【摘要】 在广义声发射检测理论和盲信号处理理论相结合的基础上,在假设两泄漏信号统计独立及检测噪声与信号统计独立的前提下,提出了一种基于双谱的管道两点泄漏定位方法,该方法在理论上可定位已经存在或正在发生的泄漏事故.依据该模型,按照独立信号双谱的特性,建立了两检测系统输出的自双谱和互双谱组成的方程组,巧妙地利用双谱域中的两条直线上的双谱值,推导了两泄漏点的定位理论公式.在双谱估计中,采用直接法和Han-ning-Poisson组合二维窗估计了观测序列的双谱值.在实验基础上,验证了该公式的正确性及该方法在工程上的可行性.实验结果表明:对于城市地下燃气管网,在0.01~0.09 MPa压力范围内,检测距离为28.6 m的情况下,定位绝对误差小于1.5 m.更多还原

【Abstract】 Based on the integration of generalized acoustic emission and the blind signal processing theory,and the hypothesis of statistical independences between the two leakage signals and between the signal and noise,a two-leak location bispectral method was presented,which can locate the existing or occurring leakage event theoretically.According to this model and the independence signal bispectrum theory,equation groups composed of auto-and cross-bispectrum were established.Two lines in the bispectral plane were involved to obtain the location expressions.Direct method and Hanning-Poisson window were used to estimate the bispectrum of the observation sequences.Feasibility and correctness of the model and location expressions were proved by experiments.Experimental results show that,for 0.01—0.09 MPa and 28.6 m of the urban buried natural gas pipelines,absolute location errors were less than 1.5 m.更多还原