Djo Mavic 2 Pro crashes against building in tripod mode

[Donvictorio]

Hi guys,

Dji has recently refused my claim towards collision of dji mavic 2 pro.

Just wanted to hear from you if that's really my fault or it's poor dji product quality ie. filtering of gps data.

I was getting ready to land,(sport mode) due to low battery, when suddenly drone started moving very fast to port (left). I saw this as I was about 30m away from drone with excellent visual). When I saw drone moving to port I immediately applied counter with my controller (pushing it to starboard/right) but drone would not react at all, it just kept moving to port, quite fast. Since there was a building nearby 25-30m towards which drone was moving, I switched to tripod mode to force slowing down and make sure all sensors are enabled. Drone actually did switch to tirpod mode(based on log) but it would not slow down at all until it hit the wall of building and crashed.

Dji claims its due to poor gps data. Now, if gps is bad (6-7 satellites in view) can it really just freak out and go at high speed to one direction without responding to my remote control?

If it had been phantom, I would have switched to full manual and just stop it but with mavic I could nothing but just watched it fly towards and obstruction and die

 

[Deleted member 114292]

On the surface it would appear it should’ve responded to your stick Commands.
You know you’re going to have to post the logs so just go ahead and do that.

 

[steve_lyt]

tripod mode does noe use sensors. p mode does

 

[Donvictorio]

tripod mode does noe use sensors. p mode does

Tripod mode uses all sensors.

P mode uses all sensors excluding side ones.

 

[Donvictorio]

On the surface it would appear it should’ve responded to your stick Commands.
You know you’re going to have to post the logs so just go ahead and do that.

Hi,

Not sure if that's the one you're referring to:

- Dji assistant log files (big file taken from drone)
- Crazy thing starts 1:28 (last movie, at 1:28 drone starts moving to port without any reason)
-attached last flight record.

Now, once again I know gps was not the best but moving to port at high speed without listening to my counter, nor slowing down at tripod mode makes me feel angry and helpless.


Is that sufficient?

 

[Simmo]

@sar104, bored this morning..... grab an expresso my friend!

 

[Donvictorio]

@sar104, bored this morning..... grab an expresso my friend!

I am sorry guys if that's obvious or boring for you.

This drone takes my three months savings and crashes on my own disbelieving eyes.

I just want to understand why is it happening like this. As person engaged in using positioning systems on daily basis at work, I know that those devices which rely on gps must have filtering, ie if due to obstruction or interference the median test is failed, device rejects GPS signal and "hovers" based on preinstalled idle settings until good position is regained.

 

[Caleb R.]

Would the pause button have had any effect in this situation?

 

[Donvictorio]

Would the pause button have had any effect in this situation?

In "normal" mode, not sure. If other modes (like fly around an object or dronie), then surely yes. I was on "normal /free" mode at this time

 

[Simmo]

I am sorry guys if that's obvious or boring for you.

This drone takes my three months savings and crashes on my own disbelieving eyes.

I just want to understand why is it happening like this. As person engaged in using positioning systems on daily basis at work, I know that those devices which rely on gps must have filtering, ie if due to obstruction or interference the median test is failed, device rejects GPS signal and "hovers" based on preinstalled idle settings until good position is regained.

Please, I was not being condisending to you... just having a dig at my friend Sar104..!

 

[Meta4]

Now, once again I know gps was not the best but moving to port at high speed without listening to my counter, nor slowing down at tripod mode makes me feel angry and helpless.

Satellite numbers dropped below 9 after 22:36.4 and the Flight Controller rated GPS Health at 1 until 23:01.1 when it dropped to zero until the end of the flight.
In the open 8 or 9 sats would usually be enough.
But if the reason for a low number of sats was the skyview being blocked by obstructions, it's quite likely that the remaining sats did not provide a good geometric spread which would result in a poor quality fix.
That's why the GPS Health was 0-1 which means you had no horizontal position holding ability at all from 22:36.4 until the end of the flight.

btw .. you launched without GPS and had no homepoint until about 1.5 minutes into the flight, when your drone finally found enough sats.

 

[Donvictorio]

That's why the GPS Health was 0-1 which means you had no horizontal position holding ability at all from 22:36.4 until the end of the flight

Do you mean that in poor satellites / gps health it is possible for drone to just go off and run to port without reacting to my controls?

I did take off with no gps fix but I was aware of this and drone behaved very normal nonetheless. Steered smooth and response was good.

 

[steve_lyt]

Did you get care refresh?. If you did you may have got it replaced

 

[Meta4]

Dji claims its due to poor gps data. Now, if gps is bad (6-7 satellites in view) can it really just freak out and go at high speed to one direction without responding to my remote control?

With no horizontal position holding ability, the drone was like driving on ice without brakes.
It could not stop and in that situation giving hard joystick input when close to an obstacle isn't going to end well.

If it had been phantom, I would have switched to full manual and just stop it but with mavic I could nothing but just watched it fly towards and obstruction and die

That wouldn't have worked at all, it would have been just the same.
No GPS meant that the drone could not stop.

 

[Meta4]

As person engaged in using positioning systems on daily basis at work, I know that those devices which rely on gps must have filtering, ie if due to obstruction or interference the median test is failed, device rejects GPS signal and "hovers" based on preinstalled idle settings until good position is regained.

Except that the drone cannot hold position without GPS.

Would the pause button have had any effect in this situation?

Not without GPS

 

[Donvictorio]

It could not stop and in that situation giving hard joystick input when close to an obstacle isn't going to end well.

I applied counter 25 m before it hit the wall, ie long before. But there was absolutely no reaction. I had an excellent visual, drone was in front of me. I see it starts moving to port, so I applied counter. Absolutely no reaction, it kept moving to port. Only then I switched to tripod and to my disappointment I saw speed wouldn't change and collision sensors would not engage, until the crash

 

[Meta4]

Is that sufficient?

Here's a short analysis of that flight data looks like: DJI Flight Log Viewer - PhantomHelp.com

 

[Donvictorio]

Meta4, your conclusion would be that flying indoors is absolutely not possible, and that's not true. I have flown my phantom 2 on manual indoors and although it's more difficult, drone listens to the commands flawlessly.

Is mavic 2 pro any worse?

 

[Meta4]

collision sensors would not engage, until the crash

Collision sensors are another thing that can't work without GPS

Meta4, your conclusion would be that flying indoors is absolutely not possible, and that's not true. I have flown my phantom 2 on manual indoors and although it's more difficult, drone listens to the commands flawlessly.

I know that it's possible to fly indoors or outdoors without GPS.
But I also understand the limitations you have flying that way.
Presumably you mean you've flown in atti mode (manual is something else entirely and very, very hard to do safely)

Is mavic 2 pro any worse?

Your Mavic had no GPS so it was in atti mode, just the way your P2 would have been.

 

[Donvictorio]

Your Mavic had no GPS so it was in atti mode, just the way your P2 would have been.

If its atti mode, why no response from me trying to move it back to starboard? Why drone was unstoppably moving to port? It would not listen to controller demand. That's the point I'm trying to make, but it seems like logs and video doesn't show it