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Question about those payload drop devices for the Mav 3/Air2s etc. My drones think the payload is the ground, so my drone keeps going up.

SteveR43

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I've use those payload drop mechanisms pretty often. But, the drones sensors will often see the payload under the drone and the drone will start rising. What brilliant designer decided to put the drop mechanism directly between, or near the ground sensors. Who else has problems with this? How do you avoid the sensors seeing the payload? Make the attachment string really long or something?

So, What did I do? I took the thing apart. Moved the battery section to in between the sensors and put the drop mechanism, just under the camera, far enough away from the sensors for the payload not to be detected. Especially in cases when the payload fails to drop. See atached pic


I have had some scary situations, where I couldn't release the payload and the drone wouldn't land. It kept going higher and higher. I got the drone back down by swinging the payload back and forth. When it swung left right forward or back out of the way of the sensor, I would push the stick down. Or I would fly in one direction to cause drag on the payload, making it move out of the way of the sensors, and push the altitude stick down at the same time. I have to come in landing while moving forward, then drag the payload on the ground until I could stop with it out of the way and then land.

RDrop Device Mav 3.jpg
 
Have you compared the position of the payload with the field of view of the VPS sensors?
Page 21 of the Mavic 3 manual 130deg but oddly I can not find it in the Air2s manual.
 
I ran into that issue with a 360-degree camera below an Air 2S before I got the camera mount into the best position where it wasn't in the sensor's field of view. When the drone begins climbing you can hold the left stick back and force it into landing mode and it will descend. I was hand catching the drone by gripping the shaft of the camera mount.

(The camera and the mount are for sale now. I haven't used it often enough to warrant keeping it. Send a PM if you're interested.)
 
I have had some scary situations, where I couldn't release the payload and the drone wouldn't land. It kept going higher and higher. I got the drone back down by swinging the payload back and forth. When it swung left right forward or back out of the way of the sensor, I would push the stick down. Or I would fly in one direction to cause drag on the payload, making it move out of the way of the sensors, and push the altitude stick down at the same time. I have to come in landing while moving forward, then drag the payload on the ground until I could stop with it out of the way and then land.
I wonder how high the drone got to before you started breathing and came up with that great solution to swing the payload. Betcha had to change your shorts by the time you got it back on the ground.!
 
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Switch to sport mode?
I tried sport mode and switching all sensors off. That didn't work. The bottom landing sensor system works differently than the lateral and top sensors. The bottom ones don't really turn off completely. They are always on in order to detect when the drone is near the ground or landing.

If the terrain is not appropriate to land on, the sensors know it and either hover the drone or elevate it. The obstacle avoidance on the bottom sensors is turned off, but not the ground/landing detection. When an object gets too close, the landing system kicks in regardless of the sensors being turned to off. Thus, my drone kept going up.

In pictures , I see these drop mechansisms using, very long string. I guess if the string is long enough, the sensors behave normally and wont dedect the object under the drone.

I like to keep my string short, so I reconstructed the drop systems to either hang from the side of the drone or hang from underneath the camera. Both keep the hanging objects out of the way of the ground detection sensor system.
 
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I tried sport mode and switching all sensors off. That didn't work. The bottom landing sensor system works differently than the lateral and top sensors. The bottom ones don't really turn off completely. They are always on in order to detect when the drone is near the ground or landing.

If the terrain is not appropriate to land on, the sensors know it and either hover the drone or elevate it. The obstacle avoidance on the bottom sensors is turned off, but not the ground/landing detection. When an object gets too close, the landing system kicks in regardless of the sensors being turned to off. Thus, my drone kept going up.

In pictures , I see these drop mechansisms using, very long string. I guess if the string is long enough, the sensors behave normally and wont dedect the object under the drone.

I like to keep my string short, so I reconstructed the drop systems to either hang from the side of the drone or hang from underneath the camera. Both keep the hanging objects out of the way of the ground detection sensor system.
Good point!
 
I tried sport mode and switching all sensors off. That didn't work. The bottom landing sensor system works differently than the lateral and top sensors. The bottom ones don't really turn off completely. They are always on in order to detect when the drone is near the ground or landing.
@SteveR43 - Good explanation. The longer string works and hopefully your new mount does too. By using some 3rd party apps some are able to turn off the bottom landing sensors. On my Mini 1 and using Litchi I could turn them off. Had to remember to turn them back on after the flight as the setting is maintained in the drone so it can cause unexpected landing problems when using DJI Fly and forgetting that the sensors are off. Have to go back into Litchi to reset.
 
I use the attached link. Does not block the sensors and has never caused issues.

We use it for Ham Radio antenna placement.

I use that one. I think I keep the payload to close to the drone. How far is your payload hanging from the drone?

I modified the one in your link. I unscrewed it, cut it in half and moved the parts to the front. The landing light sensory stays in place. The pin and servo are just under the camera. I can see the pin when my cam is tilted straight down. I like it though. I see exactly when and hopefully where the payload will land.
 
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