Research On Control System Of Upper Limb Exoskeleton Rehabilitation Robot

With the development of science and technology and the improvement of people’s living conditions,the number of elderly people is increasing,and the accompanying various elderly diseases have also increased significantly,especially the cases of hemiplegia caused by stroke have increased significantly.The number of physicians with rehabilitation experience in the current environment is gradually decreasing.Due to the gradual development of intelligent exoskeleton machinery and equipment,accurate,safe and repeatable rehabilitation training methods are provided,which reduces the burden on the physical strength,skills and energy of the attendants,making it inevitable that smart devices will replace humans.This thesis designs an exoskeleton robot system that can assist in rehabilitation training,which mainly includes the main body mechanical structure,the motor that drives the motion of each joint and the supporting drive device,the sensor module for feedback of the motor’s running state,and the power supply to provide energy for each device modules,etc.Generally,hemiplegia caused by strokes will generally go through three processes: paralysis,spasticity,and recovery.The rehabilitation robot system in this thesis can perform different auxiliary treatments for different needs of different periods during the recovery process of patients.Through the passive training and scientific movement design,all parts of the affected limb are fully stimulated,and the affected limb is stably and slowly driven to do periodic exercises,which can effectively promote the re-establishment of the active function of the affected limb.The main research and work contents of this thesis are as follows:(1)The research status of robotic systems in upper limb rehabilitation at home and abroad in recent years was sorted out and analyzed,the technical differences and demand differences between domestic and foreign countries were sorted out,and the framework of the upper limb rehabilitation robot system was completed.(2)The assembly components of each part of the upper limb exoskeleton rehabilitation robot are assembled into a molded assembly through Solid Works,the upper limb exoskeleton model is established through the improved D-H modeling method,and the connecting rod model is established in the MATLAB environment,the relevant coordinate system is set in the assembly,the urdf description model is output,the kinematics is analyzed,and the link model and the urdf model are compared and verified.(3)For passive training,an interpolation algorithm for trajectory planning based on fifth-order polynomials is proposed by analyzing the conditions for minimizing jerk,combined with human-computer interaction factors,and the movement realization and visual simulation verification are carried out in the Simulink simulation environment;for active and passive training,the position of the grasping position at the end of the master arm is obtained through spatial mapping to obtain the spatial point of the slave arm,and the curve fitting is carried out by using the least square method through a cubic polynomial.The optimized trajectory is taken as the expected trajectory of the slave arm,and the simulation verification ensures that the slave arm can follow the movement intention of the master arm smoothly and compliantly.(4)The prototype experimental system is built to complete a group of chest expansion combined exercise training actions,and verify the following effect of the slave manipulator when the patient’s main arm is pulling the main arm during the training process.The experimental results can realize that the slave arm can follow the main arm stably.At the same time,it can filter out the slight vibration caused by the fatigue of the contralateral limb and the pathological information collected by the sensor,and drive the slave arm to move steadily and gently.In the process of training,appropriate protective measures should be set to avoid accidental injuries caused by exoskeleton to limbs in rehabilitation training due to wrong instructions such as over operation.This project verifies the control system and control method of the upper extremity exoskeleton rehabilitation robot from model simulation to physical experiment.The patient sits on the seat under the exoskeleton,and the exoskeleton begins to perform the reset operation,so that the left and right mechanical arms move closer to the patient’s limbs from the outside.Assist the patient in the fixation between the exoskeleton and the upper limbs,the patient’s healthy limbs will pull the main manipulator arm to move.In the experiment process,the robot’s pose information is obtained in real time through the sensor module,and the trajectory of the master arm is mapped to the slave arm through the corresponding algorithm,and the motors of the slave arm are driven to follow.