CN108954442B - Range hood with noise reduction device and noise reduction method - Google Patents
Range hood with noise reduction device and noise reduction method Download PDFInfo
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- CN108954442B CN108954442B CN201810776758.2A CN201810776758A CN108954442B CN 108954442 B CN108954442 B CN 108954442B CN 201810776758 A CN201810776758 A CN 201810776758A CN 108954442 B CN108954442 B CN 108954442B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C15/00—Details
- F24C15/20—Removing cooking fumes
- F24C15/2021—Arrangement or mounting of control or safety systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C15/00—Details
- F24C15/20—Removing cooking fumes
- F24C15/2035—Arrangement or mounting of filters
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
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Abstract
A range hood with a noise reduction device and a noise reduction method are provided with a range hood main body and a three-dimensional space sound field noise reduction device for active noise reduction, wherein the three-dimensional space sound field noise reduction device is respectively assembled in the range hood main body. The three-dimensional space sound field noise reduction device is provided with a noise acquisition sensor for detecting the decibel of a noise source in the smoke machine main body and a noise reduction main body. The noise signals are decomposed into a plurality of sub-band signals, the sub-band signals are converted to obtain the weight vectors of the band-pass filters, the obtained weight vectors of the band-pass filters are converted to generate corresponding loudspeaker sound fields, the equal-intensity sound wave signals are transmitted to corresponding loudspeakers, and the noise sound waves generated by the range hood are offset or counteracted through the sound waves generated by the corresponding loudspeakers, so that noise reduction is achieved. The range hood solves the technical difficulty that noise and performance are mutually contradictory, and the noise generated by the range hood during operation is relatively low without causing negative influences on physiology and psychology of a user on the premise of not sacrificing the performance of absorbing oil smoke of the range hood.
Description
Technical Field
The invention relates to the field of range hoods, in particular to a range hood with a noise reduction device and a noise reduction method.
Background
The existing active noise reduction technology, for example, the application in the earphone is a point-to-point noise reduction technology, that is, directional noise reduction, which cannot effectively eliminate noise with a large range. These techniques focus on eliminating one dimension of the plane acoustic wave in a small enclosed duct or space, which is very effective at low frequency ranges (less than 500 Hz). In order to realize low noise, the existing range hood generally directly sets low air volume, namely the low noise is realized by sacrificing the performance of oil smoke absorption of the range hood, but the oil smoke absorption effect is greatly reduced; in addition, some active noise reduction devices are arranged, but the active noise reduction can only reduce the noise within 1000Hz, and the active noise reduction devices cannot be adapted to high-order acoustic modes. However, in three-dimensional space, higher-order acoustic modes cannot be ignored, and noise reduction is very difficult and complicated especially in a closed large-space pipeline. Under the general condition, a plurality of standing waves and sound waves in different directions are mutually interfered and superposed, so that the noise reduction difficulty of the three-dimensional space is greatly increased.
Therefore, aiming at the defects of the prior art, the range hood with the noise reduction device and the noise reduction method are necessary to solve the defects of the prior art.
Disclosure of Invention
One of the purposes of the invention is to provide a range hood with a noise reduction device to avoid the defects of the prior art. The range hood with the noise reduction device achieves the optimization of the performance of the range hood through the three-dimensional sound field noise reduction device, but simultaneously completes work under the operation of low noise, and solves the technical difficulty that the noise and the performance are mutually contradictory.
The above object of the present invention is achieved by the following technical means.
The utility model provides a lampblack absorber of device of making an uproar falls in area is provided with cigarette owner body and is used for the three-dimensional space sound field noise reduction device of actively making an uproar, and the three-dimensional space sound field noise reduction device assembles inside cigarette owner body.
The range hood main body is provided with a range hood main board for controlling the range hood to operate, and the range hood main board is electrically connected with the three-dimensional space sound field noise reduction device.
The cigarette machine mainboard detects the operating condition of cigarette machine main part, and when operating condition was higher than the threshold value, cigarette machine mainboard transmission pilot signal falls the device of making an uproar to three-dimensional space sound field, and the three-dimensional space sound field falls the device of making an uproar and receives pilot signal and begin to fall the work of making an uproar.
Preferably, above-mentioned cigarette machine main part still is provided with convulsions subassembly, and the convulsions subassembly is assembled inside the cigarette machine main part.
Preferably, above-mentioned cigarette machine mainboard detects the rotational speed of convulsions subassembly, and when the rotational speed of convulsions subassembly was higher than first threshold value, the cigarette machine mainboard transmits pilot signal to the three-dimensional space sound field device of making an uproar that falls, and the three-dimensional space sound field device of making an uproar receives pilot signal and begins to fall the work of making an uproar.
