Impedance Control for Stabilizing the Coupled System During Tumbling Target Capturing

Due to uncontrolled, a malfunctioned satellite or other space debris is generally tumbling, bringing great challenge to capture and remove it. In this paper, we propose an autonomous capturing strategy based on impedance control to detumbling the target. Using this strategy, the end-effectors will approach the capture point on the docking ring of target and then stabilize the tumbling target. An un-controlled space object and a space robotic system are first modeled. Dynamics model of tumbling target is established with or without external forces and torques acting on the target. And the motion characteristics of target is theoretically analyzed when there are no external forces and torques impacting on the target. Then, the capture and detumbling strategy is presented base on impedance control. The strategy has two phases. The first is approaching phase that the trajectory is planned for the arm to approach to capture point. The other one is detumbling phase that the tumbling target is stabilized. Finally, we develop an Adams-Simulink co-simulation system. Based on it, the proposed method is verified by space robotic system. Simulation results show that the end-effector will approach the capture point on the docking ring of target rapidly and then stabilize the tumbling target gradually.