Human-Inspired Robotic Assembly for Multiple Peg-In/Out-Hole Tasks in On-Orbit Refueling

Abstract

On-orbit refueling technology requires using robots with multiple peg-in-hole and peg-out-hole capabilities. However, complex contact conditions can cause jamming, thus posing significant challenges to automated refueling. To address this shortcoming, this letter proposes a human-inspired multiple peg-in/out-hole assembly method. The proposed method integrates a variable admittance force controller based on a non-diagonal stiffness matrix and a strategy for handling multiple peg-in/out-hole operations. In addition, by coupling the position and orientation stiffness, a robot's adaptability in dynamic assembly environments is significantly enhanced. Moreover, the proposed method enables autonomous posture adjustment based on real-time force sensor data and allows a robot to retry operations in case of jamming, thus eliminating the need for complex motion trajectory planning. The results of the ground refueling experiments show that the proposed method can successfully complete the multiple peg-in/out-hole tasks and effectively resist external interference. The proposed method could be of valuable reference significance for on-orbit refueling tasks.