基于时域积分的泄漏声波信号增强方法

在管道泄漏检测中,泄漏信号的信噪比是影响误报和漏报的主要因素。传统的小波去噪和EMD分解方法受小波基选择、分解尺度选择和重构分量选择的影响难以保证稳定、有效的信号增强效果。通过分析动态压力变送器的传递函数,发现动态压力变送器的输出信号中缺失了反映声波信号低频响应特性的积分项,提出了基于时域积分的、增益可调的泄漏声波信号增强方法,现场实测数据的测试结果表明:基于时域积分的泄漏信号增强方法具有稳定显著的信号增强效果和定位精度,无需复杂的参数寻优,为微小泄漏的检测以及减少误报和漏报提供了有效的技术支持。

Acoustic leak signal enhancement based on time-domain integration

Signal-to-Ratio (SNR) of leak signal is the main factor influencing on missing alarm and false alarm in pipeline leak detection. Traditional de-noising methods, such as wavelet transform and EMD decomposition, are hard to promise stable and effective signal enhancement because of the selection of wavelet base, decomposition scale or reconstruction components. Through analysis of the transfer function of dynamic pressure transducer, it is found that the integral part in the output signal of dynamic pressure transducer, which can reflect the low frequency response characteristics of acoustic signal, is missing. Therefore, a gain-adjustable acoustic signal enhancement method based on time-integration is proposed. The test results with field data show that the proposed method has better performance for the signal enhancement with precise location and no complex parameter optimization, and it also provides an effective technical support for small leak detection and decreasing of the missing and false alarm rate.