Vibration Control of the Structure with an Active Mechanical Component (Study on Vibration Control of a Flexible Shaft by a Magnetic Bearing)

For attaining rotatory high speed in actual rotating machinery, it is necessary to control many critical speeds, that is, many resonances of the machinery, using an active control bearing system. This paper investigates a design method of the active control bearing system consists of a magnetic bearing and its controller. The essence of this method is to design the controller based on the transfer function of whole structure which include flexible shaft and casing obtained by using both methods of substructure synthesis and modal analysis. In order to get suitable transaer function for controlling resonances, therefore, it becomes easy to determine the desired structure through modification of a substructure optionally. In this paper, the effectiveness of this design method indicated by theoretical approach, will be demonstrated through experiments.