基于麦克风阵列的声源定向教学实验系统设计

Design of teaching experiment system of sound source direction finding based on microphone array

定向实验是帮助雷达、声纳、通信专业的学生理解波束形成、目标定向等概念的重要手段。现有的实验往往需要在消声水池、微波暗室等大型实验室内进行,设备昂贵、场地有限,不适宜为广大初学者开设实验。基于廉价的麦克风阵列设计实现了一套空气声源定向实验系统,它用PC机采集卡采集信号,以步进电机、激光笔进行目标指示,并用Matlab GUI编制了软件系统图形化界面和多种阵列处理算法。实验系统测试结果表明,该系统对宽带语音声源具有时域频谱分析和空域波束定向的能力,在单目标定向时具有较高的精度和稳定度,在多目标定向时也有一定的分辨能力。

For students majoring in radar and sonar,the direction-finding experiment acts as an important mean to help them understand some obscure concepts,such as beam-forming and direction finding.Nowadays,the experiment is always done in anechoic pool or microwave darkroom.However,it＇s unsuitable for a mass of abecedarians,not only because of exorbitant devices and high cost,but also for the limitation of space.This paper introduces the design and development of an air sound source direction finding experiment system based on low-cost microphone array.Acquisition card plugged in PC was employed for sampling the signals,while a motor and a laser pen were employed for pointing the direction of target.The graphic interface and some algorithms of array signal processing of system were designed by using Matlab GUI.The test results show that the system was capable of spectral analyzing in time domain and beam-forming in space domain for wide-band speech signals.The system can give a stable accuracy bearing estimation of one target,and show preferable resolution ability for multiple targets.