Abstract: For a class of multi-body satellites systems with gimbal driver assembly (GDA) and small angle maneuvering antennas, the sequential return difference design method based on the two-input and two-output linear system model is proposed. And the multi-input multi-output(MIMO) controllers which include the pitch attitude control and antenna pointing control are obtained. Moreover, stability analysis of the corresponding closed-loop system is presented by the Nyquist stability criterion. Then the stability margin of the MIMO control system is obtained by calculating the minimum singular value of the system return difference matrix and the minimum singular value of the inverse return difference matrix. The two results are combined to reduce the conservativeness of the stability margin. Finally, numerical simulation results are presented to verify that the proposed controller and the stability margin method are effective.

Key words: multi-body satellites, sequential return difference method, singular value of the return difference matrix, singular value of the inverse return difference matrix, stability margin