Resonance Ratio Control for Vibration and Disturbance Suppression in Force Servoing

This paper proposes a force servo method based on PD control and resonant ratio control for suppressing both torsional vibration and disturbances in two-inertia resonant systems. Resonance Ratio Control is one of the effective control methods for two-inertia resonant systems. In this method, the resonant frequency ratio between the motor and the arm is determined based on feedback from the estimated counter torque through a disturbance observer, and vibration suppression is achieved through pole placement. However, the estimation speed of the disturbance observer should be significantly faster than the resonant frequency of the controlled system, which leads to implementation challenges. In this paper, we give the optimal speed of the disturbance observer.