Preferably, the cigarette machine main body is further provided with a rectifying plate, and the rectifying plate is assembled on the cigarette machine main body.
Preferably, the cigarette machine main board detects the telescopic length of the rectifying plate, and when the telescopic length of the rectifying plate is higher than a second threshold value, the cigarette machine main board transmits an indication signal to the three-dimensional space sound field noise reduction device, and the three-dimensional space sound field noise reduction device receives the indication signal and starts noise reduction work.
Preferably, the first threshold is 100 to 10000 rpm/min.
Preferably, the second threshold value is 0 to 30 cm.
Preferably, the first threshold value is 800 to 2000 rpm/min.
Preferably, the second threshold value is 2 to 5 cm.
Preferably, the three-dimensional space sound field noise reduction device is provided with a three-dimensional space sound field noise reduction unit and a self-adaptive noise reduction control unit, the self-adaptive noise reduction control unit is electrically connected with the three-dimensional space sound field noise reduction unit, and the three-dimensional space sound field noise reduction unit and the self-adaptive noise reduction control unit are respectively assembled on the cigarette machine main body.
Preferably, the three-dimensional space sound field noise reduction unit is provided with a noise collection sensor, a loudspeaker and an acoustic resonator, the loudspeaker is installed inside the acoustic resonator, the acoustic resonator is fixedly assembled below an air draft assembly of the cigarette machine main body, the noise collection sensor is fixedly installed on the air draft assembly, and the noise collection sensor and the loudspeaker are respectively electrically connected with the self-adaptive noise reduction control unit.
Preferably, the self-adaptive noise reduction control unit is arranged as a band-pass filter, the band-pass filter is assembled in the cigarette machine main body, and the noise collection sensor and the loudspeaker are respectively and electrically connected with the band-pass filter.
The band-pass filter receives the indication signal of the main board of the cigarette machine and starts to reduce the noise.
Preferably, the cigarette machine main body is provided with a low-damping air box for reducing broadband vibration, and the low-damping air box is assembled inside the cigarette machine main body.
Preferably, the low damping bellows is provided with a plurality of bellows plates which are joined to form a three-dimensional structure, and a noise filter which is mounted on an inner surface of the bellows plates.
Preferably, the air draft assembly is positioned inside a full surrounding structure formed by a filter screen of the air inlet and the low-damping air box; or
The air draft assembly is positioned inside a semi-enclosed structure which is composed of low-damping air boxes and at least has two completely opened structural surfaces.
Preferably, the air draft assembly is provided with a wind wheel, a volute and air guide hoods for guiding airflow to enter two sides of the wind wheel, the air guide hoods and the wind wheel are fixedly installed on the volute, the wind wheel is assembled inside the volute, and the volute is fixedly assembled inside the low-damping wind box.
The range hood of the invention decomposes noise signals into a plurality of sub-band signals, converts the sub-band signals to obtain the weight vector of the band-pass filter, converts the weight vector of the band-pass filter to generate a corresponding loudspeaker sound field, transmits equal-intensity sound wave signals to the corresponding loudspeaker, and cancels or cancels the noise sound wave generated by the range hood through the sound wave generated by the corresponding loudspeaker to realize noise reduction.
Preferably, the self-adaptive noise reduction control unit is further provided with an error return sensor, the error return sensor is fixedly installed inside the cigarette machine main body and located below the low-damping air box, and the error return sensor is electrically connected with the band-pass filter.
Preferably, the error feedback sensor is located below the speaker.
Preferably, the number of the loudspeakers and the number of the acoustic resonance boxes are K, K is larger than or equal to 1, K is a positive integer, and the loudspeakers and the acoustic resonance boxes correspond to one another.
Preferably, the acoustic resonance box is fixedly mounted on the air guide sleeve and is suspended at the bottom of the low-damping air box.
Preferably, the cone or the diaphragm of the loudspeaker faces the air inlet of the main body of the cigarette making machine, and is parallel to the air inlet or forms an included angle β, and β is less than or equal to 60 degrees.
Preferably, the noise collection sensors are fixed on the air guide sleeve, and A noise collection sensors are arranged, wherein A is more than or equal to 4, A is a positive integer, and A is more than or equal to K.
Preferably, the error feedback sensor is provided with Q, Q is a positive integer, and Q is more than or equal to 1.
Preferably, the noise collection sensor is located above the speaker.
Preferably, the number of the band pass filters is D, and D is a positive integer.
