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

将逆传输线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的幅值分布进行识别的方法，另一种是利用平均功率分布的方法。数值模拟中考虑了二维或三维声场。对几种声源进行了数值演示。两种方法都能很好地识别信号源，但FFT方法受绕射效应的影响比功率法大。结果表明，逆传输线矩阵建模方法能够较好地进行声源识别。当测点间距大于目标声的波长时，不能识别声源。通过水下实验，测得的超声换能器前方几个位置的波形与计算的正向传播过程的TLM解定性一致。然后将测量的波形输入到为反向传播开发的计算机程序中。证实了声波是向声源反向传播的。

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.