Soft Wearable Robotic Kit for Forearm Rotation and Grasping Motion Tracking Based on Embedded End-Effector-Level Sensor System

Abstract

Patients suffering from neurological and musculoskeletal disorders often experience impaired upper limb function, significantly reducing their quality of life. In recent years, wearable robots have emerged as a promising solution to facilitate rehabilitation and assist in daily activities. Among these, tendon-driven actuation has been widely adopted; however, such systems face challenges in achieving precise position control compared to direct motor-driven systems. This is primarily due to the hysteresis and backlash resulting from the high compliance and elasticity of tendons, necessitating effective compensation strategies. In this paper, we implement an embedded compact sensor system for end-effector-level position tracking in a soft wearable robot designed for forearm pronation/supination and grasping motions. By integrating sensors at the end-effector, we enable real-time motion data acquisition and establish a closed-loop feedback mechanism that effectively compensates for the limitations of tendon-driven actuation, thereby enhancing overall control accuracy. Based on the embedded end-effect-level sensing system, we introduce a novel wearable robot kit for motion tracking that comprising two parts: a sensor-only exosuit for real-time capture of user hand and forearm movements, and a motor-equipped exosuit that replicates and assists movements based on the sensor feedback. This Leader-Follower Control Mode allows for accurate capture and rapid response to user motion intent, offering a new solution for applications in tele-control, mirror therapy, and motion synchronization.