Coordinated control of relative position and attitude for spacecraft with actuator saturation

This paper deals with coordinated control problem of relative position and attitude of spacecraft with actuator saturation limit. Relative coupled dynamic model based on dual quaternion is introduced to describe their translational and rotational motions. In order to solve the actuator saturation problem, a conventional PD controller is modified by augmenting anti-windup control and intelligent integrator to increase the level of saturation allowed as well as the disturbance amplitude. The validity of the presented method and the superiority to conventional PD controller are demonstrated by numerical simulations.