Research On Kinematic Modeling And Gravity Compensation Of Shoulder Rehabilitation Exoskeleton

Stroke is one of the brain nervous system diseases with the increasing aging problem.The cause of the disease is that the human brain vascular infarction causes the brain local blood supply insufficiency,further causes the local nerve tissue damage,causes the human brain to produce the local or the comprehensive functional defect.Stroke has a high disability rate.Although it can be effectively treated in patients with acute attack,most of the survivors will leave sequelae such as hemiplegia and lose their ability to live autonomously.In order to assist in the treatment of motor nerve damage caused by stroke and provide medical rehabilitation devices with higher fitting and safer safety for patient rehabilitation training and treatment,a five-degree of freedom shoulder rehabilitation exoskeleton robot is designed in this topic.At present,most of the related rehabilitation robot research results are only composed of a single rotating joint,and the target part of the human upper limbs,the movement space and movement provided by the robot shoulder structure is not enough to fully cover and contain all the daily movement space and action,and most of the volume is large and fit with the human body is not high.Therefore,in order to get the rehabilitation robot fitting the human shoulder motion,the mechanical structure of the robot was designed in accordance with the human anatomy principle.The parallelogram mechanism located near the human shoulder blade and the ball hinge mechanism around the human glenohumeral joint were adopted to achieve higher human-machine motion compatibility.After that,the forward kinematics and inverse kinematics analysis of the robot system are carried out.Based on the traditional D-H method and combined with the design characteristics of shoulder rehabilitation exoskeleton structure,a coordinate system establishment method is improved to establish the robot mathematical model.This greatly reduces the computational complexity and computational complexity.Combined with kinematics calculation results and Monte Carlo method,the motion space simulation of robot mechanism is carried out.The Adams and MATLAB are used to model,simulate and analyze the kinematics results to verify the correctness of the kinematics analysis.Because of the high security requirement of medical rehabilitation robot,the Jacobian matrix of robot system is studied,and the existence of singular position forms in the motion space of the whole mechanism is analyzed.The maneuverability is also studied to analyze whether the robot motion performance is close to the singular position in the motion space.Finally,among the external forces that affect the motion performance of shoulder rehabilitation exoskeleton robot system,the most influential gravity priority is selected for compensation analysis,and a variety of gravity compensation methods and algorithm design are compared and analyzed.The gravity compensation torque expression of each joint motor of exoskeleton robot is calculated by using gravity compensation calculation method based on virtual displacement principle.By comparing the calculation results of Lagrange method,the correctness of using virtual displacement method is verified theoretically.Following to verify the algorithm,the mechanism model of shoulder rehabilitation exoskeleton robot is introduced into the computer aided engineering software Adams in the industry,and the whole virtual prototype of the system is established by establishing constraints,setting properties,adding motion pairs,adding drivers and editing functions.The main content of this thesis is the mechanism design and some algorithm analysis of shoulder rehabilitation exoskeleton robot designed to meet the needs of rehabilitation training of stroke patients.It lays a foundation for the development and clinical trial of the prototype in the follow-up study.