A Partition Spatial Filtering Method for Acoustic Array Configuration

Zhihong Liu,Chuijie Yi,Zunmin Liu,Ming Ma,Xilong Zhang,Rafał Burdzik

doi:10.1155/2021/6682923

Zhihong Liu, Chuijie Yi + Show 4 more

Open Access

https://doi.org/10.1155/2021/6682923

Copy DOI

Abstract

Acoustic array is a ubiquitous tool for locating and quantifying sound sources. However, its effectiveness depends greatly on the array configuration. This paper presents an array configuration method to enhance array performance, especially on the spatial resolution and the Doppler effect correction. The problem of array configuration is formulated into a position matrix determined by introducing partition spatial filtering. Irregular coaxial ring grid spacings and partition filtering conditions are suggested to control array spatial resolution. Geometrical parameters and performance indicators are constructed to quantify the relationships between the array configuration and performance. Based on these quantitative relations, the spatial variation of the array beam pattern and the Doppler effect has got adaptive adjustment. In particular, an adaptive partition algorithm is proposed to reduce computation time. The performance of the method is examined numerically and experimentally, which is compared with the other methods. The results provide the method to guide the design of a 64-microphone optimized array with high performance (1.8° spatial angle resolution and 40% Doppler frequency correction over the bandwidth from 800 Hz to 3000 Hz) and fast computing speed (18 s array generated time for 2000 arrays). Furthermore, an unusual feature of the method is that it can be utilized in the case when the source moves at a nonconstant velocity.

Highlights

Acoustic array techniques are applied for moving sources, such as cars [1], trains [2], airplanes [3,4,5], and wind turbines [6,7,8]
Adaptive Partition Filtering e performance of an irregular array, the mainlobe width, and the peak sidelobe level depends on the aperture size and the way of the microphones disposed on the grid points
Partition filtering conditions, which takes into account the sound field characteristics and array properties, were determined to quantify the relationship between the array configuration and performance. ose relations are significant to resolve the inevitable variance of array beampattern and the Doppler effect, especially for making moving wideband sources measure possible. e problem of array configuration was formulated into position matrix determinants and solved fast by employing the adaptive partition algorithm

Summary

Introduction

Acoustic array techniques are applied for moving sources, such as cars [1], trains [2], airplanes [3,4,5], and wind turbines [6,7,8]. A lot of research studies have been conducted to enhance array performance by employing maximum sidelobe level (MSL) [22], synthesizing mainlobe width (MW) and MSL [23], adopting product of frequency-averaged MLW and MSL [24, 25], using statistical characteristics of MW and MSL [18], and utilizing the relative variances of MW and MSL [26,27,28] Those methods have the ability to cover large apertures with quite few microphones, low MSL in a wide range of frequencies, and good geometry symmetry, there are some challenges in designing the high performance irregular array for the localization of moving sources. Compared with the popular irregular arrays such as logical spiral wheel array and pizza array, partition optimized array has shown superior array performance especially resolution and corrected ability of Doppler effect. e method is more suitable for designing irregular array to localize moving wideband sources

Irregular Grid Array for Moving Sources

Experiments

Findings

Conclusions