ADRC vs PID: motion control with soft connection between the motor and load.

This video shows the undisputed advantage of ADRC over PID and other techniques. The load is connected to the motor via a soft spring. The resonant frequency is less than 10 Hz but otherwise unknown. With ADRC, the closed-loop bandwidth is made greater than the unknown resonant frequency! The results show a rigidly controlled load, as though the spring effect was not even there.