Djo Mavic 2 Pro crashes against building in tripod mode

[Donvictorio]

I just want to let you know that @Donvictorio has my sympathy for something I feel it shouldn't have happened and it normally doesn't happen, and for his wilfulness of his opinions.

As I lack the ability to dig deeper into the matter I can only say that I've seen Mavic Pros performing incredibly in more than challenging situations, and I refuse any explanation that "he shouldn't have flown in those conditions because that manual says so", otherwise one what has it got a Mavic PRO for ?

Whatever it was I am pretty sure it can be isolated and discerned against all odds, being an FC biased data processing, glitch or hardware fault. I am sorry for what happened.

Thank you for those words, though DJI is a huge company and I fail to see any chances of being able to win this case.

 

[JAW]

Occasionally, after reading these crash reports, I think to myself, “what the heck did you expect?”
Then I catch myself with the old tenet:
There but for the grace of God go I.

 

[Donvictorio]

Occasionally, after reading these crash reports, I think to myself, “what the heck did you expect?”
Then I catch myself with the old tenet:
There but for the grace of God go I.

I expected drone being reliable and responsive. It wasnt.

 

[sar104]

I expected drone being reliable and responsive. It wasnt.

Right - but that's not a realistic expectation if you suddenly put it in a situation where it loses its GNSS position solution and is too high for vision positioning. It may be what you want, but it's just not physically possible with this technology.

 

[new2mavic]

When the final descent was commenced, there was a lot of abnormal oscillation in pitch and roll. May be some problems have developed in the IMU or the propulsion system ?



This is how the forward/backward speed changed with elevator input in the normal part of the flight ( in P mode ) :



Near the end of the flight, the forward/backward speed changed in the right direction but there seems to be some significant delay :



Let's look at the alieron control which the OP complained about. This is how the lateral speed changed with aileron input in the normal part of the flight. There was an instance where the lateral speed changed without aileron input. May be the craft was correcting it's position.



When "things went crazy", the craft did move sideway by itself, likely due to chasing after erroneous GPS fixes but it also responded to aileron input but again, the response seems to be significantly delayed. The failure to halt the unexpected movement of the craft was also partly due to the OP releasing the aileron stick momentarily.



It appears to me that the delayed response of the craft to control input is part of the causes of the crash. May be some fault has developed as indicated by the abnormal oscillation in pitch and roll.

 

[sar104]

When the final descent was commenced, there was a lot of abnormal oscillation in pitch and roll. May be some problems have developed in the IMU or the propulsion system ?

View attachment 96861

This is how the forward/backward speed changed with elevator input in the normal part of the flight ( in P mode ) :

View attachment 96862

Near the end of the flight, the forward/backward speed changed in the right direction but there seems to be some significant delay :

View attachment 96864

Let's look at the alieron control which the OP complained about. This is how the lateral speed changed with aileron input in the normal part of the flight. There was an instance where the lateral speed changed without aileron input. May be the craft was correcting it's position.

View attachment 96865

When "things went crazy", the craft did move sideway by itself, likely due to chasing after erroneous GPS fixes but it also responded to aileron input but again, the response seems to be significantly delayed. The failure to halt the unexpected movement of the craft was also partly due to the OP releasing the aileron stick momentarily.

View attachment 96866

It appears to me that the delayed response of the craft to control input is part of the causes of the crash. May be some fault has developed as indicated by the abnormal oscillation in pitch and roll.

That was not the problem - I explained in some detail above exactly what happened. The attitude oscillations during descent are normal, and not excessive.



The issue was that after the FC transitioned to pure inertial guidance at 1381 seconds the velocity solution was wrong - the FC thought it was moving south (to the aircraft's right), but it was actually moving north (aircraft's left).

 

[JAW]

I expected drone being reliable and responsive. It wasnt.

