該研究主要聚焦在將電腦視覺的技術應用在機械工程上，在論文內容中會介紹並解釋電腦視覺中重要的背景知識。立體視覺是目前已知不需外加主動式光源的方法中最精準的演算法，因此該研究利用立體視覺的概念去重建試料的幾何模型並設計一套靜態的模態量測系統。重建出的模型將會與已知的材料特性一起輸入到商用的有限單元法分析軟體中去計算數值解，而計算出的結果將會與實驗設備量測的結果進行比較，並確立該系統的可行性。

The thesis focuses on the application of computer vision techniques in mechanical engineering. In the contents, the important elements of computer vision are introduced and explained. The stereoscopy is the most robust algorithm that does not have to apply active light sources and has the highest accuracy. Therefore, the study applies the concept of the stereo vision to design a static modal analysis system by reconstructing the geometrical model of specimen. The reconstructed model combined with the known material properties and boundary conditions served as the input to the commercial finite element analysis (FEA) software to compute the numerical solution. The calculated results will be compared with the experimental ones acquired by the measuring instruments. In the study, a system is established to verify the feasibility of the proposed method.

ABSTRACT II
摘要 III
ACKNOWLEDGEMENT IV
TABLE OF CONTENTS V
LIST OF TABLES VIII
LIST OF FIGURES IX
CHAPTER 1 INTRODUCTION 1
1.1 Background & motivation 2
1.2 Literature review 3
1.3 Methodology 6
CHAPTER 2 CAMERA CALIBRATION 7
2.1 The camera model and coordinate transformation 7
2.2 Extrinsic & intrinsic parameters 10
2.3 Calibration method 11
2.4 Distortion model 14
CHAPTER 3 IMAGE CORRESPONDENCE 16
3.1 Features 16
3.1.2 Structured light 17
3.2 Harris corner detection 19
3.3 Scale-invariant feature transform (SIFT) algorithm 20
3.3.1 Construct scale-space 21
3.3.2 Keypoint localization 22
3.3.3 Rejection of poor keypoints 23
3.3.4 Orientation assignment 23
3.3.5 Keypoint descriptor 24
CHAPTER 4 STEREO VISION 25
4.1 The general stereo vision system 25
4.2 The ideal stereo vision system 26
4.3 Essential matrix 27
4.4 Fundamental matrix 28
4.4.1 8-point algorithm 29
4.5 Baseline 30
4.6 Rectification 30
4.7 Depth resolution 33
CHAPTER 5 MODEL RECONSTRUCTION 36
5.1 Coordinate calculation 36
5.2 Depth of field (DOF) 36
CHAPTER 6 MODAL TESTING 40
6.1 Single-Degree-of-Freedom (SDOF) system 40
6.2 Multi-Degree-of-Freedom (MDOF) system 43
6.2.1 Undamped MDOF system 44
6.2.2 Damped MDOF system 44
6.3 Signal processing 45
6.3.1 Aliasing 46
6.3.2 Discrete Fourier transform (DFT) 46
6.3.3 Fast Fourier transform (FFT) 47
6.3.4 Spectral leakage 49
6.3.5 Windowing 51
6.3.6 Digital frequency analyzer 54
CHAPTER 7 BUCKLING PROFILE 56
7.1 The Elastica 56
7.2 The derivation of curvature equation 57
7.3 The formation of buckled curve of fixed-fixed plates 60
7.4 The buckled curves of fixed-fixed plates with different bulging quantity 64
7.5 The manufacturing of curved plates 66
CHAPTER 8 MODAL ANALYSIS 67
8.1 The experiment platform 67
8.2 The experimental modal analysis equipment 69
8.3 The flow chart 70
8.4 The effect of depth resolution 71
8.5 Numerical modal analysis 74
8.5.1 Ideal model meshing 74
8.5.2 Real Model meshing 79
8.5.3 Mode shapes 81
8.6 Experimental modal analysis 89
8.6.1 FRF 90
8.6.2 Mode shapes 91
8.7 Discussion 102
CHAPTER 9 CONCLUSION 105
CHAPTER 10 FUTURE WORK 106
REFERENCE 107
APPENDIX 109

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