ACCESS METHOD TO LARGE STRUCTURE BY USING LASER SENSOR

PROBLEM TO BE SOLVED: To accurately perform positioning for the movement of a welding robot by detecting with a laser sensor the position of a large structure arranged for the robot. SOLUTION: Positional correction is performed in Y direction by detecting a transverse position as shown in (1); then, as shown in (2), an approach is carried out to a section (each room of a house) surrounded by wall members having a prescribed height; and then, as shown in (3), the position in the X direction and the height are detected with regard to the longitudinal position of a welding section having a square structure composed of the initial longitudinal and transverse of a subject unit; thereby correction is performed for the position in the X and Y directions.