Optimization of a spherical microphone array geometry for localizing acoustic sources using the generalized cross-correlation technique. (1st October 2019)

• Record Type: Journal Article
• Authors: Padois, Thomas; Doutres, Olivier; Sgard, Franck; Berry, Alain
• Is Part Of: Mechanical systems and signal processing. Volume 132(2019)
• Page Start: 546
• Page End: 559
• Publication Date: 2019-10-01
• Subjects: Optimization -- Microphone array geometry -- Source localization -- Generalized cross-correlation; Structural dynamics -- Periodicals; Vibration -- Periodicals; Constructions -- Dynamique -- Périodiques; Vibration -- Périodiques; Structural dynamics; Vibration; Periodicals; 621
• DOI: 10.1016/j.ymssp.2019.07.010
• Languages: English
• ISSNs: 0888-3270

Abstract

Highlights: The concept of aperture angle map is introduced. A cost function based on the symmetry of the aperture angle map is proposed. The optimized microphone array is used with the generalized cross correlation. The optimized array removes side lobes without increasing the main lobe surface. Abstract: Many workers are exposed daily to excessive noise levels. In order to reduce the noise exposure at the workstation, the main noise sources have to be detected. This task can be done with a microphone array and a source localization technique. Previous studies have shown promising results with time domain beamforming based on the generalized cross-correlation technique. The objective of this work is to propose an optimal spherical microphone array geometry dedicated to this technique. A cost function based on the symmetry of the aperture angle maps is proposed and is maximized using a Nonlinear Optimization by Mesh Adaptive Direct Search. Numerical results show that the optimized geometry improves the noise source map by reducing the side lobe amplitude without increasing the main lobe surface. Experimental measurements are carried out in a semi-anechoic chamber with prototyped spherical microphone arrays confirming that the optimized microphone array improves the quality of the noise source map.