Nonlinear Spacecraft Control with Applications to Combined Attitude and Energy Storage

Abstract : The period of performance for this research award was from August 2000 to January 2004. The main objective of this research was to support the Air Force efforts in the development of an Integrated Power and Attitude Controls System (IPACS) for spacecraft applications. An IPACS will combine the attitude control and power distribution subsystems onboard a spacecraft reducing the bus mass, and thus leading to increased payload. Several options for IPACS have been investigated in this work including clusters of momentum wheels and variable-speed control moment gyros. The latter seem to be ideally suited for IPACS applications since they naturally decompose the power storage/release function using the wheel acceleration, and the attitude control function using the gimbal acceleration. Consequently, the focus of this research has thus been confined to the use of VSCMG5. Several practical and theoretical issues were encountered and were successfully addressed.