Integrating cross-sectional imaging based reverse engineering with rapid prototyping

摘要

This paper presents an integrated system of cross-sectional imaging based reverse engineering (RE) and rapid prototyping (RP) for reproducing complex objects. The system consists of four modules: cross-sectional image measurement, 3D reconstruction, stereo lithography (STL) file generation, and RP slice file generation. During cross-sectional image measurement, the object to be measured is encased within resin and then milled, layer-by-layer, using an NC milling machine. After each layer is machined, a CCD camera is used to capture the newly exposed cross-sectional image of the object. The contours of the cross-sectional image are further extracted through image processing and segmentation. A collection of the contour data is acquired by the cross-sectional image measurement module. While a 3D CAD model can be reconstructed by the 3D reconstruction module from the contour data, its STL file and RP slice file are generated directly from the contour data. The algorithm for STL file generation from cross-sectional contours consists of three major steps: (1) preprocessing of cross-section images for data reduction, (2) Delaunay triangulation of contours in the first and last layers and (3) triangulation of contours between adjacent layers. This integrated system and the processing algorithms are further validated through four examples.