一种基于干涉型光纤振动传感器的信号处理方法

A Signal Processing Method Based on Interferometric Optical Fiber Vibration Sensor

对双Sagnac干涉仪进行了改进设计并提出了一种简单有效的信号处理方法.利用波分复用技术使不同波长的Sagnac干涉仪具有唯一独立的干涉光路进而产生稳定干涉信号.解调后相位信号均由2个具有时延的子信号叠加构成但不具有直接相关性,经延时或超前处理重构成一组具有固定时延差的高相似性信号.运用互相关时延估计方法可快速解算出扰动发生位置.仿真和人为扰动的测试结果表明此定位算法具有实用性和稳定性.实验结果与理论分析的一致性表明针对改进型双Sagnac干涉仪提出的信号处理方法是行之有效的,在长距离周界安防等领域具有应用前景.

In this paper,structure of a dual-Sagnac interferometer is improved and a simple and effective signal processing method is proposed.Due to wavelength division multiplexing technology,dual Sagnac interferometers with different wavelengths have their own unique and independent interference optical path.Then light beams recombine and produce stable interference signals.After demodulation,phase signals are composed of two sub-signals with different delay but not directly related.After delay or advance processing,two high similarity signals with a fixed delay difference are reconstructed.Location of disturbance can be calculated efficiently by means of time delay estimation based on cross-correlation algorithm.Test results of simulation and artificial disturbance show that the positioning algorithm is practical and stable.The agreement between experimental results and theoretical analysis indicates that the proposed signal processing method for this improved dual-Sagnac interferometer is effective and has application prospect in many areas such as long-range perimeter security.