矢量传声器多基融合定位

矢量传声器在目标声源方位(Direction of Arrival,DOA)估计方面具有天然的优势性能。在单矢量传声器实现目标声源DOA估计的基础上,利用交叉定位的思想推导多矢量传声器融合实现目标定位的模型,并给出模型的总体最小二乘解。针对奇异方位角影响估计精度的问题,利用圆概率偏差确定有效方位角后再进行融合定位。仿真分析与定位验证实验的结果表明,该方法可以实现目标声源位置估计,在消声室环境下具有较好的定位精度,有效性和实用性较强。

基于单声矢量传声器虚拟扩展的多机动声目标跟踪算法

为解决单声矢量传声器(Acoustic vector sensor,AVS)可跟踪声目标数目少、跟踪性能差的问题,提出了基于AVS虚拟扩展的多机动声目标跟踪算法.首先,引入高阶累积量预处理过程并建立高阶似然函数,不仅能够抑制高斯噪声、提高估计精度,还可通过AVS的虚拟扩展增加可跟踪目标数目.然后,在边缘化δ广义标签多伯努利(Marginalizedδ-generalized label multi-bernoulli,Mδ-GLMB)滤波框架下,提出了基于累积量的增广运动模型状态的Mδ-GLMB(Cumulants-based augumented motion model state Mδ-GLMB,Cum-AMMS-GLMB)算法.算法引入多种运动模型,并将表征不同模型的索引标号作为目标状态的增广参数,通过各模型间的加权混合获取优于单一运动模型的跟踪性能.除此之外,算法的序贯蒙特卡洛(Sequential Monte Carlo,SMC)实现过程中,依据高阶预处理获得的归一化空间谱拟合检测概率函数,抑制了杂波向可用粒子扩展,进一步增强了高似然区域的粒子.最后,推导了AVS目标跟踪的后验克拉美罗下界(Posterior cram e’r-rao lower bound,PCRLB),并通过仿真实验验证了算法的量测噪声抑制能力和声目标跟踪性能.

使用脉冲声和矢量传声器的现场测量吸声系数

使用不同声源利用矢量传声器对毛毡材料进行现场吸声系数测试,研究了不同背景下不同声源的抗噪能力。矢量传声器可以同时测得声压和质点振速信号,进而可计算得到阻抗,利用自由空间和材料表面的阻抗可计算得到材料的吸声系数。在此次实验中,使用不同声源分别在无干扰和有一白噪声干扰源的两种情况下进行测试。结果表明,使用对数扫频脉冲和巴特沃斯脉冲测试所得的吸声系数曲线更平滑,说明脉冲声可以有效降低环境反射的影响,在高噪声背景下使用对数扫频脉冲测试所得的结果基本没有受到背景噪声的影响,说明对数扫频脉冲的抗噪能力更强。因此,使用对数扫频脉冲作为声源进行测试可有效减弱环境反射和背景噪声的影响。

基于规范多元张量分解的矢量传声器阵列定向算法研究

针对矢量传声器阵列接收信号模型具有多维结构信息的特性,提出了一种基于规范多元张量分解的阵列定向算法。得益于三阶张量模型结构,相较于传统基于矩阵分解的参数估计方法,该算法可最大化利用接收信号的多维信息,获得更高精度的定向估计性能。通过理论分析证明了该算法可以满足分解唯一性条件,通过数值仿真实验证明了该算法在低信噪比和小快拍数条件下均优于传统定向算法。

MEMS矢量传声器低噪声优化设计

MEMS矢量传声器是目前已知的唯一一种可以直接精确测量声场质点振速的声学传感器,在噪声振动测量、材料特性分析以及国防领域有着广泛的应用前景。矢量传声器的自噪声水平直接影响了目标声源的有效探测距离和定向精度,是MEMS矢量传声器研制与应用的关键。本文在研究MEMS矢量传声器工作机理的基础上,分析得出敏感结构的电源模块自噪声是影响MEMS矢量传声器自噪声水平的主要因素之一。因此,本文设计制作了基于LT3045-1的低噪声电源模块,经测试其自噪声水平已接近铅酸电池。随后,将该电源模块应用于MEMS矢量传声器,有效改善了矢量传声器的自噪声性能,测得传声器自噪声水平接近于国外同类型MEMS矢量传声器产品,实现了国产低噪声矢量传声器优化制作。

矢量传声器线阵指向特性研究

麦克风阵列技术由于增加了空域处理,相较于单麦克风具有很多优势,目前已成为语音增强及语音信号处理的重要部分。为提升麦克风阵列在复杂背景环境下远场语音拾取性能,与采用传统声压传感器不同,本文拟采用矢量传声器作为麦克风阵列的基本阵元。矢量传声器能够直接测量声场的质点振速参量,并且具有与频率无关的偶极子指向性,在噪声振动测量、材料特性分析以及声学测量领域有着广泛的应用。本文首先介绍了单矢量传声器的偶极子指向性,基于此进一步研究了矢量传声器线阵的指向性理论,相较于声压传感器线阵,矢量传声器线阵可以有效改善波束指向性、降低波束旁瓣级。此外,在半消声室测试环境下,分别设计搭建了3.5 cm等间距四元电容式麦克风线阵和四元矢量传声器线阵,并对两种线阵波束指向性的实测波束图与理论波束图进行了对比分析,验证了矢量传声器线阵的波束指向特性,为进一步实现噪声抑制、混响消除等功能,提高语音信号处理质量,解决远距离拾音痛点提供了新的思路。

