Calibration of acoustic vector sensor based on MEMS microphones for DOA estimation
Calibration of acoustic vector sensor based on MEMS microphones for DOA estimation
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DOI：
10.1016/j.apacoust.2018.07.025
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发表时间：
2018-12-01
影响因子：
3.4
通讯作者：
Szwoch, Grzegorz
中科院分区：
文献类型：
--
作者：
Kotus, Jozef;Szwoch, Grzegorz
本文提出了一种自定义三维声矢量传感器（AVS）的标定方法，并对其进行了验证。基于p-p原理的AVS设备可以由标准压力传感器和信号处理系统组成。然而，为了保证准确的DoA估计，需要对每个传感器进行校准。该算法将标定过程分为两个阶段。首先，进行幅度校准，以补偿位于每个轴上的麦克风对之间的幅度差异。从校正后的传声器信号中计算出压力和速度信号后，进行第二阶段，以校正压力和速度信号之间的相位差，然后计算每个轴的强度信号。为了验证校准方法的有效性，采用低成本元件（即MEMS麦克风和DSP板）构建了参考AVS。该方法的设计假设它将适用于任何基于相同原理的AVS。为了验证校准方法，并将校准后的传感器与商用AVS的精度进行比较，进行了一组实验。实验发现，采用该方法标定的3D AVS的DoA精度与商用、高成本、工厂标定的传感器相匹配。因此，本文提出的标定方法满足了准确DoA估计的要求，适用于定制的低成本AVS设备的标定，可在环境监测、交通监控、公安系统等声源方向确定的实际应用中实现。
A procedure of calibration of a custom 3D acoustic vector sensor (AVS) for the purpose of direction of arrival (DoA) estimation, is presented and validated in the paper. AVS devices working on a p-p principle may be constructed from standard pressure sensors and a signal processing system. However, in order to ensure accurate DoA estimation, each sensor needs to be calibrated. The proposed algorithm divides the calibration process into two stages. First, amplitude calibration is performed in order to compensate for amplitude differences between pairs of microphones situated on each axis. After the pressure and velocity signals are computed from the corrected microphone signals, the second stage is performed in order to correct phase differences between the pressure and velocity signals, which then allows for computing the intensity signals for each axis. In order to validate the calibration method, a reference AVS was constructed from low cost components, namely MEMS microphones and a DSP board. The method was engineered with an assumption that it will be applicable to any AVS working on the same principle. A set of experiments was performed in order to validate the calibration method and to compare the accuracy of the calibrated sensor with a commercial AVS. It was found in the experiments that DoA accuracy of the proposed 3D AVS calibrated with the proposed procedure matches that of a commercial, high cost, factory-calibrated sensor. Therefore, the proposed calibration method fulfills the requirements of accurate DoA estimation, and it is applicable to calibration of custom built, low cost AVS devices, that may be implemented in practical applications for determining the direction of sound sources, such as environmental monitoring, traffic monitoring and public security systems.