在台灣，橋梁是常見的交通結構物，在各大城市內更有許多的高架橋道路。一般高架結構物可能會受自重、地震力、風力以及行駛車輛的影響，進而對橋梁造成微振動。其中微振動位移對結構物安全性的評估，其重要性不可小覷，所以有效的監測是非常重要的。使用自行開發的監測系統可以省去購買商用軟體的費用並且不一定必須購買整套原廠儀器，其中監測程式的功能也可以客製化修改，達到經濟且實用的目的。
線性可差分變壓器(LVDT)是一種被廣泛使用的位移感測器，其優點為靈敏度高、線性度良好。LVDT可搭配一般市面上的交流訊號放大器使用，就能夠符合其供電需求並且能顯示量測數值於訊號放大器面板。但是儀器單價昂貴，以及無法有系統地使用LVDT用來量測。使用LVM-110電壓模塊可以基本滿足LVDT供電需求並且得到電壓輸出訊號，其可以用來取代訊號放大器。LVM-110電壓模塊的優點為單價低、穩定的輸出訊號以及低供電需求。將其配合具有自動存檔功能的量測程式aa.exe、資料擷取卡(NI USB-6218)以及自製的供電設備，使用LVDT進行量測，可以建立一個自動化位移監測系統。
接著於室內使用監測系統進行一個平台測試實驗，由實驗結果可知LVDT用於監測系統可保持良好的線性度，並可計算出靈敏度。最後，使用INSTRON-8800萬能試驗機進行動態位移驗證試驗，用以檢驗此監測系統之精準度。將實驗值與理論值比較，本位移監測系統的平均誤差大約在1%~3%，此誤差屬於可接受範圍內。

In Taiwan, bridges are common transport infrastructures, and there are many elevated bridges in the major cities. Generally, elevated structures may be affected by self-weight, seismic forces, wind, and driving vehicles, and these factors can cause vibrations of the bridge. Moreover, the safety of structures is related to the vibration displacement, which cannot be underestimated. Thus, an effective automatic monitoring system of displacements is important. The use of own developed measurement system can save the cost of commercial software and does not need to buy the full sets of devices from original equipment manufacturer. Furthermore, the measuring program can customize the functions to satisfy the use of demands.
The linear variable differential transformer (LVDT) is a widely used displacement sensor, which has the advantage of high sensitivity and good linearity. The general signal amplifier on the market can be used for LVDT, which can meet the power supply requirement and return the measured voltage, but it has a high cost and cannot systematically use the LVDT for measurement. The LVM-110 voltage module can basically meet the power supply requirement and get the voltage output signal, which can be used to replace the signal amplifier. The LVM-110 voltage module is low-cost, stable output signal and low power supply requirement. In conjunction with the measuring program "aa.exe" having the automatic archiving function, data acquisition card (NI USB-6218), self-made power supply equipment, and LVDT, the automatic measurement system of displacements can be established.
Next, the sensitivity of the LVDT can be obtained from the laboratory testing experiment, and the results also showed that the LVDT has good linearity. Finally, to verify the accuracy of the measurement system, the INSTRON-8800 was used in the dynamic displacement validation experiment. The average errors of the measurement system are within the range of 1% to 3%, which is acceptably accurate.

[1] Bartoli G., Chiarugi A., and Gusella V., Monitoring Systems on Historic Buildings: The Brunelleschi Dome, Journal of Structural Engineering-Asce, 122(6), 663-673, (1996).
[2] Cao Y.H., Zhang Y., Zhao Y., and Wang M.L., Distributed Health Monitoring System for Zhanjiang Bay Bridge, Advances in Structural Engineering, 14(1), 1-12, (2011).
[3] Celebi M., and Sanli A., GPS in Pioneering Dynamic Monitoring of Long-Period Structures, Earthquake Spectra, 18(1), 47-61, (2002).
[4] Chang C.C., and Xiao X.H., An Integrated Visual-Inertial Technique for Structural Displacement and Velocity Measurement, Smart Structures and Systems, 6(9), 1025-1039, (2010).
[5] Fukuda Y., Feng M.Q., and Shinozuka M., Cost-Effective Vision-Based System for Monitoring Dynamic Response of Civil Engineering Structures, Structural Control & Health Monitoring, 17(8), 918-936, (2010).
[6] Gindy M., Nassif H.H., and Velde J., Bridge Displacement Estimates from Measured Acceleration Records, Transportation Research Record, (2028), 136-145, (2007).
