Roll axis roll during hi speed sideways.

Discussion in 'Radian' started by Fredrik Hansson 2, May 20, 2013.

  1. Fredrik Hansson 2

    Fredrik Hansson 2 New Member

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    Hi
    I guess im not the first but I cant find any good answer for it. I run latest firmware, 3 axis radian with CS 3 axis gimbal. Flight forward is fine. No drift. But flying camera gimbal sideways cause the horizon to move. Look at video.
    Horizon reset when the copter stops but it takes a while.. A fast pan trigger the same effect.

    PASSWORD: asd
    Compare horizon start to finish of this clip

    Roll gain 140, latest firmware.
    Wind is about 5m/s so its not prefectly smoot but anyway it will give you a hint.
    What can I do to reduce it? Please advise.


    /Fredrik
     
  2. Rex D Peters

    Rex D Peters New Member

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    I also have this problem as well, as you can see, the roll twitch that is in all of my videos!! I would like an answer to this problem!! Any ideas out there????
     
  3. Tim Joy

    Tim Joy Active Member

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    I think this is the drawback of the radian relying on the accelerometers too much to keep a level horizon, normally. Either you will have the roll drift or it will be level during normal flight but it will lean into the movement on acceleration.
    You can lessen the amount by accelerating slowly, or have your operator feather the roll to correct it.

    As far as roll twitch, only by reducing gear backlash/ flex in the gimbal and reducing the gain have proved to work for me.
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Hi Fredrik:
    Have you tried reducing the roll gain to around 100-120% please? It's worth a try -- please let me know if this does not improve things. It's very hard to tell you the "right" value as it so specific to the the gimbal/payload etc.

    Also can you confirm that your camera is well-balanced on the gimbal -- if you remove the servo belts the camera will stay in any position on all three axes?

    Hope this helps
    Andy.
     
  5. Fredrik Hansson 2

    Fredrik Hansson 2 New Member

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    Fly CS8, 360 gimbal with cx-760 cam.
    Camera well balanced. side and tilt but it should sit higher to be perfect.
    Will make a short test with the gain adjustment but 140 seem to be very good from all other perspectives. We often fly winds about 5-6 m/s and need aggressiv gimbal settigs to keep up with copter movements.

    Fredrik
     
  6. Fredrik Hansson 2

    Fredrik Hansson 2 New Member

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    Tested and no improvment..
    Money back?
     
  7. Gary Haynes

    Gary Haynes Administrator
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    Fredrik can you send a photo of how you have the roll Radian mounted and screen shots of the Radian configuration settings.
     
  8. Tim Joy

    Tim Joy Active Member

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    By asking to see Fredrik's setup, are you guys implying that yours does NOT do this? My impression has always been that this is just how the radian works. When you see demo footage, there is very little fast sideways movement. It happens just as much in the tilt axis, btw, but we are much less sensitive to seeing a tilt change than a roll change.
     
  9. Gary Haynes

    Gary Haynes Administrator
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    If it happens I don't notice it. And we have seen mounting issues in the past.
     
  10. Tim Joy

    Tim Joy Active Member

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    Well, now that your attention is drawn to it, I'm sure it will show up. :)

    I think for this specific reason the movi implements a gps so it knows when to trust the accelerometers and when not to.
     
  11. TROU BAYLISS

    TROU BAYLISS Member

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    Tim .do you use a radian on ur pan axsis ...? PS I get roll lean on accel as well ..
     
  12. Tim Joy

    Tim Joy Active Member

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    Yes, 3-axis radian. It seemed worse in the winter for me.
     

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