Please clarify how exactly should gimbal behave while yaw movement?
607 2 2019-2-6
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Paul Atkin
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Flight distance : 36962 ft
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Hi,

I am very confused and need to clarify how it is supposed to work.
When i power up my M2P and hold it in my hand, and perform any rotation of the drone around yaw axis, even very slow - i see how gimbal slowly 'catches up' with the body smoothing up this movement`s transition. It does same if you pitch it - it stabilizes the horizon while smoothing up yaw rotation making sure body 'jerks' are not visible.


Now, as i take off and fly it, in any mode, cinematic mode active or not, and give any amount of yaw input to rotate the drone`s body - i did it looking very closely at the drone and i am  sure it seems to rotate the whole gimbal assembly together WITH the body not smoothing much that yaw input i give.
in the 4K30 video at 1/60 shutter speed it results with a sudden 'jerk' movement of the scene as rotation progresses, i think. yaw exp is set to .15, yaw sensitivity limit is set to 55 to allow very small amount of yaw - it does not seem to matter - it moves camera, it is smooth and then 'jerks' as body is not moving perfectly smooth and gimbal ignores yaw stabilization, as it seems.


Then i went outside to freeze my fingers trying to experiment more and got even more confused. What it appears to be doing is quite odd. If i alter gimbal pitch from the horizon level at least a tiny bit down - it seems to be rotating with the body, always. If i then flip a switch moving gimbal 90deg up or down and THEN do a yaw input - i can see then how it begins to add a tiny bit of a rotational delay similar to what it is doing when i hold it in my hand - powered up but not flying. Gimbal is set in follow mode all the time, i tried turning on cinematic mode on and off - it does not seem to be making any difference.


It would be very nice to know if this is a defect of my unit or the way all those mavics work as it is not how a pro grade gimbal should operate, at all. I tried to look up online but it seems M2P model does not have those setting phantoms had and older mavics had, so, i am not sure what to expect and how it was supposed to behave.
All i can see that any rotation while filming produces a scene that 'stutters' from time to time instead of rotating smoothly, even when it rotates at a minimal speed.


Is it a defect of a feature?  
2019-2-6
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AlphaFlightNW
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Flight distance : 784265 ft
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United States
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Hello!  I would also need to know a few other factors, such as gimbal smoothness settings, speed of SD card/if you are writing to the internal storage, what firmware your on, that sort of stuff to better help. You could also look to do a gimbal calibration or post flight logs, I am not sure if gimbal would be recorded but you never know.
EDIT: Could you attach a video showing this issue?
2019-2-6
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Paul Atkin
lvl.2
Flight distance : 36962 ft
United States
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AlphaFlightNW Posted at 2-6 21:22
Hello!  I would also need to know a few other factors, such as gimbal smoothness settings, speed of SD card/if you are writing to the internal storage, what firmware your on, that sort of stuff to better help. You could also look to do a gimbal calibration or post flight logs, I am not sure if gimbal would be recorded but you never know.
EDIT: Could you attach a video showing this issue?

hi, i think it can be put on hold for now as i did quite an extensive research during last 2 days and found several things...

First - it is unfortunate, but, gimbal yaw stabilization parameters are not adjustable. it would be nice to expose yaw stabilization slider in a same way as pitch is exposed - but it is not there. Pity.
Also, what i wrote above about behavior change after 90deg swivel up/down and stands true. it is all in the gimbal code.

Second - the fact that is not exposed does not mean that it works incorrectly. it works fine and footage is produced correctly. When played on the TV directly it is not showing any stutter.

Third - SD card issue can indeed be a factor, but in my case it was not. i repeated the test using 4 different types of cards. From all cards TV played footage fine. Youtube also shows files correctly after running its conversion.

Forth - the issue. the issue sits deep in the implementation of the DirectX 3.11 codecs inside of Windows 10 and integration to GPU.
The easiest way to see it just to run the caprtured MP4 or MOV file in VLC v3 - and in any pan scene with the yaw rotation it shows as a series of microstutters - very visible and very annoying. What did confuse me - as i would never bother much to react jsut to VLC - i saw the same thing in the DaVinci Resolve that I used all the time to edit footage from my Nikons - and i never had any issue in there dealing with the content produced by those DSLRs. Nevertheless, the specific codec used by Mavic in combination with the 4K30 10bit flow - that is the sole reason of this stuttering. I got now VLC nightly build - v4.0 and it resolved the issue a bit, it still stutters, but much less. i run Nvidia 1060 card - that also maybe the issue, but, for now i ran it to the end of what i could do and i will have to pause and see if anything will get resolved by the driver updates or something else.

Gimbal tracing the body is still an issue, in my opinion, but, so far after proper review of previous files - i see all panning yaw movements to be smooth enough. not as smooth as on my storm32 based custom gimbal, but, smooth enough.
2019-2-7
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