Synthesis of fine-pointing control systems for large, flexible spacecraft

This paper considers the problem of designing attitude control systems for large space structures (LSS). The difficulties in control systems design, which arise because of special dynamic characteristics of LSS, are described, and methods for overcoming them using two types of controllers are presented. The first type of controller considered is a model-based compensator (MBC), and the second is the 'dissipative' controller which employs output feedback. Based on the numerical and analytical results obtained, the MBC can offer good performance under normal conditions, while the dissipative controller offers more robustness but perhaps reduced performance in situations involving large uncertainties.