Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/2251
標題: 電子斑點干涉技術及誤差之分析
The analysis of ESPI technique and system errors
作者: 劉昭成
Liu, zhao-cheng
關鍵字: ESPI;ESPI之技術;speckle correlation fringe pattern;speckle phase field;An automated self-marking phase-shifting algorithm;laser beam profile normalization;curve fitting;相關斑點影像量測法;斑點影像量測法;相移自動標定法;光強之振幅(B值)正規化;曲面擬合
出版社: 機械工程學系
摘要: 
本文之研究方向及目的,在藉以三軸量測架設對懸臂樑受力變形之量測實驗,對相關斑點影像(speckle correlation fringe pattern)量測法及斑點影像(speckle phase field)量測法兩種ESPI之技術做介紹和理論及邏輯之分析驗證系統分析比較,以及ESPI量測系統在影像後處理上所使用之方法可能產生之誤差做分析,以提供以提出最快速且精確之最佳ESPI量測系統。
本文實驗中所使用到技術:在最重要之取像上,會使用相移自動標定法來擷取準確之相移影像以能獲得精確之分析及量測結果,而影像後處理技術上,本實驗會引用到的技術主要有光強之振幅(B值)正規化之技術、快速傅立葉濾波(FFT)、影像重建(unwrap)、以及曲面擬合(curve fit)等方法,並在其中還會引入影像分割之概念來加快整個實驗之速度。
由整篇論文探討之結果可以發現相關影像量測法較為耗時且誤差較大,而斑點影像量測法則快速且較精確,且就curve fit的分割加速處理上以分割16等分處理之速度快且誤差也最小,所以若要快速且準確量測應變位移,在環境設備完善下建議以斑點影像量測法搭配上自動標定之相移技術及curve fit分割處理技術來量測為較佳。

A comparison study of ESPI (electrical speckle pattern interferometry) technique is presented in this article. Both the widely used correlation fringe method and the rigorous direct-speckle-field-solving approach are fully studied in details. It goes from the optical setup, phase shifting technique, laser beam profile normalization, filtering, unwrapping, to the curve fitting of the result and the further error analysis related. A 3-D deformation field of size 16 x 13 cm2 is interested here with the usage of a 10-mW He-Ne laser. An automated self-marking phase-shifting algorithm is used to monitor the phase-shifting process and to provide the frames necessary for the phase map achievement. The newly developed beam profile normalization and noise-immune phase unwrapping algorithm by our lab are applied to the experimental work and has proved successful of the proposed algorithm. Consequently, the direct-speckle- field-solving method is the suggested solution of ESPI technique with the self-marking criterion monitoring the phase-shifting process and providing the frames needed and with the noise-immune algorithm straightly applied to the ill-conditioned wrapped map, regardless any corrupt data of it.
URI: http://hdl.handle.net/11455/2251
Appears in Collections:機械工程學系所

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