Study On Rehabilitation Robot With Body Weight Support Based On Principle Of Central Pattern Generator

Rehabilitation robots have been used in gait training of lower extremities for paraplegic patients, and gradually moved towards clinical application at present. Rehabilitation robots aim to achieve rehabilitative treatment, which assists the patients in restoring their motor functions. Currently most of these robots use traditional and simple control methods, which need to be improved. The mechanism of exoskeleton also needs improvement in aspects of comfort, humanity, and safety. Based on this motivation, this work develops a novel exoskeleton system for lower extremity rehabilitation, which introduces new design concepts. A biologically-inspired method, i.e., central pattern generator(CPG), is used in the control system. The research is accomplished in the following three parts:1. Study on biologically-inspired control algorithm. The principles and implementation of CPG are investigated. The equations used to model and mimic CPG are analyzed, and relevant parameters are properly tuned. Simulation study on the CPG’s features is performed in MATLAB/Simulink to explore the effects of key parameters on the CPG’s rhythmic output and analyze the advantages and disadvantages of this control method.2. Design of lower limb exoskeleton. The lower limb exoskeleton is designed, which contains leg actuation mechanism, modulation mechanisms of gravity, leg distance and overall height, and a system support rack. ANSYS software is used for finite element analysis for the main components. ADAMS combined with MATLAB is used for dynamics analysis of exoskeleton driven by CPG.3. Realization of experimental prototype. The exoskeleton mechanical parts are manufactured and assembled. The servomotors are selected and tested. The circuit and hardware of control and communication is designed. The control software in host and slave computers is programmed, and the human-computer interface is provided. In final, the prototype is tested on three healthy subjects.This work has designed a novel rehabilitation system of lower extremity exoskeleton, which uses a bionic control algorithm(CPG) to achieve the feed-forward control that allows more natural gait patterns. It is expected that this system will bring about better physical rehabilitation for paraplegic patients.