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如何实现高效的分布式声源定位是无线传感器网络研究的热点。通过一种基于声源信号能量的分布式声源定位算法,采用交互方向的拉格朗日乘子方法将最大似然声源定位问题拆分到单个传感器节点,通过桥接传感器节点实现传感器节点之间的信息融合。由于采用声源信号衰减模型,交互方向拉格朗日乘子方法中的最优化目标函数成为非凸函数,导致定位算法容易陷入局部最优,为此提出了多重网格搜索方法。仿真结果表明,新算法与现有的分布式声源定位算法相比,具有可并行实现,可应用于任意网络拓扑,不易陷于局部最优等优点。 相似文献
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提出了一种基于上升过零点检测的双传声器声源定位方法,该方法可以根据双传声器信号时间差样本的统计特性求得信噪比,再统计满足信噪比要求的可靠时间差样本,将其转换成对应的方位角样本,最后根据样本数量的统计分析结果确定声源方位。针对不同声源、信噪比及混响条件,在实际房间中进行了定位实验。结果显示:该方法对宽带声源具有更好的定位效果;定位精度受信噪比的影响很小,但受室内混响的影响显著。 相似文献
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基于双麦克风的2维平面定位算法 总被引:1,自引:0,他引:1
基于麦克风阵列的声源定位技术受到了越来越多的关注。在视频会议、助听器、免提电话系统中,声源定位被用于检测说话人的位置信息来自动调节摄像头,或者形成波束。在各种声源定位方法中,基于到达时间差(time delay of arrival,TDOA)估计的双步定位算法是普遍采用的一种行之有效的方法。Birchfield从能量的角度出发提出了一种基于双耳电平差(interaural level difference,ILD)的双步定位算法,它通过检测多个麦克风对所接收到的信号能量比来确定声源的位置。然而,所有的这些方法如果要确定出声源在二维平面内的位置坐标,都至少需要三个麦克风。针对这一问题,本文提出了一种基于双麦克风的二维平面定位算法,类似于人的双耳定位原理,我们通过同时估计声源到达两个麦克风的能量比和时延信息,来达到定位的目的,而进一步推导出的闭合解可以用于实时地跟踪运动声源。最后的仿真结果证明了这一算法在一般的混响条件下都可以获得好的结果,然而它减小了阵列的尺寸,这对于体积受限的通信设备来说具有极大的吸引力。 相似文献
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文章以智能小车为载体,讨论声源定位技术在实际应用中的设计方案和实现。系统采用TC264微控制器作为主控芯片,采用麦克风、FM接收模块、红外测距模块等多种传感器,实现不同环境场内Chirp信号音源的寻找,并采用二倍插值互相关等方法,计算不同麦克风的到达时间差以及小车和声源的距离,完成定位。在音频数据量较大的情况下,文章以200 ms周期进行声源定位,辅助卡尔曼滤波,以5 ms控制周期完成控制,保证控制的实时性;在路径规划与速度分配方面,文章对小车运行路径做出合理规划,使其能够以较优的路径完成定位并躲避障碍物。 相似文献
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声发射技术是结构损伤检测的重要手段,声发射源定位是损伤检测的首要环节。时差定位技术具有快速、高效、精确的特点,以此设计了由菱形阵列光纤布拉格光栅(FBG)传感器构成的声发射定位系统。采用小波变换和传统阈值法提取特征信号,结合互相关法获得传感器间的信号到达时差,然后根据几何定位模型求解非线性方程组得到声源可能存在的位置,最后根据时差的正负特性进一步确定声源的准确位置,有效避免了伪声源的情况。在铝合金板上,以对角线为48 cm48 cm的监测区域进行了10组测试实验验证,平均误差为1.29 cm。 相似文献
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在麦克风阵列声源定位中,不同阵列阵型及声源频率高低均对定位结果产生影响,探讨上述不同变量对定位结果产生误差的定量分析。使用到达时间差测量(TDOA)算法,运用16个麦克风分别组成十字型、同心圆、方型、L型、Y型阵列,探讨不同形状的麦克风阵列在不同频率声源下所产生的定位误差,并在Matlab上进行仿真分析,尝试得到较为准确的声源定位结果,提出一种误差最小的用于麦克风阵列声源定位的同心圆阵列阵型。 相似文献
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Maximum likelihood multiple-source localization using acoustic energy measurements with wireless sensor networks 总被引:9,自引:0,他引:9
Xiaohong Sheng Yu-Hen Hu 《Signal Processing, IEEE Transactions on》2005,53(1):44-53
A maximum likelihood (ML) acoustic source location estimation method is presented for the application in a wireless ad hoc sensor network. This method uses acoustic signal energy measurements taken at individual sensors of an ad hoc wireless sensor network to estimate the locations of multiple acoustic sources. Compared to the existing acoustic energy based source localization methods, this proposed ML method delivers more accurate results and offers the enhanced capability of multiple source localization. A multiresolution search algorithm and an expectation-maximization (EM) like iterative algorithm are proposed to expedite the computation of source locations. The Crame/spl acute/r-Rao Bound (CRB) of the ML source location estimate has been derived. The CRB is used to analyze the impacts of sensor placement to the accuracy of location estimates for single target scenario. Extensive simulations have been conducted. It is observed that the proposed ML method consistently outperforms existing acoustic energy based source localization methods. An example applying this method to track military vehicles using real world experiment data also demonstrates the performance advantage of this proposed method over a previously proposed acoustic energy source localization method. 相似文献
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Chen J.C. Yip L. Elson J. Hanbiao Wang Maniezzo D. Hudson R.E. Kung Yao Estrin D. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2003,91(8):1154-1162
