本文選題：農(nóng)田測溫 + 光纖傳感��； 參考：《吉林農(nóng)業(yè)大學(xué)》2015年碩士論文

【摘要】：針對農(nóng)業(yè)發(fā)展趨勢及農(nóng)業(yè)耕作技術(shù)的發(fā)展現(xiàn)狀和實際問題,本文研究了溫度對農(nóng)業(yè)生產(chǎn)的影響尤其是耕作層土壤溫度對農(nóng)業(yè)的直接影響。本文進(jìn)行了新興的光纖傳感技術(shù)在農(nóng)業(yè)上應(yīng)用的可能性的研究,并對農(nóng)業(yè)免耕技術(shù)等保護(hù)性耕作方式存在的問題進(jìn)行分析,基于光纖傳感理論分析進(jìn)行系統(tǒng)選型研究,根據(jù)不同光纖測溫原理的不同,可以集成多種光纖傳感測溫系統(tǒng)。并主要分析并比較這幾種系統(tǒng)的特點并選擇最適合大面積農(nóng)田應(yīng)用的分布式光纖溫度傳感系統(tǒng),對光纖傳感系統(tǒng)測溫原理進(jìn)行深入的研究,分析了光波在光纖中傳輸?shù)纳⑸洮F(xiàn)象,找到包含溫度信息的散射光,對拉曼散射中的斯托克斯光和反斯托克斯光的物理關(guān)系進(jìn)行研究,對土壤溫度傳感系統(tǒng)溫度定標(biāo)之后,只要測量出Anti-Stokes和Stokes光強度,就能確定分布式光纖溫度傳感系統(tǒng)中光纖各個點的溫度值,從而確定溫度場的分布情況。通過各種種類測溫原理特點的研究,確定最適合大面積農(nóng)田測溫系統(tǒng)的最佳光纖傳感溫度解調(diào),測量類型。對光時域反射技術(shù)進(jìn)行研究,從而保證系統(tǒng)中反映的光纖中各點溫度信息與位置信息相互對應(yīng)。對耕作層土壤溫度的長距離/大面積實時監(jiān)測進(jìn)行了研究分析以及實驗。本文對系統(tǒng)設(shè)計中關(guān)鍵技術(shù)問題進(jìn)行了說明,并對具體實施的硬件搭建,系統(tǒng)定位技術(shù),溫度解調(diào)技術(shù),波分復(fù)用技術(shù)進(jìn)行了深入的研究,并對相應(yīng)的系統(tǒng)硬件進(jìn)行了調(diào)研,采購,測試與系統(tǒng)集成。本文也詳細(xì)介紹了相關(guān)硬件的技術(shù)指標(biāo),同時對測溫系統(tǒng)操作軟件的開發(fā)思路及軟件應(yīng)用方法進(jìn)行了解析。通過對面積農(nóng)田測溫系統(tǒng)定標(biāo)方法進(jìn)行研究,總結(jié)出具體的實驗定標(biāo)方法和A,B,K常數(shù)定標(biāo)公式及實驗方法。通過實驗得出應(yīng)用于大面積農(nóng)田的新定標(biāo)方法。除了實現(xiàn)對大面積農(nóng)田土壤的溫度分布情況實時的檢測,并定期儲存數(shù)據(jù)的基本功能外,還要實現(xiàn)定溫報警和故障報警兩個主要功能。定溫報警功能是結(jié)合農(nóng)作物的三基點溫度為基礎(chǔ)的分級報警并指明溫度對應(yīng)的地理位置。故障報警功能是根據(jù)鋪設(shè)在大面積農(nóng)田上的傳感光纜長度范圍內(nèi)采集到的電壓值得強弱判斷是否出現(xiàn)光纜斷裂或破損。最后對系統(tǒng)進(jìn)行了長期的試運行實驗,并針對長期運行過程中遇到的溫漂問題做了詳細(xì)的實驗與研究。成功解決溫漂問題之后,對系統(tǒng)的溫度分辨率、空間分辨率、測量長度、測量精度、系統(tǒng)響應(yīng)時間等做了全面優(yōu)化,系統(tǒng)實最終最大測量距離10公里,空間分辨達(dá)到1m,溫度精度達(dá)到1℃,系統(tǒng)響應(yīng)時間小于4s。
[Abstract]:In view of the development trend of agriculture and the present situation and practical problems of agricultural tillage technology, this paper studies the effect of temperature on agricultural production, especially the direct influence of soil temperature on agriculture. In this paper, the possibility of the application of new optical fiber sensing technology in agriculture is studied, and the problems of conservation tillage such as no-tillage technology are analyzed, and the system selection based on the theoretical analysis of optical fiber sensing is studied. According to the different optical fiber temperature measuring principle, many kinds of optical fiber sensing temperature measuring system can be integrated. The characteristics of these systems are analyzed and compared, and the distributed optical fiber temperature sensing system, which is the most suitable for the application of large area farmland, is selected, and the principle of temperature measurement of the optical fiber sensing system is deeply studied. The scattering phenomenon of light wave in optical fiber is analyzed, the scattering light containing temperature information is found, the physical relationship between Stokes light and anti-Stokes light in Raman scattering is studied, and the temperature calibration of soil temperature sensing system is carried out. Once the light intensity of Anti-Stokes and Stokes is measured, the temperature values of each point in the distributed optical fiber temperature sensing system can be determined, and the distribution of the temperature field can be determined. Through the study of the principle and characteristics of various kinds of temperature measurement, the optimum temperature demodulation and measurement type of optical fiber sensor which is most suitable for large area farmland temperature measurement system is determined. The optical time domain reflection (OTDR) technique is studied to ensure that the temperature information and the position information of the optical fiber reflected in the system correspond to each other. The long distance / large area real time monitoring of soil temperature in tilling layer was studied and analyzed. In this paper, the key technical problems in the system design are explained, and the system hardware construction, system positioning technology, temperature demodulation technology, wavelength division multiplexing technology are deeply studied, and the corresponding system hardware is investigated. Procurement, testing and system integration. This paper also introduces the technical specifications of the related hardware in detail, and analyzes the development idea and the application method of the operating software of the temperature measuring system at the same time. Based on the study of the calibration method of the area temperature measurement system, the specific experimental calibration method, the formula and the experimental method for the calibration of the BK constant of the area are summarized. A new calibration method applied to large area farmland was obtained through experiments. Besides the basic function of detecting the temperature distribution of large area farmland in real time and storing the data periodically, the two main functions of fixed temperature alarm and fault alarm are also realized. The function of constant temperature alarm is based on the three basis point temperature of crops and indicates the geographical position of the corresponding temperature. The function of fault alarm is to judge whether the cable is broken or broken according to the voltage collected in the length range of the sensor cable laid on a large area of farmland. Finally, the system is tested for a long time, and the temperature drift problem encountered in the long run is studied in detail. After successfully solving the temperature drift problem, the system's temperature resolution, spatial resolution, measurement length, measurement precision, system response time and so on are optimized. The spatial resolution is 1 m, the temperature precision is 1 鈩，

本文編號：1903581