双声源位置和强度识别的三维声强方法

Identification of two sound sources using the three-dimensional sound intensity method

目前在远场识别声源空间位置和强度缺乏行之有效的方法。针对此问题,提出采用四传声器进行三维声强测量,从而构建出声强、声源坐标和声功率的非车线性方程组,求解方程得出声源空间坐标和强度的方法。以3个三维声强探头对两个同频率单极子声源的识别为例,分别利用数值仿真和半消声室内的实验进行方法验证,并对声源的识别空间分辨率做了测试,得出角度识别最大误差为3.83°,为真实值的8.5%,距离识别最大误差0.1 m,为真实距离的10%。结果表明采用该方法空间坐标和声功率识别均具有很高的准确度,双声源的空间位置分辨力也优于远场声全息方法。

At present,the methods such as near-field acoustic holography and far-field beamforming are widely used to obtain sound locations.However,it is still limited for methods to identify both the sound power and locations of multiple sources in the far field.The sound intensity as a vector in the sound field can be measured by a three-dimensional sound intensity probe,and multiple sampling points of the sound field can be obtained by multiple probes.Meanwhile,for single pole sound source,the sound intensity in the sound field can be calculated from the sound power and the location of the source.Based on this principle,the sound sources can be identified through solving the inverse problem of the sound intensity in the sound field.Taking two sound sources with the same frequency as the studying case,a nonlinear equation set is established by synthesis three-dimensional sound intensity vectors on three probes in the sound field.By solving the equation set with numerical method,the spatial position and sound power of each sound source are obtained.The method is verified by both the simulation and the experiments in semi-anechoic chamber.The experimental results show that the maximum error of angle recognition is 3.83 degrees,which is 8.5% of the real value,and the maximum error of distance recognition is 0.1 m,which is 10% of the real distance.The results show that the method has high accuracy on both locating the source and estimating the sound power.By comparing the experimental results to the far field acoustic holography method,the proposed method shows better discrimination on nearby sources.