Active noise reduction method and device

A technology of noise reduction and infrasound source, applied in the direction of sound-producing equipment, instruments, etc., can solve the problems of complex, unobstructed degree of exhaust noise, difficult noise signal elimination, etc., achieve less distortion, reduce noise, and achieve ideal results Effect

Inactive Publication Date: 2008-07-02
HAIER GRP CORP +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Especially in straight pipes, the noise signal is directly transmitted outward along the direction of the pipe. Even if sound-absorbing materials are installed on the side wall of the exhaust channel, it is difficult to eliminate the noise signal in the pipe that does not touch the side wall. , and if the sound-absorbing material is placed in a blocking way in the noise channel, it will obviously block the exhaust air
The use of structural noise reduction not only makes the design of the pipeline structure more complicated, but also affects the smoothness of the exhaust air. Therefore, it is very difficult to significantly reduce the noise of household appliances with traditional methods.

Method used

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Embodiment 1

[0043] Embodiment one is an active noise reduction method, below in conjunction with the attached figure 1 The content of the embodiment is described in detail. figure 1 It is the control flowchart of this embodiment. The sound field area to be controlled can be the air inlet or outlet of air conditioner cabinets, commercial air conditioner indoor units, range hoods, or other straight passages with noise.

[0044] Step 101: Firstly, the noise source signal in the noise field is collected. The waveform signal of the noise source is collected through a microphone or other collection devices such as sensors capable of collecting acoustic vibration signals. The collection device is arranged on the central axis of the noise source pipeline, and can collect waveform signals close to real noise to the greatest extent. , and at the same time, preliminary filtering can be performed by means of software or hardware filtering to filter out the DC signal.

[0045] Step 102: Amplify the...

Embodiment 2

[0065] Embodiment two is an active noise reduction device, the following in conjunction with the attached image 3 The content of the embodiment is described in detail. image 3 It is a block diagram of the device in this embodiment.

[0066] The noise collection unit 210 uses a microphone or other sensor noise sources capable of collecting acoustic vibration signals to send out signals, and sends the collected noise source signals to the input amplification unit 220 for amplification processing, and the amplified noise source signals are then amplified. Send into the adaptive filtering unit 230, an error signal acquisition circuit 240 collects the noise source signal in the noise field and the superimposed error signal of the subsound source signal, also sends in the described adaptive filtering unit 230, the described adaptive filtering unit 230 implements the filtering process adaptively according to the above two signals, and can continuously correct while filtering out s...

Embodiment 3

[0068] Embodiment three such as Figure 4 As shown in , the pipe 1 in the figure is the sound field area to be controlled, which can be the air inlet or outlet of the air conditioner cabinet, commercial air conditioner indoor unit, range hood, or other straight passages with noise. Pipeline 1 is provided with a microphone MIC for collecting noise signals and a speaker SPK for outputting secondary sound field signals. Since the pipes that generate noise on electrical appliances are relatively regular, a set of microphones and speakers can generally be used and set on the main axis of pipe 1. In terms of location, multiple sets of microphones and speakers can also be used in application environments with complex sound fields. Figure 5 It is the circuit schematic diagram of the device of the present invention, the noise source signal collected directly by the microphone MIC is usually relatively weak, so the collection output of the microphone MIC is filtered and blocked by the ...

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Abstract

The invention relates to an active noise reducing method and an active noise reducing device, in particular to active noise reduction for noise generated by importing and exporting wind gate of electrical equipments. The characteristics of amplitude, frequency and phase of noise of noise source are detected through sampling the noise signal. A signal with the same amplitude and reverse phase is generated through filtering and anti-phase processing and output through a speaker to counteract the noise signal so as to achieve the object of noise reduction, wherein the filtered signal is modified adaptively during filtering process so that the filtered signal is closer to the noise source signal while filtering the noise, thus the effect of noise reduction is more ideal.

Description

technical field [0001] The invention relates to an active noise reduction method and an active noise reduction device for performing noise reduction processing on the noise generated by the air inlet and outlet of electrical equipment. Background technique [0002] With the development of modern industry, noise pollution has become a worldwide problem. In traditional noise control, passive noise reduction methods such as sound-absorbing materials, damping treatment, and structural noise reduction are mainly used. However, due to the long wavelength of low-frequency noise, the physical structure adopted by passive noise reduction cannot absorb long-wavelength noise well, and the above methods are not applicable. In the exhaust system of some household appliances, such as the air outlet of the indoor unit of the air conditioner, the air inlet of the range hood, etc., due to the rapid flow of air, continuous low-frequency noise is generated at the air outlet. At this time, the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/178
Inventor 李莉朱旬孙奇辉赵向阳
Owner HAIER GRP CORP
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