Finite space plane near-field acoustic holography measurement method based on spatial Fourier transform

Abstract

The invention discloses a finite space plane near-field acoustic holography measurement method based on spatial Fourier transform, which comprises the following steps: 1, establishing a free field andfinite space radiation sound field model based on a point sound source, and extracting complex sound pressure of a point sound source reconstruction surface in the free field and complex sound pressure data on a holographic surface in a finite space; 2, calculating a sound pressure angle spectrum of a point source reconstruction surface in a free field and a point source holographic surface in afinite space, and calculating a transfer operator G-1 of the reconstruction surface and the holographic surface; 3, measuring to obtain complex sound pressure data on the holographic surface with thereconstructed sound source in the limited space; and calculating a holographic surface sound pressure angle spectrum; 4, multiplying the holographic surface sound pressure angle spectrum in the step 3by the transfer operator G-1 in the step 2 to obtain a sound pressure angle spectrum on the reconstruction surface; and 5, performing wave number domain windowing on the sound pressure angle spectrumof the reconstruction surface; and performing Fourier inverse transformation on the windowed reconstructed sound pressure angular spectrum to obtain reconstructed surface sound pressure. According tothe method, the finite space test environment is considered, and the reconstruction precision is improved by solving the transfer operator in the free field and the finite space.

Description

technical field [0001] The invention relates to a measurement method for sound source identification in a limited space in the field of acoustic holography, in particular to a measurement method for a plane near-field acoustic holography in a limited space based on spatial Fourier transform. Background technique [0002] Near-field acoustic holography technology is an extremely effective sound field inversion technology. Near-field acoustic holography has very unique advantages in the field of noise identification and positioning. From the perspective of reverse thinking, the traditional problem of sound radiation is "reversely" transformed , the traditional noise reduction technology is often based on the method of calculating the radiation characteristics of the sound field by measuring the vibration velocity information on the surface of the sound source, while the near-field acoustic holography is to record holographic data in the near-field of the measured object. Field...

AI Technical Summary

Problems solved by technology

However, conventional near-field acoustic holography requires that the back side of the holographic measurement surface must be a free field. However, in practical engineering applications, the free-field conditions required for holographic measurement are often not met. At this time, when using near-field acoustic holography for sound source identification, False sound sources will be generated in the acoustic image, and the reconstruction accuracy is very low

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