Master-slave Control Research On Abdominal Minimally Invasive Surgical Robot

With the development and application of minimally invasive surgical techniques,minimally invasive surgical robots are playing a more and more important role in the modern medical field.Recently,robot-assisted vision technology has developed rapidly,while the development of robotic force sensing technology is relatively slow.Due to the harsh environment of minimally invasive surgery,the visual feedback effect is not enough to help doctors deal with the special circumstances of clinical surgery.The research on the kinematic control and force feedback of surgical robot is very important to improve the operation efficiency of doctors.The master-slave motion and force feedback control functions were realized for a robotic master manipulator with 9-DOF and a slave manipulator with 7-DOF.And we have realized the trajectory tracking and force feedback functions of the abdominal minimally invasive robot.The kinematics of the master-slave robot is studied in this paper.The kinematics of the robot mainly includes the direct kinematics solution of the desired position and inverse kinematics for the end-effort and the solution of the joint variables of the slave manipulator.The classical D-H method is used to solve the problem of robot kinematics.The key technology of the master-slave motion is the inverse kinematics problem of the robot.Based on the traditional D-H method,a new method named“position and orientation separation” is established to find the inverse solution according to the structural characteristics of the manipulator.The real-time and accuracy performance of the system are improved to realize master-slave control.The robot force feedback control functions have been researched.The six-dimensional force sensor was added in the end-effector of the slave manipulator to achieve the feedback force acquisition.Based on the master manipulator coordinate system,the Jacobian matrix is established,and the principle of virtual displacement and virtual work has been applied to decompose the feedback force / moment to the corresponding joints of the master manipulator.In this paper,the gravity compensation of manipulator is studied.And the force feedback method of joint motor is analyzed.The PID control algorithm is used to control the DC servo motor to obtain the expected torque.In this paper,the animal soft tissue experiment is designed.And the master-slave control algorithm is validated.It is mainly divided into two parts: position tracking experiment and force feedback experiment.And the effectiveness of the control algorithm is verified.