Mini drifts when over water

[280]

Slow down. That's just too confusing.


Almost? So then, not a fly away?



The two outer sensors are the infrared sensors that measure height.


Why did you have no GPS when flying outside in an area with trees? Why would covering the infrared height sensors cause the drone to uncontrollably fly sideways?

In the absence of a good GPS lock, the drone will use the centre optical sensor to fix on a ground pattern. If that pattern is moving (ripples on water, long grass waving in the wind, etc), the drone may follow that moving pattern. But that only happens when the control sticks are centred and the drone is hovering. You still always have control input. It just won't automatically brake to a halt when the sticks are released. You need to manually input some reverse stick input to slow the drone to a stop.

If it can't detect a suitable pattern (too dark, too monochrome, etc), and no GPS lock, the drone will default to ATTI mode. That only means it cannot stop and hold a fixed position in hover whenever the control sticks are centred. It will be free to drift with the wind. But it will still react to any stick inputs.


Why would GPS cause it to fly up?

Covering the infrared height sensors might cause the drone to automatically climb. For example, with the drone hovering, if you bring your hand up underneath the drone the sensors will detect your hand and interpret itself as being below the minimum 2 ft height above ground. The drone will automatically rise up to avoid your hand.

Whenever there is anything closer than 2ft underneath the drone, the infrared height sensors will cause the drone to climb. People have reported such a reaction when flying in dense fog, or when trying to descend through a cloud. But the drone can be forced to descend through such fog by pulling the throttle all the way down. If the sensors interpret the drone as being within 2ft of a surface, holding the throttle down will trigger auto-landing. The drone will then automatically slowly descend through the cloud until touching down on a solid surface. You can cancel the auto-landing at any point when necessary.

Sorry if what I said was confusing I was still a little shaken up when I wrote that. Once it started flying differently I started to panic. I didn't have GPS because I took off immediately. I probably shouldn't have even tried what I did.

Edit:
I just looked at the flight log and I didn't notice this when I took off but it switched into addi mode. I have never flown in addi mode so I had no clue what I was doing.

 

[Aviatur]

I have noticed that when ever I fly over rapids or moving water my mini seems to start drifting around. Is that because of the sensors on the bottom? Is there anyway to prevent this? This issue has almost caused me to crash a few times and I would like to not have the worry of my mini uncontrollably drifting around when its hovering over water. This has caused me to lose some shots because I was too worried about my mini crashing into a tree near the water. Do other drones like the Air 2 have this issue?

Thanks
-280

Hi 280, I encountered the same issue two times last week in Austria. I also wanted to fly over a fast running and rather wild creek. Preflight checks, OK, 12 satellites, but indeed, my Mini 2 also drifted away. I could save it by rapidly ascending it. In these shots the cam looked into the direction from where the water came.
Checking these flights afterwards in
One other flight than these 2, I crossed such a creek, whereby the cam looked to the other side, so across the stream, and that crossing succeeded....
Checking the flights afterwards in "Airdata UAV" not a single problem was detected there.
So I think it's a weakness of the downward vision system, being mislead by repetitive "pictures" or their speed in one direction. (?)

 

[Yorkshire_Pud]

Hi 280, I encountered the same issue two times last week in Austria. I also wanted to fly over a fast running and rather wild creek. Preflight checks, OK, 12 satellites, but indeed, my Mini 2 also drifted away. I could save it by rapidly ascending it. In these shots the cam looked into the direction from where the water came.
Checking these flights afterwards in
One other flight than these 2, I crossed such a creek, whereby the cam looked to the other side, so across the stream, and that crossing succeeded....
Checking the flights afterwards in "Airdata UAV" not a single problem was detected there.
So I think it's a weakness of the downward vision system, being mislead by repetitive "pictures" or their speed in one direction. (?)

I suspect that your drone's vision system may have 'latched onto' some foam or debris in the water and attempted to 'hover' over that target. I have seen at least one thread mention it and prior to that I have seen behaviour with my own drones that made me wonder if it is possible.