Research On Control Strategies Of Knee Rehabilitation Robot

At present,there are a large number of hemiplegia patients in China,but due to the uneven distribution of rehabilitation resources and the serious shortage of rehabilitation doctors,most patients do not get timely rehabilitation treatment,so the design of a robot suitable for hemiplegia rehabilitation is an urgent problem to be solved.In this context,the control strategies and the control system of the knee rehabilitation robot are studied in this paper.The main work is as follows:Firstly,the control scheme is designed.The characteristics and the treatment methods of hemiplegia are briefly introduced,which indicates that hemiplegia patients should take different exercise modes in different stages of rehabilitation.The lower limb movement is analyzed and the kinematics model of the knee joint is established.The system control requirements of the knee rehabilitation robot are put forward,and the control system and the detection system are mainly designed.Secondly,the control strategies are studied.Four control strategies of position control,impedance control,admittance control,and hybrid control are designed for hemiplegia patients at different stages of rehabilitation.Among them,position control and impedance control help patients in the early and middle stages of rehabilitation to complete passive rehabilitation training,while admittance control and hybrid control help patients in the middle and late stages of rehabilitation to complete active rehabilitation training.The stability of impedance control and admittance control is verified by Lyapunov stability analysis,and the characteristics of the four control strategies are studied by simulation under different environments.Thirdly,the control system is built.The composition of the control system of the knee rehabilitation robot is briefly described.The design of the acquisition and processing modules of force signal and torque signal is completed,including the design of the sensor calibration and the signal processing program.At the same time,the design of the control system program and the interface is completed.Finally,the control experiments are analyzed.The experiments of position control,impedance control,admittance control,and hybrid control are carried out respectively.The correctness of the four control strategies an d the rationality of the control system construction are verified by experimental analysis.