Horizon Drift or no level

Discussion in 'MōVI M10' started by Gorka Rotaeche, Oct 10, 2014.

  1. Gorka Rotaeche

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    I had several times this problem. The horizon was out of level.
    The Movi was correctly balanced. With a fresh battery. I was in the back of a van shotting a car following us. We were speedy making turns. After a while a noticed that the horizon was out of level ( roll axis).
    Next I was in the side of the van, shotting the car in parallel. The direction of the car and van was straight. After a while the horizon was out of level ( roll axis). We stopped and the Movi didn´t get it leveled position. I had to force the roll axis to get the horizon leveled.
    When you start up the Movi the roll is OK, leveled. This only happend when we are in motion with speed. I atached a picture of other situation that I was riding a Segway. The horizon out of level is clear.
    From the web of Freefly:
    "The control algorithms developed for the MōVI utilize a very high accuracy GPS. This GPS allows for acceleration correction when the gimbal is used outdoors and has a GPS signal. This feature is useful when used on cars and helicopters where sustained extreme accelerational forces can cause non-GPS aided systems to drift.I assume that this horizon driffting it happens for the aceleration and the speed of the vehicle." MOVI BAD HORIZONT.jpg

    Why does it happen?
     
  2. Lael Camak

    Lael Camak Member

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    Are you using autotune settings only? Have you tried increasing your stiffness settings?
     
  3. Gary Haynes

    Gary Haynes Administrator
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    Gorka what are your stiffness settings?
     
  4. Gorka Rotaeche

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    They are differents setup. So the stiffness changes. But I usually like a stiff roll axis.
    No Autotune.
     
  5. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Gorka: When you are outside with a good sky view, can you connect up to the MōVI with a Mac, PC or Android and see what the GPS system status is?

    Andy.
     
  6. TomSmall

    TomSmall New Member

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    We are having the same problems filming in Israel and need help asap! Everything's been working fine until today the roll (horizon) started to go dutch and kept drifting... and after a few minutes it barely even even stabilizes the C300. When rebooted it seems to work ok for a minute or twho before starting to become less responsive. It seems to have a pattern in how it will spin, it tilts as it rolls in the same fashion over and over.

    So we updated our Configurator and then the firmware, and the Movi still does the same thing. Any help greatly appreciated! We tried resetting all the settings we could find under System to default config.
     
  7. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Tom: Considering the urgency, I'd email to support@freeflysystems.com and open up a ticket. There may be other forum members who've found the cause for this, but opening the ticket is a good idea too.

    Andy.
     
  8. TomSmall

    TomSmall New Member

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    Thanks Andy, our producer got ahold of Freefly last night and we talked it over. Going through diagnostics now to try and identify the problem.
    Tom
     
  9. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    If you resolve it and have time, I think there would be several folks interested to know what you found, Tom.

    Andy.
     
  10. TomSmall

    TomSmall New Member

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    Absolutely. I'll update this thread with whatever happens.

    Tom
     
  11. TomSmall

    TomSmall New Member

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    Have to send it in for diagnostics ;( Updating firmware and resetting everything didn't fix it at all.
     
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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  13. Tim Joy

    Tim Joy Active Member

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    I'm sorry to say that this seems like classic behavior that started way back with the Radians. I think it is something fundamental to the way the algorithms determine a level horizon. I have seen it on every Movi I've used and it's the reason we keep the roll axis on the rudder stick. I've had plenty of satellites locked on and it didn't make a difference.
    It happens on the tilt too but since we control the tilt and are much less sensitive to seeing it visually it doesn't cause big issues.
    Even the roll off less than 1 degree is quite noticeable.
    I would like to be wrong, so if anyone has other experiences could show a side (tracking) shot, starting from a stop and with sustained accelerations from a vehicle or aircraft that stays level on the roll, (without external control) then I would like to find out your secret.

    My guess is that having the roll follow the gravity vector in these situations keeps it from staying off-level when it stops moving, which is something that seemd to plague the zenmuse gimbals. Coincidentally, they seemed to hold a level roll axis very well in a tracking shot, at the expense of it drifting permanently until it was reset.
     
  14. Ozkan Erden

    Ozkan Erden Distributor

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    I also have severe horizon drifts on M5. This happens especially flying sideways against the wind. Actually, I had almost zero success with long side tracking shots, I always had horizon drifts. The drift ratio depends on how fast I move.

    GPS is necessary for correcting horizon on fast and long vertical movements. But I believe Freefly's algorithm is not working properly.

    The systems without GPS has no chance fixing the horizon issue. But those who has GPS and who implements the right algorithm to fix the horizon issue, will be a winner solution for aerial videographers like us. I haven't seen a satisfactory solution yet. As far as I have seen, Zenmuse series of DJI can hold horizon better since they are fed by the flight controller.
     
  15. Wayne Mann

    Wayne Mann Member

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    Guys,

    There are no solutions for this issue currently. My Alexmos custom gimbals do not suffer too bad from horizon issues when accelerating sideways because they allow you to limit the Accelerometers authority over the gyros, but it does roll off. The point that I am trying to make is that $650,000 Cineflex V14 gimbals do the exact same thing. With the resources that they have available to them you would think that if a solution was available too anyone they would have solved this problem already.


    Wayne Mann
    www.HeliCamHDmedia.com
     
  16. Julien Grange

    Julien Grange New Member

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    We recently shot a lot of side shots, this one is the fastest and no drift...

     
  17. Ozkan Erden

    Ozkan Erden Distributor

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    Julien, at the first seconds of the footage, there's no reference point to understand if the horizon was level or not. And your tilt is down, tilting down masks the horizon issue.

    Another note: What I have experienced so far, bigger camera setups are holding horizon better; I think that's due to the higher stiffness settings. With BMCC 4K, I can get much better horizon hold performance when compared to GH4 setup.
     
  18. Julien Grange

    Julien Grange New Member

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    Sorry, just wanna help...
    If I understand, it could be interesting to increase weight on your GH4 setup...
     
  19. Ozkan Erden

    Ozkan Erden Distributor

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    pass: m5horizon

    These footages are not usable.
     
  20. Gary Haynes

    Gary Haynes Administrator
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