Robust Approach and Synchronization Control of Dual-Arm Space Robots with Noncooperative Tumbling Satellites Using Adaptive Sliding Mode Control

This paper presents an adaptive sliding mode control (ASMC) strategy for the precise and safe operation of a dual-arm free-floating space robot (FFSR) during approach and synchronization with a noncooperative object, such as a 3D tumbling defunct satellite. Unlike conventional sliding mode control (SMC), the proposed ASMC suppresses the high-frequency chattering inherent to SMC while maintaining robustness against model uncertainties, thereby enhancing the smoothness and safety of manipulator motions. A quintic Hermite spline-based trajectory planning method is developed to generate smooth end-effector paths under arbitrary boundary conditions on position, velocity, and acceleration, enabling high-accuracy synchronization with the tumbling target. Numerical simulations demonstrate that the ASMC achieves superior tracking performance, preserves the base attitude of the FFSR throughout the approach phase compared with conventional SMC and high-order SMC. These results underscore the effectiveness and practical advantages of the proposed strategy for on-orbit approach missions involving noncooperative objects.