LOST MAVIC PRO NO GPS

[Goldenmember1000]

Don’t know what’s worse , crashing your drone and hearing it or crashing it out of sight and losing it ? Whatever the cause our thoughts go with you

 

[simsurf]

Um thanks for your ( Mod Removed ) The wind took it . It was night and wasn't responding against the currents . Thanks for your words . AGAIN THERE IS NO EXPLANATION FROM ANY of u so called experts as to why gps failed for no reason. Gps should not of failed ! Simple !

Wow people here have given their time freely and helped you as much as possible. And that's ignoring the fact that flying at night is illegal in a lot of countries.

 

[GavieboyDji]

Um thanks for your Mod Removed ). The wind took it . It was night and wasn't responding against the currents . Thanks for your words . AGAIN THERE IS NO EXPLANATION FROM ANY of u so called experts as to why gps failed for no reason. Gps should not of failed ! Simple !

GPS shouldn't of just failed no but you can still fly a drone in Atti mode no gps.
Did you take off with tall buildings around you?

 

[Meta4]

Um thanks for your ( Mod Removed ). The wind took it . It was night and wasn't responding against the currents . Thanks for your words.

The wind didn't take it.
It lost position holding and that may have been confusing for an inexperienced flyer but it was perfectly controllable and could have been brought back at any time.

It was not 22 percent when drifting away. That's when it disconnected from the co trolled altogether it was flying around it self

It may have drifted with the wind but it definitely wasn't flying around itself.
The wind didn't take the drone up 400 feet.
That was a result of you pushing the left stick full forward 32 times. Each time the drone went higher.
You only brought it slightly lower a few times but always pushed it back up to the limit.
Every time you pushed the right stick forward or pulled it back the drone increased speed.
Every change of direction matches a movement of the joysticks too.

That's not ( Mod Removed ), it's plain simple fact straight from the recorded flight data.
It's hard losing a drone, harder when you don't learn anything from the experience.

AGAIN THERE IS NO EXPLANATION FROM ANY of u so called experts as to why gps failed for no reason. Gps should not of failed ! Simple !

That's because no-one knows what went wrong to stop the GPS working.
Electronic equipment occasionally fails.
It may have been a one-off glitch or it may have been a serious fault.
But the app warned you of this at 4 seconds when the drone was only 6 feet above the launch point and continued to warn you for the whole flight.

One thing I forgot to mention.
Before you talk to DJI, synch the flight data by clicking the cloud icon on your flight records page.
They will need to see the data.
If their people are any good, they'll see the same things the data is telling me but who knows, they might take pity on you (or they might not).

 

[Meta4]

Is it possible for the flight data to be incorrect ? This flyer does seem pretty adamant it was not their fault ?

Good question. Have a look at the data for yourself and see.
Start here: DJI Flight Log Viewer - PhantomHelp.com
Then look a little further to see all the movements of the drone and compare them with the joystick movements
The spreadsheet has 5300 lines of data, here's a screenshot of just 70 lines from it:

I've gone through those 5300 lines and I'd say the data appears to be consistent and no errors are apparent to me.

This flyer does seem pretty adamant it was not their fault ?

The data is telling a very different story.
Read post #27 for a short summary of the data's version of the incident
It's not unheard of for an inexperienced flyer to dispute what the data shows quite clearly.

 

[Meta4]

Did you take off with tall buildings around you?

The launch point was between buildings but that had no effect on 99% of the flight which was high above any buildings.

 

[BudWalker]

I was probably mistaken if I said that. I'm pretty sure that the OSD.xSpeed, OSD.ySpeed and OSD.zSpeed data are the sensor fusion velocities, which should be the same as the GPS velocities but are not the actual recorded GPS velocities. If you look at a DAT file then the former are the IMU_ATTI(0):velN, IMU_ATTI(0):velE, IMU_ATTI(0):velD values while the latter are the GPS(0):velN, GPS(0):velE, GPS(0):velD values. On a normal flight those are very similar, but not identical.

The DAT file will confirm one way or the other.

I see. Makes sense. But, are the IMU_ATTI:vel values the result of fusing the GPS:vel data with the accel and gyro data. If so, then that would cause the fused IMU_ATT:vel values to be incorrect if the GPS:vel data were held constant. The IMU derived path shown in your post #3 seems a bit erratic and the OP seems sure that the MP didn't follow that path.

