| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a periodic defect detecting device for band shape materials etc. and its method capable of using even if the generation period of defects changed and capable of precisely determining periodic defects generated not only at the last rolling roll, but also generated at a plurality of rolls of different diameters. <P>SOLUTION: The periodic defect detecting device comprises: a sensors 4; a small area selecting means (72, 74) for determining the positions of small areas, the area lengths of which are smaller than that of an area, so that distance intervals between adjacent small areas are all equal, in the direction of arrangement of periodic defects, and selecting a signal corresponding to the positions of the plurality of small areas from the sensor output; an evaluation index calculating means 76 for calculating the evaluation index of the mutual similarity of the signal patterns between the plurality of signals selected by the small area selecting means; a set value varying means (73, 75) for repeating the operation processing of the small area selecting means and the evaluation index calculating means while varying the positions and distance intervals of the small areas; and a period determination means 77 for determining the distance intervals as periods when the evaluation index is higher than a preset value. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
