Attitude Sensing and Dynamic Decoupling Based on Active Magnetic Bearing of MSDGCMG

This paper explores the attitude-sensing function of the magnetically suspended double-gimbal control moment gyroscope (MSDGCMG), which can combine the attitude sensing and the attitude control into a single device to achieve a compact lightweight spacecraft design. In this implementation, the two-axis angular velocity of spacecraft is sensed from the control signals in the active-magnetic-bearing control system for a high-speed rotor. Both the current- and displacement-force terms are considered in the proposed scheme in order to achieve a good tracking performance of angular velocity estimation. Furthermore, a dynamic decoupling and static compensation procedure is designed to eliminate the cross-axis angular velocity couplings. The magnetic-force-related parameters which are crucial for the control torque calculations are also experimentally identified. The simulation and experimental results obtained from an originally developed MSDGCMG prototype are used to demonstrate the effectiveness of the presented implementations.