Hi there,

newbie happy owner of a Spark, greetings from Romania !
So after couple of basic takeoff, flies, landing flights I wanted to try active tracking on my friend riding his bike.
The video can be seen here:

So, I positioned the drone slightly behind and on this right, then the tracking began as expected until, as it can bee seen on the video, on a left corner the drone lost some altitude and gently crashed into some bushes . I've got several warning/error messages after the crash on GO 4 app, but in the panic I didn't got them, something about the propelers (I guess Spark has some overload protection mechanism) and gimbal. But everything seems to be fine...

1) What was wrong ? It's because I positioned the drone on the right and on that corner there was a hill on right so the drone couldn't keep the distance to the tracked subject ?
2) In the GO 4 app I saw there is a flight activity log but I can't see those errors displayed after crash, only that "motors started", "RTH recorded", etc... Is there any way to retrieve full logs ?

A quick guess, after watching the video:
The altitude of the ground changed, the drone obviously kept its altitude.
i think, for tracking there is a starting altitude needed, which is high enough to cover all the track.
Also, I would have positioned the spark on the left side of the road. Even if the spark would have liftet its altitude, I think this chrash could have happend a little later on the hillside of the road

Edit: Check your flight height in the Go 4 App

S-e-ven Posted at 2017-11-6 02:54
A quick guess, after watching the video:
The altitude of the ground changed, the drone obviously kept its altitude.
i think, for tracking there is a starting altitude needed, which is high enough to cober all the track.

So, if I understand correctly, (at least) in Track Mode the drone will not change the altitude to keep the same distance between it and the tracked subject, so if the track is a mountain road then positioning the drone when starting at let's say 3 meters above the subject, then once the subject (cyclist) start climb the drone will not be able to follow it at a constant 3 meter above ?

muntos Posted at 2017-11-6 03:12
So, if I understand correctly, (at least) in Track Mode the drone will not change the altitude to keep the same distance between it and the tracked subject, so if the track is a mountain road then positioning the drone when starting at let's say 3 meters above the subject, then once the subject (cyclist) start climb the drone will not be able to follow it at a constant 3 meter above ?

Yes that is correct, you should have been up much higher, where you were trying to AT was extremely dangerous you could easily have hit that van lucky escape I’m sure lesson learned.

You can retrieve logs from link below just click on link and follow instructions come back here and post your link.

http://www.phantomhelp.com/LogViewer/Upload/

hallmark007 Posted at 2017-11-6 03:25
Yes that is correct, you should have been up much higher, where you were trying to AT was extremely dangerous you could easily have hit that van lucky escape I’m sure lesson learned.

You can retrieve logs from link below just click on link and follow instructions come back here and post your link.

Hi, thanks, for sure lesson learned, but I was started with a false assumption, assuming that the drone will keep the distance (including the altitude/height) constant to the subject .

Here is the flight log, but I don't see those warning/error messages in the log, probably the flight recording was considered ended and then the error messages popped up in the GO 4 app ?

I was reading on here earlier on one of the posts that if your starting altitude is <2m it will follow the terrain. Above this it will hold its altitude. I think some people are testing this out.

muntos Posted at 2017-11-6 03:40
Here is the flight log, but I don't see those warning/error messages in the log, probably the flight recording was considered ended and then the error messages popped up in the GO 4 app ?

When you crashed this log will stop, you would still have been getting warnings on your app.
It looks like others have said your craft maintained horizontal height you set from the start at approx 18ft as your subject was going downhill Aircraft was getting lower to the ground lost subject and crashed.

I will leave you link below where we were discussing active track and how it works Edd on the thread has done some testing and come up with varying results it would be worth your while posting your flight video in this thread.
Glad there is not to much damage to your spark.
Good luck


https://forum.dji.com/forum.php? ... &fromuid=260008

I am wondering now, does Obstacle Avoidance get disabled when Active Track is enabled? Shouldn't the Spark have stopped and hover instead of crashing there?

Wachtberger Posted at 2017-11-6 04:30
I am wondering now, does Obstacle Avoidance get disabled when Active Track is enabled? Shouldn't the Spark have stopped and hover instead of crashing there?

It was Luck it crashed or it may have got run over I think spark was moving to the right when it crashed not head on into the shrubbery.

hallmark007 Posted at 2017-11-6 04:50
It was Luck it crashed or it may have got run over I think spark was moving to the right when it crashed not head on into the shrubbery.

Yes indeed, that explains it. Thank you!

muntos Posted at 2017-11-6 03:12
So, if I understand correctly, (at least) in Track Mode the drone will not change the altitude to keep the same distance between it and the tracked subject, so if the track is a mountain road then positioning the drone when starting at let's say 3 meters above the subject, then once the subject (cyclist) start climb the drone will not be able to follow it at a constant 3 meter above ?

It seems like that and I guess, it also makes a sense. Because the drone calculates its altitude from HP GPS altitude and not preserve the constant altitude against the ground if it rises up.

Wachtberger Posted at 2017-11-6 04:30
I am wondering now, does Obstacle Avoidance get disabled when Active Track is enabled? Shouldn't the Spark have stopped and hover instead of crashing there?

