Mavic Mini Gymbal moving suddenly without any input

[armandobabe]

Hello, Im glad to come to this place and post something else than "Mavic Mini Lost" haha but today I was flying my mini in Mexico city, we have an elevation of (2,250m.) so everytime I fly here I have a message of High altitude (speed and elevation will be limited) but sometimes when im flying the gymbal starts doing whatever he wants, I came here just to know if anyone in here have had the same issue or something, I calibrated the compass before every flight, I recorded a video and you can see in 0:01, 0:06, 0:26 the error that im talking about

The flight log is here:

Im really amazed about all the info we can share here like the flight logs and video.

 

[lannes]

Have you tried doing a gimbal calibration in DJI Fly

 

[slup]

This has to do with gimbal angle limitations, the gimbal can manually be move between +20 (up) & -90 degrees (down) & mechanically between +35 (up) & -110 degrees (down) . In below cut out chart from your flight is one example of where the gimbal moves and stays in a new position without manual input ,

-the gimbal position starts with full down angle, -90 degrees (Purple)
-you go from 0 elevator to full forward in sport mode (Blue)
-in response to that the AC pitch forward/down near to those maximum 30 degrees that the Mini can do in Sport mode (Green)
-as the AC pitch forward the gimbal have room to move in positive direction, relative the AC, as it is at -90 degrees & still can continue pointing straight down
-directly after full positive elevator input you go full negative input (Blue)
- the AC then starts to pitch backwards with the maximum 30 degrees that the Mini can do in Sport mode (Green)
-here the gimbal doesn't have room to move enough in negative direction to maintain view straight down, the gimbal hits the end controllable position
-by hitting the negative end position the gimbal turns with the backwards pitching AC in a positive direction (purple just when it jumps up to negative 68 degrees instead of negative 90.
-this new gimbal pitch angle of negative 68 degrees will then not recover to negative 90 even though the AC pitch angle gets smaller ... and as a consequence to that you in the end of the chart apply full negative RC gimbal in order to correct the gimbal down to negative 90 again

All this is from 2 reasons ... first DJI's coding that not recover the gimbal angle if forced into the end controllable range, secondly that you operate the AC to wildly with full stick inputs & being in Sports mode. Go for P or C mode instead & be gentle with the sticks, in this way you don't force the AC to use the extreme pitch angles that will nudge the gimbal.

This behavior can't be corrected by doing a gimbal calibration as suggested earlier ...

 

[armandobabe]

This has to do with gimbal angle limitations, the gimbal can manually be move between +20 (up) & -90 degrees (down) & mechanically between +35 (up) & -110 degrees (down) . In below cut out chart from your flight is one example of where the gimbal moves and stays in a new position without manual input ,

-the gimbal position starts with full down angle, -90 degrees (Purple)
-you go from 0 elevator to full forward in sport mode (Blue)
-in response to that the AC pitch forward/down near to those maximum 30 degrees that the Mini can do in Sport mode (Green)
-as the AC pitch forward the gimbal have room to move in positive direction, relative the AC, as it is at -90 degrees & still can continue pointing straight down
-directly after full positive elevator input you go full negative input (Blue)
- the AC then starts to pitch backwards with the maximum 30 degrees that the Mini can do in Sport mode (Green)
-here the gimbal doesn't have room to move enough in negative direction to maintain view straight down, the gimbal hits the end controllable position
-by hitting the negative end position the gimbal turns with the backwards pitching AC in a positive direction (purple just when it jumps up to negative 68 degrees instead of negative 90.
-this new gimbal pitch angle of negative 68 degrees will then not recover to negative 90 even though the AC pitch angle gets smaller ... and as a consequence to that you in the end of the chart apply full negative RC gimbal in order to correct the gimbal down to negative 90 again

All this is from 2 reasons ... first DJI's coding that not recover the gimbal angle if forced into the end controllable range, secondly that you operate the AC to wildly with full stick inputs & being in Sports mode. Go for P or C mode instead & be gentle with the sticks, in this way you don't force the AC to use the extreme pitch angles that will nudge the gimbal.

This behavior can't be corrected by doing a gimbal calibration as suggested earlier ...

View attachment 91734

Thank you, so the problem may be that I was flying too wild the MM, next time I will try P or C Mode to see if this happens again. Thank you!

