like you drive your car with closed eyes, and someone teling you the direction, not by left right forward backward, but by north south west and east.

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[With The Birds]

This part i picked for the estimated time when the drone was exactly above the edge of the river.
We can see from the onboard video shows the drone is heading to the land (away from the water).
But the red arrow of the map heading oposite...

When this happened in GPS mode, it wouldn't need pilot input to crash it self, since it calculates wrong trajectory for the whole time over and over but it will never reach the desired point it should be.
It just like you drive your car with closed eyes, and someone teling you the direction, not by left right forward backward, but by north south west and east.

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I have looked at several more of my flight records, compared to images and video, I am comfortable now that the heading depicted by the red arrow in the replay is accurate (when all is good). I am now back at my original guess here, based on the discrepancy between heading and video that the compass was being effected by the bridge. Healthy drones also shows that the GPS (number of satellites) was marginal. With poor GPS lock and the incorrect compass heading in the absence of managing to command the AC to fly clear of the bridge the result here was, unfortunately, inevitable.

 

[sinxa]

I have looked at several more of my flight records, compared to images and video, I am comfortable now that the heading depicted by the red arrow in the replay is accurate (when all is good). I am now back at my original guess here, based on the discrepancy between heading and video that the compass was being effected by the bridge. Healthy drones also shows that the GPS (number of satellites) was marginal. With poor GPS lock and the incorrect compass heading in the absence of managing to command the AC to fly clear of the bridge the result here was, unfortunately, inevitable.

I'd like to see the whole video and logs of your case. do you mind share it with us?

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[With The Birds]

I'd like to see the whole video and logs of your case. do you mind share it with us?

Sent from my D5503 using PhantomPilots mobile app

The cases (mine) I am talking about are normal uneventful flights (things working as they should). I picked up the apparent discrepancy between the depicted heading in the GO app and video posted by the OP earlier and he suggested that the heading in the app might not be accurate. That doesn't seem to be the case with my own flights I looked at. My flight where I had the compass issue I haven't found, I will look for it.

 

[Meta4]

How do you avoid this? If your drone starts doing weird things in the sky is that it?

ATTI mode.
Because its only use barometer for keeping its heights and ignore GPS+compass into calculation.

There's some confusion there.
Atti mode will cause the Phantom to ignore input from the GPS
But it still uses compass data (because the Phantom cannot fly straight without good compass data).

The compass seems to have been reporting the heading incorrectly. ... Your only option is to switch to ATTI mode and fly well clear of the structure.

GPS was not a problem in this case. Ignoring GPS data, doesn't do anything to fix the bad compass data that is the problem.

 

[Meta4]

If you insist to fly on this condition especialy with P-GPS mode, it's fatal.
What you need to do when this happen is calibrate compass before flight.

Recalibrating your compass on reinforced concrete or launching from reinforced concrete is asking for compass trouble.

 

[sinxa]

There's some confusion there.
Atti mode will cause the Phantom to ignore input from the GPS
But it still uses compass data (because the Phantom cannot fly straight without good compass data).

Yes, you need compass data to fly straight, unless in ATTi mode.
Atti mode : gps and compass data is still being recorded on the flight log and displayed on the screen. But it no longer taken into positioning calculation. Because the positioning is totally handled by the pilot.

Recalibrating your compass on reinforced concrete or launching from reinforced concrete is asking for compass trouble.

Actually, in this case OP already has the problem at the first place. I just recommend recalibrate the compass just to make sure compass data is correctly reported. If that goal can't be achieved, then don't fly at that location. [emoji16]

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[Meta4]

Yes, you need compass data to fly straight, unless in ATTi mode.

You need the compass to fly straight in ANY mode, including atti mode.

 

[sinxa]

You need the compass to fly straight in ANY mode, including atti mode.

Okay, thanks for your correction.
if compass is still needed in any mode, so atti mode wouldn't help in this situation?

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[Meta4]

Yes, you need compass data to fly straight, unless in ATTi mode.
Atti mode : gps and compass data is still being recorded on the flight log and displayed on the screen. But it no longer taken into positioning calculation. Because the positioning is totally handled by the pilot.

This is incorrect.
The Phantom still requires a properly calibrated compass to be able to fly in atti mode.
The compass does not provide any position data but it supplies heading data which is necessary to fly properly

Actually, in this case OP already has the problem at the first place. I just recommend recalibrate the compass just to make sure compass data is correctly reported. If that goal can't be achieved, then don't fly at that location.

Recalibrating your compass in a location where the earth's normal magnetic field is distorted by a lot of steel is something to be avoided at all times.
Mostly your Phantom will fail to calibrate but sometimes it is possible to "successfully" calibrate in this situation.
Here's the result of on such "successful" calibration on a pier full of steel.
In this case the compass reported the calibration was correct (for the distorted magnetic field where it was calibrated - but not away from the magnetic influence)

 

[sinxa]

This is incorrect.
The Phantom still requires a properly calibrated compass to be able to fly in atti mode.
The compass does not provide any position data but it supplies heading data which is necessary to fly properly

Recalibrating your compass in a location where the earth's normal magnetic field is distorted by a lot of steel is something to be avoided at all times.
Mostly your Phantom will fail to calibrate but sometimes it is possible to "successfully" calibrate in this situation.
Here's the result of on such "successful" calibration on a pier full of steel.
In this case the compass reported the calibration was correct (for the distorted magnetic field where it was calibrated - but not away from the magnetic influence)

Yes, i remember this video. As i said, i didn't mean to say just do compass calibration and everything is gonna be fine. No i did not say that. The correct calibration not only just trusting the calibration message on the screen as everything goes fine. But we also have to make sure the red arrow's heading is correctly match the actual heading of the drone, and we should test it with some turn and hope the red arrow follows the turn as well. Other than that, we should avoid flying at this location.

You need the compass to fly straight in ANY mode, including atti mode.

Actually, there is another opinion on this.
If compass really needed on every mode, why DJI recommend to exit P-GPS mode when compass error happen? To what mode we should switch??

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