Active Vibration Control of Magnetically Suspended Wheel Using Active Shaft Deflection

A novel method is proposed to actively attenuate the synchronous vibration of a magnetically suspended wheel (MSW) on the basis of shaft deflection. Considering the nonparallelism of the rotary axis and the inertial axis of the rotor, a precise dynamic model of the MSW is established as a linear model with synchronous disturbances. To reduce the synchronous vibration torques transferred to the base, the rotor shaft is actively deflected. A reference deflection angle is scheduled according to the synchronous disturbances, and a new tracking error dynamic model is established. Then, a composite control method is designed by combining a state feedback method and a disturbance observer. The stabilities of the disturbance observer and the closed-loop system are proven by Lyapunov's stability theorem. The parameters of the disturbance observer and the state feedback controller can be obtained by solving several linear matrix inequalities. The feasibility of vibration reduction due to the proposed method is analyzed. Finally, numerical simulations and experiments are performed. The results indicate that the proposed method significantly reduces the synchronous vibration torques of the MSW.