Crashed during the active track. Not sure why...

[ShonnyRotten]

Hello

Here is the log of the flight. I hope i chose the correct file
DJI Flight Log Viewer - PhantomHelp.com

Did an active track, tracking my car. The ground wasn't elevating. Not sure why did the AC decrease it's alltitude.

Here is the video.

Please let me know what is wrong, so i can avoid it in the future.
Thanks

 

[Robert Mitchell]

I think you are mistaken. It appears to me that the terrain was rising slightly, just not enough that you could perceive it.

According to the IMU Altitude the aircraft didn’t drop, the ground rose to meet it. In fact it (aircraft) actually rose slightly, from approximately 14 feet to approximately 19 feet.

The visual position shows the ground rising to meet it.

Someone else can correct me if I’m wrong.

 

[ShonnyRotten]

I think you are mistaken. It appears to me that the terrain was rising slightly, just not enough that you could perceive it.

According to the IMU Altitude the aircraft didn’t drop, the ground rose to meet it. In fact it (aircraft) actually rose slightly, from approximately 14 feet to approximately 19 feet.

The visual position shows the ground rising to meet it.

Someone else can correct me if I’m wrong.

When looking on the video, the place where it crashed is definately way lower then the aircart initially is. (Camera is pointing forward)

 

[Robert Mitchell]

When looking on the video, the place where it crashed is definately way lower then the aircart initially is. (Camera is pointing forward)

It's impossible to judge exact level by the camera image, especially when in active track. You would need to confirm that the camera angle was not up or down by a degree or two.

But, at any rate, your data suggests that the ground rose up to meet your drone.

 

[KeithLa]

Why was there no obstacle avoidance? I've had Active Track tracking my car and it has avoided trees and power lines.

 

[Robert Mitchell]

Why was there no obstacle avoidance? I've had Active Track tracking my car and it has avoided trees and power lines.

That's a good question.

Did he have it on?

 

[ShonnyRotten]

Why was there no obstacle avoidance? I've had Active Track tracking my car and it has avoided trees and power lines.

Yes it was on. Just double checked it. "Enable Obstacle Avoidance In ActiveTrack" is on.

What can be the reason?

 

[Youser]

May have been moving too fast for OA to do anything.

 

[ShonnyRotten]

May have been moving too fast for OA to do anything.

I don't think that could have been the reason. Something is pretty strange here.

 

[tcope]

I'm not saying that this is related but let us be a little more clear, obstacle avoidance (cameras) is not what changes the Mavics altitude in Active Track Mode. The ultrasonics are what changes it.

In reviewing the logs is appears that the ground was rising, the Mavic did not and this is why it hit the ground. Off hand I don't see why the ultrasonics would not have automatically increased the altitude. However, they do become less effective at speed. I've tested them up to a fast run but not at 20mph. It is very possible that the Mavic did not process the data from thee ultrasonics at the speed it was flying and the very quick time that it took to lower from 20' down to ground level.

 

[ShonnyRotten]

I'm not saying that this is related but let us be a little more clear, obstacle avoidance (cameras) is not what changes the Mavics altitude in Active Track Mode. The Ultrasonics are what changes it.

You think there was nothing it would crash into, that's why it just "scratched" against the ground?

 

[tcope]

You think there was nothing it would crash into, that's why it just "scratched" against the ground?

Unfortunately, possible. While in AT mode, I've had the Mavic fly right at me while I was walking in front of it and I've had to jump out of the way. I've also flown it in normal mode right into a hill at almost full speed (several times) and collision avoidance worked perfectly.

Edit: let me just add, I think collision avoidance should have worked in this flight to avoid hitting the ground. This is separate then adjusting altitude in Active Track mode. But also, collision avoidance is not perfect.

 

[ShonnyRotten]

Unfortunately, possible. While in AT mode, I've had the Mavic fly right at me while I was walking in front of it and I've had to jump out of the way. I've also flown it in normal mode right into a hill at almost full speed (several times) and collision avoidance worked perfectly.

Edit: let me just add, I think collision avoidance should have worked in this flight to avoid hitting the ground. This is separate then adjusting altitude in Active Track mode. But also, collision avoidance is not perfect.

So the log is correct one, from the crash right?

 

[Goof]

A reason to use the "profile" mode in active track instead of the default mode; the aircraft will more reliably rise and fall to match the target's elevation...