Development of Sound Source Identification System Using Inverse Transmission-Line Matrix Modeling

将传输在线逆矩阵建模应用于声源识别系统。考虑了两种识别方法；一种是利用FFT的振幅分布，另一种是利用平均功率分布。数值模拟考虑了二维或三维声场。对几种声源进行了数值模拟。两种方法都能很好地识别出源，但FFT法受到衍射效应的影响，而不是功率法。结果表明，利用反传输在线矩阵模型可以有效地识别声源。对于测点间距大于客观声音波长的情况，不进行源识别。通过水下实验，超声换能器前几个位置的实测波形与计算得到的正向传播过程TLM解定性一致。然后将测量到的波形输入为反向传播而开发的计算机程序中。证实了声波向声源反向传播。

The inverse transmission-line matrix modeling is applied to a sound source identification system. Two identification methods are considered; one is the method using the amplitude distribution by FFT, and another is using the average power distribution. Two or three dimensional acoustic fields are considered for the numerical simulations. Some numerical demonstrations are made for several sound sources. The sources are well identified by both methods, but the FFT method is under the influence of the diffraction effect rather than the power method. It is found that the inverse transmission-line matrix modeling is capable for the sound source identification. The sources are not identified for the case that the separation of measurement points is lager than the wavelength of objective sound. Through the experiments under water, the measured wave forms at the several position in front of the ultrasonic transducer qualitatively agree with the calculated TLM solutions for the forward propagation process. The measured wave forms are then inputted into the computer program developed for the inverse propagation. It is confirmed that the sound waves propagate reversely to the sound source.