METHOD FOR CONTROL OF STEEL SHEETS FOR SURFACE DEFECTS USING LASER TRIANGULATION SCANNERS Russian patent published in 2023 - IPC G01N21/86 G01B11/24 B21B38/02 

FIELD: surface defects detecting and measuring.

SUBSTANCE: invention relates to a method for detecting and measuring surface defects in steel sheets in a production stream. A method for testing steel sheet for the presence of surface defects in the process of moving using an installation equipped with laser triangulation scanners, includes scanning the surfaces of sheet metal using laser triangulation scanners, while scanning is carried out with a discrete step, which is at least two times less than the minimum size alleged defects. The reflected laser radiation is received and converted by means of an optoelectronic device into a signal characterizing the profile of the investigated surface, then the signal is fed to a computing device that automatically generates a three-dimensional model of the investigated sheet metal surface. The three-dimensional model is converted into a grayscale image, each pixel of which is processed using linear spatial filtering filters with specified filtering area sizes. The difference in filter responses for each pixel of a halftone image determines the presence and size of defects on the surface of a three-dimensional model to make a decision on the use of sheet metal in production.

EFFECT: increased accuracy of determining the location and size of defects on the surface of rolled steel.

3 cl, 4 dwg