Advances in microelectronics, array processing, and wireless networking have motivated the analysis and design of low-cost integrated sensing, computing, and communicating nodes capable of performing various demanding collaborative space-time processing tasks. In this paper, we consider the problem of coherent acoustic sensor array processing and localization on distributed wireless sensor networks. We first introduce some basic concepts of beamforming and localization for wide-band acoustic sources. A review of various known localization algorithms based on time-delay followed by least-squares estimations as well as the maximum-likelihood method is given. Issues related to practical implementation of coherent array processing, including the need for fine-grain time synchronization, are discussed. Then we describe the implementation of a Linux-based wireless networked acoustic sensor array testbed, utilizing commercially available iPAQs with built-in microphones, codecs, and microprocessors, plus wireless Ethernet cards, to perform acoustic source localization. Various field-measured results using two localization algorithms show the effectiveness of the proposed testbed. An extensive list of references related to this work is also included. 相似文献
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一种改进的水下光击穿声辐射计算方法 总被引:2,自引:0,他引:2
为了从理论上对光击穿辐射声波进行定量描述,在点源模型的基础上提出了一种改进的水下光击穿声辐射计算方法,利用波动方程和水下爆炸理论求解单点击穿的辐射声波,并推导了多点击穿的辐射声波。从理论上对多点击穿的声压波形、声源级、传播特性和指向性进行了定量计算,并通过实验数据对比进行了验证。结果表明,计算与实验结果是一致的,证明了该方法的正确性和有效性;当激光能量从0.1J增大至0.8J时,声源级从182.4dB增至188.2dB;当激光能量高于0.3J时,声源级变化很小;在垂直等离子柱体的方向上声波辐射最强,在等离子柱体方向辐射最弱,所有方向上声波强度均与距离的平方成反比。 相似文献
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Brian L. F. Daku J. Eric Salt 《Signal Processing, IEEE Transactions on》2007,55(3):1024-1034
This paper proposes and examines the performance of an algorithm used to locate a finite time-duration acoustic source that may have a small time-bandwidth product. The localization algorithm hypothesizes a source location and aligns the sensor signals by removing the propagation delay for that hypothesized location. The energy of the sum of the aligned signals is calculated and the hypothesized source location with the maximum energy is the estimate of the source position. The primary contribution of this paper is the development of the expression for the variance of localization error in any specified direction. The variance expression is validated through a comparison with Monte Carlo simulations 相似文献
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Zoran M. Saric Dragan D. Kukolj Nikola D. Teslic 《Circuits, Systems, and Signal Processing》2010,29(5):837-856
In this paper, we consider the problem of acoustic source localization in a wireless sensor network based on different measured
signal quantities, such as the received signal strength (RSS), the angle of arrival (AOA) and the time of arrival (TOA). For
each of these quantities, an appropriate weighted least squares criterion function is developed to be used for sound source
localization. The weights of each criterion function take into account the decrease in the signal-to-noise ratio (SNR) with
distance from the source. In addition, RSS localization algorithm proposed in this paper provides improvement of the localization
accuracy for low SNR. Finally, separate criterion functions for RSS, TOA and AOA are used together to obtain minimal localization
error and maximal reliability of the acoustic source localization. Simulation analysis confirms improved performance of the
proposed localization algorithm. 相似文献