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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/92406


    Title: 投射式移相弦波用於微小物體形貌量測之研究;Research on the Shape Measurement of Small Objects by Phase Shifting Fringe Projection Profilometry.
    Authors: 方筱喬;Fang, Hsiao-Chiao
    Contributors: 光電科學與工程學系
    Keywords: 五步相位移;影像雜訊處理
    Date: 2023-08-17
    Issue Date: 2023-10-04 15:51:55 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 本論文介紹利用五步相位移的方式重建微小物體的三維輪廓,而相位輪廓儀對於條紋相位的精確度要求相當高,因此本論文使用經特殊設計的穿透式光罩通過成像系統投影出接近完美正弦波之投影條紋,再透過傅立葉轉換濾波以及平均化之方法過濾影像雜訊使條紋更加精確。透過多張影像平均法,拍攝所得之條紋灰階分布與理想正弦波之擬合度可達到0.9907,參考平面之條紋灰階分布可再透過傅氏轉換濾波使擬合度達到1。
    使用標準球作為待側物,透過本系統量測之平均曲率半徑為22.494 mm,標準差為3 μm,將重建結果與理想球面重疊做比較,RMSE值為10 μm。
    而由於使用三角量測法之架構具有量測工作範圍的限制,本論文提出透過位移待側物量測不同區塊並做拼接的方式還原較工作範圍大的物體的三維輪廓。
    我們分別對兩種自由區面做重建與透鏡實際描邊結果重疊進行比較,第一種透鏡之RMSE值為3 μm,第二種之RMSE值為8 μm。
    ;This paper introduces the reconstruction of the three-dimensional contour of small objects using a five-step phase-shifting method.
    For precise measurement of the phase contour, a phase-shifting profilometer with high accuracy requirements is used in this paper. It employs a specially designed transmissive optical mask to project near-perfect sinusoidal fringes through the imaging system. Fourier transform filtering and averaging methods are then applied to filter image noise and improve the accuracy of the fringes. The fitting degree of the grayscale distribution of the fringes obtained through multiple image averaging can reach 0.9907, and the reference plane′s fringe grayscale distribution can achieve a fitting degree of 1 after Fourier transform filtering.
    Using a standard sphere as the test object, the average curvature radius measured by the system is 22.494 mm with a standard deviation of 3 μm. Comparing the reconstruction result with the ideal spherical surface, the Root Mean Square Error (RMSE) value is 10 μm.
    Due to the limitations of the triangulation method′s measurement range, this paper proposes a method to reconstruct the three-dimensional contour of larger objects by measuring different sections through displacement and stitching of the test object.
    The reconstruction results of two different freeform surfaces are compared with the actual outlines of the lenses. The RMSE value for the first lens is 3 μm, and for the second lens, it is 8 μm.
    Appears in Collections:[Graduate Institute of Optics and Photonics] Electronic Thesis & Dissertation

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