Noise source identification method adopting vibration speed measurement and partial near-field acoustical holography method

Abstract

The invention provides a noise source identification method adopting vibration speed measurement and a partial near-field acoustical holography method.. The method comprises the following steps of: measuring the vibration speed of a normal mass point on a finite aperture measurement surface H positioned at a near field; performing zero-padding expansion on the vibration speed; calculating a transmission matrix between the measurement surface and a sound source surface; and finally calculating so as to obtain sound pressure on the sound source surface S and the vibration speed of the normal mass point. The vibration speed of the normal mass point is used as an input value for sound field reconstruction, so that sound field information with relatively high precision can be acquired. Compared with the conventional iterative partial near-field acoustical holography method, the method adopting the partial near-field acoustical holography method has the advantages of being simple in calculation operation, short in calculation time, high in calculation efficiency and the like and is used for identifying and positioning a noise source and reconstructing a sound field.

Description

technical field [0001] The invention relates to a noise-like sound field reconstruction and visualization method. Background technique [0002] Near-field acoustic holography is an important sound source localization and sound field visualization technology. In actual measurement, this technology usually requires the measurement aperture to be several times larger than the sound source area to effectively reduce the window effect and winding error. However, for large-scale It is difficult to satisfy this condition when the sound source is reconstructing the sound field, so people use local near-field acoustic holography technology to solve the problem of sound field reconstruction of the sound source. Existing local near-field acoustic holography techniques include: (1) Data extrapolation method. Yoshikawa studied the data extrapolation technology in the article "Acoustic Society of America" ​​(2001, Volume 110, Issue 4), and proposed two data extrapolation methods in the t...

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Problems solved by technology

Yoshikawa studied the data extrapolation technology in the article "Acoustic Society of America" ​​(2001, Volume 110, Issue 4), and proposed two data extrapolation methods in the time domain and wave number domain. The disadvantage of this method is that iterative calculation is required , the calculation process is complicated and the amount of calculation is large; (2) Patch near-field acoustic holography technology

In the article of "Acoustic Society of America" ​​(2003, Volume 113, Issue 3), Williams proposed a concept of Patch NAH through further research on the concept of near field. This method allows the measured sensor array to be smaller than the sound source and overcome the The reconstruction error caused by the finite size of the measurement aperture is reduced, and the measurement time is reduced. However, in terms of calculation time, this technology is still limited by iterative calculations. The calculation process is complicated and the efficiency is low; (3) Statistically optimal near-field acoustic holography technology

Jacobsen proposed statistical optimal near-field acoustic holography in the article "Acoustic Society of America" ​​(Volume 121, Issue 3, 2007). This method expresses the sound field as a linear superposition of plane waves and evanescent waves, and realizes sound field reconstruction. The normal particle velocity can be used as the input quantity for reconstruction, which can obtain higher accuracy results of the normal particle velocity, but the disadvantage is that it is affected by the matrix calculation and the calculation time is longer

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