【摘要】 针对噪声和光功率衰减等影响相位敏感光时域反射仪（Φ-OTDR）对振动有效定位的问题，文章提出一种Φ-OTDR系统振动定位方法。该方法对Φ-OTDR系统经外差解调后的幅值信号应用萨维茨基-戈雷滤波器（Savitzky-Golay,SG）平滑滤波，并结合自相关分析，可以实现在低信噪比情况下的振动定位。采用河马优化算法优化SG滤波窗口大小和多项式拟合阶数，既能充分保留信号高频细节，又能防止过拟合而陷入局部最优。为验证所提方法的有效性，构建了外界振动和法兰松动实验，并将该方法和移动差分定位方法、连续平均-移动差分法进行对比。结果表明，所提方法信噪比提升效果最好，在相同的振动信号条件下，该方法处理后信噪比为9.93 dB，菲涅尔反射信噪比为2.34 dB，而移动差分方法分别为-2.16 dB和-1.37 dB。所提方法为振动定位及熔接头松动等故障的早期诊断提供了一种新的解决思路。更多还原

【Abstract】 Noise and optical power attenuation affect the capability of phase-sensitive optical timedomain reflectometry （Φ-OTDR） instruments to locate vibrations. In this study, we propose a vibration location method for Φ-OTDR systems to address this issue. The amplitude signal of a Φ-OTDR system after heterodyne demodulation can locate vibrations under conditions with low signal-to-noise ratio(SNR) using a smoothing Savitzky-Golay(SG) filter and an analysis of the autocorrelation function(ACF). The size of the window for SG filtering and the order of polynomial fitting were optimized using the hippopotamus optimization(HO) algorithm to fully retain high-frequency details of the signal and prevent overfitting or falling into a local optimum. We conducted experiments with external vibration and flange loosening in which the proposed HO-SG-ACF method was compared with moving-differential, continuous average moving-differential, and moving variance average methods. The results show that the proposed method achieved the most significant improvement in SNR. After processing the same vibration signal, the SNR obtained using the proposed method reached 9. 93 dB, whereas the Fresnel reflection method yielded an SNR of 2. 34 dB. In comparison, the moving-differential method resulted in SNRs of -2. 16 dB and -1. 37 dB, respectively. Thus, our findings demonstrate that the proposed method offers a new approach to localize vibration information and diagnose faults such as loose fusion splices earlier than would be possible with other methods.更多还原