MEMS矢量传声器研究进展

矢量传声器由声压传感器和质点振速传感器复合构成,可时间同步、空间共点测量声场声压标量及质点振速矢量信息,在开展振动噪声监测、被动声测定位以及声全息成像等相关声学测试方面有着独特的优势,因而具有重要的工程应用价值。质点振速传感器是矢量传声器的核心部件,具有偶极子指向性,可直接感测声场质点振速各正交分量。基于此,介绍基于微机电系统(Micro-Electro-Mechanical System,MEMS)技术的矢量传声器的研究进展,概述MEMS矢量传声器的工作原理、设计制作及工程应用等方面的发展现状。

基于矢量传声器阵列的低频声源定位

矢量传声器由传统的声压传感器和三维振速传感器组成,提供了更加完备的声场信息,理论上具有不随频率变化的空间指向性,为小孔径阵列定位低频声源提供了可能。为了实现小孔径阵列低频声源的精确定位,提出了矢量传声器频域校准合成孔径和稀疏表示定位相结合的方法。该方法采用固定点声压传声器来校准阵列不同位置时声源初始相位信息的方式实现阵列孔径虚拟扩大,该方法易于工程实现,在频域进行校准可以减小不同频率之间的交叉项干扰,将频域校准合成孔径与稀疏表示定位方法相结合可以进一步提高低频分辨率和降低定位误差,仿真验证了该方法的有效性。

基于矢量传声器的扫描测量噪声可视化系统

矢量传声器具有与频率无关的“8”字指向性,非常适合如舱室等狭小、复杂且具有声学混响的环境中的噪声扫描测量。本文通过分析一维矢量传声器的组合指向性特性,研究基于矢量传声器组合指向性扫描测量的声场可视化的原理,进一步结合音视频采集研制了基于矢量传声器的扫描测量噪声可视化系统,并利用该系统开展了车辆舱室中模拟双声源扫描测试。结果表明,基于矢量传声器组合指向性的扫描测量可以实现声场可视化,开发的噪声可视化系统可在舱室内完成声场可视化及噪声源识别,具有实用性,进一步推动了矢量传声器的发展与应用。

基于MEMS矢量传声器的声源DOA估计

微机电系统(Micro Electro Mechanical System,MEMS)矢量传声器在声源波达方向(Direction of Arrival,DOA)估计领域具有巨大的潜力及优势。本文分析MEMS矢量传声器接收信号模型,并结合随机性最大似然原理推导矢量传声器DOA估计模型。针对时变非均匀噪声影响矢量传声器DOA估计性能的问题,提出基于空间噪声预白化的极大似然DOA估计方法。此外,开展仿真分析及园区环境下的定向验证试验。结果表明,通过噪声协方差估计矩阵对矢量传声器接收信号数据进行预白化处理,能够克服时变非均匀噪声对信号协方差矩阵的影响,实现矢量传声器对目标DOA精确估计,验证了该方法的有效性及实用性。

矢量传声器及信号采集测试平台的设计与实现

近年来,物联网应用中的信息采集和感知设备都在向小尺寸、低成本的方向快速发展。矢量传声器是一种先进的麦克风阵列,可以测量完整的声场矢量信息,能够大幅提高传声器对环境的感知能力和对数据的采集效率。由于矢量传声器是一种精密测量仪器,且价格昂贵,几乎没有应用于物联网信息感知的先例。基于此,笔者提出并设计一种低成本、小尺寸的矢量传声器原型,并搭建了信号采集测试平台,为实现独立矢量传声器的声源测向和定位奠定了基础。

矢量语音传感器微阵列

人工智能的普及促进了语音交互技术的发展,语音传感器阵列作为智能语音交互的硬件前端,成为语音交互领域的前沿研究方向。矢量语音传声器自有的偶极子指向性、零点深度以及阵列体积小便于集成的特点特别符合语音交互技术对硬件设备的要求。基于此,通过采用两组矢量敏感单元"共点正交"形成矢量微阵列实现声源空间锐化波束指向,其不受瑞利限与空间采样率限制,与传统空间离散分布的声压麦克风阵列有着本质区别,是矢量微阵列的核心优势所在。矢量微阵列传声器弥补了现有双麦阵列的不足,具有更为广阔的应用前景,作为智能语音交互的硬件前端,对推动智能语音交互领域的发展具有重要意义。