I just now realized that we already discussed this and concluded that the IMU:vel values depends on the GPS:vel data.

Ultrasonic Systems Error

So it seems unlikely that the GPS data will provide any useful info.

BTW, I've always wondered why the .txt labels the velocities like they are in x,y,z coordinates when it's actually North, East, Down.

 

[sar104]

I see. Makes sense. But, are the IMU_ATTI:vel values the result of fusing the GPS:vel data with the accel and gyro data. If so, then that would cause the fused IMU_ATT:vel values to be incorrect if the GPS:vel data were held constant. The IMU derived path shown in your post #3 seems a bit erratic and the OP seems sure that the MP didn't follow that path.

I just now realized that we already discussed this and concluded that the IMU:vel values depends on the GPS:vel data.

Ultrasonic Systems Error

So it seems unlikely that the GPS data will provide any useful info.

BTW, I've always wondered why the .txt labels the velocities like they are in x,y,z coordinates when it's actually North, East, Down.

Yes - I think that the FC fuses the compass and rate gyro data to get instantaneous yaw, and then combines that with the accelerometer and GPS velocity data to get velocity in the earth frame of reference. If the GPS velocity data are good then I would guess that it is weighted quite heavily.

If the GPS velocity data disappear then we know, from other logs, that IMU/OSD velocities are still reported, presumably from purely inertial calculations. I wonder if we will get to see the DAT file....

 

[Starz]

Wow people here have given their time freely and helped you as much as possible. And that's ignoring the fact that flying at night is illegal in a lot of countries.

Perfectly legal in USA.

 

[BenM1005]

I'm going to have a guess that you got the drone for Christmas, didn't do any research or practice and went and had some fun. I'm also going to guess that you failed to calibrate and so no GPS. Unlucky but at least you have the controller already when you buy a new drone.

 

[Meta4]

I'm also going to guess that you failed to calibrate and so no GPS.

Bad guess.
Calibrating anything is not required before flying and calibrating or not makes no difference to GPS.

 

[Goldenmember1000]

Bad guess.
Calibrating anything is not required before flying and calibrating or not makes no difference to GPS.

Did you calibrate the compass before takeoff ? Did you take off before gps was locked on ?

 

[Meta4]

Did you calibrate the compass before takeoff ? Did you take off before gps was locked on ?

It's not my drone so I did nothing.
But I have analysed his flight data and explained clearly what did happen earlier in this thread.
Calibrating the compass or not calibrating the compass would have made no difference.
You don't have to calibrate the compass before flying.

 

[sar104]

Did you calibrate the compass before takeoff ? Did you take off before gps was locked on ?

There is little point in commenting if you don't read the thread. The GPS question was answered in post #3, and this event had nothing to do with the compass.

 

[Starz]

Compass calibration phrase should be changed to “cure all”.

 

[Goldenmember1000]

Really - you can't even figure out whose drone it was? Did you have anything useful to contribute here, or do you just like posting to confuse people?

Someone had confused me , your post has come up as the original poster ???

 

[sar104]

Someone had confused me , your post has come up as the original poster ???

No - I did the analysis in post #3.

 

[TR Ganey]

No - I did the analysis in post #3.

You have to love a good challenge and I'm not talking about finding lost drones! LOL

 

[Simone / kk]

I'm 100 percent it was not my fault it started to play up the time before this night also. M thinking it was a data or wifi issue. I have 7 mins of proof the thing wa not listening t me the footage shows us how desperate I was trying to pin point where I was as I lost sight of It . I made my friend drive me around while I was hanging out her window we both looked like complete idiots I had my controller held up in the air and was making her flash her lights so I could try locate from the camera which car we were as it being night not much to see
Some one please help me how can u contact dji for replacement I don't have a receipt or the box nothing I bought it second hand
I've been looking everyday around the area I've truly given up I can't afford another one and I do use it regularly for work now I'm stuffed

 

[Simone / kk]

This is the typical ( Drone pilot not knowing what to do when GPS isn't available another words Mavic gone into atti mode and him not knowing what to do to fly it.)

If you can't see it and the wind has it drifting away which you forgot to write that point in oh but you wouldn't of inn that because the gps location was completely unknown for some reason. Hmmm do I go on