| The wrist is a joint that connects the palm of the human hand to the front arm,also known as the radiocarpal joint.As a more flexible part of the body,the normal use of wrist function is very important for daily life.But with the aging of our population,cerebral stroke is particularly prominent among many elderly diseases.According to relevant statistics,limb numbness is the most common sequelae of minor stroke,and the wrist muscle tension and stiffness are the most obvious.So the rehabilitation exercise after injury is very important,many people because of missing the best rehabilitation training time,resulting in a variety of wrist problems.For example,the poor range of motion of wrist rotation and flexion and extension function,and even the lack of freedom of wrist joint,have a great impact on the quality of life of patients.Therefore,based on the theory of human wrist anatomy,clinical rehabilitation,spatial mechanism and ergonomics,a new wrist rehabilitation mechanism(2-PRU-PRS)&R hybrid is designed in this paper,with the purpose of helping patients with wrist flexion and extension,adduction and abduction,as well as rehabilitation training of pronation and supination.The main research methods and contents of this paper mainly include the following aspects:1.Based on the principle of configuration synthesis,the configuration design of the hybrid wrist rehabilitation institution was carried out.According to the physiological structure and motion characteristics of the wrist joint,based on the design requirements of the rehabilitation institution and the theory of the space mechanism,the overall structure of the rehabilitation institution was designed and studied based on the comprehensive principle of configuration and the needs of the wrist rehabilitation.A wrist rehabilitation mechanism based on(2-PRUPRS)&R hybrid was designed,which has four degrees of freedom(3R1T),and can meet the rehabilitation needs of stroke patients with hemiplegia.Based on the concept of energy conservation and environmental protection,in order to reduce costs and energy consumption,the mechanism uses lightweight materials instead of metal materials to reduce the weight of the rods,achieving the overall lightweight design of the mechanism.2.The spiral theory is used to analyze the kinematics of the hybrid wrist rehabilitation institution.The degree of freedom of the mechanism is analyzed,and the correctness of the result is judged by the modified Grubler-Kutzbach formula,and the consistency between the degree of freedom of the mechanism and that of the wrist joint is verified.The closed-loop vector method was used to solve the inverse position solution of the mechanism,and then the particle swarm optimization algorithm was used to solve the positive position solution value,and the error between the positive solution value and the real value,namely the fitness,which provided a theoretical basis for the subsequent control of the mechanism.Finally,based on the finite space limit boundary search method,Matlab software was used to search and judge the reachable points of the mechanism in three-dimensional space,drawing the image of the working space,verifying that the reachable working space of the center of the mechanism moving platform can meet the motion range required for wrist rehabilitation training.3.The influence coefficient matrix of hybrid wrist rehabilitation institution is solved by derivation method.Based on the inverse solution of the(2-PRU-PRS)&R parallel mechanism,the velocity Jacobian matrix which can reflect the linear mapping relationship between the driving velocity of the moving pair and the velocity of the moving platform in the branch chain is obtained.At the same time,the velocity Jacobian matrix is solved again by the derivative method,and the relationship between accelerations is further solved,namely the second order motion influence coefficient matrix.The kinematic simulation of the virtual prototype is carried out by Adams software,and the obtained three branch chains include displacement,velocity,acceleration,angular velocity,angular acceleration and other respective motion characteristics to verify the safety of the mechanism.4.AnyBody biomechanical simulation software was used to analyze the effect of anybody wrist rehabilitation mechanism.By creating a real human simulation environment and simulating various motion states of human body in the real environment,clearly and completely analyze the changes of parameters such as activity,contraction and muscle strength of the main muscle groups involved in the process of rehabilitation training of patients,so as to judge the effect of rehabilitation training of institutions.In the simulation process,when the human body is in motion,the ratio between the muscle with the greatest force and the ultimate force it can bear is always less than 1,indicating that the rehabilitation effect of the hybrid wrist rehabilitation institution is good.5.The future prospect of hybrid wrist rehabilitation institutions is put forward.I hope that I can redesign the overall layout structure of this institution with multidisciplinary knowledge and make it more beautiful.In addition,it can be integrated into the human-computer interaction system to improve the acceptance of patients for hybrid wrist rehabilitation institutions.The hybrid wrist rehabilitation mechanism based on(2-PRU-PRS)&R mechanism proposed in this paper has low cost,simple configuration,and can adapt to the differences between different individuals,and meet the needs of different individuals for wrist rehabilitation training.Through theoretical analysis and simulation verification,it is proved that the rehabilitation training institutions have certain practical value and application prospect,and also provides a new scheme and idea for the research of wrist rehabilitation training institutions. |
