Laparoscopic automatic following motion planning of minimally invasive surgery robot based on safety constraints

In the master-slave operation stage of robot minimally invasive surgery, doctors need to frequently switch the control objects to adjust the position and posture of the laparoscope to obtain a better surgical field of vision, which will distract doctors' attention and lead to a decrease in the quality of laparoscopic surgery. Therefore, a laparoscopic automatic following motion planning is proposed to track the motion of surgical instruments quickly, smoothly and safely. Firstly, the position and posture adjustment conditions and adjusted visual field requirements of the distal reference point of the laparoscope are analyzed, and its path points and limit points in the task space are determined through linear trajectory planning. Then, the corresponding path points and limit points of each joint of the manipulator holding the laparoscope in the joint space are obtained by using the robotic kinematic model. Finally, the Chebyshev pseudo-spectral method and the sequential quadratic programming method are used to realize the trajectory planning of the robot joint space and the trajectory optimization based on the optimal time-smoothness. The laparoscopic following experiment shows that the maximum time of trajectory planning and optimization is 0.0362s, and the maximum speed and acceleration of the manipulator joint are no more than 1.68rad/s and 34.79rad/s2 respectively, which meets the requirements of laparoscopic real-time and smooth tracking of the distal movement of surgical instruments during laparoscopic minimally invasive surgery.