Abstract: Capture of tumbling malfunction satellites is the basis of on-orbit servicing of spacecraft. As there is no fixed grasping point or rendezvous dock and precise motion parameters can be hardly obtained, traditional capture methods can hardly be applied in grasping of the tumbling malfunctional satellite. In this paper, a novel robust outside envelope capture approach is proposed for the tumbling malfunctional satellite. With the approach, the non-cooperative targets such as the tumbling malfunctional satellite can be captured because first, the capture envelop that is formed by the capture end-effector can constraint the motion of the malfunctional satellite, and thus there is no need for a fixed grasping point; second, the slight friction between the grasping end-effector and the malfunctional satellite can decrease the relative rotation motion between the two. Based on the envelop capture approach, the grasping trajectory for the robotic arm is optimized considering the fuel cost and disturbance to the base of the satellite. To verify the effectiveness of the grasping approach, the proposed method is applied in the tumbling cube-sat capture. The experiment and simulation results demonstrate the advantage of the proposed method.

Key words: malfunctional satellite, outside envelope capture, optimal trajectory planning, motion outside envelop, grasping outside envelop