Power Consumption Reduction for Magnetic Bearing Systems during Torque Output of Control Moment Gyros

The power consumption of actuators is an important concern for the spacecraft attitude control system. This paper presents a power consumption reduction method for permanent magnet biased active magnetic bearings (AMBs) during torque output of control moment gyros (CMGs). For simplicity of analysis, a simple single degree-of-freedom (DOF) AMB system undergoing an external load force is first presented. An operating point adaptive regulation based on current-integral feedforward method is proposed to realize the coil current reduction with a reference position offset. Then the proposed method is extended to the case of the 4-DOF AMB-rotor system. In order to improve the dynamic response of the current-integral output, a dynamic regulator is incorporated into the feedforward loop. The parameter range for stability and dynamic properties of the AMB-rotor system with and without using the dynamic regulator have also be compared and discussed. Finally, experimental results on a developed magnetically suspended double-gimbal CMG prototype validate the effectiveness of the proposed method.