Study On The Control Hand Mechanism Of A Hybrid Operator For Surgery

The operation process of the isomorphic master-slave teleoperation system is intuitive,and the parallel mechanism with less freedom of the intermediate passive branch has a simple structure and high stability,and the combination of the two can be a master-slave operator system with simple control and flexible movement.A parallel mechanism with a passive branch and a flexible finger mechanism are selected to form a hybrid operator,and the intermediate passive branch is extended to the surgical field.This paper mainly studies the active end control hand mechanism of the hybrid operation operator,analyzes the performance of the selected mechanism and the principle of the control system,and provides a theoretical basis for exploring the application of this type of master-slave teleoperation system.Combined with ergonomics to select the main components,the active end control device was designed.Using the secondary development technology of CAD software,the operation space of the control hand mechanism is drawn.Based on the vector method,the kinematics analytical model of the mechanism is derived.The analytical model and the simulation model are solved synchronously by Matlab.The two sets of results are compared to verify the correctness of the kinematics model.Based on the principle of virtual work and the principle of D'Alembert,the static and dynamic analytical model of the control hand mechanism with spring action is established.The mechanical analysis model is verified by the virtual prototype built by Adams.According to the results of kinematics and mechanics analysis,a spring stiffness model for controlling the hand branch is established.Taking three specific movements as an example,the influence of spring stiffness on the operating force and the dexterity of the mechanism in different poses are analyzed.Improve the understanding of the performance of the organization,and provide ideas for improving the operating experience of the control hand and optimizing the size design of the mechanism.The "PC+ motion control card" is selected as the upper control system,and the linear displacement sensor is used to detect the branch displacement signal of the active end control hand.The slave end operator uses the electric cylinder as the actuator,and the branch sensor provides the actual displacement feedback amount,thereby establishing the master.Closed loop control system from the end position.Taking the single-branch master-slave system as an example,the model of the servo motor and the screw drive system is simplified,and the transfer model of the control system is derived.In order to improve the follow-up performance of the master-slave position,a fuzzy adaptive PID algorithm is used for the control system.The simulation model of the control system was built by Simulink,and the step response curve of the system was observed to verify the improvement of the system performance by the optimized algorithm.