Coordinated control of spacecraft attitude and its manipulator

When a robot arm is mounted on a satellite to perform tasks, satellite attitude must be stabilized to keep communication link and to generate electrical power from its solar panels. Most past studies about free-flying space robots assume that the satellite platform is uncontrolled. Since performance of the space qualified onboard computer is not enough to handle the complicated control system, coordinated control of the robot manipulator control system and the satellite attitude control system is proposed in this paper. The robot control system estimates the angular momentum which the robot arm will produce. The satellite attitude control system compensates the robot arm's reaction by the feed forward momentum control. The robot control system also controls robot arm motion not to generate excess reaction against the satellite platform.