Research On Control System Of Upper-limb Exoskeleton Rehabilitation Robot

Due to the increase of the elderly population over 60 years old and the changes in people's eating habits and so on,the incidence of stroke has been greatly improved in China.Postoperative stroke patients have sequelae such as hemiplegia,which requires exercise rehabilitation training to restore their body functions.However,there are few hospitals with rehabilitation treatment in China,and the number of regular rehabilitation physiotherapists is insufficient.Therefore,the contradiction between the shortage of rehabilitation treatment resources and the patients' sports rehabilitation needs is increasingly evident.With the rapid development of robot technology,detection technology,wireless communication and other technologies,the use of rehabilitation robots to pull patients' limbs for rehabilitation exercise can not only reduce manpower,but also enable patients to receive professional care,and also collect exercise data to give objective evaluation of rehabilitation effect.In this paper,in response to the needs of upper limb exercise rehabilitation of patients with hemiplegia,the control system of upper-limb exoskeleton rehabilitation robot with good human-machine integration and interaction was designed,which mainly includes robot actuator,drive mechanism,upper main control computer,bottom motion controller,sensor module,physiological indicator detection module,energy module,etc..The rehabilitation robot which can sense the movement intention and has a good human-machine interface,can complete tasks such as patient information collection,program development,motion control,and set safety protection measures.The robot meets the need to replace the artificial method to exercise the upper limbs of patients with hemiplegia.The main research and work contents of this paper are as follows:(1)System composition design.The system design of the robot is completed,combinedwith the needs and indicators of the upper-limb exoskeleton rehabilitation robot,through the research and analysis of the current advanced technology of the upper-limb rehabilitation robot.Referring to the upper arm length parameters and the active joint angle of the human body,the upper-limb exoskeleton rehabilitation robot is designed mainly from the five-degree-of-freedom form of the two-arm isomorphism.Further,the design of hardware selection such as control architecture and motor is completed according to the requirements of the control system.(2)Analysis of motion model.The motion model analysis of the upper-limb exoskeleton rehabilitation robot was carried out.Through the human upper limb model under homogeneous coordinate changes,the Monte Carlo algorithm is used to obtain the active space of the wrist of the upper limb of the human body.The D-H motion model of rehabilitation robot is established,the forward and inverse kinematics formulas are analyzed,and the wrist motion space of rehabilitation robot is obtained by simulation.It is verified that the range of motion of the designed robot is basically consistent with that of human upper limb and meets the needs.Furthermore,the rehabilitation trajectory of the robot training arm is planned to make the training trajectory smooth and flexible,and the kinematics foundation is laid for the control problem.(3)Design of master-slave training method.Design a variety of exercise patterns to meet the needs of different hemiplegia patients.In order to improve the human-computer compatibility,a master-slave training control method based on fuzzy approximation is designed,which enables patients' affected limbs to cooperate with healthy limbs according to the motion intention of healthy limbs.The stability of the master-slave training controller is verified by Lyapunov function,and the simulation results verify the effectiveness of the method,which ensures the rehabilitation effect of the slave arm following the master arm.In the training process,a dual-track parallel protection mechanism is designed to protect the patient's safety by using the robot state and the patient's physiological condition.(4)Construction of control system.On the basis of kinematics model and training control method,the hierarchical control method which combines the bottom motion control with the upper-level main control management is applied to the upper-limb exoskeleton rehabilitation robot control system.Trio BASIC language designed the bottom motioncontrol subroutine and completed the motion control and information acquisition of rehabilitation robot.Using Visual Studio 2017 software and C# language,a upper-level main computer management system is designed.It mainly completes the functions of task planning,operation control command issuance and information management.It provides a good communication interface between rehabilitation robots and human beings,and improves the intelligence and interpersonal interaction of rehabilitation robots.(5)Application validation of prototype test.Two groups of actions are completed to verify the tracking accuracy and range of motion of the robot,which can meet the requirements of rehabilitation training.This subject studied the upper-limb exoskeleton rehabilitation robot control system.The patient wears the main arm through the healthy side limbs,and the diseased side limbs are worn from the slave arm for exercise rehabilitation training.At the same time,the control system can control the real-time according to the collected information and prevent secondary injury to the patient.The control system has good robustness and high accuracy of track following.It provides a good man-machine interface and information management system,and can acquire the data of patients' status and evaluation effect in the process of rehabilitation exercise by intelligent method,which provides data support for improving training program and improving medical level and has great significance in the field of robotics and rehabilitation medicine.