Segmented hybrid motion-force control for a hyper-redundant space manipulator

Abstract

A hyper-redundant space manipulator (HRSM) refers to a robotic arm with a large number of degrees of rotational freedom. It can be used in narrow environments for on-orbit maintenance. Most existing control work on HRSMs focuses on how to avoid obstacles and drive the end effector to the target position. However, in this study, utilizing a purposeful contact between the HRSM and the environment is proposed to improve the control performance. A segmented hybrid motion-force control strategy for an HRSM is developed. The designed contact is viewed as a support point, dividing the HRSM into several segments. For different segments, hybrid motion-force controllers are formulated to achieve a stable support or the desired motion of the end effector. The equations of motion of the HRSM are first established through Kane's equation. Then, a segmented hybrid motion-force control is formulated. Numerical simulations demonstrate the effectiveness of the manipulator model and control strategy in improving the accuracy of trajectory tracking.