Abstract: Space non-cooperative target capturing is challenging due to the lack of gripping points and the dynamics of the capture targets. A novel multi-finger caging-based gripping path design algorithm with a "Leader-Follower" mode for space non-cooperative targets is proposed. Firstly, to reduce the degrees of freedom, we divide the fingers of the multi-fingered mechanism into one leading finger and the other following fingers. Then, the base joint of the leading finger is controlled to track the caging point using the error control strategy to realize the synchronous motion with the target. In addition, the concept of "One Way Distance" is introduced to measure the similarity between the shape of the leading finger and the caging edge, and the Rapid-exploring Random Trees algorithm is adopted to search the joint angles of the leading finger that can cause the minimum one way distance. Furthermore, possible configurations of the other following fingers are determined according to the structural model of the multi-fingered mechanism. Finally, caging conditions are utilized to obtain effective caging configurations. The proposed algorithm is applied in the caging of a moving planar non-cooperative target and a moving three-dimensional non-cooperative target, respectively. The simulation results show that the proposed algorithm is both applicable for general space non-cooperative target capture and efficient in reducing computational complexity.

Key words: space non-cooperative target capture, caging algorithm with "Leader-Follower" mode, synchronous motion, one way distance, structural model