What is self-excitation?
  • Hello,

    What exactly (in terms of physical behavior) is self-excitation?

    As far as I understand, due to the rotation of the static magnetic field of the rotor, there is an induced current into the field coils of the stator, which is producing a magnetic field, counter acting against the rotating magnets. Right?

    But why could this happen at all? There is no short circuit between the coils, so no current could flow. And the impedance of the controller-output should be high enough to dampen any induced current ?
  • It could be that, but to what is this question related to? As related to Basecamp board I would understand it more as the system starting to vibrate and feeding more energy to the vibration.
  • I want to understand, what BaseCam is defining with the state called "self-excitation". Is it only a software related issue, which is wrongly described with a physical behavior?
  • It would help if you would post a citation. I do not know how it could be a SW only thing.
  • from the manual:

    "The tuning process does a simple job: it gradually increases P,I,D values until system enters in selfexcitation
    state. Self-excitation means maximum possible gains are reached. "

    So what is self-excitation in this manner?
  • That means that the hole system starts vibrating. It does not need any external forces to cause the vibration, but too high or wrong PID values cause it. But it is not only PID values that cause it. If the gimbal is improved, higher PID values can be archived.

    The goal is to get high P and reasonably high 'I' (with support of D, filtering etc.) or actually that is the mean to archive good stabilization. After that the Follow and Joystick/RC parameters and possibly some other parameters need to be tuned and some practice how to use the gimbal to archive the final goal, good looking video.

    I am quite happy how the sequence starting at 0:33 worked on this video , I am finally learning how to walk without mowing too much up and down, but once again forgot it at the sequence starting at 2:43