MoVI Pro vibration

Discussion in 'MōVI Pro' started by Stefan Helborg, Mar 16, 2017.

  1. Stefan Helborg

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    Hi

    Today I was out and flying with my MoVI Pro. The footage is very shaky and it swings very much occasionally. The wind was about 5-6 meters per second

    I fly with RED, a lightweight 50mm lens and MoVI Pro with two batteries. It is very well ballanced. I made an auto calibration at 70%, while it was hovering a few meters above the ground. I flew with the green dampers, but know that I with that weight probably should use the black ones. Do not expect that it can have as much to say that it can destroy the clip completely.

    Should I calibrere it on the ground, while I hold the drone, and it is not enough to use auto calibration?

    I have a task on Tuesday, and must therefore have found the error by then ...

    Hope someone can help their settings ...

    Here are some clip of the vibration. Password: shake


     
    #1 Stefan Helborg, Mar 16, 2017
    Last edited: Mar 16, 2017
  2. Graham Futerfas

    Graham Futerfas Well-Known Member

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    Hi Stefan, I'm no expert in drone work, but I find the Movi Pro tends to Auto-Tune kind of high. Not sure how you're supporting the Movi when calibrating it on the Alta, but when I AutoTune at 50% (lower than your setting of 70%), I often have to go in and manually reduce one or two of the motor stiffnesses because I get vibration and buzzing.

    With that payload, what values are you getting in your stiffness and filter settings? Are you tuning while the gimbal is just sitting on the ground? What Heading Assist setting are you using?

    I would try manually tuning your motors and see where they start to buzz and act up.

    It does appear like you're getting drone vibration translated to the Movi, but again, that's not my expertise.
     
  3. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Stefan:

    If you handhold the ALTA above the ground (without the motors running, of course!) and you "hand fly" it around, do you still see the same problem?

    The two things that seem to create issues are that the tuning of the MoVI is wrong and that's either causing the MoVI itself to oscillate, or possibly it's allowing ALTA vibration through to the camera.

    Also is there anything on the MoVI that is at all waggly (technical term) that might be causing the MoVI to "hunt" for stability?

    Andy.

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  4. Stefan Helborg

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    Everything on the MoVI is tight and clean. I will try to hand fly it around. Also I will chanhe the ALTA damping to the black ones, and also use Compas heading instead of GPS heading on the MoVI.

    Im still a little confuset about how to calibrate, if I should do it, while it's hovering or when I hold the ALTA still....?
     
  5. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Stefan: Suspend the ALTA with some cord from a a hook in the ceiling or a C-stand with counterbalance (or have some one hold the cord), then autotune. You must autotune the MoVI in the same physical setup that you intend to use it in otherwise it fools the autotune. The autotune is very good, but it's not perfect -- so you will probably need to make some adjustments to the settings up or down afterwards, but, for the same camera/lens/accessories on the MoVI, once you have it dialed in, the settings should be repeatable.

    Hope that helps.
    Andy

    Forensic Software & sUAV / Drone Analyst : Photographer : Videographer : Pilot (Portland, Oregon, USA): Trees=2, Ground=1, Props=11. :(
    The Ground Is The Limit™
    ---------- Forensic Drone Analyst : Forensic sUAV Analyst : Forensic Unmanned Aircraft Analyst : Forensic Drone Expert
     
  6. Stefan Helborg

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    Hi again

    Out testing today. Got a calmer image by setting Heading Assist to OFF. In Compass mode it seems very nervous and shaky. It seems, though, that I still have some small wiggle in my roll axis, and it seems kind of nervous, which I could not get rid of ... I flew with RED, light lens, Connex downlink, MoVI Pro, black dampers on the ALTA. I autotuned the MoVI while it was attached to the ALTA, that hung in a cord. After that, I finetuned it while it was hovering 5-8 meters above the ground.

    Are there some who have any suggestions for changes?

