Study on Interior Acoustic Source Localization Based on Nearfield Acoustical Holography
Near-field acoustical holography(NAH) is a powerful tool for identifying noise sources and visualizing sound fields since it allows sound fields that are measured on a two-dimensional surface (the hologram surface) to be used to reconstruct an entire three-dimensional wave field. NAH assumes sound sources to radiate into a completely free-field or a semi free-field. When the sound source is located in complex acoustic nearfields such as a vehicle cabin, NAH has some limitations to identify and locate sound sources. With respect to the free-field, the interior sound field will be entirely different in NAH. The difference is mainly that interior sound field is more likely reverberant. Therefore, the method based on NAH cannot be accomplished directly; otherwise the pseudo-source will be generated. As a result, the method of source location for interior noise field has to do with the properties of reverberation to distinguish between “active source and “passive source using the acoustic holography. In this paper, statistically optimal near-field acoustical holography (SONAH) techniques are applied to locate sound sources with the reflected sound field. Firstly, SONAH in the presence of reflection plane parallel to the source plane is investigated. The incoming and outgoing waves are separated by measuring the sound pressure on two parallel hologram planes closed to the sound source based on the acoustic superposition principle. Secondly, NAH in the presence of reflection plane perpendicular to the source plane is analyzed. On the basis of acoustic mirror image principle, the reflected sound field can be replaced with an infinite series of images of the pressure distribution measured between the perpendicular surfaces. Finally, the above techniques are combined to apply NAH to a fully enclosed space. The assumptions are that enclosed walls are hard and perpendicular to the measurement plane, and the reconstructions can be performed only on parallel planes which do not pass through the parallel reflection plane.
SONAH Interior Acoustic Source Location reflection acoustic superposition acoustic mirror image
Jianghua Deng Xiandong Liu Xinghu Li Yingchun Shan
School of Traffic Science and Engineering,Beihang University,Beijing,100083 CHINA
国际会议
第六届国际振动工程会议(The 6th International Conference on Vibration Engineering)(ICVE’ 2008)
大连
英文
2008-06-04（万方平台首次上网日期，不代表论文的发表时间）