Near-field acoustic holography fast algorithm based on complex ray wave superposition

Abstract

The invention provides a near-field acoustic holography fast algorithm based on complex ray wave superposition, and relates to the technical field of acoustics. The method comprises the following steps: 1) selecting the shape of holographic and virtual equivalent source surfaces; 2) constructing a complex ray wave superposition method through a ray wave function; 3) solving expansion of an unknown source strong density function Fourier; and 4) reestablishing complex sound pressure and vibration velocity of a sound field. The method can overcome problems in the prior art under a non-conformal measurement condition, can not only enable calculation accuracy to be very high, but also enable solution to be unique; and meanwhile, fastness is achieved.

Description

technical field [0001] The invention relates to the technical field of acoustics, in particular to a fast algorithm based on complex ray wave superposition near-field acoustic holography. Background technique [0002] Because NAH (Nearfield acoustic holography, NAH for short) can reconstruct the entire sound field, theoretically, the acoustic information at any point in the sound field can be easily obtained. This is the feedback control strategy for any single-point or multi-point (observation point) test in the past. are incomparable. However, in order to meet the real-time requirements, it is necessary to start from the rapid measurement of the complex sound pressure (sound intensity) or vibration velocity on the holographic surface and the fast algorithm of the sound field reconstruction, so as to minimize the time lag between the sound field reconstruction and the control system. It has truly become an effective means for real-time monitoring of the sound field and clo...

AI Technical Summary

Problems solved by technology

However, there is still a big gap between the above algorithms and the ideal sound field space transformation algorithm, and there are more or less different defects: such as the planar, cylindrical and spherical Fourier space transformation algorithm and the SONAH of the planar, cylindrical and spherical surface, etc. , they are only suitable for sound sources with regular shapes such as planes, cylinders, and spheres. For the sound field inversion of sound sources with irregular shapes, these methods can at best obtain the complex sound pressure and vibration velocity on the reconstruction surface with a similar regular shape. , but the vibration details (vibration velocity, etc.) The characteristic of ill-posed problems is that the system matrix may be "ill-conditioned" (larger condition number)

The biggest flaw is that it is only suitable for sound field reconstruction on regular-shaped sound source surfaces such as planes, cylinders, and spheres.

The biggest flaw is: there is a "conformal" problem, regularization processing is required, and the calculation accuracy and efficiency are not high

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