时分复用光纤光栅系统的边缘滤波解调与标定

Edge Filtering Demodulation and Calibration of Fiber Grating System Based on Time-Division Multiplexing

为实现高空间分辨率和高测量精度的准分布式光纤光栅应变传感系统,研究了基于时分复用光纤光栅传感系统的解调和标定方法。将波分复用和时分复用技术相结合,得到两个低反射率光纤光栅的应变灵敏度分别为33.40με/mV和38.47με/mV,标定的非线性误差为2.8%。基于光纤光栅光谱边缘滤波技术,构建时分复用光纤光栅应变传感系统,提出复用光纤光栅应变的交叉传感解调算法,实验测试并解调两个光纤光栅的交叉传感数据。实验分析表明,单次测量传感系统的最大误差为18με,应变量大于100με时的传感相对误差小于5%,满量程600με的引用误差小于2%。

To achieve the quasi-distributed fiber grating sensing system with high spatial resolution and high measurement accuracy, the demodulation and calibration methods for the fiber grating sensing system are studied based on the time-division multiplexing technology. By combining the wavelength-division multiplexing technique with the time-division multiplexing technique, the obtained strain sensitivities of the two fiber gratings with a low reflectivity are 33.40 με/mV and 38.47 με/mV, and the non-linear error of the calibration is 2.8%. A time-division multiplexing fiber grating strain sensing system is established based on the edge filtering technique of the fiber grating spectrum. The cross-sensing demodulating algorithm of the multiplexing fiber grating strain is derived, and we test and demodulate the cross-sensing data of the two fiber gratings by experiments. The results show that the maximum error of the sensing system for a single measurement is 18 με, the relative error is less than 5% under the condition that the strain is more than 100 με, and the quoted error is less than 2% when the full scale is 600 με.