A biomimetic apparatus for sound-source localization
A biomimetic apparatus for sound-source localization
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一种用于声源定位的仿生装置
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
P. Krishnaprasad
中科院分区：
文献类型：
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作者：
A. A. Handzel;S. Andersson;M. Gebremichael;P. Krishnaprasad
声源定位系统通常由自由场麦克风阵列组成。我们提出了一种基于自然界中观察到的原理的定位系统的设计，其中定向声传感演变为依赖于只有两只耳朵的头部衍射。定位是使用产生的频率相关的声学相位和两耳之间的强度差异进行的。这些耳间函数可以通过将头部建模为球体来解析计算。现在，我们报告了这些想法在一个带有两个反向放置的麦克风的人造头部中的第一次成功实现。为了确定声源方向，我们定义了一个与耳间函数相关联的合适度量。真正的源方向由测量值与理论函数表之间的度量的全局最小值给出。该系统在宽带信号源上进行了测试，即使在非理想的混响实验室环境下也表现良好。为了比较，我们还使用基于声间时延的标准互相关算法计算了源方向。我们的方法执行更准确，并允许使用更短的信号持续时间。这项工作的一个关键动机是设计有效的方法来引导机器人在声源环境中导航。本文所述的装置安装在实验室的移动机器人上。
Sound source localization systems are typically made of free field microphone arrays. We have proposed the design of a localizing system based on the principles observed in nature, where directional acoustic sensing evolved to rely on diffraction about the head with only two ears. Localization is performed using the resultant frequency dependent acoustic phase and intensity differences between the two ears. These interaural functions can be computed analytically by modeling the head as a sphere. Now we report the first successful implementation of these ideas in an artificial head with two antipodally placed microphones. In order to determine source direction, we define a suitable metric associated to interaural functions. The true source direction is given by the global minimum of the metric between a measurement and a table of theoretical functions. The system was tested with a broadband source and was found to perform well even in a non-ideal reverberant laboratory environment. For comparison, we also calculated the source direction using the standard cross-correlation algorithm which is based on interaural time delay. Our approach performs more accurately and allows to use briefer signal durations. A key motivation for this work is to devise effective means to guide robotic navigation in environments with acoustic sources. The apparatus described in this paper is installed on a mobile robot in the laboratory.