一种热对流式MEMS二维质点振速传感器

由空气质点振速传感器和声压传感器组成的矢量传声器是测量声场空间信息的重要方式。本文设计了一种新型热对流式二维质点振速传感器,不同于传统平行线式传感机制,该器件由多线进行交叉连结形成一个中央十字加热器和四个直角测温线,构成新的局域加热和温度传感方式,基于此设计能够获得更高的灵敏度并具有理想的正交性。通过数值分析对其传感机制进行了详细分析,并使用MEMS工艺进行器件制备和性能验证。实验结果表明,该器件具有良好的响应灵敏度和接近完美的正交指向性。所提出器件在体积受限的声场测量中具有潜在应用价值。

Analysis of SNR for Acoustic Vector Sensor Linear Array in Volume and Surface-generated Noise Fields

Acoustic vector sensor consists of pressure and particle velocity sensors,which measure the three-dimensional acoustic particle velocity,as well as the pressure at one location at the same time.By preserving the amplitude and phase information of the pressure and particle velocity,they possess a number of advantages over traditional scalar sensors.Signal-to-noise ratio (SNR) gain (which is often called array gain) is one of such advantages and is always interested by all of us.But it is not unchangeable if the spatial correlation of the noise field varies.Much more important,it is difficult to be given if the noise becomes complex.In this paper,spatial correlation of the vector field of isotropic volume-noise and surface-generated noise has been introduced briefly.Based on the results,the combined SNR output of a vector linear array is investigated and the maximum gain is given in the specified noise.Computer simulation shows that the output of one array in the same noise is not the same in different gestures.And then we find the best gesture through SNR calculation and obtain the biggest gain,which has important meaning to guide how to deploy an array in practice.We also should use the array with respect to the characteristics of the real ambient noise,especially in anisotropic noise field.

Fast direction of arrival algorithm based on vector-sensor arrays using wideband sources

An acoustic vector sensor(AVS)can capture more information than a conventional acoustic pressure sensor(APS).As a result,more output channels are required when multiple AVS are formed into arrays,making processing the data stream computationally intense.This paper proposes a new algorithm based on the propagator method for wideband coherent sources that eliminates eigen-decomposition in order to reduce the computational burden.Data from simulations and lake trials showed that the new algorithm is valid:it resolves coherent sources,breaks left/right ambiguity,and allows inter element spacing to exceed a half-wavelength.

The Representation of a Broadband Vector Field

Compared to a scalar pressure sensor, a vector sensor can provide a higher signal-to-noise ratio （SNR） signal and more detailed intbrmation on the sound field. Study on vector sensors and their applications have become a hot topic. Research on the representation of a vector field is highly relevant for extending the scope of vector sensor technology. This paper discusses the range-frequency distribution of the vector field due to a broadband acoustic source moving in a shallow-water waveguide as the self noise of a surface ship, and the vector extension of the waveguide impulse response measured over a limited frequency range using an active source of known waveform. From theory analysis and numerical simulation, the range-frequency representation of a vector field exhibits an interference structure qualitatively similar to that of the corresponding pressure field but, being quantitatively different, provides additional information on the waveguide, especially through the vertical component. For the range-frequency representation, physical quantities that can better exhibit the interference characteristics of the wavegaide are the products of pressure and particle velocity and of the pressure and pressure gradient. An image processing method to effectively detect and isolate the individual striations from an interference structure was reviewed briefly. The representation of the vector impulse response was discussed according to two different measurement systems, also known as particle velocity and pressure gradient. The vector impulse response representation can not only provide additional information from pressure only but even more than that of the range-frequency representation.

Study on the influence of the subsurface buoy＇s vibration on the vector sensor due to ocean current

Subsurface buoy systems,especially equipped with the vector sensor,have more and more extensive applications in military and civilian regions.However,their acoustic performances are constrained by the vibration resulting from the unavoidable ocean current in some degree.The influence of such vibrations is quantitatively analyzed by means of modeling the simplified models of two deployment configurations involving the positive buoyant buoy and neutral buoy system.The corresponding formulas are deduced respectively for the deployment configuration buoy systems in the motion state firstly.Then the simulation software is developed and some numerical simulations are put up via the Runge-Kutta method.The simulation results and theoretical analysis indicate that the neutral buoy will be an excellent design protocol in engineering application in comparison with the positive buoyant buoy.

Direction-of-arrival estimation for a uniform circular acoustic vector-sensor array mounted around a cylindrical baffle

This work investigates the direction-of-arrival(DOA) estimation for a uniform circular acoustic Vector-Sensor Array(UCAVSA) mounted around a cylindrical baffle.The total pressure field and the total particle velocity field near the surface of the cylindrical baffle are analyzed theoretically by applying the method of spatial Fourier transform.Then the so-called modal vector-sensor array signal processing algorithm,which is based on the decomposed wavefield representations,for the UCAVSA mounted around the cylindrical baffle is proposed.Simulation and experimental results show that the UCAVSA mounted around the cylindrical baffle has distinct advantages over the same manifold of traditional uniform circular pressure-sensor array(UCPSA).It is pointed out that the acoustic Vector-Sensor(AVS) could be used under the condition of the cylindrical baffle and that the UCAVSA mounted around the cylindrical baffle could also combine the anti-noise performance of the AVS with spatial resolution performance of array system by means of modal vector-sensor array signal processing algorithms.