Research On Impedance Control Technology Of Craniotomy Robot

Craniotomy is a common way to treat craniocerebral injury,cerebral hemorrhage,and intracranial tumors.At present,the traditional artificial craniotomy operation takes a long time and is very easy to cause fatigue of the doctor.Spatters generated during the operation may cause the doctor to be infected.In response to such problems,a craniotomy robot system is proposed,which has good safety,reliability,and humanmachine interaction,and can realize fine operations such as skull drilling,milling,and grinding.In the process of fenestration of the skull,it is necessary to ensure that the robot can effectively separate the bone flaps,but also to ensure that important nerve tissues in the skull are not damaged.Therefore,the impedance control method is adopted to ensure the reliability and safety of the operation.In this thesis,the design requirements of the craniotomy robot system are analyzed in detail,the software and hardware architecture of the craniotomy robot system is completed,a new impedance control method is proposed,and the reliability of the method is proved by simulation.This research is supported by the National Natural Science Foundation of China project "Research on the autonomous control method of craniotomy robot based on multi-mode information perception",and carried out the research on "the impedance control technology of craniotomy robot".The main research contents and results are as follows:First of all,the traditional artificial craniotomy operation room layout,surgical procedures and problems existing in the operation are studied and analyzed.Under the premise of comprehensively considering the requirements of surgery and the reliability,safety,and human-machine interaction of robot-assisted craniotomy,a craniotomy robot system for skull fenestration surgery is proposed.Based on this,the layout of the operating room suitable for robot-assisted craniotomy is designed,and the specific surgical procedure of robot-assisted craniotomy is introduced.Secondly,the kinematic characteristics and working space of the craniotomy robot are analyzed.The forward kinematics model of the craniotomy robot was established by the improved DH method,the inverse kinematics model of the craniotomy robot was established based on Pieper’s criterion,and the established forward and inverse kinematics models were verified by Matlab Robotics Toolbox.Based on the Monte Carlo method,the workspace analysis of the craniotomy robot is completed.Then,in order to ensure that the robot can complete the surgical approach established by the doctor with high precision during the operation,the trajectory planning and trajectory tracking control methods of the craniotomy robot are studied.Based on the interpolation method,the trajectory planning of the surgical robot is realized.The method based on torque feedforward control and torque feedback control realizes the trajectory tracking control of the joint space of the craniotomy robot.On this basis,considering the impact of the end effector on the motion performance of the surgical robot,the dynamic compensation method is used to further ensure the motion accuracy of the joint space of the surgical robot.Based on the improved decomposition speed control method,the trajectory tracking control of the surgical robot in Cartesian space is realized.Finally,in order to ensure the safety of robotic craniotomy,through the study of traditional impedance control methods and their improved methods,an impedance control method with faster force tracking speed and smaller force tracking error is proposed--model reference adaptive variable impedance control.The proposed impedance control method was simulated and verified by Matlab/Simulink and Matlab/Sim Mechanics co-simulation.