雙相機系統於應變量測之應用

Application of the Dual Camera System in Strain Measurement

蔡瑞峰(Jui-Feng Tsai)

指導教授 ： 黃仲偉

中原大學/工學院/土木工程研究所/碩士(2011年)

https://doi.org/10.6840/CYCU.2011.00084

摘要

數位影像量測係根據物體在變化前、後數位影像間的相對位置，分析物體表面觀測點位的空間資訊，進而推算出位移場、應變場或其他相關的物理量。隨著攝影與計算的進步與普及，數位影像量測於實驗力學的應用隨之大幅增加。然而目前對於數位影像量測仍缺乏具體的方式來評估其量測的優劣，亦即對於量測的精確性與穩定性仍無量化的指標可供判斷。
　　本研究之目的即在於利用誤差傳播的理論，建構三維影像量測的誤差層級。推導出影像識別誤差對三角定位誤差以及後續應變分析誤差的影響，並利用本團隊所開發之雙相機影像量測系統進行實際驗證。經由零應變實驗、平板拉伸實驗以及圓柱試體抗壓實驗的測試顯示：本研究之雙相機系統在位移量測之解析度可達0.23像素，而應變計算之解析度可達0.05 %。

關鍵字

數位影像量測 ； 誤差傳播 ； 雙相機系統 ； 應變計算

並列摘要

Digit image measurements are based on the digit images of an object before and after deformation. Through the spatial information analyses on the image of an object surface taken from two cameras, related data such as displacement fields, strain fields, and crack positions et al. can be obtained. In the past few years, the rapid improvement and popularization of digital camera technology have greatly facilitated the applications of the digital image measurement in experimental mechanics. However, there still lacks of an appropriate index to estimate the accuracy and precision of the digit image measurements.
　　The aim of this research is to construct the error level of three-dimensional digit image measurement based on the theory of error propagation. The error of strain calculation in the three-dimensional image measurement resulted from the errors of stereo-match and triangulation in image processing are firstly derived. The analytical formula is then verified by an in-house developed dual-camera system. Through the zero-strain experiment, plate tensile test, and cylindrical compressive test, experimental results demonstrate that the resolution of the developed dual-camera system can achieve 0.3 pixel in displacement measurement and 0.05% in strain measurements.

並列關鍵字

digital image measurement ； error propagation ； dual-camera system ； strain calculation

參考文獻

陳北亭，2009，數位影像量測於結構實驗之應用，中原大學土木工程學系碩士論文。

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