Noise reduction method and device for fan noise
阅读说明:本技术 风扇噪音的降噪方法及装置 (Noise reduction method and device for fan noise ) 是由 耿卓 王辉 孟凡冉 于 2019-09-23 设计创作,主要内容包括:本发明提供了一种风扇噪音的降噪方法及装置,涉及主动降噪技术领域,风扇噪音的降噪方法包括以下步骤:采集噪声信号;获取风扇的转速信息,并根据风扇的转速识别出该转速对应的固有频率;根据所识别出的固有频率,在噪声信号中读取与该固有频率对应的特定频段的声信号;产生与该特定频段的声信号对应的反相位声信号,以将该特定频段的声信号中和。本发明提供的风扇噪音的降噪方法通过采集风扇的转速,从采集噪声信号中拾取与所述转速对应的特定频段的声信号,然后进行反相位处理,与所述风扇的特定频段的声信号进行中和抑制,进而达到消除风扇噪声的目的,反馈效果良好,能够有效消除风扇的噪音。(The invention provides a noise reduction method and a noise reduction device for fan noise, which relate to the technical field of active noise reduction, and the noise reduction method for the fan noise comprises the following steps: collecting a noise signal; acquiring rotating speed information of the fan, and identifying the natural frequency corresponding to the rotating speed according to the rotating speed of the fan; reading an acoustic signal of a specific frequency band corresponding to the natural frequency from the noise signal according to the identified natural frequency; an anti-phase acoustic signal corresponding to the acoustic signal of the specific frequency band is generated to neutralize the acoustic signal of the specific frequency band. The noise reduction method for the fan noise provided by the invention has the advantages that the rotating speed of the fan is collected, the sound signal of the specific frequency band corresponding to the rotating speed is picked up from the collected noise signal, then the anti-phase processing is carried out, and the sound signal of the specific frequency band of the fan is neutralized and suppressed, so that the purpose of eliminating the fan noise is achieved, the feedback effect is good, and the noise of the fan can be effectively eliminated.)
1. A method for reducing noise of a fan is characterized by comprising the following steps:
collecting a noise signal;
acquiring rotating speed information of the fan (10), and identifying the natural frequency corresponding to the rotating speed according to the rotating speed of the fan (10);
reading an acoustic signal of a specific frequency band corresponding to the natural frequency from the noise signal according to the identified natural frequency;
an anti-phase acoustic signal corresponding to the acoustic signal of the specific frequency band is generated to neutralize the acoustic signal of the specific frequency band.
2. The fan noise reduction device is characterized by comprising a noise acquisition module (100), a monitoring module (200), a natural frequency processing module (310) and an anti-phase processing module (320); the noise acquisition module (100), the monitoring module (200) and the anti-phase processing module (320) are respectively connected with the natural frequency processing module (310);
the noise acquisition module (100) is used for acquiring a noise signal;
the monitoring module (200) is used for acquiring the rotating speed information of the fan (10) and identifying the natural frequency corresponding to the rotating speed according to the rotating speed of the fan (10);
the natural frequency processing module (310) reads an acoustic signal of a specific frequency band corresponding to the natural frequency from the noise signal according to the identified natural frequency;
the anti-phase processing module (320) is used for generating an anti-phase sound signal corresponding to the sound signal of the specific frequency band so as to neutralize the sound signal of the specific frequency band.
3. The fan noise reduction apparatus according to claim 2, comprising a secondary sound source output unit (400), wherein the secondary sound source output unit (400) is connected to the anti-phase processing module (320);
the secondary sound source output unit (400) is capable of receiving the anti-phase sound signal, generating a noise reduction signal corresponding to the anti-phase sound signal, and neutralizing the noise reduction signal with the sound signal of the specific frequency band.