 

[lannes]

This has to do with gimbal angle limitations, the gimbal can manually be move between +20 (up) & -90 degrees (down) & mechanically between +35 (up) & -110 degrees (down) . In below cut out chart from your flight is one example of where the gimbal moves and stays in a new position without manual input ,

-the gimbal position starts with full down angle, -90 degrees (Purple)
-you go from 0 elevator to full forward in sport mode (Blue)
-in response to that the AC pitch forward/down near to those maximum 30 degrees that the Mini can do in Sport mode (Green)
-as the AC pitch forward the gimbal have room to move in positive direction, relative the AC, as it is at -90 degrees & still can continue pointing straight down
-directly after full positive elevator input you go full negative input (Blue)
- the AC then starts to pitch backwards with the maximum 30 degrees that the Mini can do in Sport mode (Green)
-here the gimbal doesn't have room to move enough in negative direction to maintain view straight down, the gimbal hits the end controllable position
-by hitting the negative end position the gimbal turns with the backwards pitching AC in a positive direction (purple just when it jumps up to negative 68 degrees instead of negative 90.
-this new gimbal pitch angle of negative 68 degrees will then not recover to negative 90 even though the AC pitch angle gets smaller ... and as a consequence to that you in the end of the chart apply full negative RC gimbal in order to correct the gimbal down to negative 90 again

All this is from 2 reasons ... first DJI's coding that not recover the gimbal angle if forced into the end controllable range, secondly that you operate the AC to wildly with full stick inputs & being in Sports mode. Go for P or C mode instead & be gentle with the sticks, in this way you don't force the AC to use the extreme pitch angles that will nudge the gimbal.

This behavior can't be corrected by doing a gimbal calibration as suggested earlier ...

View attachment 91734

Great analysis, but how does this explain the behavior of the gimbal at 0.27 seconds in the video, the AC seems to be going down, moving slowly forward and the camera flicks forward quickly ?
There doesn't seem to be any aggressive flying at this time.

 

[armandobabe]

There doesn't seem to be any aggressive flying at this time.

Tbh idk if that is an agressive flight, since im new in this hobby, but it may dont look an agressive flight because of the smoothness and stabilization of the gymbal, but not sure. Its true that I was recording in sport mode and I think the drone should record smoothly in every mode, cause that is made for the gymbal, next time I will calibrate the gymbal before the flight

 

[lannes]

Tbh idk if that is an agressive flight, since im new in this hobby, but it may dont look an agressive flight because of the smoothness and stabilization of the gymbal, but not sure. Its true that I was recording in sport mode and I think the drone should record smoothly in every mode, cause that is made for the gymbal, next time I will calibrate the gymbal before the flight

I can't see you flying forward quickly, you are just moving slowly forward and coming down when the camera flicks upwards.
So for me this is not aggressive flying, you are not even yawing around quickly.

If the gimbal problem continues in the other flight modes, I don't think it's the result of aggressive flying

 

[slup]

Great analysis, but how does this explain the behavior of the gimbal at 0.27 seconds in the video, the AC seems to be going down, moving slowly forward and the camera flicks forward quickly ?
There doesn't seem to be any aggressive flying at this time.

@lannes @armandobabe ... My chart directly from the provided flightlog is from 0.27sec in the vid. And the log shows exactly what happened, it's correct that the AC is commanded to descend but also to go forward with maximum elevator which pitch the AC forward nearly to max 30 degrees. The gimbal can handle that AC pitch as it's positioned at -90 degrees. But short after a full back elevator input is given while still descending ... that input pitch the AC shortly backwards with nearly 30 degrees, that movement pushes the gimbal into the maximum command limit of -90 degrees & well beyond ... that nudge the gimbal to a new pitch angle of 68 degrees which then later needs to be corrected manually by the pilot.

You can't judge out from a video clip ... the initial full elevator forward are disguised both by the gimbal that in this moment can handle the AC pitch, and the altitude of nearly 90 meters. But looking into the flightlog reveals the true facts.

With an understanding of this ... then yes the flight was "wild" in the sense that full stick inputs were constantly used in most directions & in Sport mode, this with the gimbal in an end position ...

This picture perhaps makes it easier to understand the relations between AC pitch & the maximum command angles for the gimbal. The picture shows why the gimbal pitch down when the AC go forward with full speed in Sport mode.