Research On Master-slave Control And Force Perception Of Single-hole Laparoscopic Surgical Robot

With the accelerated aging of the population and the rising incidence of chronic diseases,traditional surgical methods are no longer able to meet the needs of patients,and minimally invasive surgical robots have become the new solution.As the latest development direction of minimally invasive surgical robots,single-hole laparoscopic surgical robots have significant advantages such as being minimally invasive,delicacy,and flexible,and have become a research hotspot in the surgical robot industry.However,its highly integrated system also places higher technical demands on the surgical robot,which requires a higher degree of freedom to perform complex surgical operations in a limited space,making it more difficult to achieve precise control of the robot.Moreover,limited by the robot size and working environment,force sensors are difficult to apply,and how to obtain the interactive force of the surgical procedure has also become a difficult research problem.To address the above problems,this paper presents an in-depth study of the master-slave control strategy and the force perception method of the single-hole laparoscopic surgical robot designed and developed by the laboratory itself.Firstly,the mechanism design method of the single-hole laparoscopic surgery robot is studied,its mechanical configuration,degree of freedom distribution and transmission scheme are analyzed,and the robot kinematic model is further solved based on the triple space mapping theory.The kinematic model from robot joint space to workspace is solved by the rotation matrix method and analytical method,and the mapping relationship from robot drive space to joint space is solved based on the design principle of the wire drive scheme so that the mapping relationship between wire displacement in drive space and end position of the robot arm can be obtained,which lays the foundation for the implementation of robot master-slave control.The robot workspace was also analyzed based on the Monte Carlo method,and the rationality of the robot structure design was verified by comparing it with the operating space of common minimally invasive surgery.Secondly,a hand-eye coordinated proportional master-slave control strategy based on positional increments is proposed.Based on the analysis of the heterogeneous robot control system,the robot master-slave coordinate system is established,and the intuitive control of the surgical robot under the endoscopic view is realized by the method of coordinate pose transformation.Safe and precise operation is achieved by incremental and proportional control.A defibrillation algorithm for the main manipulator was also designed to filter the hand tremor,and experiments showed that the proposed defibrillation algorithm can effectively reduce the tremor signal.Third,a force observer based on an adaptive sparse general regression neural network is proposed to address the problem that it is difficult for a singlehole laparoscopic surgery robot to acquire the interactive forces during surgery.The proposed force observer is based on a machine learning approach to predict the interaction forces between the robot and the environment without resorting to the robot’s dynamics parameters.In addition,to improve the accuracy of the force observer,a feature selection method combining the wrapping method and the sparse regularization method is innovatively proposed in this paper for determining the best input features of the force observer.And two new criteria are defined to eliminate the useless support vectors from the model.The bandwidth parameters of the force observer model are also optimized by an improved antlion optimization algorithm.The effectiveness of the force observer design method was verified experimentally.Finally,a complete experimental study of the proposed master-slave control strategy and force observer is performed.Intuitive control experiments,masterslave following experiments and proportional mapping control experiments were designed to validate the master-slave control strategy.The experiments showed that the single-hole laparoscopic surgery robot can accurately achieve intuitive control and proportional mapping control.Design force estimation experiments under different environments based on heterogeneous teleoperated platforms to verify the effectiveness of the force observer.