Research And Implementation Of Flexible Driving Hand Rehabilitation Robot Control System

The high prevalence of stroke is a major cause of impaired hand function.The treatment and rehabilitation of patients with hemiplegia has become a research topic in modern rehabilitation medicine and rehabilitation engineering.At present,at home and abroad,the main methods are by strengthen the strength of muscle and complete exercise learning to recover or improve motor functions of the hand.Among various methods of hand rehabilitation,robot-assisted rehabilitation is widely used.The main task of a hand rehabilitation robot is to assist the patient's hand joints and fingers to complete flexion / extension movements.The flexible driving hand rehabilitation robot has the characteristics of light weight and high fit with human hands.In recent years,although researchers at home and abroad have conducted a lot of research on this,due to the lack of mechanical structure,the motion transmission is inaccurate and the control is difficult.This paper mainly focuses on the control system of a flexible-driven hand rehabilitation robot,where the coupling between the hand rehabilitation robot and the human hand have been fully considered.The soft rehabilitation gloves are controlled by controlling the elongation of Bowden wire,so as to drive the patient's hand to complete the flexion / extension training of the finger joint,and can generate sufficient fingertip force at the fingertip to assist the patient to complete the daily gripping action.This can improve the effect of rehabilitation training for patients with hand dysfunction.The work of this paper is as follows:(1)Design the overall scheme of flexible-driven hand rehabilitation robot control system.Based on the existing hand rehabilitation robot body,the hardware platform and software platform are designed and optimized further.(2)Perform kinematic analysis on the rehabilitation hand.The 3D motion capture system is utilized to capture the trajectory of the rehabilitation training process for the coordinates of the joints of the hand rehabilitation robot,thereby calculating the bending angle of the fingers at each moment according to the coordinates.Using the data of Bowden wire elongation and finger bending angle,the mathematical model of hand rehabilitation robot was established through systematic identification method.(3)Based on the sliding mode control algorithm,the position controller of the hand rehabilitation robot is designed to ensure the stability of the system.Aiming at the chattering problem caused by sliding mode control,the gain parameters of the sliding mode control are adaptively adjusted online,such that the chattering caused by the sliding mode control method is weakened.The MATLAB simulation results show that the designed controller can achieve the safety and accuracy proposed in rehabilitation medicine and design.(4)Based on the compliance control theory,the closed-loop impedance control algorithm for the position is studied.On the existing position controller,an impedance control outer loop is added.The difference between the actual force and the expected force is processed to obtain the position correction amount,and the desired position is tracked by the position controller to realize the control of grip.The MATLAB simulation results verify the reliable force tracking ability of the control method.(5)Build experimental platform,the position control experiment and the grip control experiment are tested.The results show that the steady-state accuracy of finger bending angle controlled by adaptive sliding mode can reach up to 2°,and the rise time can reach up to 0.47 s.The steady-state accuracy of finger grip controlled by impedance control based on adaptive sliding mode position control can reach up to 0.6N,and the rise time can reach up to 0.27 s.The flexible-driven hand rehabilitation robot control system has a high precision,a fast response,a good robustness,which is validated in the experiment.The flexible driving hand rehabilitation robot control system will not only enhance the rehabilitation effect of patients with hand function disorders,and speed up the recovery process,but also promote the development of the cause of rehabilitation,better solve the problem of human-computer interaction,and make technology truly serve people's lives.