Lost connection and the M2P Drone

[DJI Aldo]

Hello,

July 21, after a few minutes flight, my drone lost connection from RC. It had been three long frustrating days of search but I have not found it yet.
All the information you can find it at the docs and pics attached.

Note: the possibility to have been found it by others is almost zero as the terrain is almost untouchable by people.

Please give me as much help and advice as possible!

Thank you in advance!

Aldo

 

[msinger]

Here's your uploaded log file:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

 

[DJI Aldo]

Here's your uploaded log file:

DJI Flight Log Viewer | Phantom Help

Upload and view flight logs from your DJI drones

www.phantomhelp.com

We have followed these instructions already and we cannot find it yet

 

[msinger]

I was just posting your log so others could review it

 

[DJI Aldo]

I was just posting your log so others could review it

Thanks buddy

 

[msinger]

The last recorded location was at 41.29781309, 19.80331134. The aircraft had plenty of altitude and battery power to make it home. Since that didn't happen, it likely shut off and dropped to the ground near that last recorded point.

Did you try plugging those coordinates into the map app on your mobile phone and walk in the direction it was heading?

And I'm guessing you saw the message below at the beginning of your log. The aircraft detected the battery was not installed properly for some reason.

"Battery not installed properly. Please ensure that the battery is installed before taking off."

 

[DJI Aldo]

I have search this coordinate(41.297803,19.803311) beceause I was thinking that is the last conntact point.after work I will try your coordinates.i wish that work this time.
Thank you all.

 

[Meta4]

I have search this coordinate(41.297803,19.803311) beceause I was thinking that is the last conntact point.after work I will try your coordinates.i wish that work this time.

His numbers are almost the same as yours.
They are only one metre apart

 

[DJI Aldo]

His numbers are almost the same as yours.
They are only one metre apart

Just now I confirmed the some location as before,just a little bit away.there is a lot of bushes and I controlled step by step.is posible that the aircraft move away after losing connection?I dont now what to do more.after work I will go there and I will cut all those bushes behind this point.
If someone have an idea I wait for it.
Thank you aganin

 

[sar104]

It's not going to be at the last recorded coordinates (the yellow pin below). You have to factor in its velocity and the wind field to compute the descent path. That gives the following for velocity and distance as a function of time:



Plotting that descent track (green) on Google Earth gives the following result. It should be near the red pin.

 

[DJI Aldo]

It's not going to be at the last recorded coordinates (the yellow pin below). You have to factor in its velocity and the wind field to compute the descent path. That gives the following for velocity and distance as a function of time:

View attachment 78157

Plotting that descent track (green) on Google Earth gives the following result. It should be near the red pin.

View attachment 78156

Ok thank you.i will go and search around the red pin, if not there maybe is in the back of the hill.
Thanks

 

[DJI Aldo]

Sorry another thing that I forget.it is a big antena for high signal on tv transmision in tha midle of takeoff point and the last contact point

 

[sar104]

Ok thank you.i will go and search around the red pin, if not there maybe is in the back of the hill.
Thanks

It's going to be within a few meters of the red pin.

Sorry another thing that I forget.it is a big antena for high signal on tv transmision in tha midle of takeoff point and the last contact point

That wasn't the problem. As @msinger noted above, the battery reported being improperly installed when you started up, and likely disconnected mid-flight.

 

[DJI Aldo]

It's going to be within a few meters of the red pin.


That wasn't the problem. As @msinger noted above, the battery reported being improperly installed when you started up, and likely disconnected mid-flight.

I was thinking that the batt was ok.but maybe I am wrong. At the 16 00 I will be there and search the area again.
Thank you very mutch

 

[JimD19]

sar104, if you ever wanted to host a webinar for data analysis, I'm sure it would break all Nielsen rating records. That distance/time chart with North, East, and Down, and then using it to compute the trajectory from the last known point, is amazing (and unfathomable to me). If you ever wanted to share that wizardry, I think we'd all be all ears!

 

[sar104]

sar104, if you ever wanted to host a webinar for data analysis, I'm sure it would break all Nielsen rating records. That distance/time chart with North, East, and Down, and then using it to compute the trajectory from the last known point, is amazing (and unfathomable to me). If you ever wanted to share that wizardry, I think we'd all be all ears!

Thanks. It's actually not as difficult as it looks even though there is no closed-form solution - it's a numerical (finite-difference) solution to the simple drag-limited equations of motion in three dimensions for an object with a mass and drag coefficient representative of whichever drone is involved. I wrote a short program that takes the initial conditions (drone velocity and height, wind speed, wind direction, vertical wind gradient) and then iteratively calculates forwards, displaying the position and velocity as a function of time and, writing the position data directly to a kml format that opens directly in Google Earth.

So it does require some familiarity with using finite difference techniques to solve non-linear differential equations, mathematical programming software in which to implement it, and some text manipulation programming to write output into the kml format. Even though it's a rather simple example of those methods, the interested audience for this would probably be quite limited.

 

[Olav van Gerven]

Thanks. It's actually not as difficult as it looks ...

So it does require some familiarity with using finite difference techniques ...

Not as difficult? I suggest I get you the coffee, you keep doing the math. Some cookies with it? Or Pasta?

 

[JimD19]

I'm in agreement with Olav! I'm an engineer by training (many, many years ago), and there's no way I could keep up with that!

 

[DeeRose]

Thanks. It's actually not as difficult as it looks even though there is no closed-form solution - it's a numerical (finite-difference) solution to the simple drag-limited equations of motion in three dimensions for an object with a mass and drag coefficient representative of whichever drone is involved. I wrote a short program that takes the initial conditions (drone velocity and height, wind speed, wind direction, vertical wind gradient) and then iteratively calculates forwards, displaying the position and velocity as a function of time and, writing the position data directly to a kml format that opens directly in Google Earth.

So it does require some familiarity with using finite difference techniques to solve non-linear differential equations, mathematical programming software in which to implement it, and some text manipulation programming to write output into the kml format. Even though it's a rather simple example of those methods, the interested audience for this would probably be quite limited.

It's a shame you couldn't apply a user friendly interface for that and market it for us coefficient challenged folks. I would purchase it.

 

[rfc]

It's a shame you couldn't apply a user friendly interface for that and market it for us coefficient challenged folks. I would purchase it.

It wouldn't be the same. It's not the interface that matters; it's the underlying brilliance that counts. And even if it could be purchased by us all, and we all did our own analyses, it'd...well, quite frankly, it'd suck.

In the case of @sar104, it's really the blessings he brings to this community helping those that have had the unfortune of losing/crashing their Aircraft. It's a joy (for me at least) to just read and absorb as much as I can as some of these events unfold.