Arm Swing Training and Effectiveness Evaluation of a Cable-Driven Upper Limb Rehabilitation Robot

Abstract

Upper limb rehabilitation robots enable precise and repetitive joint-specific training and have become an important approach for post-stroke motor function recovery. To address the rehabilitation needs of stroke patients, this paper develops a 4-degree-of-freedom (DOF) cable-driven upper limb rehabilitation robot, establishes a coupled human-robot dynamic model, and designs a proportional-derivative (PD) controller to achieve trajectory tracking during passive arm swing rehabilitation training. Theoretical analysis demonstrates that the closed-loop system is uniformly ultimately bounded in the presence of disturbances and asymptotically stable in the disturbance-free case. Robot-assisted arm swing rehabilitation experiments show that the tracking errors of all joints remain within 5°, validating the effectiveness of the proposed PD controller. Furthermore, human metabolic indicators, including oxygen uptake per kilogram $\left(\mathrm{VO}_{2}\right)$ and heart rate (HR), are employed to evaluate the rehabilitation assistance effect. Results indicate that robot-assisted training reduces the exercise burden of the subject. These findings verify the feasibility and effectiveness of the proposed upper limb rehabilitation robot for arm swing rehabilitation training.