Fine tuning of the gimbal in order to remove vibrations
  • Dear all,
    I am working on a gimbal (frame from hobbyking) with Turnigy LD9017 Brushless Gimbal Motors and a 32 bis controller. The camera is well balanced but I still have some problems to fine tuning the pid settings.
    Actually this is my settings
    ROLL: 54 0.07 31 Power 160 + 50 Poles 27
    PITCH: 32 0.04 16 Power 130 + 50 Poles 27
    YAW: 16 0.01 10 Power 190 + 50 Poles 27

    The main problem are three:
    1)when I walk I see residual vibrations (high frequency). I don't understand if the vibrations come from too much corrections or if it is the gimbal that is to slow to correct.
    2) If i shaker the gimbal, sometimes (when I shaker yaw + roll) the gimbal become crazy and fast rotate of ~90° (on)
    3) Some time the yaw motor starts to vibrate without no reason (no shake only a slow turn).

    Can you help me?

    Thank you very much
  • 27 is a strange pole count. is your motor 27 poles according the spesifications? Use the motor auto to set inverted status, but set pole count manually.
  • I correct the number. The motors have 22 poles. The strange things ids that all the problems are bigger. If I try aouto PID configurations the numbers group up a lot but the system is really unstable and full of vibrations. No I idea to solve my problems.
  • Set all PID first low. The autotune using good stability setting one axis at time in order Pitch, Roll, Yaw.

    When done se if there is remaining vibrations in any gimbal holding position, if there is autotune the vibrating axis again on that position.

    But before you do this make absolutely sure that you have carefully followed the basic setup procedure. i.e gimbal is mechanically ok, basic setup is well performed, you do not have unnecessary RC channels assigned at this time etc. Then PID tune. If you PID tune before everything else is ok, it is just waist of time.
  • Thank you. I think that the gimbal is mechanically ok and quite stabilized. (I hope). The accelerometers are calibrated and well fixed to the frame (I used a inox bolt to fix sensor to the frame. I use the holes on the sensors).

    What have I to check about RC? Are there basic configurations? I never touch nothings about advanced tuning.

    One strange things:
    - I auto tuned poles and inversion of the motors and one time it said yaw was inverted (but nothings work) and the second one it said that the yaw is not inverted (and the system barely works)

    Furthermore, I think to have a bed settings on power. Have you got some hints to properly set the motor power?

  • Set motor power higher, but after seting check frequently that motors do not get hot.

    After seting power higher redo the motor auto, and leave inverted as set by it, but correct poles to actual polecount.

    Default RC is ok, but better set them nothing connected

    If your power is not suffisient and motors are cold, you might need to use higher voltage battery. Verify also the battery calibration an set compensate voltage drop