Development of defect detection algorithm in cold rolling

In this paper, we propose the defect detection algorithm using the image processing in cold rolling. This algorithm consists of two separated parts: defect detection of the steel sheet in a rolling process and defect detection of the cutting plane in a side trimming process. The objective of the crack and hole detection is to find the position and diameter of holes and some information of cracks such as the depth, width, position, and type. Furthermore, the objective of the defect detection for the cutting plane is to find the position of defects on the cutting plane, the number of those, and the thickness ratio between the cutting plane and the cold rolled steel sheets. Experimental results show that the proposed algorithm finds the defect information of cold rolled steel sheets satisfying the processing-speed constraint of 30 frames/sec.