Hand-eye calibration method, computer program for executing the same, and robot system

Hand-Eye Calibration System

This technology is a geometric calibration method that calculates the relative transformation matrix X between a vision system and a working tool. It utilizes multiple vision data points and tool position data acquired by rotating (pivoting) the end-effector of a robot arm around a fixed pivot point.

Conventional hand-eye calibration methods are complex yet yield low accuracy, and the discrepancy between the reference coordinate systems of the vision system and the working tool makes precise control difficult.

This technology constrains the positional change of the end-effector through a pivoting motion, calculates the vision system position vector and the tool marker position vector at each location, and then mathematically minimizes errors using the transformation matrix relationship between the pivot point and each device to derive the transformation matrix X. Applicable to robotic gripping, precision measurement, and automated equipment, it provides a hand-eye calibration method using pivoting motion to improve the accuracy of calculated results in vision-based intelligent industrial robots.

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Key Features:

• A step of acquiring a first image of a pattern when the end-effector is at a first position and a second image of the pattern when the end-effector is at a second position, using a vision system provided on the end-effector.
• (C) A step of calculating the transformation matrix X between a specific point and the vision system, using the transformation matrix between the pivot point and the vision system, the transformation matrix between the pivot point and the specific point, and vectors A and B.
• A step of obtaining vector B from the position of the vision system at the first position to the position of the vision system at the second position, using the first and second images.
• are the rotation matrix and translation vector of X, is the translation vector of E, and is the translation vector of F.