针对有限光源带宽条件下光纤布拉格光栅传感网络重叠复用的解调瓶颈, 提出基于峰值匹配分布式估计算法的波长解调方法, 将光纤布拉格光栅传感网络重叠光谱的解调问题转化为函数优化问题, 利用理论光谱与重叠光谱之间的差异构建优化模型, 通过峰值匹配分布式估计算法对该优化模型进行求解得到各光纤布拉格光栅的传感值.分布式估计算法采用高斯混合模型构建描述光纤布拉格光栅传感网络的解空间概率分布, 由概率模型采样产生新的种群个体, 并引入峰值匹配算子消除光纤布拉格光栅峰值错配, 通过反复进化最终得到最优解.采用该方法对不同规模数量的光纤布拉格光栅传感网络进行解调实验, 结果表明该方法在大规模光纤布拉格光栅光谱完全重叠的情况下, 平均误差可控制在10 pm以内; 与现有其他解调技术相比, 其具有更高的解调精度, 能够解决光纤布拉格光栅传感网络光谱在部分重叠甚至完全重叠情况下的波长解调问题, 为提升光纤布拉格光栅传感网络复用数量提供了新的解调途径.

In order to address the wavelength demodulation of the overlapped spectra for the fiber Bragg grating sensor networks with limited source bandwidth, a wavelength demodulation method based on peak match estimation of distribution algorithm is proposed. The proposed method transforms the wavelength demodulation problem into a function optimization problem, where the optimization model is constructed through minimizing the difference between the theoretical spectra and the overlapped spectra. The peak match estimation of distribution algorithm is applied to solve the optimization model and obtain the sensing data for each fiber Bragg grating. Estimation of distribution algorithmutilizes the Gaussian mixture model to build probability distribution of the solution space for fiber Bragg grating sensor network, and the probability model can generate new individuals in the evolution of estimation of distribution algorithm. The peak match operator is introduced into the estimation of distribution algorithm to avoid the mismatch of the peak values of fiber Bragg gratings and obtain the final optimal solution. The experiments are conducted under different numbers of fiber Bragg grating sensor network using the proposed method. The experimental results demonstrate that the proposed method yields the mean errors within 10 pm for the large scale fiber Bragg grating sensor network even when the spectra of fiber Bragg gratings are completely overlapped. Compared with other demodulation methods, accuracy of the proposed method is higher, and it can well solve the wavelength demodulation problem when the spectra of fiber Bragg gratings within the network are partially or completely overlapped. The proposed method provides a new way to improve the multiplexing capability of fiber Bragg grating sensor networks.