In this paper, we proposed an optimisation method to solve the problem of sound source localisation and calibration of an asynchronous microphone array. This method is based on the graph-based formulation of the simultaneous localisation and mapping problem. In this formulation, a moving sound source is considered to be observed from a static microphone array. Traditional approaches for sound source localisation rely on the well-known geometrical information of the array and synchronous readings of the audio signals. Recent work relaxed these two requirements by estimating the temporal offset between pair of microphones based on the assumption that the clock timing of each microphone is exactly the same. This assumption requires the sound cards to be identically manufactured, which in practice is not possible to achieve. Hereby an approach is proposed to jointly estimate the array geometrical information, time offset and clock difference/drift rate of each microphone together with the location of a moving sound source. In addition, an observability analysis of the system is performed to investigate the most suitable configuration for sound source localisation. Simulation and experimental results are presented, which prove the effectiveness of the proposed methodology.

中文翻译：

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异步麦克风阵列校准和声源跟踪

本文提出了一种优化方法来解决异步麦克风阵列的声源定位和校准问题。该方法基于同时定位和映射问题的基于图的表述。在这种表述中，认为从静态麦克风阵列观察到运动声源。用于声源定位的传统方法依赖于阵列的众所周知的几何信息以及音频信号的同步读取。最近的工作通过基于每个麦克风的时钟时序完全相同的假设来估计一对麦克风之间的时间偏移，从而放宽了这两个要求。这种假设要求声卡的制造方式相同，实际上这是不可能实现的。因此，提出了一种方法来共同估计每个麦克风的阵列几何信息，时间偏移和时钟差/漂移率以及移动声源的位置。另外，执行系统的可观察性分析以调查最适合声源定位的配置。仿真和实验结果表明，证明了所提方法的有效性。