Hovering issues (video)

[moswissa]

Ok guys I'm about ready to send this bird back to DJI. I've calibrated the IMU, sensors, gimbal, and controller . As you can tell from the video, this isn't normal behavior. Everything else is completely fine but this got me annoyed. I've been flying phantoms for 4 years. Never had this problem. Any help before I send it back?

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[CactusJackSlade]

Maybe try turning off your bottom sensors and see what happens. Does this only happen at night, or daytime too?

 

[Egika]

Have you tried the same thing in daylight in a less GPS obstructed place?

 

[moswissa]

Maybe try turning off your bottom sensors and see what happens. Does this only happen at night, or daytime too?

I'll try to turn them off. I don't remember if it behaved like this at night. I'll have to try. Does yours do this at night?

 

[Egika]

I'll try to turn them off. I don't remember if it behaved like this at night. I'll have to try. Does yours do this at night?

it's pretty dark in your video - that's why the question came.
visual sensors don't work very well in the dark and the app should also tell you about this fact

 

[moswissa]

it's pretty dark in your video - that's why the question came.
visual sensors don't work very well in the dark and the app should also tell you about this fact

It did say low ambient light but I thought it's referring to the camera

 

[Egika]

Yeah. That's referring to the visual positioning system.
Try again under better light and with good GPS reception and report back

 

[kona]

You need a lot of light for the vision only system (no GPS because indoors) to work. Also, a carpet will absorb the sonar signal. When I tried with mine it was moving up and down and sideways uncontrollably and crashed before I could land it.

 

[Egika]

You need a lot of light for the vision only system (no GPS because indoors) to work. Also, a carpet will absorb the sonar signal. When I tried with mine it was moving up and down and sideways uncontrollably and crashed before I could land it.

Seems to be outdoor in front of the garage...

 

[Vasco]

As far as i can see issue is with the vertical position of craft .
Mavic maintains vertical position with Ultrasonic sensors (up to 13 meters from ground) , barometer and GPS (at higher altitudes).
Mavic at your video is GPS in P-mode (i.e Slow green light flashing). At this altitude Mavic maintain vertical position with ultrasonic sensors ( if VPS is on ) so nothing to do with ambient low light.
Most probably something to do with ultrasonic sensor , or barometer. At this altitude GPS can not have enough pression to assist Mavic for vertical stability.

 

[Rabid Machina]

the driveway looks like it is sloped, could be sonar sensors are only receiving some of the sound waves emitted. I'd say the Mavic is doing a pretty good job considering the conditions. I could be wrong though.

 

[Cyberpower678]

As far as i can see issue is with the vertical position of craft .
Mavic maintains vertical position with Ultrasonic sensors (up to 13 meters from ground) , barometer and GPS (at higher altitudes).
Mavic at your video is GPS in P-mode (i.e Slow green light flashing). At this altitude Mavic maintain vertical position with ultrasonic sensors ( if VPS is on ) so nothing to do with ambient low light.
Most probably something to do with ultrasonic sensor , or barometer. At this altitude GPS can not have enough pression to assist Mavic for vertical stability.

Umm...what? You realize VPS means Visual Positioning System right? Of course it uses the visual sensors to maintain position.

 

[msinger]

GPS is not used to hold the vertical position while hovering. In poor lighting conditions (as shown above), the Mavic is not going to be able to hold a rock solid steady vertical hover. As suggested above, try this test again during the day with VPS enabled. If all works well, then all is okay.

 

[Vasco]

Umm...what? You realize VPS means Visual Positioning System right? Of course it uses the visual sensors to maintain position.

Vertical position maintain by ultrasonic sensors.
Horizontal position maintain by visual means (camera)

 

[moswissa]

Umm...what? You realize VPS means Visual Positioning System right? Of course it uses the visual sensors to maintain position.

Yeah that confused me too. Ok well I'll go ahead and try this again during the daytime and see if it makes a difference

 

[Pablo_s]

Hi Moswissa,
could you try to hover over a different surface? I found sometimes that the sonar does not work well over wet grass.

 

[ElGuapo]

Go to a park and try to hover in broad daylight away from any metallic surfaces.

I've had this issue with a Phantom 3 Pro and a Phantom 4 flying too close to metallic surfaces. A year ago I launched the P3 from the company's shipping dock ( I hope my Boss is not reading this post, Lol ) and behaved just like in your video. That same afternoon I went to a park and everything was fine.

 

[Cyberpower678]

Vertical position maintain by ultrasonic sensors.
Horizontal position maintain by visual means (camera)

Again, that is wrong. The VPS sensors on the bottom use two cameras to obtain a 3D image. This 3D image is used to not only maintain horizontal position, but vertical too, as it now sees how high it is from the ground.

 

[HFMan]

According to the user manual, the Downward Vision System consists of BOTH the camera and sonar sensors. In low light, visual assistance is going to be marginal, especially in low light over a non-descript driveway. Downward Vision System is only used between .3 and 13 meters.

 

[Vasco]

Again, that is wrong. The VPS sensors on the bottom use two cameras to obtain a 3D image. This 3D image is used to not only maintain horizontal position, but vertical too, as it now sees how high it is from the ground.

I do not believe this is correct