Compressed sensing theory-based rotating sound source Doppler effect elimination method

Abstract

The invention discloses a compressed sensing theory-based rotating sound source Doppler effect elimination method. The method comprises the steps: setting a measurement surface in a rotating sound source radiation sound field, randomly selecting H measurement points from N measurement points which are uniformly disposed on a measurement surface in the circumferential direction, installing microphones, and obtaining a sound pressure signal containing a Doppler effect; establishing a corresponding relation of the coordinates of the measuring points where the microphones are located under a static column coordinate system and a rotating column coordinate system rotating along with a rotating sound source; based on a compressed sensing theory, reconstructing by utilizing the sound pressure signals acquired by the H microphones to obtain a circumferential modal amplitude under the static column coordinate system; and according to a circumferential modal amplitude and the corresponding relationship between a sound pressure angular spectrum under the static column coordinate system and the sound pressure angular spectrum under the rotating column coordinate system, obtaining the sound pressure without the Doppler effect at the measurement point where each microphone is located, and eliminating the Doppler effect. According to the invention, the limitation of an Shannon-Nyquist sampling law is broken through, the number of microphones is reduced, the microphones are allowed to be randomly distributed in the circumferential direction, and the measurement cost and the installation difficulty of the microphones are reduced.

Description

technical field [0001] The invention relates to a method for eliminating the Doppler effect in the field of noise, more specifically a method for eliminating the Doppler effect of a rotating sound source based on compressed sensing theory. Background technique [0002] During the operation of mechanical products, the noise of working parts is often used as an important indicator to evaluate its operating status. However, working parts in a rotating state, such as fans, propellers, fans, etc., directly monitor their operating status and often get wrong results. The root cause of the wrong results is that there is a gap between the rotating parts and the microphone The Doppler effect caused by relative motion will cause amplitude distortion and frequency shift to the collected acoustic signal. Eliminating the Doppler effect of rotating sound sources plays an important role in the operation monitoring of components in actual engineering. [0003] The current relatively advanc...

AI Technical Summary

Problems solved by technology

However, in actual engineering, due to the limitation of installation conditions, the microphones often cannot be evenly distributed. Because of the need to follow the Shannon-Nyquist sampling law, the number of microphones is often required to be large, resulting in increased measurement costs, and the subsequent test data collection, storage and Analysis has put forward higher requirements

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