基于光频域反射技术的光纤传感网络研究

Research on optical fiber sensor network based on optical frequency domain reflection technology

研究基于光频域反射技术的光纤传感网络,提升待监测对象温度与应变的测量精度。在光频域反射技术基础上引入光纤Bragg光栅技术,构建具有分立式与分布式的两层混合式光纤传感网络;分立式光纤传感网络层利用光纤Bragg光栅技术解调光栅放射光中心波长变化量,获取待监测对象温度值;分布式光纤传感网络层通过计算光纤瑞利散射的光谱平移量实现应变的连续分布式传感,利用频域干涉测量法,计算光纤传感器中心波长变化量,获取待监测对象应变值。同时两层混合式光纤传感网络利用傅立叶插值后的互相关法提高光谱平移量的光谱分辨率,提升光纤传感网络的测量精度。实验证明:所研究光纤传感网络测量的中心波长值与实际温度值、应变值拟合程度高,测量精度高。

The optical fiber sensor network based on optical frequency domain reflection technology is studied to improve the measurement accuracy of temperature and strain of the object to be monitored. Based on the optical frequency domain reflection technology,the fiber Bragg grating technology is introduced to construct the two-layer hybrid fiber sensing network with separation and distribution. The segmented fiber sensing network layer uses the fiber Bragg grating technology to demodulate the wavelength change of the emitting optical center of the grating to obtain the temperature value of the object to be monitored. The distributed fiber sensor network layer realizes the continuous distributed sensing of strain by calculating the spectral translation of Rayleigh scattering of the fiber. The frequency domain interferometry method is used to calculate the central wavelength variation of the fiber sensor and obtain the strain value of the object to be monitored. At the same time,the two-layer hybrid fiber sensor network uses Fourier interpolation cross-correlation method to improve the spectral translation of the spectral resolution and improve the measurement accuracy of the fiber sensor network. The experimental results show that the central wavelength value measured by the optical fiber sensor network has a high fitting degree with the actual temperature value and strain value,and the measurement precision is high.