Based on feedback linearization and ultimate boundedness theory, a new approach to attitude control of the space station using control moment gyros (CMG\u27s) is presented. A linearizing transformation is derived to obtain a simple linear representation of the nonlinear pitch axis dynamics. A feedback control law for trajectory tracking is derived when there is no disturbance torque acting on the space station. For attitude control in the presence of uncertain torque input, an additional control signal is superimposed such that in the closed-loop system, attitude responses are uniformly ultimately bounded and tend to a small set of ultimate boundedness. Extension of this approach to linearization of the coupled yaw and roll axis dynamics and control is presented. Simulation results for the pitch axis control are obtained to show that in the closed-loop system precise attitude control is accomplished. (Abstract shortened with permission of author.)
