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標題: | 運用複合式投光之三維光學形貌量測法精進 Improvement on the 3-D Optical Measuring Profile Method using Hybrid Projection Light |
作者: | Wei-Zhi Zeng 曾暐智 |
指導教授: | 陳亮嘉(Liang-Chia Chen) |
關鍵字: | 複合式結構光,數位影像關聯係數法,相移法,相位模糊,三維光學形貌量測, Hybrid Projection Light,Digital Image Correlation,Phase Shifting,Phase Ambiguity,3-D optical measurement, |
出版年 : | 2016 |
學位: | 碩士 |
摘要: | 傳統相移法在遇到量測形貌上有不連續點之處,常會有相位模糊之問題發生,造成相位展開時,條紋波數判斷錯誤,而得到錯誤的高度資訊,所能量測的斷高大小有所限制。而利用雷射光斑的數位影像關聯係數法,在量測時會有深度解析度較差、量測結果的邊界容易產生重建錯誤等問題存在。目前在本實驗室有發展一套利用數位影像關聯係數法結合相移術之三維光學形貌量測系統,但其缺點有設計上的缺陷、校正困難以及結合演算法不完善等問題,有待精進改善之。
本研究其目的將原有量測方法加以精進,所使用的方法可分成兩部份。第一部份,藉由投影機調製光斑圖案與相移條紋圖案,以取代原有使用雷射投影光斑圖案以及LED經光柵產生條紋圖案的投光系統,並使用單一相機取代原本雙相機架構。第二部份,本研究將改善原本系統架構之演算法,使演算法獲得量測精確度之提升。 本研究之新系統相較於原系統,其光學系統具有架構簡單、校正容易等優點。而實驗量測結果顯示,本系統量測5 mm高度之塊規,其百分誤差可以控制在0.1%。由此,可看出本研究在斷高量測之精確性上有所提升。並且在量測具有一定高度且表面形貌複雜之物體時,其具有良好之量測能力。 The conventional phase shifting method in general encounters phase ambiguity problem at non-continuous area of measured surface. While doing phase unwrapping, the wrong fringe number generally generates undesirable measured error of height information. However, measuring with digital image correlation method using laser speckle has a lower axial resolution and easily produces measured error at the edge area of measured surface. Formerly, there was a 3-D shape measurement system using digital image correlation method combined with phase shifting method in our laboratory. However, the drawbacks waiting for improvement in this system include its poor optical design, being difficult in system calibration and with poor algorithm. The objective of this research is to simplify the system mentioned above. For the developed methods, it can be categorized into two parts. First, the speckle pattern and fringe pattern can be both modulated by a digital light projector to replace the former hybrid laser speckle and fringe pattern generated by using a grating and a LED. Also, two cameras in this system is reduced into single camera. Second, the 3-D measurement algorithm is improved for more versatilities in application and higher measurement accuracy. The advantages of the newly developed system includes its simple optical structure, easy calibration and achieving higher measurement accuracy. As seen in the measurement results, the height measured error can be kept within 0.1% of the total measurable range. From being capable of measuring some samples, it indicates that the developed system has its unique advantages in measuring surfaces with complex profiles and discontinuous edges. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/18962 |
DOI: | 10.6342/NTU201603109 |
全文授權: | 未授權 |
顯示於系所單位: | 機械工程學系 |
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