After viewing the image of your flight environment in post #25, my first thought was,
”good luck with that landing“

 

[Donvictorio]

After viewing the image of your flight environment in post #25, my first thought was,
”good luck with that landing“

With considerable experience on phantom 2 where I have flown on manual mode (not atti), where I would flip drone, fly indoors and do pretty much all movement I want I was confident to fly mavic inside the tall buildings district. My mistake was to assume drone would listen to my command even at deteriorating gps signal. Unfortunately dji mavic 2 pro is not a drone you want to fly without excellent gps coverage.


Edit : M2P is great but I should have programed the mode button to have atti available on my instant demand.

 

[Donvictorio]

Dji's reply :

Regarding your inquiry, please note that when the aircraft was under tripod mode, the Omnidirectional Obstacle Sensing does not fully cover the circumference of a 360-degree arc. DJI warranty does not cover any loss caused by crashing when flying left or right, even when ActiveTrack or Tripod mode is activated. Please be aware of your surroundings and App notifications when operating the Mavic 2 to ensure safety.

Also, we noticed that before turning in to Tripod mode, the aircraft was under Sport mode. Please note that when the aircraft works under Sport mode, due to the big motion inertia, the braking distances will be extended and there will be a reasonable delay of response to the remote control commands. That's why you said you tried to stop drone but it kept moving. Then when the aircraft turned into tripod mode, there is still a velocity to the motion tangential component towards left. So if you released all the controller sticks to idle, the aircraft was still moving and it could not avoid the buildings.

 

[JAW]

Edit : M2P is great but I should have programed the mode button to have atti available on my instant demand.

True, but not everyone’s comfortable with hacking their Mavic2

 

[sar104]

True, but not everyone’s comfortable with hacking their Mavic2

It's not a hack, in my opinion, because it does not involve messing with the firmware code. It's functionality that DJI put into the firmware, is enabled on other models, and can be enabled on the Mavics using DJIs software.

 

[Deleted member 114292]

It's not a hack, in my opinion, because it does not involve messing with the firmware code. It's functionality that DJI put into the firmware, is enabled on other models, and can be enabled on the Mavics using DJIs software.

Can you do this with the latest code?

 

[sar104]

Can you do this with the latest code?

I have it set on my M2P running the latest firmware.

 

[Deleted member 114292]

I have it set on my M2P running the latest firmware.

If I change _mode[0] from 12 to 3 will that make T mode atti mode?
Do I need to save it to the AC after the change?

 

[sar104]

If I change _mode[0] from 12 to 3 will that make T mode atti mode?
Do I need to save it to the AC after the change?

That will do it. Just hit enter - it saves automatically.

 

[JAW]

It's not a hack, in my opinion, because it does not involve messing with the firmware code. It's functionality that DJI put into the firmware, is enabled on other models, and can be enabled on the Mavics using DJIs software.

Is this easily done? It would be nice to have the ability to access ATTI mode!

 

[sar104]

Is this easily done? It would be nice to have the ability to access ATTI mode!

Mavic 2 Atti mode

I haven't seen anyone else mention it so, just in case anyone is interested, I can confirm that it is possible to switch the M2P into ATTI mode by changing the mapping on the flight mode switch using the same DJI Assistant functionality as with the MP. I altered the Sport mode setting (8) to...

mavicpilots.com

More details in this specific post:

 

[JAW]

I haven’t checked your link yet........I was viewing this YT vid where he says you can’t do the mod for a M2Z without disabling downward OA. ???

Will check your link now, thanks

 

[Deleted member 114292]

Do we have a sticky for this? I found your excellent explanation of this. Also there are several threads for the version you need but mostly there were dead links.
I did find one link that worked and did this - yet to test it.

 

[sar104]

I haven’t checked your link yet........I was viewing this YT vid where he says you can’t do the mod for a M2Z without disabling downward OA. ???

Will check your link now, thanks

I don't have a zoom, but I've never heard anyone report that it didn't work on the zoom. The only difference between the aircraft is the camera, and I cannot imagine what OA would have to do with the problem. I suspect they did something wrong.