Research On Force Compensation Of Master-slave Minimally Invasive Surgery Robot System

With the progress of science and technology and the demand of social development,telerobot technology has gradually become a hotspot of robot research,and has been widely used in many fields.In medical field,the force telepresence of master-slave teleoperation system has become the focus of many researchers.This paper expounds the research status of force telepresence and analyzes the master-slave minimally invasive surgical robot system,and two major problems in the system are pointed out:the master manipulator has induced feedback force and induced displacement.In order to solve the problems mentioned above,the research work in this paper is as follows.The kinematic analysis for the master-slave minimally invasive surgical robot system is performed by using the exponential product formula.At the same time,the inverse kinematics analysis of the master manipulator Phantom Desktop is carried out,and spatial and body Jacobian matrices of the master and slave manipulators are derived to lay the foundation for realizing force feedback motion control based on model.By using screw theory and Lagrangian method,the Coulomb plus Viscous friction model is chosen to establish the complete dynamic model of the master manipulator Phantom Desktop,which takes joint friction into consideration.After the linearization processing for the complete dynamic model of the master manipulator,the least square method is used to identify the dynamic parameters of the master manipulator.At last,the correctness of the dynamic model of the master manipulator and the reliability of dynamic parameter estimation are validated by torque contrast experiments.The causes and compensation principles of induced feedback force and induced displacement are analyzed,and the corresponding induced feedback force and induced displacement compensation strategies are proposed at the same time.The force feedback experiment is carried out by using the existing equipments force feedback master manipulator Phantom Desktop and universal manipulator WAM arm to build the experimental platform,and the results indicate that the induced feedback force compensation method of the master manipulator is correct and effective.By establishing the model of the operator's hand and simulating the real feedback force,the simulation experiment is carried out for the induced displacement of the master manipulator,and the results demonstrate the correctness of the induced displacement compensation strategy of the master manipulator.The two-port network model is used to analyze the master-slave teleoperation robot system,and three performance evaluation indexes of the system are proposed and expounded on this basis.The general four-channel bilateral control structure of the master-slave teleoperation robot system is analyzed,and its two kinds of control structures applied to different situations are introduced,which are position error based control and direct force feedback control.The force-position compensation control units are implanted into the direct force feedback control structure to form a teleoperation bilateral control architecture with force-position compensation,which lays the foundation for realizing the accurate position teleoperation with precise force feedback in the master-slave minimally invasive surgical robot system.