Agile rest-to-rest attitude maneuvering of spacecraft using pyramid-type SGCMG based on iteratively recalculated optimal trajectory

Abstract

This paper is concerned with the agile rest-to-rest attitude maneuvering of spacecraft using pyramid-type single-gimbal control moment gyroscopes (SGCMGs). In this method, the gimbal rate command to the SGCMGs is determined by calculating the pair of optimal trajectories of the attitude and the gimbal angles without any “steering law”. Thus, the proposed method does not suffer from the singularity problem causing the increase in control error and settling time. Before maneuvering, the pair of the initial optimal trajectories of the attitude and the gimbal angles is calculated by the minimum-time problem. Then, to compensate for errors in maneuvering caused by disturbances and/or modeling errors, the trajectories of the attitude and the gimbal angles are recalculated and updated frequently during the control. In this paper, optimization problems for generating and updating the trajectories are formulated, and specific control algorithms are provided. Finally, numerical simulations and ground experiments with an air floating table are performed to verify the feasibility and effectiveness of the proposed control method. For the rest-to-rest attitude maneuver, the proposed method can be adapted not only to the presence of modeling error in the inertia tensor, but also to the failure of one or two CMGs in the SGCMG system, without changing the control algorithm. These demonstrate the high robustness and practicality of the proposed method.