Distributed Optimization Method for Spacecraft Attitude Control and Vibration Suppression

To achieve high-precision attitude control, vibration suppression is required for large spacecraft. The actuators for attitude control and/or vibration suppression can be installed centralized or distributed. In the former case, some vibration suppression methods are based on trajectory planning 1,2, while others are integrated in attitude control law 3. The capabilities of these methods for vibration suppression are limited due to their open-loop design-based attribution or lack of dedicated actuators for vibration suppression. Hence, attitude control and vibration suppression based on distributed actuators are becoming a research hotspot. Various types of actuator have been scattered across the spacecraft for vibration suppression, including piezoelectric actuators (PZTs) 4,5 and control moment gyroscopes (CMGs) 6–13. The concept of angular momentum being studied as a distributed parameter was first introduced by D’Eleuterio and Hughes 6,7. By importing infinitesimal angular momentum devices tothe elastic body, the frequencies, coupled modes, and damping can be controlled. To facilitate engineering application, Hu et al. 10–13 proposed a practical methodology for active vibration suppression and attitude control of flexible structures by CMGs. In Hu’s studies, the angular momentum is discretely distributed in the structure rather than continuously 6,7. According to the model in 11, Guo et al. proposed a modal force compensator method 14 and a null-motion based method 15 to suppress vibration. Different from the idea of designing the control law and the steering law of actuators together 10–15, Hu et al. 16,17 proposed two control law design methods for attitude control and vibration suppression. The advantage is that the proposed methods can be used for systems with different kinds of actuators.