Optical 3D geometry reconstruction, or more specific, fringe projection profilometry, is a state-of-the-art technique for the measurement of the shape of objects in confined spaces or under rough environmental conditions, e.g., while inspecting a wrought-hot specimen after a forging operation.
View Article and Find Full Text PDFThe limits of traditional lightweight engineering are being extended by the development of hybrid components. Lightweight potential is especially high when using dissimilar materials, e.g.
View Article and Find Full Text PDFIn the Collaborative Research Centre 1153, Tailored Forming, the geometry of hot measurement objects needs to be captured quickly, areally, and with high precision. The documentation of the hybrid components' shrinkage behavior directly after the forming process can yield insight into the development of residual stresses. In this paper, we present a fringe projection measurement setup designed for the topography measurement of high-temperature steel shafts, comprising two cameras with different lenses and a projector.
View Article and Find Full Text PDFTo optically capture the topography of a hot measurement object with high precision, the light deflection by the inhomogeneous refractive index field-induced by the heat transfer from the measurement object to the ambient medium-has to be considered. We used the 2D background oriented schlieren method with illuminated wavelet background, an optical flow algorithm, and Ciddor's equation to quantify the refractive index field located directly above a red-glowing, hot measurement object. A heat transfer simulation has been implemented to verify the magnitude and the shape of the measured refractive index field.
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