Jitter / Vibration

Discussion in '3 Axis Gimbal' started by Jason Toth, Sep 1, 2013.

  1. Jason Toth

    Jason Toth Active Member

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    Hi, just wondering if/how anyone else is reducing gimbal vibration. Below video shows when I tap the gimbal legs (I tap 3 times with a second or so between), the camera of course shakes but it seams to keep shaking for a bit like the design accentuates things? Thanks, J

     
  2. Dave King

    Dave King Well-Known Member

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    Reduce the gains on the tilt and roll radians.
     
  3. Jason Toth

    Jason Toth Active Member

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    Sorry forgot to mention that this is with the Radians off (on doesn't make a difference either). Its just vibration/movement of the carbon gimbals its self.
    [​IMG][​IMG]
     
  4. Gary Haynes

    Gary Haynes Administrator
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    Jason not sure that it is a valid test. Tapping it isn't the type of constant vibration from the motors. But the camera will move because it is a pendulum. Try the same test with the Radian's running.
     
  5. Jason Toth

    Jason Toth Active Member

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    Yeah it's a lame test. But if I even just hold the whole gimbal and just move it to mimic when airframe is attached. The camera/lens bounces even With the slightest of movements. I'm using an allied drones Echo for antivibration, which works well But again the camera just seems to jiggle when you can touch the gimbal
     
  6. Jason Toth

    Jason Toth Active Member

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    Yeah with Radians on or off its the same. If you guys tap yours does it do the same (keeps bouncing / vibrating slightly for a bit)?
     
  7. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    When the gains are set right, the bouncing dies away very quickly -- it's being dampened by the Radians. But when the gains are set too high, the bouncing gets worse until the gimbal threatens to shake itself apart. If the gain is set too low, the vibrations are not properly dampened by the Radians so they last longer, but do die away.

    The sweet spot is easily overlooked -- usually because you're increasing/decreasing the gains by steps of say 10%. You can certainly do that to find the likely sweet spot, but then you need to sneak up on it 1% at a time. If you can view/record the video from the camera, you can play it back and get some general idea of just how much bouncing you're getting and what the decay time is.

    Hope this helps.
    Andy.
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    By the way, are you tapping the camera sideways with the gimbal on your bench in your first posting? In which case, what you're seeing is the vibration being dampened by the O-rings, I suspect (rather than by the Radians). The Radians will dampen rotary motion around the tilt, roll, and pan axes. But tapping the camera sideways is more of a horizontal translation (assuming the C of G of the camera/gimbal is spot on the tilt/roll/pan axes).

    Tap the top of the lens in a downward motion to test the tilt axis. Tap the top of one of the side booms to test the roll axis. Those kinds of taps will induce rotary motion. Suspend the copter/gimbal from the battery plate and tap the side of one of the landing gear to test pan.

    Hope this helps.

    Andy.
     
  9. Jason Toth

    Jason Toth Active Member

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    That helps! Appreciate it, was not getting the fine with the gains. Take care, Jason
     

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