Research On The Control Of Teleoperation Surgery System With Time-varying Delay

The existence of time delay will affect the stability of teleoperation surgical system and the telepresence of surgeon.This subject mainly researches on the modeling of teleoperation system.The wave variable method in the communication with time-varying delay,the design of the control algorithm of the slave robot manipulator,and the control and stability analysis of the teleoperation system are studied in this paper.Firstly,the positive kinematics model of the master manipulator and the forward and inverse kinematics of the slave manipulator are established by using the POE method,the kinematic space of the master and slave manipulator is analyzed,and the kinematic mapping relationship of the master-slave manipulator is established by incremental mapping method,Lagrange method is used to model the dynamics of the slave manipulator,which paves the way for the design of control algorithm.Finally,the control of teleoperation system is realized by combining wave variable and sliding mode control method based on disturbance observer.A sliding mode control method based on disturbance observer is designed to solve the problem that the slave manipulator can track the trajectory of the master tactile manipulator quickly and robustly.In this method,the sliding mode controller is used as the feedback controller and the disturbance observer as the feedforward compensator.The disturbance observer is designed to estimate and compensate the modeling uncertainty and unknown external disturbance of the manipulator in real time,which guarantees the strong robustness of the system under the minimum sliding mode gain and greatly reduces the chattering problem caused by sliding mode control.The experimental results show that the control algorithm can ensure the surgical manipulator track the command signal quickly and accurately.A teleoperation system based on the combination of the improved wave variable method and the sliding mode control algorithm based on disturbance observer is built.The passivity of the system is analyzed,and the stability of the system is proved.The experiment shows that the surgical manipulator has a good track tracking effect of the command from the master side when there is external disturbance,at the same time,the operator can feel the interaction between the surgical instrument and the simulated human tissue.