In order to obtain effective and intuitive acoustic characteristics,the energy distribution of acoustic signal during the leakage process of natural gas pipelines was clearly portrayed based on the Hilbert-Huang transform (HHT)method.Acoustic signals were acquired by experiments and then processed by using the empirical mode decomposition to obtain intrinsic mode functions(IMFs).The IMFs were transformed by HHT to get the instantaneous frequency,Hilbert spectrum and marginal spectrum.According to the time-frequency spectrum acquired by HHT of the acoustic signals in field measurements,effective acoustic characteristics were extracted.The results show that the acoustic signals can be processed by HHT to extract effective characteristics,which can provide a criterion for leak detection.%为获得有效直观的音波特征量，采用基于希尔伯特-黄变换的时频分析方法对输气管道泄漏音波能量分布清晰刻画。通过搭建实验管道获得泄漏信号，并对该信号进行经验模态分解（EMD）获得有限数量的固有模态函数（IMF），对 IMF 进行希尔伯特变换求解瞬时频率，获得信号的时频谱、边际谱；对实验所得泄漏信号进行希尔伯特黄变换，获得信号时频谱；据所得时频谱分析泄漏音波信号特性，获得有效音波特征量。结果表明，希尔伯特黄变换能清晰刻画音波信号的时频域特性，通过希尔伯特黄变换可获得输气管道泄漏音波信号的有效特征量，从而为泄漏检测技术提供支持，进而为输气管道音波法泄漏检测技术应用奠定基础。
展开▼
