Study on Measuring Medium and Heavy Plate Flatness and Spot Center Extraction Algorithm

Abstract

Oblique incidence lasertriangulation was used to detect medium and heavy plate flatness in this paper.The article mainly focused on point laser spot center extraction algorithm. Infielddetection of medium and heavy plate flatness, according to the problem of thepoint laser spot center extraction difficulty in interference condition, andfor enhancing lightness of spot center filed, an extraction algorithm of pointlaser spot center is put forward in this paper which combines threshold methodand square-weighted gray level based on floor board effect and traditionalcentroid method. Under no interference condition, point laser spot centerextraction using traditional centroid method has high accuracy. In the fielddetection with dusts, oil drops, water drops or other interferences,measurement precision has since fallen sharply. On this background, accordingto a kind of point laser spot center with the interference of water drops oroil drops, classification extraction algorithm of point laser spot center wasput forward in this paper. At the first level, the spot and the drop contourwas extracted with Sobel Operators. At the second level, the spot area wasextracted. And then, this spot area center was extracted by a point laser spotcenter extraction algorithm which combines threshold method and square-weightedgray level. And the center we get is point laser spot center. The validationresults show that with the water drop interference, the accuracy with a pointlaser spot center extraction algorithm which combines threshold method andsquare-weighted gray level is obviously improved by 94.17% than the traditionalcentroid method.

High-efficiency flatness detection method for medium-thick steel plates based on multiline parallel laser vision

“…In the early stages of development in the steel industry, the flatness of the medium-thick steel plates was mainly judged manually to determine the plate quality, but efficiency, accuracy, and stability were low 6 . From the perspective of current flatness detection methods, there are mainly two types: contact and noncontact 7 , 8 . Contact types from the early development of three-coordinate inspection to capacitive or inductive-based new probe detection had high accuracy, but were expensive and easily caused surface scratches and wear, largely limiting the development and application of contact detection.…”

“…6 From the perspective of current flatness detection methods, there are mainly two types: contact and noncontact. 7,8 Contact types from the early development of three-coordinate inspection to capacitive or inductive-based new probe detection had high accuracy, but were expensive and easily caused surface scratches and wear, largely limiting the development and application of contact detection. Noncontact types mainly include electromagnetic, displacement, vibration, and optical imaging.…”