基于零电平处信号导数分析的分布式光纤传感定位算法研究

A distributed sensing positioning algorithm based on derivative analysis at zero level of signal

为了提高基于双Mach-Zehnder干涉(DMZI)原理的分布式光纤传感系统的性能,提出一种基于零电平处信号导数分析的快速定位算法。利用信号在零电平处的导数大小,提取信号中最高频率附近的一段进行时延估计,进而获得扰动发生位置。由于提取信号的频率和带宽相对较大,因此系统的定位误差较小。与离散小波提取起始点信号相比,本文算法能够适应更多的扰动事件类型,且由于离散信号导数计算的复杂度远低于离散小波的傅里叶变换,运算时间大幅降低,提高了系统的实时性。实验结果表明,本文算法在10M/s采样率下,最大定位误差为20m,而且计算时间少于0.13s。

In order to improve the performance of dual Mach-Zehnder interferometer （DMZI） distributed optical fiber sensing system, a positioning algorithm based on signal derivative analysis is proposed in this paper. By means of the derivative value at the zero level of the signal, the algorithm first extracts high frequency part from the original signal and then delay estimation is carried out for this part of signal to get the invasion event location. Since the frequency and bandwidth of the extracted signal are relatively large,the positioning error of the system is small. Compared with extracting the signal of starting point by discrete wavelet,the algorithm can adapt to more vibration event types and due to the computation of derivative is much lower than the Fourier transform, the computation time is significantly reduced and the real-time performance is improved. Experimental results show that by using sampling rate of 10 M/ s,the algorithm has a low positioning error of 20 m and the processing time is less than 0.13 s. The performance of the system is improved.