光學掃描技術於實體模型重建之運用

Application of Optical Scanning Technology for Reconstructing Surface Model

莊禮彰(Li-Chang Chuang) ； 鍾添東(Tien-Tung Chung)

《航空安全及管理季刊》 3卷4期 (2016/10) Pp. 311-327

摘要

基於逆向工程的概念，可利用非接觸式三維掃描儀量測殘骸或結構組件的幾何外型，於三維量測後可取得待測物的三維點雲資料，經計算後以STL(Stereolithography)檔案輸出，STL檔案亦可在商業CAD軟體中以三角網格的形式呈現。本研究利用待測物的STL檔案，擷取三角網格模型之特徵邊緣，依其輪廓擬合成非均勻有理B樣條曲線。昆氏曲面可由端點相連的四條非均勻有理B樣條曲線擬合而成，進一步擬合成更為平滑的立方B樣條曲面，經由布林運算後，數個立方B樣條曲面即可重建出最後的曲面模型。此外，本研究利用商業套裝軟體處理三維點雲資料，藉由幾何特徵建構出實體曲面模型，經疊合三維點雲資料實體曲面模型後，驗證兩者之幾何誤差。

關鍵字

逆向工程 ； 非接觸式三維掃描 ； 三角網格 ； 特徵邊緣 ； 事故調查

並列摘要

Based on the concept of reverse engineering, the ＂Reverse Engineering Module＂ for this project uses a non-contact 3D scanner to measure 3D shapes of wreckages or structural components. After 3D scanning, 3D data points of the scanned objects can be obtained. Using corresponding software for 3D scanner, the final 3D object shape can be exported as a STL (Stereolithography) file, which can be imported into commercial CAD software and displayed as triangular meshes. With the given STL file of a scanned object, feature edges can be extracted from triangular mesh models, and then be fitted into NURBS curves based on 3D profiles of the scanned object. A Coons surface can be fitted with four adjoined NURBS curves. Then, Coons surfaces can be converted to more smooth cubic B-spline surfaces. The final surface model can be reconstructed from several trimmed cubic B-spline surfaces by applying Boolean operations. Another research topic is reconstructing the surface model from3D data points through business software package, and comparing the errors between the surface model and 3D data points.

並列關鍵字

Reverse engineering ； non-contact 3D scanner ； triangular meshes ； feature edges ； Occurrence Investigation

參考文獻

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