AUTOMATIC CALIBRATION METHOD FOR ROBOT SYSTEM

摘要

An automatic calibration method for a robot system, including steps of: providing a ball-rod member comprising a connection rod and a sphere connected to one end of the connection rod; fixing the other end of the connection rod to an end execution tool mounted on a flange of a robot; controlling the robot to move a center of the sphere to the same one target point in various different poses under the guidance of a vision sensor, and calculating a transformation matrix Ts of the center of the sphere with respect to a center of the flange based on pose data of the robot at the same target point; and calculating a transformation matrix Tt of a center of the end execution tool with respect to the center of the flange according to a following formula (1): Tt = Ts * Tc (1), wherein Tc is a transformation matrix of the center of the end execution tool with respect to the center of the sphere, and Tc is known and constant. It needs to identify only the center of the sphere of the ball-rod member by the vision sensor, without a need to identify the center of the end execution tool. Since the sphere has a regular geometry, it is easy to identify the center of the sphere, improving the calibration accuracy and efficiency of the robot system.