As far as I know, from the manual, the OA will be disable once you engage the profile mode active track. Otherwise, OA should be active unless you disable it manually. I saw some footage in youtube, sparky will stop and hover when it run into a tree.

ku8az Posted at 2017-11-6 06:32
It seems like that and I guess, it also makes a sense. Because the drone calculates its altitude from HP GPS altitude and not preserve the constant altitude against the ground if it rises up.

Not official, I suppose the downward visual/3D sensing system can give the drone some idea how high it's flying over the ground. For a limited height and/or speed of course.

Edd_88 Posted at 2017-11-6 06:57
Not official, I suppose the downward visual/3D sensing system can give the drone some idea how high it's flying over the ground. For a limited height and/or speed of course.

Yep, indeed, it can.
I found out, flying on a slope, but RC- controlled, that the Drone follows the profil if flown close (1/2m was it in my case) to the ground.
In both directions.
When I started (slowly, very slowly) from lower ground, it followed and flew about a meter up and after the "top", it went down again.
The other way, flying to lower ground, was a bit inconsistant. One time it followed the ground, one time it stayed in the height, meaning the distance to ground was rising.
And the obstacle avoidance system is a bit a pain in the ....!
I flew sidewards, passed a treeish thing and with nothing in the flightpath, but the tree in the Obstacle distance, Spark stopped!

That was close and very lucky of you that the van did not hit the drone, a bit dangerous place to try the AT for the first time, I'll suggest to get more fly experience in a big open area with no other people or vehicles involved there you also can try all the intelligent fly modes so you can learn how they work in a safe place for others, you and your drone...remember always fly safe.

muntos Posted at 2017-11-6 03:12
So, if I understand correctly, (at least) in Track Mode the drone will not change the altitude to keep the same distance between it and the tracked subject, so if the track is a mountain road then positioning the drone when starting at let's say 3 meters above the subject, then once the subject (cyclist) start climb the drone will not be able to follow it at a constant 3 meter above ?

That's right, the only drone that does have terrain follow is the Mavic, but not little Spark.

Edd_88 Posted at 2017-11-6 06:42
As far as I know, from the manual, the OA will be disable once you engage the profile mode active track. Otherwise, OA should be active unless you disable it manually. I saw some footage in youtube, sparky will stop and hover when it run into a tree.

No OA is active in active track mode and will avoid obstacles and it is correct what you seen on you tube AC will stop and hover if it comes on obstacles.

But in this case, the obstacle came in sensor range, after the Spark already flew sideways in it!

Viking-Pilot Posted at 2017-11-6 08:29
That's right, the only drone that does have terrain follow is the Mavic, but not little Spark.

P4Pro as well.

hallmark007 Posted at 2017-11-6 09:15
P4Pro as well.

Hahaha...yeah I know but I was saying for the lower price and smaller drones category, MP is advertised with that feature as a plus.

Two things. One, flying around horses pulling carts on streets is stupid. Two, you need to invest more time learning about your drone before you start doing advanced tests with active track.  I suggest you read the latest version of the online manual.  

Oracle Miata Posted at 2017-11-6 09:39
Two things. One, flying around horses pulling carts on streets is stupid. Two, you need to invest more time learning about your drone before you start doing advanced tests with active track.  I suggest you read the latest version of the online manual.

First, I have read the manual, flying modes, video tutorials, and nowhere it states that when following and object it doesn't preserve also the height to that object (in my mind tracking an object in a 3D environment also applies to the the Z from XYZ coordinate plane).
Secondly, I know that road very well and the traffic is very light (maybe one car/cart in 20-30 minutes), there was such a bad timing that at that moment not only a van but also horses were passing by.

muntos Posted at 2017-11-6 10:07
First, I have read the manual, flying modes, video tutorials, and nowhere it states that when following and object it doesn't preserve also the height to that object (in my mind tracking an object in a 3D environment also applies to the the Z from XYZ coordinate plane).
Secondly, I know that road very well and the traffic is very light (maybe one car/cart in 20-30 minutes), there was such a bad timing that at that moment not only a van but also horses were passing by.

In my defense please take a look at the picture with the road, you can see that there is no traffic

muntos Posted at 2017-11-6 10:07
First, I have read the manual, flying modes, video tutorials, and nowhere it states that when following and object it doesn't preserve also the height to that object (in my mind tracking an object in a 3D environment also applies to the the Z from XYZ coordinate plane).
Secondly, I know that road very well and the traffic is very light (maybe one car/cart in 20-30 minutes), there was such a bad timing that at that moment not only a van but also horses were passing by.

In my defense please take a look at the picture with the road, you can see that there is no traffic

muntos Posted at 2017-11-6 10:17
In my defense please take a look at the picture with the road, you can see that there is no traffic

It will be really helpful if you export your flight data and the black box for further analysis. Please upload to dropbox and post the link here. We will try our best to locate the problem.

S-e-ven Posted at 2017-11-6 08:14
Yep, indeed, it can.
I found out, flying on a slope, but RC- controlled, that the Drone follows the profil if flown close (1/2m was it in my case) to the ground.
In both directions.

1/2m (0.5m) over ground?!. You are brave.

Edd_88 Posted at 2017-11-6 23:34
1/2m (0.5m) over ground?!. You are brave.

Yes, indeed!
And very, very carefully on the "forward" joystick, then