Design And Simulation Of Master Manipulator For Robotic Minimally Invasive Surgery System

Compared to traditional surgery, minimally invasive surgery has less trauma anddiscomfort to patients, and the cycle of recovery is shorter. With the successfulapplication of robotics in minimally invasive surgery, the labor intensity of doctors isgreatly reduced, and the quality of surgery is improved. Currently the minimally invasivesurgical robotic systems are mainly master-slave structure. The pros and cons of thedesign and performance of the master manipulator play a vital role for the performanceof the entire robot system. The general-purpose master manipulator which is muchsuccessful can’t meet the demand for the use of minimally invasive surgery. Therefore,we urgenlyt need a master manipulator to meet the minimally invasive surgical robotsystem requirements.This article is in view of the national863project "The common key technologiesand demonstration application of the celiac chest minimally invasive surgery robot”. Onthe basis of the current situation of the minimally invasive surgical robot at home andabroad as well as force feedback master manipulator, we’ve designed a kind of sixdegrees of freedom of master manipulator with haptic feedback which meets the needs ofabdominal surgery. We also research its kinematics, dynamic modeling and simulationbased on virtual prototyping. The specific work is as follows:Firstly, the overall program of the master manipulator and the mechanical structureare designed. Based on the theoretical basis of the robot technology, according to thedemand for minimally invasive surgery, the robot with six degrees of freedom in seriesconfiguration is determined. The work space of a single master manipulator covers a200×250mm3cylinder indicators, using motor and wire transmission decelerationdevices to achieve the master manipulator feedback. The master manipulator is alsodetailed designed to have the functions of zero positioning, limit safety and gravitycompensation.Secondly, kinematics and dynamics modeling and analysis according to the mastermanipulator are developed. Use the improved DH to establish a kinematic model of themaster manipulator, and then achieve the kinematic equations, inverse kinematicsequations, and the velocity model by calculating. On this basis, this paper completes thescale synthesis of the master manipulator, determines the best size parameters, and alsomakes a comfortable working space for the master manipulator. The analysis of themaster manipulator dexterity is completed by the reciprocal of the Jacobian matrixcondition number as an index, which proves that the design meets the work space andergonomic requirements; The Lagrange equations of the dynamics modeling of themaster manipulator is completed by the institutional division and block solving; Throughthe establishment of the power of Jacobian, the method that mapping the force feedback of the assistant manipulator the force to the joint motor torque of the master manipulator.The maximum torque of the joint motor of the master manipulator is obtained by specificcalculation, and the analysis and computation tasks of the force feeling of the mastermanipulator is completed.Finally, according to the manpower actual operating characteristics to set the jointmotor drive function, the virtual prototype developed by ADAMS software is establishedto simulate the performance of the master manipulator. The correctness is proved.According to the working space for the target cylinder to set the trajectory of the end ofthe main hand, developing the comprehensive simulation of kinematics and dynamics,the correctness and feasibility of the overall theoretical studies are proved. On this basis,the applied weight and the kinetic compensation to a combination of gravitycompensation strategy is propose, and is verified by simulation the effectiveness of thestrategy.