Self-adaptive frequency modulation semi-active noise control method

A kind of noise control, semi-active technology, applied in the direction of sounding equipment, instruments, etc., can solve the problem that semi-active control cannot be achieved

Inactive Publication Date: 2009-09-30
HARBIN ENG UNIV
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Problems solved by technology

Without a semi-active control algorithm, the purpose of semi-activ

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  • Self-adaptive frequency modulation semi-active noise control method
  • Self-adaptive frequency modulation semi-active noise control method
  • Self-adaptive frequency modulation semi-active noise control method

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Embodiment Construction

[0033] The present invention is described in more detail below in conjunction with accompanying drawing example:

[0034] combine figure 1 , the composition of the self-adaptive FM semi-active noise control device includes: as a closed sound field 1 to be controlled; microphone 3, microphone 4, bandpass filter 5, DSP controller 6, stepping motor driver 7, DC power supply 8, stepping The motor 9 and the semi-active vibration absorber 2 constitute a semi-active noise control system. The semi-active vibration absorber-Helmholtz resonator 2 is installed in the upper part of the closed system 1, and the internal sound pressure signal of the Helmholtz resonator is measured by the microphone 3, and the opening of the Helmholtz resonator is measured by the microphone 4 sound pressure signal, the two signals pass through the bandpass filter 5 at the same time, and the signal output from the filter 5 is connected to the DSP controller 6 .

[0035] The control program in the DSP contro...

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Abstract

The invention provides a self-adaptive frequency modulation semi-active noise control method. Two microphones are utilized to measure an internal sound pressure signal and an opening sound pressure signal of a semi-active sound absorber-helmholtz resonator; after wave filtration, an integral value within a period judges whether the resonance frequency of the resonator is positioned at excitation frequency; and a DSP controller sends a corresponding control signal to drive the operation of a stepping motor through a stepping motor driver if the resonance frequency deviates from the excitation frequency. The method can perform real-time adjustment, and can meet the requirement on tracing the excitation frequency; and the whole performance of sound absorbers using the method can be effectively improved.

Description

(1) Technical field [0001] The invention relates to a closed space (cabin) noise control technology, in particular to an adaptive frequency modulation semi-active noise control method based on a dot product control algorithm. (2) Background technology [0002] As an important environmental pollution, indoor or cabin noise has been paid more and more attention by people. Indoor or cabin noise control is a very important task in both military and civilian fields. The use of Helmholtz resonators to absorb sound is a widely used sound absorption and noise reduction technology. Because of its simple structure and effective control of noise with a small frequency range, Helmholtz resonators have become the implementation of noise important means of control. However, the sound absorption frequency of the traditional Helmholtz resonator is determined at the beginning of the design, and cannot be changed with the change of the excitation frequency and system characteristics. Theref...

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Application Information

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IPC IPC(8): G10K11/172
Inventor 杨铁军靳国永李玩幽叶黎明刘志刚
Owner HARBIN ENG UNIV
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