Research On Master-Slave Force Control Of Laparoscopic Surgical Robot

In recent years,minimally invasive laparoscopic surgical robot has been widely used in surgical operations because of its advantages such as high accuracy,small trauma,quick postoperative recovery and so on,and it has a wonderful development prospect.Surgical robot force control related issue is an important part of the whole system,and it has far-reaching research significance.It mainly includes the force balance of the master manipulator,study on boundary force algorithm of motion space of master and slave hand,force detection,force feedback control.This article will make further research on the above issues,aims to improve the transparency of the minimally invasive laparoscopic surgery robot system,the accuracy and security.Firstly,the self-force balance of the master manipulator is studied.According to the structure features of the master manipulator itself,this article selectes the iterative Newton-euler equation to establish dynamics model.Through the motor compensation method,that is,the torque output by each joint motor of the master manipulator is used to compensate the dynamic information generated during the motion,such as gravity,friction and inertia.Then,the dynamics model is verified by co-simulation with simulation softwares,and this article carries out an experiment to verify the correctness of the above self-balancing algorithm.It solves the fatigue and misoperation problems of doctors during operation,and lays a foundation for the follow-up research.Secondly,the boundary force algorithm of motion space of the master and slave hands are studied respectively.For the master manipulator,this article selects an appropriate boundary force application method,and establishs an optimization model based on simulated annealing algorithm to optimize the applied range of the force.For the slave arm,the method of boundary force is determined,and the feedback strategy based on the master-slave mapping model is proposed.The problems of hard collision between the operating robot and its own mechanical limit are solved.Meanwhile,the safety of the operation and the stability of the system are improved.Thirdly,the detection and feedback of the interaction force between surgical instruments and focal tissues are studied.A force detection model is established based on a six-dimensional force/moment sensor,which eliminated the errors caused by the dynamics information of the instrument itself.And it can accurately detect the contact force of instrument and tissues.After that,the contact force is fed back to the operator through the master manipulator to realize the force feedback function.Then,a additional displacement of force feedback compensation algorithm is proposed.By establishing the force feedback prediction and compensation model which joints master manipulator and human hand,the error is compensated and the precise force feedback control is realized.It solves the current problem of the lack of force feedback function of most surgical robot systems.This function greatly improves the doctor’s sense of force presence and the safety of surgery,and it provides the possibility for future clinical application.Finally,a verification platform for relevant research contents is built for experimental verification.First,the realizability of the boundary force algorithm of the master-slave motion space is verified by simulating specific surgical actions.Next,this article carries out experiments to verify the correctness and accuracy of the interaction force detection model.Then the master-slave force feedback experiment is carried out,The effectiveness of the force feedback and additional displacement compensation algorithm are verified by comparing the quantitative indicators such as the peak value of the feedback force.