基于表贴式应变传递的光纤光栅匹配解调研究

Research on matched filtering demodulation of fiber Bragg grating based on surface attached strain transfer

  • 摘要: 光纤布拉格光栅传感器应用前景广阔,限制其大量实际应用的主要障碍是传感信号的高速高精度解调。介绍了一种匹配光栅滤波解调的方法及系统:数值模拟了反射式匹配滤波解调法,并对表贴式应变传递模型进行了改进,建立了光纤-胶体-压电堆叠三层模型,通过仿真确定了光纤光栅黏接在压电堆叠上的具体参数;搭建了匹配解调系统,探究了在压电堆叠上黏接多根光纤光栅来扩宽解调范围的方法,并以希尔伯特变换寻峰算法实现了光纤光栅中心波长的解调。黏接两根光纤光栅时系统的解调范围为1 540.121 nm~1 541.474 nm,最大偏差为8.6 pm,波动均值为5.4 pm,解调范围、精度、稳定性等性能指标良好,能够满足某些场景波长解调的需求。该解调系统具备一定的参考意义和实用价值。

     

    Abstract: The fiber Bragg grating sensor has a broad application prospect, and the main obstacle limiting its practical application is the high speed and high precision demodulation of the sensing signal. The article introduced a matching grating filtering demodulation method and system. The reflectance matching filtering demodulation method was numerically simulated, and the strain transfer model was improved to establish a three-layer model of fiber- adhensive-piezoelectric stack. The specific parameters of fiber Bragg grating bonding on the piezoelectric stack were determined by simulation. Finally, the matching demodulation system was constructed. The method of expanding the demodulation range by bonding multiple fiber Bragg gratings on the piezoelectric stack was explored, and the center wavelength demodulation of fiber Bragg grating was realized by Hilbert transform peak-finding algorithm. The demodulation range of the system is 1 540.121 nm-1 541.474 nm, the maximum deviation is 8.6 pm, and the mean fluctuation is 5.4 pm, whose demodulation range, precision and stability are good. It can meet the wavelength demodulation requirements in specific applications. The demodulation system has certain reference significance and practical value.

     

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