Calibration system for compensation of arm length variation of an industrial robot due to peripheral temperature change

Abstract

A calibration system for compensating variation of robot arm length of an industrial robot because of temperature change. The system comprises a temperature variation insensible calibration jig having a pair of rectangular hexahedrons of different sizes which are combined with each other above and below and have a plurality of measuring points marked thereon. A noncontact sensor unit relatively measures a teach-in measuring point of the calibration jig and compares the measured value of the teach-in point with initially inputted value thereof, thereby calculating the variation of the robot arm length caused by the temperature change. The noncontact sensor unit includes a camera for measuring a center of the teach-in measuring point and a laser displacement sensor (LDS) for measuring relative distance between the robot hand and the teach-in measuring point and sensing three-dimensional relative error. The arm length variation is calculated, using differential value between the initially inputted value and the measured value of the teach-in measuring point, in accordance with the method of least squares.

Dependencies are inferred from the claim text.