Preferably, the noise filtering device is a low damping noise filter plate.
Preferably, the low-damping noise filter plate is provided with a panel main body and a reinforcing structure, wherein the panel main body and the reinforcing structure are distributed with a plurality of through holes for eliminating noise, and the reinforcing structure is fixed on the panel main body.
Preferably, the reinforcing structure is at least one of a reinforcing rib, a rivet, a guide edge, a fixing frame, a groove or a convex hull.
Preferably, the noise filter device is provided with a sound absorbing portion which is fitted between the low-damping noise filter plate and the wall surface of the low-damping bellows.
Preferably, the outer surface of the low damping bellows is fitted with a foam board, an asphalt board or a rubber board.
Preferably, the noise reduction frequency range of the three-dimensional space sound field noise reduction device is 100Hz to 2000 Hz.
The noise reduction method comprises the following steps:
determining and fixing the positions of A noise acquisition sensors, Q error feedback sensors and K loudspeakers;
step two, determining a transfer function T from an initial noise source to a noise acquisition sensor1Transfer function T of loudspeaker to target noise reduction space2And transfer function T of noise collection sensor to target noise reduction space3；
Step three, A noise acquisition sensors are dividedCollecting noise acquisition sensor signals, specifically R, in the region of the cigarette machine1(n)，......，Ri(n),......,RA(n), i is more than or equal to 4 and less than or equal to A, i is a positive integer,
q error feedback noise sensors collect signals of the error feedback sensors respectively in the areas, specifically epsilon1(n)，......,εv(n),......,εQ(n), v is more than or equal to 1 and less than or equal to Q, and v and Q are positive integers;
step four, converting the noise acquisition sensor signals collected by the A noise acquisition sensors obtained in the step three into R (n) ═ R1(n)......Ri(n).......RA(n)]After Q noise acquisition sensors are corrected, the signal of the error return sensor is converted into epsilon (n) ═ epsilon1(n)......εv(n)......εQ(n)]；
Step five, correcting R (n) in step four into R (n) through the formula (I)
Step six, the D band-pass filters of the three-dimensional space noise reduction control unit enable the D band-pass filters obtained in the step five
The corresponding decomposition into L subbands: r is1(k)，......，rg(k)，......，rL(k) Correspondingly decomposing the four results into L subbands: e.g. of the type1(k)，......，eg(k)，......，eL(k) L is more than or equal to g and more than or equal to 2, and L and g are positive integers;
step seven, the sub-band r obtained in the step six is used1(k)，......，rg(k)，......，rL(k) And e1(k)，......，eg(k)，......，eL(k) Calculating adaptive weight coefficients w of L subbands by filtering X least mean square1(k)，......，wg(k)，......，wL(k)，w (K) is a matrix of K × A × D, r (K) is Q × (A × K × D), e (K) is a matrix of Q × D;
step eight, the L sub-bands of the D band-pass filters are subjected to self-adaptive weight coefficients w1(k)，......，wg(k)，......，wL(k) Performing fast Fourier transform to convert into L × Z frequency bands, wherein Z is a matrix of K × A × D;
step nine, superposing the L multiplied by Z frequency bands obtained in the step eight by a frequency superposition method to form a unique A multiplied by K matrix signal frequency;
step ten, carrying out Fourier inverse transformation solution on the frequency of the A multiplied by K matrix signal obtained in the step nine to obtain a weight vector W of the band-pass filterij(n), wherein j is more than or equal to 1 and less than or equal to K, and i is more than or equal to 4 and less than or equal to A;
step eleven, obtaining the weight vector W of the band-pass filter in the step elevenij(n) converting to generate K loudspeaker sound fields, wherein the K loudspeaker sound fields respectively correspond to S1(n)，.....，Sj(n)，.....,SK(n), wherein j is more than or equal to 1 and less than or equal to K, and acquiring an initial noise source R through a noise sensor according to a formula (II)i(n) and the bandpass filter weight vector Wji(n) to estimate the final noise field S of the j-th loudspeaker output signalj(n)，
Wherein the content of the first and second substances,
is Wij(n) a transpose of the matrix,
is Ri(n) by T2Transposed matrix after transfer function, Sj(n) is an equal intensity acoustic signal 180 ° opposite to the noise source;
step twelve, the equal intensity sound wave signal S1(n)，.....，Sj(n)，.....,SK(n) transmitting to the K loudspeakers respectively;
thirteen, error feedbackThe sensor detects the effect, iterates and corrects the self-adaptive weight coefficient to obtain the final self-adaptive weight coefficient meeting the requirement and obtain Sj' (n), go to step fourteen;
step fourteen, with Sj' (n) the final equal intensity sound wave signal is correspondingly transmitted to the corresponding loudspeaker.
