Zan Ming, Xu Zhongming, Huang Linsen, Zhang Zhifei
State Key Laboratory of Mechanical Transmission, Chongqing University, 174 Shazhengjie, Chongqing 400044, China.
College of Automotive Engineering, Chongqing University, 174 Shazhengjie, Chongqing 400044, China.
Sensors (Basel). 2020 Feb 6;20(3):865. doi: 10.3390/s20030865.
Near-field acoustic holography (NAH) based on equivalent source method (ESM) is an effective method for identifying sound sources. Conventional ESM focuses on relatively low frequencies and cannot provide a satisfactory solution at high frequencies. So its improved method called wideband acoustic holography (WBH) has been proposed, which has high reconstruction accuracy at medium-to-high frequencies. However, it is less accurate for coherent sound sources at low frequencies. To improve the reconstruction accuracy of conventional ESM and WBH, a sound source identification algorithm based on Bayesian compressive sensing (BCS) and ESM is proposed. This method uses a hierarchical Laplace sparse prior probability distribution, and adaptively adjusts the regularization parameter, so that the energy is concentrated near the correct equivalent source. Referring to the function beamforming idea, the original algorithm with order can improve its dynamic range, and then more accurate position information is obtained. Based on the simulation of irregular microphone array, comparisons with conventional ESM and WBH show that the proposed method is more accurate, suitable for a wider range of frequencies, and has better reconstruction performance for coherent sources. By increasing the order , the coherent sources can be located accurately. Finally, the stability and reliability of the proposed method are verified by experiments.
基于等效源法(ESM)的近场声全息术(NAH)是一种识别声源的有效方法。传统的等效源法侧重于相对较低的频率,在高频时无法提供令人满意的解决方案。因此,人们提出了其改进方法——宽带声全息术(WBH),该方法在中高频具有较高的重建精度。然而,对于低频的相干声源,其精度较低。为了提高传统等效源法和宽带声全息术的重建精度,提出了一种基于贝叶斯压缩感知(BCS)和等效源法的声源识别算法。该方法采用分层拉普拉斯稀疏先验概率分布,并自适应调整正则化参数,使能量集中在正确的等效源附近。借鉴函数波束形成的思想,将原有的 阶算法进行改进,可以提高其动态范围,进而获得更准确的位置信息。基于不规则麦克风阵列的仿真,与传统等效源法和宽带声全息术的比较表明,该方法更准确,适用于更宽的频率范围,对相干源具有更好的重建性能。通过增加阶数 ,可以准确地定位相干源。最后,通过实验验证了该方法的稳定性和可靠性。