4. The noise reduction apparatus for fan noise according to claim 3, wherein the secondary sound source output unit (400) comprises a power amplifier circuit (410) and a speaker (420), the power amplifier circuit (410) is connected to the inverse phase processing module (320) and the speaker (420), respectively;
the power amplification circuit (410) can amplify the noise reduction signal generated by the anti-phase processing module (320);
the loudspeaker (420) can receive the noise reduction signal amplified by the power amplification circuit (410) and output a secondary sound source for restraining fan noise.
5. The fan noise reduction device according to claim 4, wherein the fan noise reduction device comprises a noise signal processing module (330) and a fan speed processing module (340); the noise signal processing module (330) is respectively connected with the noise acquisition module (100) and the natural frequency processing module (310); the fan rotating speed processing module (340) is respectively connected with the monitoring module (200) and the natural frequency processing module (310);
the noise signal processing module (330) is used for converting the time domain signal picked up by the noise acquisition module (100) into a frequency domain signal which can be identified by the natural frequency processing module (310);
the fan rotating speed processing module (340) is used for receiving the rotating speed information of the fan (10) picked up by the monitoring module (200) and converting the rotating speed information of the fan (10) into the natural frequency which can be identified by the natural frequency processing module (310).
6. The fan noise reduction apparatus according to claim 5,
the noise acquisition module (100) is a microphone (101), and the output end of the microphone (101) is connected with the input end of the noise signal processing module (330);
the monitoring module (200) is a displacement sensor (201), and the output end of the displacement sensor (201) is connected with the input end of the fan rotating speed processing module (340); the displacement sensor (201) is arranged on the side, facing away from the microphone (101), of the fan (10) and is used for reading the rotating speed of the fan (10).
7. The fan noise reduction apparatus according to claim 6, wherein the microphone (101) is located between the fan (10) and the speaker (420), and a center of the fan (10), the microphone (101) and the speaker (420) are aligned.
8. The fan noise reduction device according to claim 7, wherein the microphone (101) is connected to the engine compartment cover (30) by a fixing iron piece (102);
the loudspeaker (420) is connected with the engine room covering piece (30) through a loudspeaker fixing seat (421).
9. The fan noise reduction device according to claim 8, wherein the speaker holder (421) is provided with a spherical hinge head, and the speaker (420) is provided with a spherical groove matched with the spherical hinge head, so that an angle of the speaker (420) facing the fan (10) is adjustable.
Technical Field
The invention relates to the technical field of active noise reduction, in particular to a noise reduction method and device for fan noise.
Background
The active noise reduction technology is to generate reverse sound waves equal to external noise through a noise reduction system to neutralize the noise, so that the noise reduction effect is realized.
The existing self-adaptive active noise reduction device with the error sensor picks up a noise signal by a microphone, then inputs an active noise reduction chip to perform noise inversion processing, amplifies the noise signal by a power amplifier circuit, outputs the noise signal by using a noise reduction loudspeaker, completes superposition offset of the noise signal between the noise reduction loudspeaker and an air outlet of a fan air duct, picks up a noise effect after noise reduction by using the error sensor to perform secondary adjustment on the noise reduction loudspeaker, and further achieves the purpose of effectively eliminating fan noise.
The noise reduction device has the following disadvantages: the device has a complex structure, and under the working condition that a plurality of sound sources are mutually superposed in the engine compartment, the noise signals picked up by the error sensor after noise reduction have large errors and poor feedback effect, and the noise under the frequency band with large fan noise contribution can not be completely eliminated.
Disclosure of Invention
The invention aims to provide a fan noise reduction method and device, and aims to solve the technical problems that the existing noise reduction device is complex in structure, noise signals picked up by an error sensor after noise reduction have large errors and poor feedback effect under the working condition that multiple sound sources in an engine compartment are mutually superposed, and the noise of a fan cannot be completely eliminated.
