Design And Research Of Lower Limb Rehabilitation Exoskeleton Robot Driven By Pneumatic Muscle

With the increasing aging population in China,the number of patients with dyskinesia caused by diseases or other reasons is increasing.In today’s society,in order to meet the needs of daily life,these disabled groups need some assistive devices to help reduce the incidence of complications,so as to improve the quality of life.However,the assistive devices on the market,such as crutches and wheelchairs,can only achieve the effect of mechanical movement,and can not make patients have the feeling of "autonomous walking".The lower limb rehabilitation exoskeleton robot is a kind of auxiliary power training device which is used to wear on the patients’ lower limbs or the outside of the trunk.By coordinating with the patients,it can provide support for the patients and help the lower limbs to achieve the purpose of helping the patients to walk normally.At present,the exoskeleton robot still has the disadvantages of the heavy body and low safety of human-computer interaction.Considering that the pneumatic muscle has the characteristics of lightweight,large driving force,good flexibility,and similar characteristics to human muscle,this paper will study the lower limb rehabilitation exoskeleton robot driven by pneumatic muscle,and provide important basic technical support for medical rehabilitation robot.The main research work of this paper includes(1)The structure design of Lower Limb Rehabilitation Exoskeleton Robot.Based on the analysis of the characteristics of the existing exoskeleton rehabilitation robots at home and abroad and the existing pneumatic muscle drive source,the design principle and overall design scheme of the lower limb rehabilitation exoskeleton robot driven by the pneumatic muscle are proposed.According to the Asian human body parameter standard,the geometric size and mechanical structure of the lower limb rehabilitation exoskeleton robot are determined.The joint structure,other parts structure,and the whole mechanism of the lower limb rehabilitation exoskeleton robot are modeled by Solidworks modeling software,and the driving system is determined.The angle data is fitted by MATLAB software,and the joint angle is simulated and analyzed.(2)Mechanical analysis of Lower Limb Rehabilitation Exoskeleton Robot.The D-H method is used to analyze and model the hip joint,knee joint,and ankle joint of the lower limb rehabilitation exoskeleton robot.The forward kinematics solution is carried out,and the inverse kinematics solution is completed based on the geometric relationship of each part of the lower limb.Based on the Lagrange equation,the dynamic model of the lower limb rehabilitation exoskeleton robot is established,and the dynamic model of one leg is deduced.The gait and output torque of lower limb rehabilitation exoskeleton robots are simulated by ADAMS software.(3)Research on joint characteristics and modeling of an exoskeleton robot.The static characteristics of the pneumatic muscle were analyzed by using the antagonistic pneumatic muscle pair with high flexibility as the driving source.The mathematical model of the pneumatic muscle was established by the polynomial fitting method.The working principle of the joint driven by the pneumatic muscle is analyzed.The single joint antagonistic pneumatic muscle model and the two degrees of freedom model of hip and knee joint driven by the pneumatic muscle are established.(4)Research on the control strategy of exoskeleton type lower limb movement.Based on the mathematical model of the pneumatic muscle driven joint established in the previous paper,the motion accuracy control problem of the joint is transformed into the problem of tracking the desired target command of the target object at the end of the joint,and the motion control simulation of the lower limb rehabilitation exoskeleton is carried out.The traditional PID control model and fuzzy PID control system model are established by using Simulink.The simulation results of related joints show that the fuzzy PID control method can control joint motion more accurately.