Dynamics and vibration suppression of space structures with control moment gyroscopes

• Control moment gyros are adopted as actuators for vibration suppression of space structures.
• The equations of motion incorporate the detailed dynamics of the CMGs.
• The modal characteristics and system controllability and observability are investigated.
• The optimal placement problem of the CMGs on the flexible structure is considered.
• An angular velocity feedback control law is designed and the stability is proved.

This paper presents a new and effective approach for vibration suppression of large space structures. Collocated pairs of control moment gyroscope (CMG) and angular rate sensor are adopted as actuators/sensors. The equations of motion of a flexible structure with a set of arbitrarily distributed CMGs are developed. The detailed dynamics of the CMGs and their interactions between the flexibilities of the structure are incorporated in the formulation. Then, the equations of motion are linearized to describe the small-scale motion of the system. The optimal placement problem of the actuators/sensors on the flexible structures is solved from the perspective of system controllability and observability. The controller for the vibration suppression is synthesized using the angular rates of the locations where the CMGs are mounted and the gimbal angles of the CMGs. The stability of the controller is proved by the Lyapunov theorem. Numerical examples of a beam structure and a plate structure validate the efficacy of the proposed method.