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Active noise attenuation system and sound absorption method on basis of minimum quadratic sum of reflecting acoustic pressure

A minimal and active technology, applied in the direction of sounding equipment, instruments, etc., can solve the problems of not being able to manufacture electronic control systems and not developing, and achieve the effects of light weight, direct control and small size

Inactive Publication Date: 2012-09-12
HENAN UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the limitations of electronic technology and other aspects at that time, the required electronic control system could not be manufactured, so the technology could not be developed for a long time. It was not until the end of the 1960s, with the development of electronic technology, that the research on active noise reduction was resumed. rise up

Method used

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  • Active noise attenuation system and sound absorption method on basis of minimum quadratic sum of reflecting acoustic pressure
  • Active noise attenuation system and sound absorption method on basis of minimum quadratic sum of reflecting acoustic pressure
  • Active noise attenuation system and sound absorption method on basis of minimum quadratic sum of reflecting acoustic pressure

Examples

Experimental program
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Effect test

Embodiment 1

[0057] like figure 2 , based on the minimum square sum of the reflected sound pressure of a single piezoelectric ceramic wafer. Since the piezoelectric ceramic wafer is relatively thin, the elongation caused by the applied voltage is located in the direction perpendicular to the polarization direction. For the applied voltage ,strain for:

[0058] (7)

[0059] in, is the thickness of the piezoelectric ceramic wafer, is the strain constant of the piezoelectric ceramic wafer. like figure 2 As shown, the piezoelectric ceramic chip is pasted on the simply supported plate, and the bidirectional longitudinal force generated will be applied on the surface of the simply supported plate, and a moment will be generated on the simply supported plate. This moment is:

[0060] (8)

[0061] (9)

[0062] (10)

[0063] (11)...

Embodiment 2

[0117] The sound absorption layout based on the minimum square sum of reflection sound pressure of multiple piezoelectric ceramic wafers is as follows: image 3 Shown:

[0118] For applied voltage , No. Piezoelectric Ceramic Chip Strain for:

[0119] (36)

[0120] in, for the first The thickness of the piezoceramic wafer, is the strain constant of the piezoelectric ceramic wafer. image 3 The piezoelectric ceramic chip is pasted on the simply supported plate, and the bidirectional longitudinal force generated will be applied on the surface of the simply supported plate, and a moment will be generated on the simply supported plate. This moment is:

[0121] (37)

[0122] (38)

[0123] According to formula (37), the first The longitudinal moment of the piezoelectric ceramic chip added to the surface of the simply supported plate, the equation of motion of the simply supported plate...

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Abstract

The invention discloses an active noise attenuation system and a sound absorption method on the basis of minimum quadratic sum of reflecting acoustic pressure, and relates to the technology of sound attenuation. The method comprises the following steps that: reflecting acoustic pressure is detected through a sound sensor; piezoelectric ceramic chips are adhered to a panel; certain voltage is applied to the piezoelectric ceramic chips, and due to piezoelectric effects of piezoelectric ceramics, the panel is vibrated; the detected reflecting acoustic pressure and sound radiation pressure caused by panel vibration are expressed as total reflecting acoustic pressure, and the total reflecting acoustic pressure is input into a control filter for filtering; the filtered signal is input into a processor module for calculation; the voltage and frequency applied to the piezoelectric ceramic chips are calculated under the condition of the minimum quadratic sum of the total reflecting acoustic pressure; and the calculated voltage and frequency are sent to the piezoelectric ceramic chips again through a frequency converter. By the active noise attenuation system and the sound absorption method, a good active sound adsorption effect can be achieved.

Description

technical field [0001] The invention relates to a noise elimination technology, in particular to an active noise elimination system and a sound absorption method based on the minimum square sum of reflected sound pressures. Background technique [0002] In the 1960s, active noise reduction aroused great interest among scholars. Active noise cancellation refers to the use of sound waves generated by the secondary sound source to offset the noise generated by the primary sound source, so that the designated space can generate real-time secondary sound and primary sound that are equal in amplitude and opposite in phase to the noise source at the place. Noise superposition makes the noise sound pressure value in the studied space reach the desired control target, and finally achieves the purpose of noise reduction. However, due to the limitations of electronic technology and other aspects at that time, the required electronic control system could not be manufactured, so the tec...

Claims

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Application Information

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IPC IPC(8): G10K11/172
Inventor 刘刚田曹慧敏尹更新朱丹君霍银磊尤曌颖
Owner HENAN UNIV OF SCI & TECH
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