面向高精度显微手术机器人的 RCM 机械臂误差补偿方法

To achieve robot-assisted minimally invasive surgery, manipulator with remote center motion (RCM) mechanism is widely used in surgical robot system. Especially, microsurgery with particularly precise operation requires higher precision and safety of the robot. Aiming at the characteristics of fundus microsurgery robot, based on kinematic calibration, an error compensation method is proposed to reduce positioning error, RCM bias and inverse kinematics solution time. The error model of the robot is established and the geometric parameters are identified; Based on the function and characteristics of the mechanism, the kinematic equations and error compensation model between RCM and end-effector points are established, redundant degrees of freedom are used to compensate the RCM bias in real time. An efficient inverse kinematics method for simultaneous compensation of RCM bias and end-effector position error is realized by analytical solution. Experiments are carried out on the developed surgical robot platform, the results show that the end-effector positioning error reduce to 0.1426 mm. Compared with the iterative method, the RCM bias is reduced by 92.72% and calculation efficiency increased by 89.97%. The effectiveness of the proposed method is verified, which is of great significance to improve the operation precision and safety of the microsurgery robot.