[7] Gindy M., Vaccaro R., Nassif H., and Velde J., A State-Space Approach for Deriving Bridge Displacement from Acceleration, Computer-Aided Civil and Infrastructure Engineering, 23(4), 281-290, (2008).
[8] Jang S., Jo H., Cho S., Mechitov K., Rice J.A., Sim S.H., Jung H.J., Yun C.B., Spencer B.F., and Agha G., Structural Health Monitoring of a Cable-Stayed Bridge Using Smart Sensor Technology: Deployment and Evaluation, Smart Structures and Systems, 6(5-6), 439-459, (2010).
[9] Kaito K., Abe M., and Fujino Y., Development of Non-Contact Scanning Vibration Measurement System for Real-Scale Structures, Structure and Infrastructure Engineering, 1(3), 189-205, (2005).
[10] Kim S.H., Yoon C., and Kim B.J., Structural Monitoring System Based on Sensitivity Analysis and a Neural Network, Computer-Aided Civil and Infrastructure Engineering, 15(4), 309-318, (2000).
[11] Lee J.J., Fukuda Y., Shinozuka M., Cho S., and Yun C.B., Development and Application of a Vision-Based Displacement Measurement System for Structural Health Monitoring of Civil Structures, Smart Structures and Systems, 3(3), 373-384, (2007).
[12] Li H., Ou J.P., Zhao X.F., Zhou W.S., Li H.W., Zhou Z., and Yang Y.S., Structural Health Monitoring System for the Shandong Binzhou Yellow River Highway Bridge, Computer-Aided Civil and Infrastructure Engineering, 21(4), 306-317, (2006).
[13] Nakamura S., GPS Measurement of Wind-Induced Suspension Bridge Girder Displacements, Journal of Structural Engineering-Asce, 126(12), 1413-1419, (2000).
[14] Park H.S., Lee H.M., Adeli H., and Lee I., A New Approach for Health Monitoring of Structures: Terrestrial Laser Scanning, Computer-Aided Civil and Infrastructure Engineering, 22(1), 19-30, (2007).
[15] Park K.T., Kim S.H., Park H.S., and Lee K.W., The Determination of Bridge Displacement Using Measured Acceleration, Engineering Structures, 27(3), 371-378, (2005).
[16] Reynolds P., Pavic A., and Ibrahim Z., A Remote Monitoring System for Stadia Dynamics, Proceedings of the Institution of Civil Engineers-Structures and Buildings, 157(6), 385-393, (2004).
[17] Shin S., Lee S.U., Kim Y., and Kim N.S., Estimation of Bridge Displacement Responses Using FBG Sensors and Theoretical Mode Shapes, Structural Engineering and Mechanics, 42(2), 229-245, (2012).
[18] Stephen G.A., Brownjohn J.M.W., and Taylor C.A., Measurements of Static and Dynamic Displacement from Visual Monitoring of the Humber Bridge, Engineering Structures, 15(3), 197-208, (1993).
[19] Oppenheim, A.V., and Schafer, R.W., Discrete-time signal processing, Englewood Cliffs, NJ: Prentice Hall, (1989).
[20] Kwon Y.H., Butterworth Digital Filters, (1998).
[21] 林世豐、陳良基，「濾波器簡介」，Chip123，DSP專欄(2001)。
[22] 朱聖浩，「結構實驗」，國立成功大學土木工程研究所，結構實驗課程講義(2002)。
[23] 羅仕炫、林獻堂，「感測器原理與應用(含實驗)」，新文京開發出版股份有限公司(2003)。
[24] 許桂樹、陳克群，李怡銘，「感測器原理與應用」，金華圖書股份有限公司(2007)。
[25] 盧家鋒，「濾波器設計原理與應用實作：函式的定義與傳呼」，國立陽明大學物理治療暨輔助科技學系，醫學訊號分析原理與MATLAB程式應用實作課程講義(2013)。
[26] 劉立泰，「微振監測自動化系統程式之建立」，國立成功大學土木工程研究所，碩士論文(2004)。
[27] 邱建智，「監測自動化系統C程式之建立」，國立成功大學土木工程研究所，碩士論文(2012)。
[28] 李信昌，「層狀土壤受表面諧和負載、地震力作用下之地表振動特性與減振機制之研究」，國立成功大學土木工程研究所，博士論文(2013)。
[29] 郭百胤，「監測系統用於振動及變位量測之研究」，國立成功大學土木工程研究所，碩士論文(2013)。