Method for realizing reverberant field focusing by using random array

A reverberation sound field and sound focusing technology, which is applied in the field of reverberation sound field focusing by using random arrays

Active Publication Date: 2009-12-30
INST OF ACOUSTICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the defects of the existing sound field focusing method, thereby proposing a method for realizing reverberant sound field focusing by using a random array, the method retransmits the received signal by the random array after inverting the time domain The principle of space-time domain focusing at the receiving point realizes the reverberation sound field focusing when the array elements are randomly arranged and the frequency response between the array elements is different.

Method used

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  • Method for realizing reverberant field focusing by using random array
  • Method for realizing reverberant field focusing by using random array
  • Method for realizing reverberant field focusing by using random array

Examples

Experimental program
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Effect test

Embodiment 1

[0070] In this example, if figure 1 As shown, on the ground of the reverberation room (5.1m in length, 4.9m in width, and 4.0m in height), four loudspeaker units with a power of 20W are randomly placed in an array, and a microphone unit is placed at the desired focal point for Measure the received signal at the desired point, place another microphone directly in front of the focus point, and move the position of the microphone forward at an interval of 3cm to measure the focus signal at other points other than the desired point. Use the Pulse instrument of Danish B&K company to record the received signals collected by the two microphones, and write the code on the matlab software of the PC to realize the time-domain inversion and amplitude amplification processing of the received signal corresponding to the desired focus point recorded by the Pulse instrument .

[0071] The specific implementation process of this embodiment includes the following steps:

[0072] 1) First se...

Embodiment 2

[0079] In this example, if figure 2 As shown, 4 loudspeaker units are randomly placed on the ground of the reverberation room, and the same three steps as described in Embodiment 1 are used to mix the single-cycle sinusoidal pulse signals with frequencies of 600Hz, 1000Hz and 3000Hz in a 4-element random array. Acoustic field focusing experiment.

[0080] When the microphone unit slides along the X-axis, Y-axis and Z-axis at intervals of 3 cm, the sound pressure peak values ​​of the focus signals corresponding to the three frequency source signals are measured on the three coordinate axes with the distance difference (the position of the microphone The change curve of the distance from the desired focus point). Figure 10 , 11 and 12 show the normalized distribution curves of the sound pressure peaks of the focus signals corresponding to the source signals with frequencies of 600Hz, 1000Hz and 3000Hz on the X-axis, Y-axis and Z-axis respectively.

[0081] Comparing these c...

Embodiment 3

[0083] In this example, if image 3 As shown, in the reverberation chamber, the 4-element line arrays are respectively placed at the positions of the four speaker units mentioned in Embodiment 2, and the three steps described in Embodiment 1 are also followed at these four position points. The reverberation sound field focusing experiment of the 4-element linear array is carried out on the single-cycle sinusoidal pulse signals with frequencies of 600Hz, 1000Hz, and 3000Hz respectively, and the results of the reverberation sound field focusing experiment of the 4-element linear array and the 4-element random array are compared.

[0084] When the microphone unit slides along the X-axis, Y-axis and Z-axis at intervals of 3 cm, the sound pressure peak values ​​of the focus signals corresponding to the three frequency source signals are measured on the three coordinate axes with the distance difference (the position of the microphone The change curve of the distance from the desire...

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Abstract

The invention relates to a method for realizing reverberant field focusing by using a random array. The method comprises the following steps: 1) when the random array synchronously transmits same source signals under a reverberant environment, recording receiving signals acquired by a microphone at an expected position; 2) processing the recorded receiving signals by time domain inversion and amplitude amplification; and 3) transmitting the time domain inversion signals amplified in step 2) by the random array so as to generate sound focusing at the expected position. The method has the advantages that array elements can be randomly placed; focusing blur produced by phase difference among the array elements can be fully eliminated; a Green's function between a source point and an expected focusing point is solved by adopting an experimental measurement method instead of the prior calculation or estimation method, and the calculation burden is removed; the array element distance breaks through the limitation of half wavelength; and under the condition that the array element numbers are the same, the space domain resolution focused by the random array is slightly greater than the space domain resolution focused by a linear array.

Description

technical field [0001] The present invention relates to the technical field of sound field control, in particular, the present invention particularly relates to a method for realizing reverberation sound field focusing by using a random array. Background technique [0002] Sound field focusing is to increase the sound intensity in a desired area of ​​space as much as possible, and to reduce the sound intensity at any other point outside the area as much as possible. In order to achieve the focus of the sound field, the spatial distribution of the array radiated power is usually changed by adjusting the amplitude and phase of the array elements, so that the radiated power falls in the desired area to the greatest extent and minimizes the transmission of the power to other areas. Give way. Sound field focusing can control the sound in a certain desired area, so that the best reception effect can be achieved in this area, and the interference caused by the sound to other areas...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/16G10K15/08
Inventor 杨军马登永匡正
Owner INST OF ACOUSTICS CHINESE ACAD OF SCI
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