Sound source positioning method suitable for hollow spherical array

Abstract

The invention discloses a sound source positioning method suitable for a hollow spherical array. The method combines the advantages of the hollow spherical array and maximum likelihood estimation and accurately positions a spatial sound source direction by using a maximum likelihood estimation strategy while not influencing a spatial sound field. The sound source positioning method has advantages of (1) reducing computation complexity by converting a signal received by a microphone into a spherical harmonic domain; (2) obtaining high spatial resolution and positioning accuracy by using the maximum likelihood estimation strategy; (3) avoiding division of a spherical Bessel function and solving the poor robustness of the hollow spherical array at a zero-point-corresponding frequency of the spherical Bessel function; (4) achieving direct expansion to a broadband, reducing the expansion complexity of a spherical array broadband positioning algorithm, and being suitable for a reverberant sound field, and (5) being suitable for rigid spherical arrays and spherical arrays using directional microphones, besides the hollow spherical arrays.

Description

1. Technical field [0001] The present invention proposes a sound source localization method suitable for hollow sphere arrays, combining the advantages of hollow sphere arrays and maximum likelihood estimation, and using the maximum likelihood estimation strategy to process spherical harmonic domain signals without affecting the spatial sound field , avoid spherical Bessel function division, accurately locate the direction of the spatial sound source, and the localization method can be effectively extended to the processing scene of broadband signals. 2. Background technology [0002] The spherical microphone array has a rotationally symmetrical structure and can design beams pointing in any direction in space. It is widely used in direction of arrival estimation, room impulse response analysis, sound source localization, and room structure prediction. It is a hot topic in recent years. The hollow sphere array can obtain spatial information without affecting the measured sou...

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Problems solved by technology

[0003] The literature [I.Balmages&B.Rafaely, Open-sphere designs for spherical microphone arrays] proposes a structure using a double-layer hollow sphere array, which can avoid the robustness of the hollow sphere array at the zero point of the spherical Bessel function in the sound source localization Weaker question, but requires twice the number of microphones

The literature [B.Rafaely, The spherical-shell microphone array] proposes a spherical-shell microphone array structure, which can avoid the problem of weak robustness of the hollow spherical array at the zero point of the spherical Bessel function, but the radius of the microphone unit is not fixed. more complex

The literature [B.Rafaely, Bessel nulls recovery in spherical microphone arrays for time-limited signals] skips the frequency corresponding to the zero point of the spherical Bessel function in the ball array broadband sound source localization, which has high robustness, but the method is less flexible. Low

Patent CN 102866385A and patent CN 103592628A respectively propose a sound source localization method based on spherical harmonic domain subspace decomposition and a spherical harmonic domain real-valued weight beamforming, which can be applied to hollow spherical arrays and obtain higher spatial resolution, but the above two methods do not extend to wideband and are not suitable for reverberant sound fields

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