Improvement method for feeding back water bed effect of active noise control system

A feedback control system and water bed technology, applied in the direction of sounding devices, instruments, etc., can solve problems such as difficult to ensure effective and reliable numerical solutions, and achieve the effects of improved water bed effect, unconstrained optimal design controller, and flexible frequency characteristics

Inactive Publication Date: 2010-11-17
NANJING UNIV
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Problems solved by technology

The difficulty of the constrained optimization method is that it is difficult to guarantee an effective and reliable numerical solution

Method used

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  • Improvement method for feeding back water bed effect of active noise control system
  • Improvement method for feeding back water bed effect of active noise control system
  • Improvement method for feeding back water bed effect of active noise control system

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Embodiment Construction

[0024] The method for improving the water bed effect proposed by the present invention is characterized by: optimizing the feedback controller by widening the noise amplification frequency band and uniform noise amplification in the noise amplification frequency band; and implementing the optimized feedback controller by using a digital filter. The method will be described in detail below by taking an analog feedback active noise control system as an example.

[0025] (1) Measure the frequency characteristics of the single-channel feedback controller and secondary channel before the improvement of the system, and draw the Nyquist curve of its open-loop frequency characteristic function, as shown in the attached figure 1 shown. In the frequency ranges from 150Hz to 202Hz and 262Hz to 631Hz, the curves enter a circle with the Nyquist point as the center and a radius of 1, so the noise in the above two frequency bands is amplified. In the frequency range from 203Hz to 261Hz, the...

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Abstract

The invention discloses an improvement method for feeding back the water bed effect of an active noise control system, which can avoid system modeling and realize unconfined optimization design of a design controller. The method comprises the following steps of: (1) optimizing the open loop frequency characteristic function of a system via noise amplification amount in a widening noise amplification frequency band and an even noise amplification frequency band; (2) dividing the secondary channel frequency characteristic function by the optimized feedback open loop frequency characteristic function to obtain the optimized controller frequency characteristic; and (3) optimizing the controller with a digital filter. The method has the advantages that the system modeling can be avoided, the unconfined optimization design of the controller can be easily realized, and the digital filter is used for optimizing the controller with flexible frequency characteristic and can be used for improving the water bed effect of the active noise control system with different control demand. The method can be used for estimating the noise amplification minimum peak value realized by the system.

Description

1. Technical field [0001] The invention relates to the noise control of the feedback active noise control system, and mainly proposes an improvement method for the phenomenon that the noise of a certain frequency band increases when the noise of another frequency band is reduced, that is, the water bed effect. 2. Background technology [0002] Feedback active noise control is mainly used in engine noise reduction of vehicles, noise reduction of vehicle passenger compartments, and traffic noise reduction; noise reduction of air-conditioning ducts, transformers, blowers in industry, etc.; headphones, earplugs and noise in daily life Noise reduction in places, etc., especially in places where there is a lot of noise or the generation of noise is incoherent. However, the mechanism of feedback active noise control determines that the noise reduction of each frequency in the noise is not isolated. When the noise of a certain frequency band is reduced, the noise of another frequenc...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/178
Inventor 张丽敏祖峰磊邱小军
Owner NANJING UNIV
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