The representation of the three-dimensional noise reduction model is supervised by expressing the cost function of the full band of formula (III) as the mean square error of the error sensor signal,
where n is the iteration index through the adaptive algorithm.
Preferably, the above
Wherein epsilonv(n)＝A(n)+Sj(n)·T2Where A (n) is the final noise field created by the initial noise source after transmission through the interior space of the machine.
Preferably, the step thirteen concretely comprises the steps of,
step 13.1, presetting a noise value Γ (n) ═ C of the error feedback noise sensor, where C is the noise value of the area where the error feedback noise sensor is located, and judging Γ (n) and [ a (n) -Sj(n)T2]2When [ A (n) -S ] isj(n)T2]2When the value is more than C, the step 13.2 is entered, when the value is [ A (n) -S [)j(n)T2]2When the temperature is less than or equal to C, entering the step 13.4;
step 13.2, mixing w1(k)，......，wg(k)，......，wL(k) Respectively substituting formula (IV) to respectively obtain new w1(k+1)，......，wg(k+1)，......，wLL adaptive weight coefficients of (k +1), μ being a convergence factor, are entered in step 13.3,
w (k +1) ═ w (k) + [ μ r (k) e (k) ] formula (IV);
step 13.3, let w1(k+1)＝w1(k)，......，wg(k+1)＝wg(k)，......，wL(k+1)＝wL(k) Respectively taking the weight vectors of the filter, and entering the step eight;
step 13.4, let Sj(n)＝Sj' (n), proceed to step fourteen.
Preferably, the above C value ranges from-0.001 dB to 0.001 dB.
Another object of the present invention is to provide a noise reduction method for a range hood with a noise reduction device, which is performed by the above noise reduction method.
The range hood with the noise reduction device is provided with a range hood main body and a three-dimensional space sound field noise reduction device for actively reducing noise, wherein the three-dimensional space sound field noise reduction device is assembled in the range hood main body. The cigarette machine main part is provided with the cigarette machine mainboard of control lampblack absorber function, and the cigarette machine mainboard is connected with the device electricity of making an uproar that falls in three-dimensional space sound field. The cigarette machine mainboard detects the operating condition of cigarette machine main part, and when operating condition was higher than the threshold value, cigarette machine mainboard transmission pilot signal falls the device of making an uproar to three-dimensional space sound field, and the three-dimensional space sound field falls the device of making an uproar and receives pilot signal and begin to fall the work of making an uproar. The range hood of the invention decomposes noise signals into a plurality of sub-band signals, converts the sub-band signals to obtain the weight vector of the band-pass filter, converts the weight vector of the band-pass filter to generate a corresponding loudspeaker sound field, transmits equal-intensity sound wave signals to the corresponding loudspeaker, and cancels or cancels the noise sound wave generated by the range hood through the sound wave generated by the corresponding loudspeaker to realize noise reduction. The range hood is provided with a range hood main body and a three-dimensional space sound field noise reduction device for actively reducing noise, wherein the three-dimensional space sound field noise reduction device is assembled inside the range hood main body. The low-damping bellows can enable incident waves and reflected waves to have different phases at a specific distance from the reflecting surface, so that sound waves of noise can be mutually offset, and the intensity of the noise is reduced. The fully-enclosed structure or the semi-enclosed structure can optimize the performance of the range hood, but simultaneously complete the work under the operation of low noise, solve the technical difficulty of mutual contradiction between noise and performance, and have relatively low noise generated when the range hood operates without sacrificing the performance of oil smoke absorption of the range hood, and avoid negative influences on physiology and psychology of users. Meanwhile, the invention designs and optimizes the specific installation position of the three-dimensional space sound field noise reduction device in the range hood, and obtains the most effective noise reduction effect and the space range of effective noise reduction. Moreover, the noise reduction method of the range hood with the noise reduction device is mainly characterized in that a signal processing method of a plurality of sub-bands is adopted and a filter least mean square (F-XLMS) algorithm is combined, so that a large amount of calculation can be effectively reduced, and the noise reduction effect of a three-dimensional space is improved. Meanwhile, the calculated amount is inversely proportional to the number of sub-bands, so that the stability of the system can be enhanced, and the convergence can be fast. Another advantage of this method is that it can remove signal delay and improve the overall noise reduction effect.
Drawings
The invention is further illustrated by means of the attached drawings, the content of which is not in any way limiting.
