Research On Lower Limb Rehabilitation Exoskeleton Driven By Artificial Muscle

At present,the patients with lower limb injuries have an increasing demand for the rehabilitation exoskeletons.However,the lower limb exoskeletons on the market are expensive,and there are some disadvantages such as heavy weight and poor flexibility.It is difficult to meet the needs of rehabilitation groups.In view of the above situation,a flexible exoskeleton system for unilateral rehabilitation of lower limb is designed based on the study of lower limb function.The exoskeleton is combined with a user's waist,thigh and shank through fixators with airbags.The exoskeleton is driven by antagonistic pneumatic artifical muscles.The tension produced by artificial muscle contraction is applied to the lower limb of the body through the attachments and the fixators.This exoskeletion can assist the flexion and extension of the hip and knee joints of patients with a certain walking ability.The static characteristics and dynamic characteristics of the double parallel pneumatic artificial muscles are studied by a series of experiments.The hardware configuration and control algorithms of the system are analyzed to improve the response performance of artificial muscles.These studies can provide basis for the application of artificial muscles in exoskeletons.Based on the kinematics model and dynamic model,the impacts of the connection points of artificial muscles to the maximum length,the maximum contraction rate and the minimum assist force arm are analyzed.Thus,a suitable arrangement scheme can be obtained to optimize the rehabilitation effect of the exoskeleton.The control system for the exoskeleton can obtain posture information of the lower limb through three posture measurement nodes located at waist,thigh and shank.Data fusion algorithm can control the action of the artificial muscles to realize the assistance of the exoskeleton to the user.In order to test the recovery effect of the exoskeleton system,a prototype test platform is built,and the performance of the attitude measurement node and the assisting effect of the exoskeleton are studied.