Aititude Control of Flexible Communications Satellites

This paper investigates alternate control techniques for the attitude control of a three axis stabilized flexible communications satellite consisting of a large reflector and a solar array. The control configurations consisted of three classes: Class 1 sensors and actuators co-located on the central body, Class 2 actuator on the central body and sensors distributed, and Class 3 -actuators and sensors distributed. Criteria are developed for modal truncation. The results indicate that Class 2 can cause instability and. is not generally a desirable design approach. An experimental setup to study the effects of flexibility on attitude control per-formance during slew maneuvers and wheel desaturation is also discussed.