APPARATUS AND METHOD FOR ON-LINE DETECTING WELDING PART OF STRIP SHEET

摘要

An apparatus and a method for on-line detection of a welded part of a strip sheet are provided to maximize a detection rate of welded parts by irradiating laser beams aslant to the width direction of the strip sheet being transferred, measuring changes in intensities of the reflected laser beams, and analyzing a plurality of successive pulse-type signals generated when the laser beams pass the welded part. An apparatus(10) for on-line detection of a welded part of a strip sheet comprises a plurality of laser reflectivity measuring units(11), and a signal processing unit(12). The laser reflectivity units are arranged in a line having a predetermined angle(theta) with respect to the width direction of a strip sheet(1) being transferred, each irradiating laser beams onto a surface of the strip sheet to measure reflectivity of the strip sheet from the laser beam reflected from the surface. The signal processing unit detects a welded part(2) of the strip sheet if a plurality of reflectivity patterns are repeated by the successive laser reflectivity measuring units.