Controller Design of Flexible Spacecraft Attitude Control

Abstract

A controller design method for flexible spacecraft attitude control is presented. The design method uses the frequency domain approach. The system is first described by partial differential equation with internal damping model. Then the frequency response is analized, and the three basic characteristics of flexible system, namely, average function, lower bound and upper bound are defined. A compensator design method is proposed on the basis of these characteristics. The result shows that the direct velocity feedback combined with weak lag networks seems to be the optimum in the sense that the bandwidth required for the actuator is the narrowest. This approach is very robust and immune to the parameter changes such as mode frequency variations. This is because the design mehtod is based on only the general information of flexible structure and not on the specific ones. Some experiment is performed to investigate the validity of the method.