Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/1829
標題: 結合Minimum Lp - Norm與區塊接合技術應用於ESPI之相位展開研究
Unwrapping ESPI phase maps by the hybrid algorithm of the Minimum Lp - Norm method and the subamp - stitching method
作者: 陳聖奇
C.S.Chi
關鍵字: 區塊接合;可靠度;相位展開
出版社: 機械工程學系
摘要: 
在利用光干涉現象的量測技術中,要從干涉結果中取出我們所要的待測物理量要依靠所謂的「相位展開技術」。當處理對象含有高雜訊,如電子斑點干涉術所得之結果,則相位展開技術就必須更為強健才能順利展開,目前的相位展開技術已有能力處理高雜訊連續面的相位圖展開,但是若原始相位本身就存在著不連續的現象,如剪切平面,則在相位的展開上還有很多問題。
本論文以Dennis C. Ghiglia和Louis A. Romero在1996年所發表的“Minimum LP - Norm Phase Unwrapping”為基礎來解決剪切面的相位展開問題,並針對此方法的缺點,如:運算時間太長,剪切線靠邊、岔開量太大時相位展開不完全…等,提出一新式的區塊接合演算法來加以克服。此演算法藉由比對區塊間重疊處的展開結果來建立區塊間的可靠度權值,再由可靠度的高低依序進行區塊接合的動作,避免接合路徑穿過包含剪切線的區塊所造成的相位展開錯誤。此外,亦可以調整區塊間可靠度的方式,簡單且快速地引入額外的限制條件來修正得到的結果。
藉由結合Minimum LP – Norm method與區塊接合技術,我們得以大幅改進ESPI剪切相位圖展開的運算效率與展開結果的正確性。

Interferometer System provides high accuracy, non-contact, whole-field…etc. properties in the micro-scale measurement. In the interferometer system, phase unwrapping is an important step to retrieval the measured phase which is wrapped by arctangent function into the -modulo. But the Electron speckle Pattern Interferometry (ESPI) fringe patterns are contaminated with high levels of speckle noise. It will cause some problem in phase unwrapping process. Besides, the fractures or discontinuities over the surface of the object will make the phase unwrapping fail too.
The minimum Lp - norm algorithm is a robust tool to cope with these situation, but this algorithm still have some problem. Its solution will converge into a local minimum, but sometimes it's not the result we want. In this thesis, we integrate the minimum Lp - norm method with the submap-stitching algorithm to solve this problem. We can import known conditions easily by adjust the parameter of reliability to fix the unwrapped result. And the submap-stitching algorithm will save a lot of processing time in the iterative loop. We will proof the effectiveness of this propose method by unwrapping the simulation and experimental wrapped map in this paper.
URI: http://hdl.handle.net/11455/1829
Appears in Collections:機械工程學系所

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