雷射線結構光應用於物體表面及3D輪廓之精細量測

Laser structure light applies to measure the surface and three-dimensional structure of objects meticulously

吳軒孝(Shiuan-shiau Wu)

指導教授 ： 張榮森

國立中央大學/理學院/光電科學研究所/碩士(2007年)

摘要

本文雷射線結構光應用於物體表面及3D輪廓之精細量測
主要是在發展一種快速簡易非接觸式的量測方法，並以程式來監測物體表面的變化和形狀。利用光學量測的優勢，本系統有非接觸性、非破壞性、儀器架設快速、全場域的量測、不受量測空間侷限等優點。且本系統的光源來自雷射光源，故可以做較長距離的量測，不同陰影量測法有距離上的限制。
系統將拍攝的影像資訊匯入電腦以MATLAB做分析，接著再做質心法的動作，我們以像素法做為分析的基本原則，先選擇一個基準點作為參考點，再算出其他各點相對於基準點的位置差，也就是其他各點所在的位置與基準點差多少個像素，把差異的像素再換算成實際高度，而完成待測物的表面觀測。校正部份我們以此系統量測一完全平面，由於是完全平面，所以在量測表面時，理論值應該是沒有高低起伏，而我們得到的最大誤差約為7um。除此之外，我們將線結構光掃過整個物體表面，計算出整個面的變化。此研究方法對於快速大範圍量測，可以很快的得到待測物表面的形狀。由於投射的線結構光非常的細小，因此也可用來量測更小的透鏡曲率，及平坦度、3D等量測。最後以本實驗室的點結構光三角量測法，將其應用於天帝教之氣功態脈博測量，分析天帝教接主炁前與後的脈博振幅變化。

關鍵字

疊紋 ； 三角量測法 ； 光學質心法 ； 光學量測 ； 結構光

並列摘要

The research ”Laser structure light applies to measure the surface and Three-dimensional structure of objects meticulously” develops a kind of fast and simple measurement method mainly. Monitor the change and form of the object surface automatically. This system has untouchable, non-destructive, erect the system quickly which also can measure the whole field land, not measures by the space limitation. However,the light source of this system comes from the laser light source, so it can do the long distance measurement that different from the measurement of shade law has distances restriction.
Take the photo image into computer and make analysis in MATLAB. We take the movements of the centroid law. We regard law of picture element as the basic principle of analysis, choose a datum point to regard as the reference point, calculates again that the position relative to datum point of other each point. That is to say how much picture element the position of other each point difference from the datum point. Convert the difference to the actual height again, Then it finish the measuring on surface of the thing to observe.
Correcting some, we measure and examine a complete level with this system. Because of complete level, while measuring the plane surface, theory value should have no level to rise and fall. And the biggest error which we get is about 7um (± 3.5um ). In addition, we have swept line structure on the whole object surface, and calculate out the whole change of object surface. The research approach can examine big range amount and to get the information of objects quickly. Because line structure light is extraordinary and tiny, so it can be use examines smaller lens camber, and smooth degree, 3D examined etc, more accurately. Finally, we introduce the triangular measurement law using in the pulse of Tien-di Chiou. Make the change of pulse in measurement, while they get the ‘chi’ adjacently. And analyze the pulse on time.

並列關鍵字

Moire ； triangular measurement ； optical centroid law ； structure light ； optical measurement

參考文獻

Photo- grametry”, Applied Optics, Vol.18, 1979.

Measuring Profilometry of 3-D Diffuse Objects”, Applied Optics,

[5] O. Kafri and I. Glatt, “The physics of Moire Metrology”, New York,

Wiley, c1990.

[9] Reid ID. 1996. Projection calibration of a laser-strip range finder.