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Method for estimating noise reduction effect of active noise control system

An active noise control and noise technology, applied in the field of noise reduction, can solve the problems that there is no good solution for the prediction and real-time display of the noise reduction effect, and it is difficult to realize, so as to achieve strong engineering application value, low implementation cost, Effects for easy evaluation and feedback

Pending Publication Date: 2021-08-20
西安艾科特声学科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the current engineering application research only focuses on the performance of the algorithm, applicable scenarios, etc., and there is no good solution for the prediction and real-time display of the noise reduction effect. Usually, the evaluation of a noise reduction system is to use special measuring equipment to collect before and after noise reduction. Noise, calculate its noise reduction amount, usually express the size of its effect in dB or dB(A)
This requires that the system must collect the noise before and after noise reduction in the time domain to be consistent or very close to ensure that the calculation of the noise reduction effect is not affected, but this is difficult to achieve in practical engineering applications

Method used

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  • Method for estimating noise reduction effect of active noise control system
  • Method for estimating noise reduction effect of active noise control system
  • Method for estimating noise reduction effect of active noise control system

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0055] The noise reduction effect estimation method of the active noise reduction system is mainly composed of three parts: signal acquisition, filtering and estimation. Such as figure 1 A method for estimating the noise reduction effect of an active noise control system includes the following steps,

[0056] S1. The error microphone picks up the error signal E of the secondary sound field in real time;

[0057] S2. The primary noise signal D=E-Y of the estimation error point, wherein, the acoustic signal at the point E of the error microphone that the secondary sound source S arrives at the error microphone E through the secondary path H is Y;

[0058] S3. Calculate the sound pressure level of the primary sound field and the secondary sound field at the error point;

[0059] S4. The sound pressure level difference between the primary sound field and the secondary sound field is the noise reduction amount, which can be used to evaluate the noise reduction effect. The error ...

Embodiment 2

[0061] The calculation process of the noise reduction amount of the adaptive active noise control system is as follows:

[0062] a. Record the real-time noise signal E of the error point, and the real-time output signal S of the secondary sound source;

[0063] b. The secondary sound source S reaches the acoustic signal Y at point E of the error microphone through the secondary path H:

[0064] Y=H T S

[0065] c. Calculate the primary sound field, that is, the desired signal D:

[0066] D=E-Y

[0067] d. Calculate the noise level L of the primary sound field and the secondary sound field respectively d and L e :

[0068] where d(n) is the sound pressure signal at a certain moment of the desired signal D

[0069] Where e(n) is the sound pressure signal at a certain moment of the error signal E

[0070]e. Noise reduction L V calculate

[0071] L V = L d -L e

[0072] Thus, the estimation of the noise reduction amount of the system is completed.

[0073] From ...

Embodiment 3

[0075] The practical application of the noise reduction calculation method for a single-channel system is divided into the following steps:

[0076] a. Error signal pickup:

[0077] The real-time noise signal e(n) of the error point is collected in real time by the error microphone of the system.

[0078] b. Calculate the estimated value of the secondary acoustic signal y(n) at the error point:

[0079] y(n)=h(m)*s(n) where h(m) is the channel transfer function from the secondary sound source to the error microphone

[0080] c. Calculate the estimated value d(n) of the primary sound field signal at the error point:

[0081] d(n)=e(n)-y(n)

[0082] d. Calculate the noise level of the primary sound field and the secondary sound field at the error point:

[0083] The formula for calculating the sound pressure level is: where p ref =2.0×10 -5 , p is the average sound pressure,

[0084] which is

[0085]

[0086] From the above, we can get the sound pressure level L ...

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Abstract

The invention discloses a noise reduction effect estimation method for an active noise control system, and the method comprises the following steps: S1, picking up a secondary sound field and an error signal E in real time through an error microphone; s2, estimating a primary noise signal D = E-Y of an error point, and a sound signal Y of a secondary sound source S reaching an error microphone E point through a secondary path H; s3, calculating sound pressure levels of the primary sound field and the secondary sound field of the error point; s4, taking the sound pressure level difference between the primary sound field and the secondary sound field as the noise reduction amount, wherein the noise reduction amount can be used for evaluating the noise reduction effect. According to the method, the noise reduction effect, namely the noise reduction amount, is calculated and estimated in real time; the control strategy can be changed according to the estimated noise reduction amount, so that the method has very high engineering application value; extra hardware facilities do not need to be added, and the implementation cost is low; the technology is suitable for personnel working at fixed points in a noise environment for a long time, such as noise reduction systems arranged in cabs and passenger cabins of airplanes, locomotives, automobiles and the like, and the performance of the noise reduction systems can be evaluated and fed back in real time.

Description

technical field [0001] The invention relates to the technical field of noise reduction, in particular to a method for estimating the noise reduction effect of an active noise control system. Background technique [0002] With the development of economy and industrialization, noise pollution has become an environmental problem that cannot be ignored. Long-term exposure to high noise environment will cause harm to people's hearing and physical and mental health. General noise can also reduce people's quality of life and work efficiency. Intense noise can lead to acoustic fatigue of mechanical equipment and certain industrial structures, and long-term effects will shorten their lifespan. In the military field, noise problems will affect the combat performance and ergonomics of some technical weapons. Therefore, noise control is an important task in both military and civilian fields. In recent years, Active Noise Control (ANC) technology has developed rapidly. [0003] At pre...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/178
CPCG10K11/1781G10K11/1787
Inventor 代海玉昊昕李荣宁晓峰张彦峰樊宝文刘玲
Owner 西安艾科特声学科技有限公司