The invention provides a noise reduction method of fan noise, which comprises the following steps:
collecting a noise signal;
acquiring rotating speed information of the fan, and identifying the natural frequency corresponding to the rotating speed according to the rotating speed of the fan;
reading an acoustic signal of a specific frequency band corresponding to the natural frequency from the noise signal according to the identified natural frequency;
an anti-phase acoustic signal corresponding to the acoustic signal of the specific frequency band is generated to neutralize the acoustic signal of the specific frequency band.
The invention provides a noise reduction device for fan noise, which comprises a noise acquisition module, a monitoring module, a natural frequency processing module and an anti-phase processing module; the noise acquisition module, the monitoring module and the anti-phase processing module are respectively connected with the natural frequency processing module;
the noise acquisition module is used for acquiring a noise signal;
the monitoring module is used for acquiring the rotating speed information of the fan and identifying the natural frequency corresponding to the rotating speed according to the rotating speed of the fan;
the natural frequency processing module reads an acoustic signal of a specific frequency band corresponding to the natural frequency from the noise signal according to the identified natural frequency;
the anti-phase processing module is used for generating an anti-phase acoustic signal corresponding to the acoustic signal of the specific frequency band so as to neutralize the acoustic signal of the specific frequency band.
Furthermore, the fan noise reduction device comprises an infrasound source output unit, and the infrasound source output unit is connected with the anti-phase processing module;
the secondary sound source output unit can receive the anti-phase sound signal, generate a noise reduction signal corresponding to the anti-phase sound signal, and neutralize the sound signal of the specific frequency band.
Furthermore, the infrasound source output unit comprises a power amplifier circuit and a loudspeaker, and the power amplifier circuit is respectively connected with the anti-phase processing module and the loudspeaker;
the power amplifier circuit can amplify the noise reduction signal generated by the anti-phase processing module;
the loudspeaker can receive the noise reduction signal amplified by the power amplifier circuit and output a secondary sound source for inhibiting fan noise.
Furthermore, the fan noise reduction device comprises a noise signal processing module and a fan rotating speed processing module; the noise signal processing module is respectively connected with the noise acquisition module and the natural frequency processing module; the fan rotating speed processing module is respectively connected with the monitoring module and the natural frequency processing module;
the noise signal processing module is used for converting the time domain signal picked up by the noise acquisition module into a frequency domain signal which can be identified by the inherent frequency processing module;
the fan rotating speed processing module is used for receiving the rotating speed information of the fan picked up by the monitoring module and converting the rotating speed information of the fan into the natural frequency which can be identified by the natural frequency processing module.
Furthermore, the noise acquisition module is a microphone, and the output end of the microphone is connected with the input end of the noise signal processing module;
the monitoring module is a displacement sensor, and the output end of the displacement sensor is connected with the input end of the fan rotating speed processing module; the displacement sensor is arranged on one side, back to the microphone, of the fan and used for reading the rotating speed of the fan.
Further, the microphone is located between the fan and the speaker, and the center of the fan, the microphone and the speaker are in a straight line.
Further, the microphone is connected with the engine compartment covering piece through a fixed iron sheet;
the loudspeaker is connected with the engine compartment covering through the loudspeaker fixing seat.
Furthermore, a spherical hinge head is arranged on the loudspeaker fixing seat, and a spherical groove matched with the spherical hinge head is arranged on the loudspeaker, so that the angle of the loudspeaker facing the fan is adjustable.
The noise reduction method of the fan noise provided by the invention comprises the steps of collecting noise signals; acquiring rotating speed information of the fan, and identifying the natural frequency corresponding to the rotating speed according to the rotating speed of the fan; reading an acoustic signal of a specific frequency band corresponding to the natural frequency from the noise signal according to the identified natural frequency; an anti-phase acoustic signal corresponding to the acoustic signal of the specific frequency band is generated to neutralize the acoustic signal of the specific frequency band. The method comprises the steps of picking up the rotating speed of a fan, identifying the natural frequency of the fan corresponding to the rotating speed, reading an acoustic signal of a specific frequency band corresponding to the natural frequency from a collected noise signal, generating an anti-phase acoustic signal corresponding to the acoustic signal of the specific frequency band, and neutralizing and inhibiting the acoustic signal of the specific frequency band of the fan, so that the purpose of eliminating the noise of the fan is achieved. The noise reduction method for the fan noise provided by the invention has the advantages that the rotating speed of the fan is collected, the sound signal of the specific frequency band corresponding to the rotating speed is picked up from the collected noise signal, then the anti-phase processing is carried out, the feedback effect is good, and the noise of the fan can be eliminated.