Fig. 1 shows a signal transmission relationship of a range hood with a noise reduction device according to the present invention.
FIG. 2 is a perspective view showing the structure of embodiment 1.
Fig. 3 is a side view of fig. 2.
Fig. 4 is a partial perspective view of fig. 2.
Fig. 5 is an exploded view of fig. 4.
FIG. 6 is a schematic perspective view of a low damping windbox.
Fig. 7 is a schematic structural diagram of a noise filtering device.
FIG. 8 is a top view of a low damping windbox.
Fig. 9 is a front view of a low damping bellows.
Fig. 10 is a schematic diagram of an included angle between the speaker and the air inlet.
FIG. 11 is a schematic view showing the structure of a low-damping bellows, wherein A in FIG. 11 is a full-enclosed structure, B in FIG. 11 is an alternate angle A in FIG. 11, C in FIG. 11 is a half-enclosed structure, and D in FIG. 11 is an alternate angle C in FIG. 11.
Fig. 12 is a schematic signal flow diagram illustrating a noise reduction signal processing method according to the present invention.
FIG. 13 is a schematic diagram of the bandpass filter processing of the noise acquisition sensor signal and the error return sensor.
In fig. 1 to 13, the following are included:
a main body 1 of the cigarette machine,
Low damping bellows 11, noise filter 111, sound absorbing part 112, reinforcing structure 113, through hole 114, screen 115,
An air draft assembly 12, a wind wheel 121, a volute 122 and a flow guide cover 123,
A rectifying plate 13,
A three-dimensional space sound field noise reduction device 2,
The three-dimensional space sound field noise reduction unit 22, the noise acquisition sensor 221, the loudspeaker 222, the acoustic resonator 223,
An adaptive noise reduction control unit 23, a band-pass filter 231, an error feedback sensor 232,
A cooking range 3.
Detailed Description
The technical solution of the present invention is further illustrated by the following examples.
Example 1.
A range hood with a noise reduction device is provided with a range hood main body 1 and a three-dimensional space sound field noise reduction device 2 for actively reducing noise, wherein the three-dimensional space sound field noise reduction device 2 is assembled inside the range hood main body 1, as shown in figures 1 to 10. The cigarette machine main part 1 is provided with a cigarette machine main board for controlling the operation of the cigarette machine, and the cigarette machine main board is electrically connected with the three-dimensional space sound field noise reduction device 2.
The cigarette machine mainboard detects the operating condition of cigarette machine main part 1, and when operating condition was higher than the threshold value, cigarette machine mainboard transmission pilot signal falls device 2 to three-dimensional space sound field noise reduction, and three-dimensional space sound field noise reduction device 2 receives pilot signal and begins to fall the work of making an uproar.
The cigarette machine main body 1 is further provided with an air draft assembly 12, and the air draft assembly 12 is assembled inside the cigarette machine main body 1. The cigarette machine mainboard detects the rotational speed of convulsions subassembly 12, and when the rotational speed of convulsions subassembly 12 was higher than first threshold value, cigarette machine mainboard transmission pilot signal falls device 2 to three-dimensional space sound field noise reduction, and three-dimensional space sound field noise reduction device 2 receives pilot signal and begins to fall the work of making an uproar. The first threshold of the present invention is 100 to 10000rpm/min, wherein the first threshold is preferably 800 to 2000rpm/min, and the first threshold of the present embodiment is 800 rpm/min.
The cigarette machine body 1 is also provided with a flow rectification plate 13, and the flow rectification plate 13 is assembled on the cigarette machine body 1. The cigarette machine mainboard detects the flexible length of cowling panel 13, and when the flexible length of cowling panel 13 was higher than the second threshold value, cigarette machine mainboard transmission pilot signal falls device 2 to three-dimensional space sound field noise reduction, and three-dimensional space sound field noise reduction device 2 receives pilot signal and begins to fall the work of making an uproar. The second threshold value of the invention is 0-30 cm, wherein the second threshold value is preferably 2-5 cm, and the second threshold value of the embodiment is 3 cm.
The first threshold value and the second threshold value are set, so that the noise reduction main body can be prevented from working when a small noise source is generated by the range hood main body 1 under the condition of less oil smoke, the service life of the noise reduction main body can be prolonged, and energy can be saved.
The three-dimensional space sound field noise reduction device 2 is provided with a three-dimensional space sound field noise reduction unit 22 and a self-adaptive noise reduction control unit 23, the self-adaptive noise reduction control unit 23 is electrically connected with the three-dimensional space sound field noise reduction unit 22, and the three-dimensional space sound field noise reduction unit 22 and the self-adaptive noise reduction control unit 23 are respectively assembled on the cigarette machine main body 1.
