A Steering Method With Multiobjective Optimizing for Nonredundant Single-Gimbal Control Moment Gyro Systems

Abstract

The steering problems are investigated for nonredundant three single-gimbal control moment gyros (SGCMGs), in which no null-motion can be utilized to avoid the singular gimbal configurations. A gimbal configuration far away from the singularity is selected as a candidate nominal configuration, and a comprehensive multiobjective optimal cost function is constructed with respect to the actual gimbal angular vector error, the gimbal command variation, and the torque output error. By minimizing the cost function, an optimal gimbal angle command formula is derived consequently, and a corresponding equivalent gimbal angular rate command formula is also presented. Moreover, according to the pattern of the rest-to-rest attitude maneuver, dynamically weight-adjusting strategies for the cost function are designed, and a complete steering scheme for the nonredundant SGCMG system is built up based on the derived algorithms of the gimbal command. The proposed steering method can guarantee successful singularity-avoiding during the attitude maneuver and gimbal-returning back to the vicinity of the nominal angles at the end of the maneuver, and its effectiveness is verified by both numerical simulations and experimental tests.