Structural design and simulation analysis of a lower-limb assistive exoskeleton robot

Abstract

This paper presents a comprehensive investigation into a lower-limb assistive exoskeleton robot, with emphasis on structural design and simulation-based analysis. First, the structural design and three-dimensional (3D) modeling of the exoskeleton were completed, establishing a digital model for subsequent dynamic analysis and visualization verification. Second, a dynamic model was developed based on the joint motion relationships of the exoskeleton, and the 3D model was exported as a United Robotics Description Format (URDF) file and then imported into the Simscape platform for dynamic simulation to verify the correctness of the model. Accordingly, a human-exoskeleton coupling model was constructed in OpenSim, and simulations of level-ground walking as well as stair ascent and descent were carried out, providing a basis for joint trajectory function fitting. Subsequently, the exoskeleton model was imported into RViz for visualization analysis, where the model coordinate systems and link hierarchy were examined, laying a foundation for control system integration and applications in the ROS2 environment. Finally, an impedance control simulation model was established, and comparative experiments were conducted under different impedance parameter combinations to qualitatively analyze the dynamic response characteristics of the system. The results show that this work has established a relatively complete technical route, which can provide support for subsequent control strategy optimization and prototype development.