Research on Robot Calibration Based on Laser Tracker

摘要

With the development of intelligent manufacturing, robot absolute positioning accuracy plays an important role in advanced applications. Aiming at improving the absolute positioning accuracy of serial robot, a calibration experiment is conducted with a laser tracker, the effects of the kinematic calibration are evaluated by comparing the position errors. Firstly, the kinematic model of the robot is established according to the method of Denavit-Harteriberg parameter, and the geometric parameters of the robot to be corrected are selected. Secondly, the error function is established with measurement result of the end reflector position and calculation result by DH matrix of the corresponding position. Thirdly, the actual geometric parameters are obtained by solving the error function using LM algorithm. Finally, the kinematic model of robot system is corrected by these parameters. The result shows that the maximum/mean/root-mean-square (RMS) position errors are reduced 47.48 %/37.98 %/40.40 % after calibration.