Robot teaching program correction method

A robot teaching program correction method for controlling a robot comprising the steps of:

• (1) preparing an industrial-robot teaching program including a plurality of teaching points and corresponding program position data off-line without using the robot;
• (2) obtaining measured position data of one teaching point on a workpiece in a sensor coordinate system by mounting a vision sensor to a wrist flange of the robot and detecting the one teaching point by the vision sensor;
• (3) converting program position data for the detected one teaching point in the teaching program into program position data in a sensor coordinate system in accordance with a calibrated positional relation between the sensor coordinate system and a robot wrist flange coordinate system;
• (4) estimating an error of the robot wrist flange coordinate system based on a difference between the measured position data for the one teaching point obtained in the above Item (2) and the program position data obtained in the above Item (3);
• and
• (5) correcting program teaching point data corresponding to the teaching points included in the teaching program based on the estimated error of the robot wrist flange coordinate system estimated in the above Item (4).

A robot teaching program correction method comprising the steps of:

• (1) preparing an industrial-robot teaching program including a plurality of teaching points and corresponding program position data off-line without using the robot;
• (2) obtaining measured position data for one teaching point on a workpiece in a sensor coordinate system by mounting a vision sensor to an end effector of the robot and detecting the one teaching point by the vision sensor;
• (3) converting program position data for the detected one teaching point in the teaching program into program position data in a sensor coordinate system in accordance with a calibrated positional relation between the sensor coordinate system and a tool coordinate system;
• (4) estimating an error of the tool coordinate system based on a difference between the measured position data of the one teaching point obtained in the above item (2) and the program position data obtained in the above Item (3);
• and
• (5) correcting program teaching point data corresponding to the teaching points included in the teaching program based on the estimated error of the tool coordinate system estimated in the above Item (4).

A method for correcting a robot teaching program which includes a plurality of teaching points comprising the steps of:

• forming a mark on a portion of a workpiece;
• identifying the formed mark by a robot vision sensor;
• selecting a teaching point from the plurality of teaching points in the teaching program corresponding to the identified mark;
• measuring a position of the identified mark by the vision sensor;
• and
• correcting a portion of said plurality of teaching points by calculating a difference between the selected teaching point and the measured position of the identified mark.