Coordinated Control of Spacecraft's Attitude and End-Effector for Space Robots

This letter addresses the coordinated control of the spacecraft's attitude and the end-effector pose of a manipulator-equipped space robot. A controller is proposed to simultaneously regulate the spacecraft's attitude, the global center-of-mass, and the end-effector pose. The control is based on a triangular actuation decomposition that decouples the end-effector task from the spacecraft's force actuator, increasing fuel efficiency. The strategy is validated in hardware using a robotic motion simulator composed of a seven degrees-of-freedom (DOF) arm mounted on a six DOF base. The tradeoff between control requirements and fuel consumption is discussed.