Abstract: Rotor imbalance can lead to synchronous disturbances of magnetically suspended flywheel (MSFW), and reduce the attitude control accuracy and the load accuracy of spacecrafts. An open-loop bearing force compensation method is proposed to attenuate the unbalance vibration. The control goal is to inhibit the synchronous section of bearing forces, the dynamics of rotor is set up, and the characters of rigid rotor imbalance are analyzed. A displacement stiffness force compensation mechanism and two switches for open and closed loop control and displacement stiffness force compensation control are added to the adaptive notch filter to inhibit the unbalance vibration of bearing forces. The method is suitable for the MSFW property of crossing critical speed frequently, especially for magnetically suspended reaction wheel (MSRW). Simulation and experiment results demonstrate that the method has good inhibitory effect on the unbalance vibration of flywheel rotor in the whole speed range.

Key words: Active vibration control, Magnetic bearing, Magnetically suspended flywheel, Unbalance vibration