Frame IMU makes gimbal unstable.
  • Hi All.
    I have built a couple of gimbals over the last few years to be used on multirotor drones.
    This last week I have been trying to eliminate an annoying ‘tumble’ that my new 3 axis (NEX5 size) gimbal sometimes does. If it loses steps or collides with the frame it can sometimes try for a minute to get itself level again, tumbling like a headless chicken. Ive striped everything down and calibrated again and tested each axis is working well individually.
    I have just noticed that its 99% eliminated if the frame IMU is deselected. The frame IMU is calibrated and correctly orientated. I have it mounted above the yaw axis but on the ‘copter’ side of antivibration rubbers. Should it be mounted more rigidly to the main yaw motor plate? I have tried just about every tuning thing I can think of. Turning up power helps but the motors are on the warm limit already.
    Any advice appreciated.
  • Anybody any ideas? System seems much more stable when frame IMU is deselected.
  • Have now moved the frame IMU below YAW. Seems a bit better. However if the gimbal gets toppled, with frame IMU DEselected it will smoothly erect its self. With frame IMU selected it has a mad few seconds trying to erect. Is this normal?