The three-dimensional space sound field noise reduction unit 22 is provided with a noise collection sensor 221, a loudspeaker 222 and an acoustic resonator 223, the loudspeaker 222 is installed inside the acoustic resonator 223, the acoustic resonator 223 is fixedly assembled below the air draft assembly 12 of the cigarette machine main body 1, the noise collection sensor 221 is fixedly installed on the air draft assembly 12, and the noise collection sensor 221 and the loudspeaker 222 are respectively electrically connected with the self-adaptive noise reduction control unit 23.
The adaptive noise reduction control unit 23 is set as a band-pass filter 231, the band-pass filter 231 is assembled inside the cigarette maker main body 1, and the noise collection sensor 221 and the speaker 222 are electrically connected with the band-pass filter 231 respectively. The band pass filter 231 receives the indication signal of the cigarette machine main board and starts to reduce noise.
The cigarette machine main body 1 is provided with a low-damping air box 11 for reducing broadband vibration, and the low-damping air box 11 is assembled inside the cigarette machine main body 1.
The low-damping bellows 11 is provided with a plurality of bellows plates and a noise filter 111, the plurality of bellows plates are spliced to form a three-dimensional structure, and the noise filter 111 is assembled on the inner surface of the bellows plate.
The draft assembly 12 of this embodiment is located within a half enclosure having at least two structural faces fully open, as shown in fig. 6, C in fig. 11 and D in fig. 11, and comprising a low damping bellows 11.
The air draft assembly 12 is provided with a wind wheel 121, a volute 122 and fairings 123 for guiding airflow to enter two sides of the wind wheel 121, the fairings 123 and the wind wheel 121 are fixedly installed on the volute 122, the wind wheel 121 is assembled inside the volute 122, and the volute 122 is fixedly assembled inside the low-damping wind box 11.
The noise signals are decomposed into a plurality of sub-band signals, a weight vector of a band-pass filter 231 is obtained through conversion, the obtained weight vector of the band-pass filter 231 is converted to generate a corresponding loudspeaker 222 sound field, the equal-intensity sound wave signals are transmitted to the corresponding loudspeaker 222, and the noise sound waves generated by the range hood are offset or counteracted through the sound waves generated by the corresponding loudspeaker 222, so that noise reduction is achieved.
The adaptive noise reduction control unit 23 is further provided with an error return sensor 232, the error return sensor 232 is fixedly installed inside the cigarette machine main body 1 and below the low-damping air box 11, and the error return sensor 232 is electrically connected with the band-pass filter 231. The error return sensor 232 is located below the speaker 222.
The speaker 222 of the present invention is used to receive the signal of the adaptive noise reduction control unit 23 and generate sound waves 180 ° opposite to the noise source. The error feedback sensor 232 is used for detecting the performance of the adaptive noise reduction control unit 23, and the algorithm of the adaptive noise reduction control unit 23 performs signal feedback on the three-dimensional space sound field noise reduction unit 22.
The three-dimensional space sound field noise reduction unit 22 is configured to decompose the signal of the noise collection sensor 221 or the signal of the error return sensor 232 into a plurality of sub-bands, receive the wave frequency of the noise source transmitted by the noise collection sensor 221 and the signal of the error return sensor 232, perform an operation, and output a signal to the speaker 222.
The noise collection sensors 221 of the present invention are provided with a, a is greater than or equal to 4, a is a positive integer, and a is greater than or equal to K, and the noise collection sensors 221 of the present embodiment are specifically provided with 4.
The error feedback sensors 232 of the present invention are provided with Q, Q is a positive integer, Q is greater than or equal to 1, and the number of the error feedback sensors 232 of the present embodiment is specifically set to 2.
The noise collection sensor 221 is located above the speaker 222, and the number of the band pass filters 231 is D, where D is a positive integer. The band pass filters 231 of the present embodiment are set to 4.
It should be noted that the number of the speakers 222 of the present invention may be set to 2, or may be set to be any positive integer; the number of the noise collection sensors 221 may be set to 4, or may be set to any positive integer greater than 4; the number of the error feedback sensors 232 can be set to be 2, or can be set to be any positive integer; the number of the band pass filters 231 of the present invention may be 4, or may be any positive integer, and the specific implementation manner is determined according to the actual situation.
