Active noise control system and method based on improved FxLMS algorithm

A technology of active noise control and algorithm, applied in the research field of secondary channel modeling method, can solve the problems of secondary channel modeling divergence, noise reduction performance degradation, system easy to diverge, etc.

Pending Publication Date: 2018-10-16
CHONGQING UNIV OF POSTS & TELECOMM
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The fixed step size is easy to cause the divergence of the secondary channel modeling in the ANC system when the environment changes suddenly, thus affecting the noise reduction performance of the ANC system; in add

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  • Active noise control system and method based on improved FxLMS algorithm
  • Active noise control system and method based on improved FxLMS algorithm
  • Active noise control system and method based on improved FxLMS algorithm

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[0060] The technical solutions in the embodiments of the present invention will be described clearly and in detail below with reference to the drawings in the embodiments of the present invention. The described embodiments are only some of the embodiments of the invention.

[0061] The technical scheme that the present invention solves the problems of the technologies described above is:

[0062] The ANC system proposed by the present invention adopts Matlab8.6 for simulation.

[0063] as attached figure 1 The reference noise signal x(n) shown is input from the reference microphone, and after being processed by the ANC control system, a control signal y(n) is generated, and y(n) drives the speaker to send out a secondary signal. If the frequency of the anechoic signal emitted by the loudspeaker is the same as that of the reference noise signal and the amplitude is opposite, they will cancel each other out, thereby achieving the effect of noise reduction. The error microphon...

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Abstract

The invention discloses an active noise control system and method based on an improved FxLMS algorithm. The active noise control system mainly comprises five modules as follows: (1) the FxLMS algorithm, (2) a secondary channel, (3) a performance monitor, (4) a variable-power white noise generator, and (5) a main channel path. The invention aims at improving noise reduction performance of an ANC system as well as modeling precision and convergence rate of the secondary channel; in accordance with innovation points, a training signal (auxiliary random white noise) of the secondary channel undergoes power scheduling, and then performance in (2) is observed, wherein injection of the auxiliary random white noise in the (4) is stopped when a following relation is satisfied: [mu]Smax-[mu]S<[alpha](1*10<-5><[alpha]<1*10<-3>), and injection of the auxiliary random white noise in the (4) is started once again when a following relation is satisfied: 20log10|f(n)|<0. Therefore, mutual transformation of the secondary channel between online modeling and offline modeling is achieved, and the finally obtained ANC system is relatively high in modeling precision and noise reduction performance. Theactive noise control system has the characteristics of simple structure, easy adaption to environmental change and big-variance auxiliary white noise and the like.

Description

technical field [0001] The invention belongs to the technical field of noise elimination, and in particular relates to a research on a secondary channel modeling method in an active noise control system (ANC) for low-frequency noise elimination based on an FxLMS algorithm. Background technique [0002] In recent years, with the continuous growth of industrial equipment such as fans, engines, compressors and transformers, acoustic noise has gradually become a serious problem. The traditional noise reduction method is passive noise control: using acoustic packaging, installing mufflers, and designing sound insulation structures to reduce noise. The noise reduction effect achieved in the range is insignificant and bulky and costly. The active noise control (ANC) has a good noise reduction effect on low-frequency noise [1] , and thus received great attention. [0003] As an important part of noise cancellation, ANC's main design challenge is related to the secondary channel. ...

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Application Information

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IPC IPC(8): G10K11/178
CPCG10K11/17813G10K2210/3035G10K2210/3028G10K2210/3012
Inventor 袁军刘东旭唐晓斌王巍王冠宇吕韦喜
Owner CHONGQING UNIV OF POSTS & TELECOMM
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