The Control Algorithm For The Surgical Teleoperation System Based On Virtual Surgery

With the development of science and technology,teleoperation robot has a wide application prospect in medical field.But the teleoperation robot based on network also faces some challenges.The existence of network delay will affect the stability and telepresence of the teleoperation system.Therefore,the master-slave teleoperation robot system based on virtual simulation prediction is studied in this paper.By establishing a virtual simulation system on the host control platform,the instability of teleoperation system caused by delay is solved thoroughly.At the same time,doctors can see and feel the interaction between the slave surgical manipulator and tissues in real time on the main control platform,and improve the doctor's sense of immediacy.Firstly,a virtual surgery simulation system is built on the host control platform,and the simulation model of tissue and surgical manipulator is established.When the doctor controls the master manipulator at the master end,the virtual surgery simulation system can simulate and simulate the interaction scene between the slave surgical manipulator and the tissue,and calculate the corresponding interaction force,which acts on the doctor's hand through the master manipulator.The problem of the instability of teleoperation robot caused by delay is solved fundamentally.In order to accurately calculate the interaction force between surgical manipulator and tissue,the sliding least squares method is used to identify the parameters of physical model of virtual organization,thus the interaction model of virtual organization is established.Secondly,because of the instability of the virtual surgery simulation system itself,this paper designs an energy-limiting force feedback control algorithm based on the passive theory to ensure the stability of the virtual surgery interaction process.The experimental results show that the algorithm can maximize the force feedback fidelity of the system under the premise of ensuring the stability of the system.Since the soft tissue physical model has individual heterogeneity,we can only obtain a general force tactile model before operation,so the corresponding model may not be accurate.In order to improve the accuracy of interactive force prediction,the parameters of physical model of virtual organization are modified on-line by using the real-time measured data of instrument displacement and real interaction force in the operation process.Provide doctors with force feedback closer to the real power of interaction to improve the doctor's sense of on-the-spot.Finally,the experiment platform of teleoperation robot based on virtual simulation and prediction is built,and the practical experiment is carried out.The experimental results show that the virtual surgery simulation prediction method can improve the stability of the robot system and improve the accuracy of master-slave trajectory tracking.The online model correction algorithm can accurately identify the parameters of the force tactile model in the operation tissue,thus reducing the error between the virtual interaction force and the real interaction force.