Slow resonance ratio control for vibration suppression and disturbance rejection in torsional system

In the resonance ratio control, which the authors proposed for vibration suppression and disturbance rejection in a torsional system, the estimation speed of the disturbance observer should have been much faster than the resonance frequency of the controlled system. However, too fast a disturbance observer sometimes causes an implementation problem. In this paper, the authors give the optimal speed of the disturbance observer and propose a novel technique named “slow resonance ratio control”. It does not have any fast part in the controller. It also enables us to design the speed control and the vibration suppression control almost completely independently