Kinematics Calibration of Spraying Robot based on Laser Tracker

A method for industrial spraying robot calibration by using laser tracker is presented in this paper. Firstly, the structure of spraying robot is analysed and the coordinate systems of each joint are configured based on D-H method; Secondly, the kinematics model of spraying robot is established, and the error model of the spraying robot is established based on the differential transformation. Thus the functional equation between the position error of the end-effector and the D-H parameters is obtained; Thirdly, laser tracker is used to measure the actual position of the end-effector, and the error of D-H parameters of each joint are iteratively solved based on the kinematics error model; Finally, the error value is compensated to the robot motion control model for verification. The results of the experiment show that the absolute precision of the robot is improved greatly after calibration.