The Optimized Mechanical Structure Design of the Exoskeleton’s Lower Limb Knee Joint Based on Sitting Posture Knee Rehabilitation

This study aims to develop an exoskeleton device optimized for seated knee joint rehabilitation, designed in a modular manner, and it is divided into four key components: motion sensors, motor-worm gear units, thigh/shank fixation modules, and connecting pins. SolidWorks is utilized to construct a 3D model for verifying structural rationality, integrating worm gear transmission dynamics analysis, kinematic simulation, structural strength testing, and multi-condition adaptability research. The device incorporates self-centering mechanical structures, adaptive admittance control, and elastic joint stabilization technology. Moreover, the adaptive admittance control algorithm can dynamically adjust output torque based on real-time sensor feedback. Results indicate that the exoskeleton can be assembled and disassembled within 5 minutes, achieving a 60% volume reduction after disassembly. With a motion range of 0°~120° matching human physiological trajectories and a 40: 1 transmission ratio meeting driving force requirements, it is adaptable to patients with heights ranging from 150~185cm and at different rehabilitation stages, enabling precise flexion-extension training and safety protection.