Hello Fellow Flyers,

Yesterday afternoon we were shooting in the parking lot of an industial complex between buildings. We were testing active track with multiple people walking in/out from different directions but crossing paths (or reappearing from behind an object) to see how well active track keeps track of multiple objects.

Obstacle avoidance was on and working. We had tested it before hand by walking towards the drone to see the drone reverse fly towards a building and then stop.

At the end of our 2nd battery of fly time, we got the low battery warning. We flew for another minute or so and then used the smart controller to send the drone back to HOME which was straight across the parking lot.

The Drone stopped active track. It stablilized it's flight motion. It rotated a bit and then started flying in reverse and flew right into a Concrete building.

I'm really confused as to why the drone was flying in the opposite direction of home and also why the reverse sensors allowed the drone to fly right into a building when returning to home, when we had checked this function under normal flight and active track in advance.

Did we do something wrong? or was this a malfunction?

Thanks for sharing your knowledge and experience with those of us who are always learning.

Dave B

You may want to upload your flight data here and some knowledgable members will be able to take a look at what may have happened.

We'll never know without seeing the recorded flight data.

I am not quite sure on sharing the Flight Data

I have the Smart Controller - In the FlightRecord folder I found 2 files from the flight

THis is the .TXT file --- https://www.dropbox.com/s/7ge2tfxzlkokp5f/DJIFlightRecord_2020-05-09_%5B14-03-09%5D.txt?dl=0


For the DAT files there are 3 files within a 6 min time frame -- Which is strange because the flight that crashed was 22 min long. And after the crash we replaced the props and tried to fly but never got off the ground.

Here are the 3 Dat files

https://www.dropbox.com/s/rukduyaigodn605/20-05-09-02-02-36_FLY034.DAT?dl=0

https://www.dropbox.com/s/gww8m4xykdvu44p/20-05-09-02-26-26_FLY035.DAT?dl=0

https://www.dropbox.com/s/h3u8ldtssjymkip/20-05-09-02-29-54_FLY036.DAT?dl=0


I was able to review the flight record on the smart controller. And it shows the drone switching to Return to home and then flying backwards into an object, then a motor obstruction.


If this is not the right way to share flight Data - I apologize I have not done it before and I did a bunch of searches and couldn't find much details.

The smart controller did SYNC all my flights -- But I have not been able to figure out where the Flight Records are in my DJI account.

Thank you for any help you can provide.

Dave B

Hi,

The active track was stopped because of a low power RTH.
Last part of the active track your MP2 was almost hovering, when RTH kicked in drone turned to the home heading. Looks like that moment a "Upward Obstacle Detected" was detected, drone pitches up to 25 degrees so it started to move backwards, increasing speed to max 1.6 m/s.
To stop the backward speed drone started to picth donw, but at that time it already hit the buillding.

It is, IMO,  never a good idea to fly the batt that low so that it will automatically enter a RTH mode.
When this happens flying under tree`s ect, or close to objects....it will surprise you.

I do not have a MP2 myself, so i do not really know what action the drone takes if a Upward Obstacle is sensed. In your flight it reacted by pitching up.

In the DAT is logged "EMERGENCY BREAK. RC VIB!", wich is linked (afaik) to the obstacle sensing.


cheers
JJB

I have come across definite issues with Active Track, which is why I don't trust it in certain environments.  I've had to stop my Mavic 2 from slamming into a building or other objects.  I never did try it with a low battery though.  It would be nice if Active Track was greatly improved on the Mavic 2.  That is the one major feature that seems nice on the Skydio, though, I'm content with my Mavic.

Neo Supreme Posted at 5-11 02:59
I have come across definite issues with Active Track, which is why I don't trust it in certain environments.  I've had to stop my Mavic 2 from slamming into a building or other objects.  I never did try it with a low battery though.  It would be nice if Active Track was greatly improved on the Mavic 2.  That is the one major feature that seems nice on the Skydio, though, I'm content with my Mavic.

Active track was not the problem in this case.
The drone cancelled Active Track when RTH initiated.
The issue was flying so close to obstacles.

the low battery rth crashed my m2 on a tree. No damage but i did disable it for ever. it is unnecessary and dangerous. Just need to pay attention on battery level which i always do. i was landing wile low battery rth started.The drone got high altitude and flew against the tree. I learned 2 lessons. How to quickly cancel automatic fly. I have practiced it and now i manage do it very fast. And the second lesson was the importance of disabling the low batt rth which is dangerous.

Labroides Posted at 5-11 04:42
Active track was not the problem in this case.
The drone cancelled Active Track when RTH initiated.
The issue was flying so close to obstacles.

Yeah I read that.  Though I didn't make that apparent, I was simply chiming in with my experience with Active Track.

Does this accident fall under a warranty issue?  Will DJI analyze the flight data before having me send it in?

If the flight data shows it was avoiding an obstacle above it, so it flew backwards into a brick wall. The Satellite overlay of the flight shows it's outside in a parking lot with no powerlines, or trees, or signs anywhere above the drone. And why would it fly backwards, where it knew there was a wall - the video of the crash shows that in front of the drone (and above and in front) was clear when it started moving backwards.


Thanks for helping me thru this first crash --- Frustrating experience.

Dave B