    In clip 3 it is intentionally I roll in the roll axis :)

    Autotune 75%
    Pan 114 / Roll 113 / Tilt 128 Stiffness
    Pan 4 / Roll 1 / Tilt 1 Filter
    Pan 58 / Roll 27 / Tilt 33 Hold strenght
    Jolt Rejection 0
    Gyro Filter 5
    Output (Master) Filter 2
    Handheld mode
    Heading Assist OFF

    password: test





     
  7. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Just my $.02 but you should auto-tune the gimbal while it's flying OR while holding the BOOMS/ARMS of the ALTA. NOT the top handle. The top handle is attached to the gimbal so you are actually not letting the gimbal suspend on the dampners. I would also check and see if you have any odd vibrations from the ALTA. That will mess things up. I can tell you that the MoVI Pro is solid in the air. Here is our test with a 100mm lens in 4k on our Epic which equated to 174mm. It was rock solid.



    Josh
     
  8. Graham Futerfas

    Graham Futerfas Well-Known Member

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    Hi Stefan, did you change your Output Filter to 2, or did it AutoTune that way? I was under the impression that if Output Filter is at any other value than '1', it overrides the other filters... At least I think that's how it used to work. Maybe things have changed? I can't find that in the current documentation.
     
  9. Stefan Helborg

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    Hi Josh. I did the calibration with slings on two of the arms, so no contact with the handle of course :) I saw your video before, and think it looked really good. Will you please share your settings of your MoVI? What camera (weight) did you have on your MoVI?

    Yes I change the Output filter to 2. I felt like at better result.

    It seems like the only major issue now is the roll that is kind of loose and wobly...

    Here is how I do the calibration (this is with the old M15)

     
    #9 Stefan Helborg, Mar 21, 2017
    Last edited: Mar 21, 2017
  10. Ben Platts

    Ben Platts Active Member

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    Hi Stefan. I seemed to get fairly good results with these settings the other day.

    Autotune Percentage,70
    Gyro Filter,5
    Heading Assist,3
    Output Filter,1
    Output Pan Filter,9
    Output Roll Filter,3
    Output Tilt Filter,5
    Pan Hold Strength,15
    Pan Stiffness,107
    Roll Hold Strength,12
    Roll Stiffness,132
    Tilt Hold Strength,12
    Tilt Stiffness,97

    The thing I find confusing with the Pro is that my auto tune settings jump around so much from one tune to the next. I can do an auto tune with the Alta suspended or in flight and get a Pan stiffness of maybe 97, then do another one immediately after without changing a single thing and the pan stiffness will drop to 75! Makes it difficult to get an accurate idea abut what settings are best in different scenarios. Im going to keep test flying. I've done about 4 days test flying and am getting near to being happy with the results but still am not sure about the most reliable way to quickly retune the gimbal for a different set up. With my M15 I tuned it once until the results were good then didn't retune it for about a year as the results were great with every new set up I put on it. With the Pro there seems to be a very fine line between it being good and it either having too high a stiffness setting (wobbles) and it being too low (very loose and bumpy). I get results which are pretty good and try and increase or decrease a value by 2 or 3 and the results are drastically different. Im sure we'll get there in the end! I'll up date after doing more testing.
     
    jim mundell and Graham Futerfas like this.
  11. Stefan Helborg

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    Thanks Ben.

    Heading assist 3, what is that? GPS, OFF og Compass ?
     
  12. Ben Platts

    Ben Platts Active Member

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    Its Compass.
     
  13. Josh Lambeth

    Josh Lambeth Well-Known Member

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    Honestly I only auto-tune with it set to 75%. I haven't touched a single other setting on the MoVI Pro. I do this on every lens-change/camera change, pretty much evertime a camera gets mounted. I've only once had it not do a good tune but that was because I bumped it pretty hard while it was tuning itself. It's REALLY important to have the camera package balanced perfectly, or near perfect.

    Josh
     
  14. Ben Platts

    Ben Platts Active Member

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    Hi Josh. Out of interest have you done anything to correct the Pros natural unbalanced pan axis. I mounted my link to counter balance the Pros natural back swing to the left so the pan is perfectly balanced on both the side and front to back axis and wondered if you'd done the same or if you were getting good results with it as is?
     

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