光纤光栅传感器双光栅匹配解调法的深入研究
文献类型：学位论文
| 作者 | 裴金成 |
| 学位类别 | 硕士 |
| 答辩日期 | 2007 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 向世清 |
| 关键词 | 光纤传感 光纤光栅传感器 解调技术 双光栅匹配解调法 |
| 其他题名 | Further Study on Two Matched Gratings Interrogation Method of Fiber Grating Sensor |
| 中文摘要 | 双光栅匹配解调法是一种已经具备商用化前景的波长解调技术，但是其目前仍存在原理上的非连续线性、解调范围小等缺点。本论文在其已有基础上进行了进一步的深入研究，在解决其所存在的三方面的问题中取得了良好的成果，为研制出高性能、低成本、满足绝大多数实际工程需求的匹配光栅解调系统做出了实际的努力。 主要工作包括以下三个方面： 提出了一种线性解调理论模型，研究表明，若两个解调光栅的带宽相等，则两个探测器输出电压之比的对数与被测传感光栅的中心波长呈严格的线性关系。考虑实际情况中存在偏置电压的问题，对该模型进行了必要的修正。将该线性解调模型用于光纤光栅应变传感系统的信号解调，并进行了实验验证。实验表明，解调系统的输入输出具有非常好的线性关系，拟合线性度达到0.999以上。实验的测试结果中也确实发现存在偏置电压。在消除部分偏置电压后，系统的灵敏度得以提高了十多倍，线性解调范围也扩大了一倍以上。 研究了可调谐双光栅匹配解调系统，该系统结合了双光栅匹配解调法解调速度快和扫描解调法解调范围大的优点，扩大了原有系统的解调范围，增强了解调系统的实用性。同时，调谐技术的引入，也使得该系统具备了同时解调多个光栅中心波长的能力，相应的原理也在本文得到了讨论。由此所设计的系统动态响应速度不受扫描速度的影响，可消除光强抖动所带来的随机误差，数据处理更为简单，实用化前景更好。 提出了一种可消除交叉敏感的双光栅解调系统，从理论上证明了其消除交叉敏感的能力。该系统只要将解调光栅之一置于与传感光栅相同的温度环境中（不受应变影响），使其同时发挥解调光栅和温度补偿光栅的作用，就能实现温度和应变的分离。另外，另一解调光栅的中心波长受一温度控制器的控制，通过温度调谐，可以保证系统的解调范围不受环境温度变化的影响。 将三方面的进展整合进一个新型的光纤光栅传感器解调系统并由此构成新颖的光纤光栅传感器系统，具有响应速度快，测量精度高、重复性好、数据处理方式简单、结构简单、成本低等优势，将会为光纤光栅传感器的不断发展提供新的方式架构。这一创新性工作也是本文研究整体上的一个收获。 |
| 英文摘要 | Two matched gratings interrogation technique is a newly interrogation method of fiber Bragg grating sensor. There are some problems in this method remaining to be studied further, such as theoretically non-continuum linear, small interrogation range, and so on. So this dissertation aimed at further studying of these problems. After studying three styles of changes to the existing structure of the two matched gratings interrogation technique, some favorable results obtained. The results show that, the study here will be great helpful to improve the application capabilities of FBG interrogation system on high performance, low cost, and all kinds of engineering requirements. The main contents including: A “real linear” demodulation theory model is proposed and studied. It shows that, a linear formula between the logarithm of the output ratio and centre wavelength of the sensing FBG can be obtained if the bandwidth of the two interrogation FBGs are equal. The model was modified with consideration of the fact that the output of the detectors have added voltage offset. The linear interrogation model was experimentally investigated. The results show that, the input-output of the interrogation system has perfect linear relation, and the draft linearity reached to more than 0.999. After eliminating part of the added voltage offset, the sensitivity was improved more than 10 times and the linear interrogation range was extended more than 1 times. A tunable two matched gratings interrogation system was proposed and studied. It combined the advantages of the fast response speed in two matched gratings interrogation method and large interrogation range in scanning interrogation method, extended the interrogating range of the former system, and enhanced the practicability of the systems. With the introduction of tuning technology, several Fiber Bragg Gratings’ wavelengths can be demodulated by one interrogation system, and the corresponding theory has been discussed. The dynamic response rate is not influenced by scanning speed. The system eliminates the random error introduced by source intensity fluctuating, and benefits to simpler data process manner and better commercial foreground. A FBG sensor system with cross-sensitivity discrimination based on two matched gratings interrogation technique was also designed and studied. With one interrogation grating playing the role of temperature compensation grating simultaneously, the discrimination of wavelength drifts induced by temperature and strain was resolved, at the same time, it holds the advantages of the existing two matched gratings interrogation method. Besides, another interrogation grating was stick on a temperature controller so that the change of environment temperature can not influence the dynamic range of the sensor system. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16598]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 裴金成. 光纤光栅传感器双光栅匹配解调法的深入研究[D]. 中国科学院上海光学精密机械研究所. 2007. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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