The noise filtering device 111 is a low damping noise filtering plate, the low damping noise filtering plate is provided with a panel main body and a reinforcing structure 113, the panel main body is distributed with a plurality of through holes 114 for eliminating noise, and the reinforcing structure 113 is fixed on the panel main body. The reinforcing structure 113 of the present invention is at least one of a reinforcing rib, a rivet, a guide edge, a fixing frame, a groove, or a convex hull. The noise filter 111 is provided with a sound absorbing portion 112, and the sound absorbing portion 112 is fitted between the low-damping noise filter plate and the wall surface of the low-damping air box 11. The reinforcing structure of the present embodiment is a reinforcing rib.
It should be noted that the reinforcing structure of the present invention may be a rivet, a guide edge, a fixing frame, a groove, or a convex hull, or may be any combination of a plurality of types, and the specific embodiment is determined in actual circumstances.
The reinforcing structure functions to enhance the rigidity of the low damping noise filter plate.
The principle of the invention is as follows: the cigarette machine mainboard detects the operating condition of cigarette machine main part 1, and when operating condition was higher than the threshold value, cigarette machine mainboard transmission pilot signal falls device 2 to three-dimensional space sound field noise reduction, and three-dimensional space sound field noise reduction device 2 receives pilot signal and begins to fall the work of making an uproar. The cigarette machine mainboard detects the rotational speed of convulsions subassembly 12 or the flexible length of cowling panel 13, and when convulsions subassembly 12 or cowling panel 13's behavior was higher than the threshold value, cigarette machine mainboard transmission indicating signal falls device 2 to three-dimensional space sound field noise reduction, and three-dimensional space sound field noise reduction device 2 receives indicating signal and begins to fall the work of making an uproar and produce and be 180 reverse sound waves offset with it with inside noise source, realizes falling the mesh of making an uproar. When noise generated by the range hood contacts the fully-enclosed structure or the semi-enclosed structure of the low-damping air box 11, most incident waves propagating in the opposite direction interfere with reflected waves. Meanwhile, the noise reduction is carried out by the resonance principle of the range hood, when the noise resonates with the natural frequency of the low-damping air box 11, when the resonance occurs, the oscillating sound waves violently penetrate into and out of the through hole 114 in the air, and the sound energy of the noise is converted into friction loss in the process, so that the purpose of eliminating the target frequency noise is achieved.
This area falls lampblack absorber of device of making an uproar is provided with cigarette machine main part 1 and is used for the three-dimensional space sound field noise reduction device 2 of initiatively falling the noise, and three-dimensional space sound field noise reduction device 2 assembles inside cigarette machine main part 1. The cigarette machine main part 1 is provided with a cigarette machine main board for controlling the operation of the cigarette machine, and the cigarette machine main board is electrically connected with the three-dimensional space sound field noise reduction device 2. The cigarette machine mainboard detects the operating condition of cigarette machine main part 1, and when operating condition was higher than the threshold value, cigarette machine mainboard transmission pilot signal falls device 2 to three-dimensional space sound field noise reduction, and three-dimensional space sound field noise reduction device 2 receives pilot signal and begins to fall the work of making an uproar. The range hood of the invention decomposes noise signals into a plurality of sub-band signals, converts the sub-band signals to obtain the weight vector of the band-pass filter 231, converts the weight vector of the band-pass filter 231 to generate a corresponding loudspeaker 222 sound field, transmits the equal-intensity sound wave signals to the corresponding loudspeaker 222, and cancels or cancels the noise sound wave generated by the range hood through the sound wave generated by the corresponding loudspeaker 222, thereby realizing noise reduction. The low damping bellows 11 of this lampblack absorber can make incident wave and reflection wave have different phases under the specific distance with the plane of reflection to the sound wave of noise can offset each other, thereby the intensity of noise reduction. The fully-enclosed structure or the semi-enclosed structure can optimize the performance of the range hood, but simultaneously complete the work under the operation of low noise, solve the technical difficulty of mutual contradiction between noise and performance, and have relatively low noise generated when the range hood operates without sacrificing the performance of oil smoke absorption of the range hood, and avoid negative influences on physiology and psychology of users. Finally, the invention designs and optimizes the specific installation position of the three-dimensional space sound field noise reduction device 2 in the range hood, and obtains the most effective noise reduction effect and the space range of effective noise reduction.
Example 2.
The utility model provides a lampblack absorber of device of making an uproar falls in area, other characteristics are the same with embodiment 1, the difference lies in: the outer surface of the low damping bellows 11 of this embodiment is fitted with a foam board.
It should be noted that the outer surface of the low damping bellows 11 of the present invention may be equipped with a foam board, or may be equipped with any one of a foam board and a rubber board.
