The vibration suppression control of the two-mass resonant system using the H∞ filter

In industrial motor drive systems, a shaft torsional vibration is often generated when a motor and a load are connected with a flexible shaft. This paper treats the vibration suppression control of such a system. Recently a new method has been developed which estimates the unknown state variables by using the reduced order observer and feeds back these state variables by using a pole placement design method. This state feedback control method can control the command following property and the load disturbance suppression property independently. In this paper, a vibration suppression control method of a two-mass resonant system using an H_∞ filter is proposed. The proposed control method uses the H_∞ filter as an observer of the state feedback controller. The H_∞ filter has good estimating property about an unknown input. To show the validity of the H_∞ filter, under the same controller, the authors compared real shaft torsional torque with estimated shaft torsional torque in case of using the state observer or the H_∞ filter, respectively. As a result, they confirmed that the H_∞ filter had excellent estimating property. Experimental results show the validity of the proposed controller and the proposed controller is compared with the state feedback controller using the state observer