The fan noise denoising device provided by the invention utilizes the fan noise denoising method, under the working condition that a plurality of sound sources in an engine compartment are mutually superposed, the monitoring module is utilized to pick up the rotating speed of the fan, the sound signal of the specific frequency band of the fan is read according to the inherent frequency of the fan corresponding to the current rotating speed, and an anti-phase signal is generated, so that the condition that the noise signal picked up by an error sensor after denoising has large error is avoided, and the noise of the fan can be effectively eliminated.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a flow chart of a method for reducing fan noise according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a noise reduction device for fan noise according to an embodiment of the present invention;
fig. 3 is a structural diagram of a noise reduction device for fan noise according to an embodiment of the present invention;
FIG. 4 is a schematic view illustrating an installation of a noise reducer for fan noise according to an embodiment of the present invention;
fig. 5 is a schematic view illustrating an installation of a speaker of the noise reduction apparatus for fan noise according to the embodiment of the present invention.
Icon: 10-a fan; 20-a radiator; 30-engine compartment cover; 100-a noise acquisition module; 101-a microphone; 102-fixing iron sheets; 200-a monitoring module; 201-displacement sensor; 300-a controller; 310-natural frequency processing module; 320-an anti-phase processing module; 330-a noise signal processing module; 340-a fan speed processing module; 400-infrasound source output unit; 410-a power amplifier circuit; 420-a speaker; 421-loudspeaker fixing seat.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments, and it should be understood that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1 and 3, the noise reduction method for fan noise provided by the invention comprises the following steps:
collecting a noise signal; the noise signal includes a noise signal of the
The rotation speed information of the
The natural
The
The noise reduction method of the fan provided by the invention comprises the steps of picking up the rotating speed of the fan and identifying the natural frequency of the
Specifically, the step of generating an anti-phase acoustic signal corresponding to the acoustic signal of the specific frequency band to neutralize the acoustic signal of the specific frequency band includes: generating an anti-phase acoustic signal with equal amplitude and opposite phase with the acoustic signal of the specific frequency band by using the
As shown in fig. 2, the noise reduction apparatus for fan noise provided by the present invention includes a
Specifically, the output end of the
The
The
The natural
The
The noise reduction device for fan noise provided by this embodiment includes an infrasound
Specifically, the infrasound
The
The
The fan noise reduction device comprises a noise
The noise
Fast Fourier Transform (FFT), a general term for an efficient and fast computational method for computing a Discrete Fourier Transform (DFT) using a computer, is abbreviated as FFT.
The fan
Specifically, the
Wherein m is the number of blades of the
Specifically, the
The
The
As shown in fig. 4, the noise reduction device for fan noise provided in this embodiment is disposed in an engine compartment of an excavator, and includes a
As shown in fig. 2, the
The
Wherein the
Preferably, the center of the
The
The
Preferably, the
Specifically, as shown in fig. 5, the bottom of the
In summary, the noise reduction method for fan noise provided by the invention collects noise signals; acquiring the rotating speed information of the
The fan noise reduction device provided by the invention utilizes the fan noise reduction method, under the working condition that a plurality of sound sources in an engine compartment are mutually superposed, the
The fixing jig and the method for mounting the
The fan noise reduction device provided by the invention is not limited to be arranged on an engine compartment and the number of the fan noise reduction devices is not limited to one set.
The source of infrasound emitted by the
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
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