Adaptive Control of a Tendon-Driven Manipulator for the Capture of Non-Cooperative Space Targets

This is the authors' abstract. We don't add key points for this paper.

Orbital debris in Earth orbit poses a threat to the future of spaceflight. To combat this issue, the rigid capture of these non-cooperative orbital targets is enabled through the use of dexterous robotic manipulators. This paper proposes a novel robotic mechanism for capture and active servicing missions on non-cooperative targets; specifically, a tendon-driven manipulator is developed in this work. The capture mechanism is a prototype symmetric two-link gripper driven by an open-ended cable-sheath transmission mechanism. Since the cable-sheath transmission mechanism is a non-linear time varying hysteretic system, two separate adaptive control strategies were compared against the open-loop and proportional-integral-derivative controlled performance of the closed-loop gripper. Specifically, an indirect control method and a direct L1 controller are proposed. Experimental results demonstrate that the adaptive controllers show better tracking performance of a joint trajectory over the proportional-integral-derivative and uncontrolled cases, while the L1 controller performs best under dynamic conditions, and the indirect controller performs best in steady state.