本文的主旨是以雷射結構光法量測海床的表面粗糙度。在結構光法中，我們以CCD(Charge Coupled Device)攝影機來擷取雷射線偏移的位置。因為CCD攝影機的鏡頭周圍會有扭曲的光學現象，讓畫面中的物體產生形變，所以不能直接從影像上看出物體的實際尺寸。對於這種非線性變化，我們使用經緯線格點來對攝影機作校正。我們的做法是將一塊精密加工出網格控制點的壓克力板，以CCD擷取此板影像後，利用曲線擬合的方式描述畫面裡由控制點所形成的經緯線。模仿地圖的製作原理，將CCD的鏡頭當成地圖，以內差這些經緯線的方式推算校正板影像中特徵點的位置，最後經查表法將圖素座標(pixel)轉成工程座標(mm)，完成CCD的校正。我們設計三個驗證實驗來檢測量測系統的精度。第一個實驗是量測校正板上特徵點之間的距離，檢驗校正鏡頭光學扭曲的效果。第二個是量測已知尺寸加工物的雷射斷面影像，藉由量測加工物的高度與寬度，檢驗系統量測雷射斷面的效果。第三個實驗是藉由量測樂高積木上小圓柱的高度，檢驗系統對於量測物體表面微小起伏變化的能力。實驗結果驗證系統的量測精度，達到誤差在1%以內。然後我們才進行人造沙波的設計與量測分析。人造沙波模型的製作，材料是用一塊210mm * 210mm * 30mm的壓克力，沙波波形產生在中央150mm見方的正方形範圍裡。沙波波形的振幅範圍最大±8mm，最小±1.5mm。我們繪製出沙波的等高線圖及表面重現圖，來分析測量的結果。分析的方法是從重現的沙波表面切取斷面資料，將波形理想值與測量值作比較。由結果可知，沙波波形理想值與測量值的誤差在±2mm以內。為了測試系統對於濁度的容忍度，我們將量測沙波的實驗加入可改變環境濁度的條件，然後再作分析。由實驗結果可知，系統可在環境濁度2.3NTU(Nephelometric Turbidity Unit)以下維持穩定運作，沙波波形理想值與測量值的誤差也維持在±2mm以內。

This work studies the application of laser structured light scanning to measure the small scale roughness of seabed. We use a CCD camera to capture the dislocation of laser light. The location of the laser light in pixel coordinates can be converted into world coordinates if the CCD camera is calibrated. We propose an algorithm which is analogous to the idea of longitudes/latitudes in map projection. The idea is to place a calibration board to be aligned with the laser scanning sheet. On the calibration board, grid points of 50mm are laid to represent the intersection of the longitudes and latitudes. The position of a point in pixel coordinates can be obtained by referring to its neighboring graticule. We designed three experiments to verify the accuracy of the system: The first experiment consists of measuring the distance between feature points on the calibration board, then check and correct the optic distortion effects of the lenses. The second experiment is to measure the slice of laser scanning image of a known object, and check the accuracy of our laser scanning system by measuring the object's height and width. In the third experiment, we measure an object which has a small height variety of its surface, to test the resolution of the system. The results indicate that the error is under 1%, only then that we proceed with the design, analysis, and measurement of artificial seabed. The artificial seabed model is made by using a 210mm * 210mm * 30mm acrylic board with sand ripples forms in the 150mm * 150mm square. The amplitude of the ripples is no higher/larger than ± 8mm, and no lower/smaller than ± 1.5mm. Contour map of the sand ripples would be plotted to analyze the results obtained from the measurements. The analysis is carried out by obtaining slice data from a reconstructed surface of the sand ripples, then compare it with the theoretical values. From the result we know that the error between sand dune ideal wave index and measured index is in the range of ± 2mm. To further test the system's tolerance with turbidity, we incorporate conditions which would alter environmental turbidity into the seabed experiments before running the experiments for analysis. The results show that the system is able to maintain a stable performance in an environment below 2.3 NTU (Nephelometric Turbidity Unit), and the error between ideal sand dune ideal wave index and measured index is still in the range of ± 2mm.

第一章 緒論
1.1前言…………………………………………………………………..1
1.2文獻回顧……………………………………………………………..2
1.3研究目的……………………………………………………………..4
第二章
結構光量測法………………………………………………………...5
2.1攝影機校正模式……………………………………………………..6
2.1.1 參數估計法…………………………………………………….6
2.1.2 對映函數法…………………………………………………….8
2.1.3 經緯線格點校正法…………………………………………….9
2.2經緯線擬合………………………………………………………….11
2.3轉換範例…………………………………………………………….11
2.4網格控制點的求取………………………………………………….13
2.5雷射光源固定架製作……………………………………………….13
第三章
實驗架構……………………………………………………………..16
3.1實驗設備…………………………………………………………….16
3.2線性滑軌控制與影像處理軟體…………………………………….18
3.3實驗規劃…………………………………………………………….20
3.3.1 實驗一：校正板上幾何圖形驗證……………………………21
3.3.2 實驗二：加工物量測分析……………………………………24
3.3.3 實驗三：樂高積木模型表面重現分析………………………26
第四章
人造沙波設計與量測分析…………………………………………..28
4.1人造沙波的設計及改良…………………………………………….28
4.2數據分析…………………………………………………………….30
4.3濁度因子…………………………………………………………….38
第五章
結語…………………………………………………………………..52
5.1討論………………………………………………………………….52
5.2結論………………………………………………………………….54
5.3後續發展…………………………………………………………….55

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