Issue 37

I. Mazur et alii, Frattura ed Integrità Strutturale, 37 (2016) 287-296; DOI: 10.3221/IGF-ESIS.37.38 289 Figure 1: Placement of ASIS equipment The system that received from the video cameras a primary image of surfaces corrects the general background that always should be constant in time for the correct classification of defects. Several algorithms of detection of defects (for the vertical, horizontal and diagonal contrast, of thin and lengthy, of dark or light defects) are used in parallel to the received. Then a morphological grouping of the obtained signs occurs for the obtaining of the information necessary on the stage of classification. A method, based on the method of classification spheres is realized for the classification of defects in the given system of control of quality of surface. A comparison of found defects of surface with the samples of defects from the existing data base on which the classification is based is in the foundation of method. Not less than 20-40 samples of analogous defects are necessary to have in the data base for the automatic classification of defects. The results of the processing are transmitted to the control station informing the operator of the mill about the state of the surface of the rolled metal after the classification of image and also are recorded to the data base for the further analysis of the quality of the rolled metal. The main difficulties arised on the stage of development of ASIS on mill 2000, consisted in the setting of the system for the detection of defects on the current assortment of the mill and also in «training» of the system to classify the detected defects. The training consisted in the accumulation of samples of defects in the data base (base of «knowledge of defects»). The actions on the setting of the system of control of quality of the surface consisted out of four stages for the obtaining of maximum of detection of surface defects: - fragmentation of assortment of steels rolled on the mill for the groups by the outward appearance of the surface of the rolled metal; - decrease of quantity of water on the upper the surface of the rolled metal; - determination in the system of threshold valuation of contrast of detection of defects for the groups singled out in the assortment of steels; - creation of class file. The whole assortment of the mill 2000 was divided for the five groups by the outward appearance of the surface after short-lived operation of the system because the surfaces of steel strip are different by the outward appearance (for example, transformer steel grades have, for the most part a homogeneous grey surface, of dynamo steel grades and carbon steel grades have a dark and heterogeneous): group 1 – rolled metal 10UA, 20 and transformer steel grade; group 2 – rolled metal 08U, DC04 and St3sp;