用于声学波束成形的传声器阵列设计与优化

Design and optimization of microphone array for acoustic beamforming

针对目前传声器阵列对于中低频声源(尤其200 Hz以下低频)识别分辨率低的问题,本文提出了一种基于波束成形算法的、对于中低频声源(150~2500 Hz)识别性能较好的传声器阵列。该传声器阵列采用渐开线螺旋臂的形式,多条螺旋臂围绕阵列中心均匀分布。采用田口法对阵列几何参数进行了选取和优化,分析出最佳参数组合和几何参数对螺旋阵列性能影响的贡献度大小。在最佳参数组合下,将本文提出的螺旋阵列与其他阵列结构进行对比分析。结果表明:该螺旋阵列的最佳参数组合为传声器个数30,孔径500 mm,旋臂数10,基圆半径110 mm;对于阵列综合性能影响最大的是传声器个数,贡献度为28.93%;其次是基圆半径和旋臂数,贡献度分别为22.76%和21.15%;影响最小的是孔径,贡献度为16.75%。对比结果表明:本文提出的阵列波束宽度系数CBW值最小,为433.590 m/Hz,分辨性能最佳;动态范围均值为7.03 d B,标准差为2.88 d B,动态性能良好。

Aiming at the problem that the current microphone array has low recognition resolution for medium and low frequency sound sources(especially low frequencies below 200 Hz),this paper proposes a microphone array design based on beamforming algorithm that has better recognition performance for medium and low frequency sound sources(150~2500 Hz).The microphone array adopts involute as the form of spiral arm,and multiple spiral arms are evenly distributed around the center of the array.The Taguchi method is used to select and optimize the geometric parameters of the array,and the optimal combination of parameters and the contributions of geometric parameters to the performance of the spiral array are analyzed.Using the best combination of parameters,the spiral array proposed in this paper is compared with other array designs.The results show that the best parameter combination of the spiral array is 30 microphones,500 mm aperture,10 arms,and base circle radius 110 mm;the parameter that has the greatest impact on the overall performance of the array is the number of microphones,with a contribution of 28.93%;The base radius and the number of arms contribute 22.76%and 21.15%,respectively;the smallest impact is the aperture,which contributes 16.75%.The comparison results show that the array beamwidth coefficient value proposed in this paper is the smallest,433.590 m/Hz,and the resolution performance is the best;the average dynamic range is 7.03 dB,the standard deviation is 2.88 dB,and the dynamic performance is good.