本文選題：隧道監(jiān)測　切入點(diǎn)：分布式光纖傳感　出處：《南昌航空大學(xué)》2015年碩士論文

【摘要】：地鐵隧道是大型基礎(chǔ)設(shè)施中服役期限比較長的工程。鑒于地鐵隧道滲漏、結(jié)構(gòu)裂縫以及空間狹隘長、環(huán)境封閉的火災(zāi)威脅生命安全和造成經(jīng)濟(jì)損失,本課題進(jìn)行分布式光纖傳感技術(shù)在地鐵隧道監(jiān)測中的研究。本論文首先對分布式光纖傳感技術(shù)發(fā)展進(jìn)行了分析、比較和論述,重點(diǎn)論述布里淵光時(shí)域反射(BOTDR)技術(shù);接著研究布里淵散射傳感機(jī)理,建立布里淵散射與應(yīng)變和溫度傳感模型,為BOTDR傳感系統(tǒng)的研發(fā)奠定基礎(chǔ);然后分析了FFT算法和Mallat小波算法提取布里淵頻移信號(hào),比較兩種算法提取應(yīng)變布里淵頻移信號(hào)靈敏度,從而提高測量精度;最后利用LabVIEW開發(fā)平臺(tái)編程實(shí)現(xiàn)虛擬BOTDR傳感系統(tǒng)監(jiān)測地鐵隧道VI程序,同時(shí)通過仿真測試結(jié)果進(jìn)行分析得出該系統(tǒng)能很好的滿足本課題的要求。本文的主要工作和研究成果如下:(1)設(shè)計(jì)并實(shí)現(xiàn)了基于LabVIEW的BOTDR傳感系統(tǒng)監(jiān)測地鐵隧道VI程序。通過仿真虛擬應(yīng)變和溫度的監(jiān)測與實(shí)際監(jiān)測相比,誤差分別大約為1.82%和8.33%。該結(jié)果表明搭建的虛擬監(jiān)測系統(tǒng)比較理想,從而在沒有硬件條件下,虛擬器件代替實(shí)體器件、虛擬處理,自定義模塊和函數(shù),通過修改參數(shù)設(shè)置來完成對布里淵散射分布式光纖傳感技術(shù)的研究,從而大大降低了成本。(2)對本課題的BOTDR傳感系統(tǒng)虛擬程序,采用了新的、穩(wěn)定的“狀態(tài)機(jī)和事件結(jié)構(gòu)結(jié)合”的設(shè)計(jì)模式。該設(shè)計(jì)模式能夠很好解決基本狀態(tài)機(jī)的問題,從而提高了程序運(yùn)行效率。該系統(tǒng)VI程序獨(dú)特之處還有設(shè)計(jì)了數(shù)據(jù)采集存儲(chǔ)模塊,通過LabVIEW和數(shù)據(jù)庫Access的連接,建立地鐵隧道參數(shù)數(shù)據(jù)庫,有利于儲(chǔ)存地鐵隧道參數(shù)重要信息,根據(jù)這些重要的參數(shù)信息加強(qiáng)隧道科學(xué)管理和提高隧道技術(shù)水平。(3)建立了基于FFT算法對BOTDR傳感系統(tǒng)中的布里淵頻移信號(hào)的頻譜分析技術(shù)以及基于Mallat小波算法對布里淵頻移信號(hào)特征提取。通過對比兩種算法對布里淵頻移信號(hào)的分析,Mallat小波算法能夠更快速準(zhǔn)確提取布里淵散射信號(hào)特征,從而為實(shí)際沿光纖檢測信號(hào)的特征提取提供了重要參考意義,而且該算法對于其它分布式光纖傳感技術(shù)有很好的參考價(jià)值,通用性很強(qiáng)。
[Abstract]:The subway tunnel is a project with a long service life in a large infrastructure. In view of the leakage of subway tunnel, structural cracks and narrow space, fire in closed environment threatens the safety of life and causes economic losses. In this paper, the development of distributed optical fiber sensing technology is analyzed, compared and discussed, with emphasis on Brillouin optical time domain reflectance (BOTDR) technology. Then the Brillouin scattering sensing mechanism is studied, and the Brillouin scattering and strain and temperature sensing models are established, which lays the foundation for the research and development of BOTDR sensing system, and then analyzes the FFT algorithm and Mallat wavelet algorithm to extract Brillouin frequency shift signals. The sensitivity of strain Brillouin frequency shift signal is obtained by comparing the two algorithms, and the measurement accuracy is improved. Finally, virtual BOTDR sensor system is programmed to monitor VI program of subway tunnel by using LabVIEW development platform. At the same time, through the analysis of the simulation test results, it is concluded that the system can meet the requirements of this subject very well. The main work and research results of this paper are as follows: 1) designed and realized the BOTDR sensor system based on LabVIEW to monitor the VI distance of subway tunnel. By simulating the virtual strain and temperature monitoring, compared with the actual monitoring, The error is about 1.82% and 8.33%, respectively. The results show that the virtual monitoring system is ideal, so that the virtual device can replace the physical device, the virtual processing, the custom module and the function without hardware. The research of Brillouin scattering distributed optical fiber sensing technology is completed by modifying the parameter setting, thus greatly reducing the cost. The stable design pattern of "combining state machine with event structure" can solve the problem of basic state machine well and improve the running efficiency of program. The VI program of the system is unique, and the module of data acquisition and storage is also designed. Through the connection of LabVIEW and database Access, the subway tunnel parameter database is established, which is helpful to store the important information of subway tunnel parameters. According to these important parameter information, we strengthen the scientific management of tunnel and improve the technical level of tunnel. We establish the spectrum analysis technology of Brillouin frequency shift signal in BOTDR sensor system based on FFT algorithm and the analysis of Brillouin frequency shift signal based on Mallat wavelet algorithm. By comparing the two algorithms to analyze Brillouin frequency shift signal, Mallat wavelet algorithm can extract Brillouin scattering signal features more quickly and accurately. It provides an important reference for the feature extraction of the detection signal along the optical fiber, and the algorithm has a good reference value for other distributed optical fiber sensing technology, and has a strong versatility.
【學(xué)位授予單位】：南昌航空大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U456.3;TN253

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相關(guān)期刊論文 前2條

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本文編號(hào)：1684408