Research On Motion Control Of Manipulator For Assisted Puncture

Percutaneous puncture surgery is currently a popular minimally invasive surgery.The key to its success is to precisely control and position the puncture needle to the needle entry point on the patient’s body surface at an optimal puncture angle,and to reach the patient’s body surface through a smooth and collision-free path.pin point.In this project,the motion control of SEED-S6H4 D assisted puncture manipulator is studied for the problems of inaccurate puncture point control positioning,poor puncture angle,and collision in traditional puncture surgery.The main research work is as follows:1)In view of the clinical needs and existing problems of traditional puncture surgery,it is proposed to use the mechanical arm to realize puncture surgery to assist precise control and positioning.Combined with the needs of the manipulator for puncture surgery,this paper selects the high-performance lightweight six-axis collaborative manipulator SEED-S6H4 D as the auxiliary puncture manipulator,paving the way for the study of motion control of the auxiliary puncture manipulator.2)The forward and inverse kinematics and working space of the six-axis collaborative manipulator SEED-S6H4 D were analyzed to verify its rationality as an auxiliary puncture manipulator.Combining with the path planning and design of medical puncture surgery,aiming at the shortcomings of traditional inverse kinematics solution such as low precision and complicated solution process,a solution algorithm for inverse kinematics of manipulator based on improved particle swarm optimization(PSO)optimization BP neural network is proposed,namely IPSO-BPNN algorithm.The algorithm introduces dynamic inertia weights and asynchronous time-varying learning factors into the standard PSO algorithm,optimizes the BP neural network with the improved PSO algorithm,and solves the inverse kinematics for the auxiliary puncture manipulator.The simulation results show that the maximum error range of the joint angle output by the manipulator in the working space is[-0.0821°～0.0813°].3)According to the actual needs of percutaneous puncture surgery,the spatial trajectory planning of the SEED-S6H4 D assisted puncture manipulator was studied.Through the comparison of simulation experiments,the quintic polynomial interpolation method was selected for planning.In order to avoid the collision of the assisted puncture manipulator with obstacles during the puncture operation,a fusion of artificial potential field method(APF),asymptotically optimal rapid search random tree star(RRT~*)and target bias(GB)strategy obstacle avoidance planning algorithm,that is,the GB-P-RRT~* algorithm.This algorithm improves the RRT~* algorithm.Firstly,the GB strategy and the APF algorithm are introduced in the sampling to optimize the selection of sampling points and generate reasonable sampling points;It grows towards the synthesis direction of attraction and repulsion to obtain a more effective trajectory;finally,the obtained path is smoothed with a cubic B-spline curve,so that the puncture needle at the end of the auxiliary puncture robot arm can reach accurately with an optimal collision-free path.The puncture entry point of the patient’s epidermis.Finally,based on the ROS platform,20 simulated puncture experiments were carried out on the medical human bone model by using the SEED-S6H4 D assisted puncture manipulator in the environment of simple obstacles and complex obstacles.The experimental results show that the robotic arm can achieve an average control positioning accuracy of 0.67 mm,and can avoid obstacles in the environment,meeting the precision and obstacle avoidance requirements of puncture surgery.