Precision attitude control of symmetric spinning bodies

Abstract : Motivated by the arc-second pointing requirement of the Unsupported Gyroscope experiment and other satellite applications, this research investigates the problems associated with the precision attitude control of symmetric spinning bodies. An attitude control system is synthesized and then is studied by analog simulation. Controller performance and limitations are evaluated, using a laboratory model called the Spinning Vehicle Simulator (SVS). A technique devised at Stanford University in 1966 that simplifies the design of spinning-vehicle attitude controllers is used to select controller gains. The resulting system, simulated on an analog computer, produces excellent response characteristics and is insensitive to vehicle parameter or gain changes. The magnitude of the attitude error is shown to have zero-frequency and spin-frequency components proportional to the magnitude of body-fixed and inertially fixed moments, respectively. (Author)