摘要：Abstract. Additive manufacturing technologies are further developing from prototype to serial production. Thistrend requires rising challenges to the process-accompanying quality assurance. Optical in situ quality controlapproaches show great potential to generate accurate measurement data, which are essential for feedback control. If a reliable referencing concept for the layer-by-layer measured data is guaranteed, contour informationcan be used during the manufacturing to correct occurring geometrical deviations. Within this scientific study,two methods of optical, referenced in situ control of lateral displacements of additive manufactured contours arepresented. In the first approach the 2-D contour of the melting pool is analysed in relation to a position-stablereference system implemented in the powder bed. The second approach uses the translucent contour of deeperlayers covered with powder as a reference. Within the image evaluation several pre-processing steps like calibration, undistortion, rectification, illumination correction and low-pass filtering are essential for reliable andcorrect geometric measurements. The following adapted contour detection and position determination of the referenced melting pool contours are based on an extended edge detection algorithm according to Canny (1986).With the evaluation of further manufacturing layers of already lowered powder bed levels, it is possible to specify the influence of powder application on geometrical displacements separately. This is done by a comparisonof the position of the detected powder-covered melting pool contours with the previously applied melted region.Consequently a better understanding of lateral contour displacements within the additive manufacturing processis the goal, which is important for a process-accompanying correction of geometrical deviations.
