Geometric surface inspection of raw milled steel blocks

Abstract

In the production of raw steel blocks the surface should be free of surface defects. Flaws degrade the quality and deteriorate the treatment in subsequent production steps. The surface of the steel blocks is covered with scale which causes a strongly alternating reflectance property. Due to this fact traditional intensity imaging techniques yield inferior performance. Therefore, light sectioning in conjunction with fast imaging sensors is applied to gather the range image of the steel block. Once the surface height data have been acquired, they must be analyzed with respect to unwanted cavities on the surface. Three different methods for the surface approximation treated, whereby the first algorithm is based on a line-wise examination of the acquired profiles by unwrapping the surface using spline interpolation. The further two methods refers to surface segments based on polynomials and singular value decomposition. © Springer-Verlag 2004.