An Algorithm of Data Point Pre-processing to Extract the Design Features for Geometry Reconstruction in Reverse Engineering
| Autor: | Ming-Chih Huang, 黃銘智 |
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| Rok vydání: | 2000 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 88 The objective of this thesis is to develop an algorithm of pre-processing the data points, measured from existing objects, for feature-curve fitting and geometry reconstruction in reverse engineering. The problem in reverse engineering is that the huge amounts of data points are hard to be handled in most CAD systems. Not only is file size a concern, but also the original measured points are with irregular format, unequal distribution and even incompleteness to be difficultly fitted into the B-spline form directly. Additionally, in product design, the design features, which are useful for further manipulation, must be extracted while rebuilding the geometric model in reverse engineering. Therefore, the technology of restoring and segmenting data points for feature curve regeneration is very important to reconstruct the geometric model of an existing object. By the proposed approach, the original measured data points can be regrouped to extract the design features for regenerating individual curves, with the format in which the data points achieve the requirements of fitting into the B-spline form with good shape and high quality. This algorithm consists of four parts: (1) segmentation of data points; (2) regressing data points into an explicit non-parametric equation; (3) regeneration of data points; and (4) determining knot points. The proposed approach has been implemented by using several examples for practical application in reverse engineering. The result of the implementation proves the viability of integrating the approach with commercial CAD systems. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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