Multistage Angular Momentum Management for Space Station Attitude Control

Abstract

A multistage attitude control and momentum management (ACMM) control strategy is proposed for space stations. The ACMM, which includes closed-loop angular momentum feedback (CAMF) and torque equilibrium attitude (TEA) tracking, is achieved using the gravity gradient and an aerodynamic torques. The CAMF is employed as the normal flight mode, and TEA tracking is used to unload the angular momentum after attitude stabilization. Hence, the angular momentum imparted by the attitude control device does not need to be unloaded using thrusters during the entire operating phase. The system performances, especially the relationship between the environmental torques and the attitude, are analysed. The internal model principle is utilized to suppress the attitude fluctuation during the CAMF mode, and a quintic polynomial is utilized to realize TEA tracking. The pole placement algorithm, which can obtain the feedback matrix in the linear quadratic regulator (LQR) without choosing a weight matrix, is introduced to design the LQR controllers. This approach is demonstrated for a future Chinese space station, and the simulation results verified the effectiveness of the proposed control algorithm.