Design Analysis And Resistance Compensation Research Of Abdomen And Chest Minimally Invasive Surgery Robot’s Remote Center Mechanisms

In recent years, the people’s need for medical and health levels are increasingsharply，and the continuous development of science and technology makes the robotassisted minimally invasive surgery gradually into people’s lives. Its based oncommon minimally invasive surgery, and presented many unique advantages,manyuniversities and research institutions at home and abroad, has a strong interest in therobot assisted surgery system,have carried out relevant research and achieved manyresults.In this paper, with the support of national "863" plan project"Abdomen andchest minimally invasive surgery robot’ common key technology and demonstrationapplication",this thesis has designed a remote center mechanisms which can be usedon the abdomen and chest minimally invasive surgery robot system’s manipulatorhand. This thesis implements the remote center mechanisms’ in-house hollow lineand electromechanical integration design.The remote center mechanisms canachieve free switch between the initiative mode and passive mode.This thesis is based on light-duty, miniaturization, integration and high stiffnessdesign concept, has designed a remote center mechanisms which can be used on theabdomen and chest minimally invasive surgery robot system’s manipulatorhand,including the mechanical structure, drives, sensors and control system.Throughthe analysis of minimally invasive surgery robot system operation condition andperformance requirements,this thesis got the design requirements of the remotecenter mechanisms, designed the remote center mechanisms according the designrequirements,and used the finite element analysis software ANSYS to analysis theremote center mechanisms’ stiffness and strength.This thesis use the method of D-H kinematics to analysis the remote centermechanisms’ kinematics,got the forward kinematics solution and inverse kinematicssolution and Jacobian matrix of the remote center mechanisms.Use the method ofLagrange equation, analysis the dynamics of the remote center mechanisms,solveout the dynamics equation,and used MATLAB calculate the maximum drivingtorque of each joint,laid a certain foundation for later study.This thesis use the three-dimensional design software Pro/E carry out thekinematics simulation of the remote center mechanisms,get the motion curve of theend of the surgical instruments.This thesis use the dynamics analytical softwareADAMS carry out the dynamic simulation of the remote center mechanisms.Underthe action of specific movement function, got the curve of the joint torque.Thetheoretical analysis results and the simulation analysis results are compared, in o rderto determine the correctness of the analysis.In order to achieve the goal of free switch between the initiative mode and passive mode,use the method to compensate the resistance by the motor,designed acontrol system based on state observer for resistance compensation,allowing doctorsto preoperative adjust the remote center mechanisms easily,and has carried on theMatlab/Simulink simulation,Show that the resistance compensation control systemcan better meet the design requirements.