Bizzare crash, M2P insists on flying into hedge

[romelus]

Hey, got referred here from the MP2 forum. Hopefully someone can solve the mystery!

I've been flying drones since 2013, so not a newbie here. The other day I had my M2p hovering at low level, then noticed it drifting toward a fence / hedge. I pull it back gently but it starts to really want to go toward it! I pull back with more force and it's barely making a difference. There are trees in the opposite direction so I don't want to over correct. I turn the drone away from the hedge and push the stick to move it away, but it decides to go sideways and straight back into the hedge!

The drone clipped the hedge and fell to the ground, luckily no major damage and has flied fine since. I'm puzzled as I've never seen this before. I don't think the chain link fence could cause enough interference, it's a normal fence and I've been near similar fences before. There was nothing strange in the hedge, just normal cedar. Any ideas?

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[Meta4]

I've been flying drones since 2013, so not a newbie here. The other day I had my M2p hovering at low level, then noticed it drifting toward a fence / hedge. I pull it back gently but it starts to really want to go toward it! I pull back with more force and it's barely making a difference. There are trees in the opposite direction so I don't want to over correct. I turn the drone away from the hedge and push the stick to move it away, but it decides to go sideways and straight back into the hedge!

You lowered the drone until it was 7 feet above something.
Shortl after at 14:26.3 this warning message shows in the flight data:Obstacle Avoided. Revise Flight Route
You made unsuccessful efforts to move the drone backwards and to its right with full stick inputs but the data shows 7 more Obstacle Avoided. Revise Flight Route messages.

Translation Obstacle Avoidance is telling you that it's detected an obstacle blocking the drone's path in the directions you are trying to push it.
Through all of this the drone was resisting your atttempts to direct it and only moving very slowly.

At 14:41.8 this message showed: Upward obstacle Detected
At the time you had the right stick pushed full over to the right and halfway back.

At 14:42.1 the pitch, roll and yaw data indicates that the drone collided with an obstacle.

You were fighting against OA which was trying to prevent you crashing into whatever it perceived as an obstacle.
Full stick inputs is not the way to deal with that.
Eventualy you crashed at low speed.

 

[romelus]

You lowered the drone until it was 7 feet above something.
Shortl after at 14:26.3 this warning message shows in the flight data:Obstacle Avoided. Revise Flight Route
You made unsuccessful efforts to move the drone backwards and to its right with full stick inputs but the data shows 7 more Obstacle Avoided. Revise Flight Route messages.

Translation Obstacle Avoidance is telling you that it's detected an obstacle blocking the drone's path in the directions you are trying to push it.
Through all of this the drone was resisting your atttempts to direct it and only moving very slowly.

At 14:41.8 this message showed: Upward obstacle Detected
At the time you had the right stick pushed full over to the right and halfway back.

At 14:42.1 the pitch, roll and yaw data indicates that the drone collided with an obstacle.

You were fighting against OA which was trying to prevent you crashing into whatever it perceived as an obstacle.
Full stick inputs is not the way to deal with that.
Eventualy you crashed at low speed.

Thank you for the analysis. This was a driveway. The drone was close to a hedge, and on the other side, further away, were some trees.

The problem started when I noticed the drone drifting toward the hedge.

As you noticed, I tried to move the drone away from the hedge, which it was very close to. I tried moderate stick moves first but as it began to fight me, I tried bigger stick moves, however the drone eventually overrode stick commands and dove into the hedge.

At 14:41.8 when it detected upward obstacle, I think it was already into the hedge and gimbal overloaded shortly after due to it flipping over.

The way I understand it, when the drone detects an obstacle, it tries to hover, but this time it decided to move. Also, even if it detected obstacles on both sides, it moved toward the much closer obstacle, then resisted commands to move away from the obstacle. I would estimate that during the problem period, it was less than 1m / 3ft away from the hedge on the left, while the tress on the right side were 3m / 10ft away.

What would your suggestion be in this situation? I was trying to land when it started moving toward the hedge, I think if I didn't move the sticks it would have clipped the hedge by itself.

 

[Meta4]

This was a driveway. The drone was close to a hedge, and on the other side, further away, were some trees.
The problem started when I noticed the drone drifting toward the hedge.

The drifting may have been because the drone had descended to within VPS range and the driveway surface was not suitable for the VPS to allow good horizontal position holding.

As you noticed, I tried to move the drone away from the hedge, which it was very close to. I tried moderate stick moves first but as it began to fight me, I tried bigger stick moves, however the drone eventually overrode stick commands and dove into the hedge.

You tried four times to reverse the drone and each time it was blocked by OA.
If OA won't respond to gentle stick moves, full stick moves when close to obstacles, are not a good idea.

At 14:41.8 when it detected upward obstacle, I think it was already into the hedge and gimbal overloaded shortly after due to it flipping over.

The upward obstacle message was at 14:41.8
The data indicates the collision happened afterwards at 14:42.1

The way I understand it, when the drone detects an obstacle, it tries to hover, but this time it decided to move.

The drone doesn't "decide" anything.
If you do nothing, it does nothing.

Also, even if it detected obstacles on both sides, it moved toward the much closer obstacle, then resisted commands to move away from the obstacle.

The lateral sensors are of very limited use and would not have detected anything.
Here's the relevant section of the manual:

The Lateral Vision Systems requires better lighting and more textured or clearly marked obstacles, and cannot sense dynamic objects, such as moving people, vehicles, tree branches, or blinking lights. ​

The Lateral Vision Systems are only available in some Intelligent Flight Modes and Tripod Mode. ​

The angular speed is limited to 24° /s and the lateral flight speed is limited to 18 mph (29 mph).​

Your Mavic would have only been responding to perceived obstacles in frontof, behind and above the drone

I would estimate that during the problem period, it was less than 1m / 3ft away from the hedge on the left, while the tress on the right side were 3m / 10ft away.
What would your suggestion be in this situation? I was trying to land when it started moving toward the hedge, I think if I didn't move the sticks it would have clipped the hedge by itself.

I would never try to land so close to a obstacles.
If I got into a situation where OA was making things difficult, the obvious way out of this would have been to go upwards.