Comparison of Resonance Ratio Control and H^∞ Control on Speed Control of Two-mass System

Abstract

In the industrial motor drive systems such as industrial plants and industrial robots, a torsional vibration is often generated because of the elastic elements in torque transmission. This vibration makes it difficult to achieve quick responses of speed and may result in damage to the plant. Such system is simply modelled as a two-mass system. Many control methods have been examined to suppress the torsional vibration. One of the typical approach is the state feedback control using the observer. Another approach is based on the modern robust control theory. In this paper, the closed-loop characteristics of two types of speed control systems such as the resonance ratio control using the disturbance observer, which is based on the state feedback approach, and H^∞ control, which is based on the modern robust control theory, are compared. The control performance such as the vibration suppression and the disturbance rejection are examined by the simulations and the experiment. The robust stability against the parameter variation, the model uncertainties and noise is also examined. From several examinations, the feature of these control system are clarified.