Design And Analysis Of Cable-driven Active Flexible Needle Puncture Robot Mechanism

Flexible needle puncture is one kind of minimally invasive interventional surgery,which uses a flexible needle with a certain angle to puncture.In this paper,the optimization design and analysis of the puncture robot of flexible needle,especially the needle feeding mechanism are carried out.First of all,in order to meet the task requirements of the flexible needle piercing robot,the mechanism of the position and attitude adjustment mechanism of the robot is designed.The complex 5-DOF mechanism is simplified by decomposing the DOF reasonably.The principle of pose adjustment,the design concept and significance of the mechanism are described.Finally,the three-dimensional motion mechanism and attitude adjustment mechanism are designed,and the virtual prototype is built by Solid Works 3D modeling software.Secondly,the kinematic analysis of the flexible needle piercing robot is carried out,the trajectory of the ball pair of the mechanism is calculated by the geometric analytic method,and the mapping relationship between each point in the trajectory of the ball pair and the pose of the needle end is established,which is expressed as matrix transformation.The pose matrix of the needle feeding mechanism at the end of the robot is calculated,and the kinematic variables of each joint are known,then the needle feeding mechanism at the end of the robot can be calculated In the same way,the inverse matrix is used to solve the inverse problem of the robot,and then the movement distance and rotation variables of each joint of the robot can be obtained through the position and attitude of the needle feeding mechanism at the end of the robot.The kinematics model of the robot is established by using the Sim Mechanics toolbox of Simulink software MATLAB,the position coordinates of each joint are set,and the workspace of therobot is output to pave the way for the subsequent analysis.The workspace of flexible needle piercing robot is formed by linear rotation,and the specific measurement index is given.In order to consider the influence of the end velocity of the flexible needle piercing robot on the feed of the needle end,the divergence angle is proposed as the measurement.Based on the maximum working space volume and divergence angle,the structural parameters of the flexible needle piercing robot are designed and multi-objective optimized,and a virtual prototype of the robot is built.Finally,the mechanism is analyzed in detail.The static and modal analysis of the whole machine is carried out by using ANSYS software,and the overall force situation and the sixth order vibration mode under the typical attitude are obtained.Then Adams is used to model the dynamics of the system to obtain the stress of the key components in the process of motion.This paper mainly focuses on the optimal design and analysis of the flexible needle piercing robot,kinematics analysis and Workspace Analysis of the robot,stress analysis and stress deformation analysis of the robot,and mechanical analysis of the key components under the dangerous attitude to verify the rationality of the design.The results show that the design of the mechanism is reasonable.