Yaw problem while tilting
  • Hello,

    I wonder if someone could help me solve this problem, or at least give me some new ideas!

    I am currently using a 3 axis gimbal, with the basecam 32 bit controller, but I'm having some problems with the yaw stabilization. It all goes well when the camera is leveled, but when reaching a certain roll position, the gimbal starts to shake and sometimes goes crazy. You can see this on the video below (around 0:09 the shakes begin).

    I have tried using different GUI+firmware versions (tried 2.40 and 2.55) and in the video I'm using version 2.56b4 (latest beta version) with the frame IMU mounted above the yaw.

    I have used the auto-tuner for the PIDs, and tuned by myself, messed with the Outer PI controller and with motor powers (I have even tried with all the motors at full power). I have checked and re-checked the gimbal balance. All of my efforts produced the same result, good stabilization when camera is leveled, but crazy shakes and instability on certain roll positions.

    Assembled Gimbal Weight: 380gr
    Camera Weight: around 120gr
    Motors: 4xBGM4108-130

    Hope someone can help me!
  • What fo you have installed on the gimbal, does not look very solid? What way has the gimbal been configured, what is the axis order? Is it balanced? If you move the gimbal so that two motor axis are in same direction, it is in gimbal lock and will not work well.
  • Thank you for your answer Garug!

    You actually solved this for me, as soon as you asked the axis order, I remembered there was an option to configure it on the GUI. My hardware axis order is ROLL-PITCH-YAW, and the firmware was configure to PITCH-ROLL-YAW. As soon as I changed this, the behaviour completely changed, it now works much better, and as I expected! Even gimbal lock is almost completely handled.

    Thank you very much for the help, is it possible to give me a hint as to why this axis configuration is so important? Why does it work poorly when not configured properly?
  • I would like to understand this as well. axis order?
  • It is not easy to understand not to explain https://en.wikipedia.org/wiki/Axis–angle_representation

    Best to experiment. Keep the gimbal axis order as the gimbal is mechanically configured. with Eulers angles you can experiment. they affect how the gimbal moves under RC control, etc. Best starting point for that is also the actual gimbal axis order.

    The most used configuration (all most all gimbals) is PITCH-ROLL-YAW.