Hi,

I was wondering if anyone has had the issue where the mavic is actively tracking a target and suddenly moves towards the target to follow it but overshooting the target.

I was tracking another drone without any issues when suddenly the mavic closes in to the target nearly colliding with it.

It could be something i did wrong, i'm just trying to figure this out so it won't result in a collision when i try it again.


I posted the video for the friend i was tracking ... it happens in the last few seconds... feel free to skip forward, this video was shot for club purposes.



Kind regards,

According to the video, the drone turned around directly facing the strong light for a moment, just to verify, the drone was only doing Active Tracking, no sticks operating during that time, right?

No stick movement .. well when i noticed the other drone coming close so quick i used the left stick to move away (down) but as it was in active track i think the reaction was too slow anyway. (You can see the drone dropping a bit after the near miss... so i think i was too late anyway )

The only thing i noticed in the video afterwards is close before the near miss the drone drops slightly below the horizon blending in with the background, maybe that triggered something?

I really have no idea, but liked the video!

Incentio Posted at 2017-10-17 04:04
No stick movement .. well when i noticed the other drone coming close so quick i used the left stick to move away (down) but as it was in active track i think the reaction was too slow anyway. (You can see the drone dropping a bit after the near miss... so i think i was too late anyway )

The only thing i noticed in the video afterwards is close before the near miss the drone drops slightly below the horizon blending in with the background, maybe that triggered something?

Agree, ActiveTrack is based on video recognition.  When the tracked drone blended in with the background, I'm betting it lost the lock completely.

Montfrooij Posted at 2017-10-17 10:27
I really have no idea, but liked the video!

Thnx

Griffith Posted at 2017-10-17 11:58
Agree, ActiveTrack is based on video recognition.  When the tracked drone blended in with the background, I'm betting it lost the lock completely.

Yeah , but in that case, when it does i think it should do a full stop instead  trying to fly towards the position..

I just hope it was a freak accident ... i'm a bit reluctant to try it again ... althought we have one of the best shots of the guy's drone ever

My experience with Active Track: the software seems to calculate the speed and speed increase and tries to predict and estimate how the tracked object will behave. So if You constantly increase speed and suddenly stop or change direction the calculated estimation for path and speed lags (of course), and if change of speed or direction is too quick MP overshoots the target. I tested this at ice-skating, with car and motorcycle. Only with bicycles and walking/running this does not seem to happen. So I try to avoid abrupt changes of speed and direction and it might also be different with a more powerful smartphone/tablet with a faster processor (I use Note 4)

Incentio Posted at 2017-10-17 23:20
Thnx

You're welcome!

I'm surprised the MP didn't lose the lock way before that moment, I found the other drone quite difficult to see when the object drone was flying over the back ground of the uncut grass at the beginning of the video, a little later it also was quite difficult to see when flying with the trees in the background.

Angelo26 Posted at 2017-10-18 00:13
My experience with Active Track: the software seems to calculate the speed and speed increase and tries to predict and estimate how the tracked object will behave. So if You constantly increase speed and suddenly stop or change direction the calculated estimation for path and speed lags (of course), and if change of speed or direction is too quick MP overshoots the target. I tested this at ice-skating, with car and motorcycle. Only with bicycles and walking/running this does not seem to happen. So I try to avoid abrupt changes of speed and direction and it might also be different with a more powerful smartphone/tablet with a faster processor (I use Note 4)

This is true. There is a predictive behavior element in the Tracking algorithm.  However, I think it's done completely  in the Mavic, so your smartphone isn't directly involved once the target is selected.

Bigga J Posted at 2017-10-18 01:31
I'm surprised the MP didn't lose the lock way before that moment, I found the other drone quite difficult to see when the object drone was flying over the back ground of the uncut grass at the beginning of the video, a little later it also was quite difficult to see when flying with the trees in the background.

At those points i wasn't active tracking ... the movie was quickly slapped together to send to a friend...

Only the last part was shot with active track.

Angelo26 Posted at 2017-10-18 00:13
My experience with Active Track: the software seems to calculate the speed and speed increase and tries to predict and estimate how the tracked object will behave. So if You constantly increase speed and suddenly stop or change direction the calculated estimation for path and speed lags (of course), and if change of speed or direction is too quick MP overshoots the target. I tested this at ice-skating, with car and motorcycle. Only with bicycles and walking/running this does not seem to happen. So I try to avoid abrupt changes of speed and direction and it might also be different with a more powerful smartphone/tablet with a faster processor (I use Note 4)

I use the CrystalSky from DJI so that should not be an issue...

I guess i need to get a better feel as to how the active track reacts to different situations... I allready watched alot of youtube movies to see what can go wrong with active track.. thats why i thought i give this a go high above any obstacle.

On a different note the obstacle avoidance system warned me with beeps on the RC but didn't brake at all...

Incentio Posted at 2017-10-18 07:08
I use the CrystalSky from DJI so that should not be an issue...

I guess i need to get a better feel as to how the active track reacts to different situations... I allready watched alot of youtube movies to see what can go wrong with active track.. thats why i thought i give this a go high above any obstacle.

Methinks that it has to do with smartphone used since active track can only be initiated with a smartphone attached. When I used my Xperia Z Ultra Active Track was almost unusable, with Note 4 it is much better ...............

Methinks that it has to do with smartphone used since active track can only be initiated with a smartphone attached. When I used my Xperia Z Ultra Active Track was almost unusable, with Note 4 it is much better ...............

Angelo26 Posted at 2017-10-19 00:00
Methinks that it has to do with smartphone used since active track can only be initiated with a smartphone attached. When I used my Xperia Z Ultra Active Track was almost unusable, with Note 4 it is much better ...............

I think the Crystalsky can use the activetrack as well ... actually i have used it before... It's just in this particular situation the drone overshot the target.

https://www.dji.com/crystalsky





It's like a tablet especially designed for DJI drones.

I'm coming to the conclusion i just have to be very carefull while using active track because it can behave eraticaly in some situations.

Well, CrystalSky is just a smartphone running android but without phone-function ................ There is just the difference of manufacturer like smarties from Huawei are different from Samsung or LG or Sony in their internal components and screen but they are ALL just Android smartphones like CrystalSky

Incentio Posted at 2017-10-18 07:03
At those points i wasn't active tracking ... the movie was quickly slapped together to send to a friend...

Only the last part was shot with active track.

Ah, OK thanks .... I did wonder how the Mavic was able to keep track in such poor visibility conditions for the drone.

Thanks for the clarification.

Angelo26 Posted at 2017-10-19 01:18
Well, CrystalSky is just a smartphone running android but without phone-function ................ There is just the difference of manufacturer like smarties from Huawei are different from Samsung or LG or Sony in their internal components and screen but they are ALL just Android smartphones like CrystalSky

I know it runs android.. what i meant is that i think that DJI would make a dedicated screen for their drones capable of calculating everything needed to make their own software work

If it doesn't i would be a poor design but i don't feel it has bad performance ... (i do have the occasional crash though // app resets // )

Incentio Posted at 2017-10-19 03:41
I know it runs android.. what i meant is that i think that DJI would make a dedicated screen for their drones capable of calculating everything needed to make their own software work

If it doesn't i would be a poor design but i don't feel it has bad performance ... (i do have the occasional crash though  // app resets // )

Regarding poor design .................. remember Galaxy Note 7 .............