NONLINEAR REGULATION OF SPACE STATION - A GEOMETRIC APPROACH

This paper presents a new approach to control system design for the no nlinear regulation and angular moments management of the space station in the presence of disturbance torque based on geometric control theo ry. The aerodynamic disturbance torque is treated as the output of an exosystem that is Poisson stable. An output zeroing submanifold for th e pitch, yaw, and roll dynamics is obtained. A control law is obtained such that in the closed-loop system the trajectories converge to this manifold and the desired equilibrium state is attained. For the synth esis of the controller, the states associated with the exosystem are g enerated using measurement on the attitude angles and angular rates. S imulation results are presented to show that in the closed-loop system , attitude regulation and moments management are accomplished in spite of the presence of the aerodynamic disturbance inputs.