標題: Implementation issues of the nearfield equivalent source imaging microphone array
作者: Bai, Mingsian R.
Lin, Jia-Hong
Tseng, Chih-Wen
機械工程學系
Department of Mechanical Engineering
公開日期: 31-一月-2011
摘要: This paper revisits a nearfield microphone array technique termed nearfield equivalent source imaging (NESI) proposed previously. In particular, various issues concerning the implementation of the NESI algorithm are examined. The NESI can be implemented in both the time domain and the frequency domain. Acoustical variables including sound pressure, particle velocity, active intensity and sound power are calculated by using multichannel inverse filters. Issues concerning sensor deployment are also investigated for the nearfield array. The uniform array outperformed a random array previously optimized for far-field imaging, which contradicts the conventional wisdom in far-field arrays. For applications in which only a patch array with scarce sensors is available, a virtual microphone approach is employed to ameliorate edge effects using extrapolation and to improve imaging resolution using interpolation. To enhance the processing efficiency of the time-domain NESI, an eigensystem realization algorithm (ERA) is developed. Several filtering methods are compared in terms of computational complexity. Significant saving on computations can be achieved using ERA and the frequency-domain NESI, as compared to the traditional method. The NESI technique was also experimentally validated using practical sources including a 125 cc scooter and a wooden box model with a loudspeaker fitted inside. The NESI technique proved effective in identifying broadband and non-stationary sources produced by the sources. (C) 2010 Elsevier Ltd. All rights reserved.
URI: http://dx.doi.org/10.1016/j.jsv.2010.08.017
http://hdl.handle.net/11536/25864
ISSN: 0022-460X
DOI: 10.1016/j.jsv.2010.08.017
期刊: JOURNAL OF SOUND AND VIBRATION
Volume: 330
Issue: 3
起始頁: 545
結束頁: 558
顯示於類別:期刊論文


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