The foam board, the foam board or the rubber board functions to block the transmission of noise to the outside, thereby reducing the noise level.
Compared with embodiment 1, the noise reduction effect of the range hood of the embodiment is better.
Example 3.
The utility model provides a lampblack absorber of device of making an uproar falls in area, other characteristics are the same with embodiment 1, the difference lies in: the extraction assembly 12 of this embodiment is located inside the fully enclosed structure formed by the screen 115 of the air intake and the low damping bellows 11, as shown at a in fig. 11 and B in fig. 11.
Compared with embodiment 1, the seamless full-enclosure structure of the present embodiment can prevent the noise sound wave from propagating to the outside, and can improve the noise reduction effect better.
Example 4.
A range hood with a noise reduction device is characterized in that the noise reduction frequency range of a three-dimensional space sound field noise reduction device 2 is 100 Hz-2000 Hz.
The limitation that the active noise reduction in the prior art can only reduce the noise within 1000Hz is broken through, and the noise frequency domain of the maximum 2000Hz is effectively reduced.
Example 5.
A range hood with a noise reduction device and a noise reduction method are shown in figures 12-13, and comprise the following steps:
step one, determining and fixing the positions of A noise acquisition sensors 221, Q error return sensors 232 and K loudspeakers 222;
step two, determining the transfer function T from the initial noise source to the noise collection sensor 2211The transfer function T of the speaker 222 to the target noise reduction space2And the transfer function T of the noise collection sensor 221 to the target noise reduction space3；
Thirdly, the A noise acquisition sensors 221 respectively collect the signals of the noise acquisition sensors 221 in the regions in the space of the cigarette machine, specifically R1(n)，......，Ri(n),......,RA(n), i is more than or equal to 4 and less than or equal to A, i is a positive integer,
q error feedback noise sensors collect the signals of the error feedback sensors 232 respectively in the areas where the sensors are located, specifically epsilon1(n)，......,εv(n),......,εQ(n), v is more than or equal to 1 and less than or equal to Q, and v and Q are positive integers;
step four, converting the noise collection sensor 221 signals collected by the a noise collection sensors 221 obtained in step three into R (n) ═ R1(n)......Ri(n).......RA(n)]After the Q noise collection sensors 221 correct the signal of the error feedback sensor 232 is converted into epsilon (n) ═ epsilon1(n)......εv(n)......εQ(n)]；
Step five, correcting R (n) in step four into R (n) through the formula (I)
Step six, the D band-pass filter 231 of the three-dimensional space noise reduction control unit enables the D band-pass filter 231 obtained in the step five
The corresponding decomposition into L subbands: r is1(k)，......，rg(k)，......，rL(k) And correspondingly decomposing the data obtained in the step four into L subbands: e.g. of the type1(k)，......，eg(k)，......，eL(k) L is more than or equal to g and more than or equal to 2, and L and g are positive integers;
step seven, the sub-band r obtained in the step six is used1(k)，......，rg(k)，......，rL(k) And e1(k)，......，eg(k)，......，eL(k) Calculating adaptive weight coefficients w of L subbands by filtering X least mean square1(k)，......，wg(k)，......，wL(k) W (K) is a matrix of K × A × D, r (K) is Q × (A × K × D), e (K) is a matrix of Q × D;
step eight, adapting the L sub-band adaptive weight coefficients w of the D band-pass filters 2311(k)，......，wg(k)，......，wL(k) Performing fast Fourier transform to convert into L × Z frequency bands, wherein Z is a matrix of K × A × D;
step nine, superposing the L multiplied by Z frequency bands obtained in the step eight by a frequency superposition method to form a unique A multiplied by K matrix signal frequency;
step ten, carrying out Fourier inverse transformation solution on the frequency of the A multiplied by K matrix signal obtained in the step nine to obtain the weight vector W of the band-pass filter 231ij(n), wherein j is more than or equal to 1 and less than or equal to K, and i is more than or equal to 4 and less than or equal to A;
step eleven, obtaining the weight vector W of the band-pass filter 231 in the step elevenij(n) converting to generate K speaker 222 sound fields, the K speaker 222 sound fields corresponding to S1(n)，.....，Sj(n)，.....,SK(n), wherein j is more than or equal to 1 and less than or equal to K, and acquiring an initial noise source R through a noise sensor according to a formula (II)i(n) and the weight vector W of the band pass filter 231ji(n) to estimate the final noise field S of the output signal of the jth speaker 222j(n)，
Wherein the content of the first and second substances,
is Wij(n) a transpose of the matrix,
is Ri(n) by T2Transposed matrix after transfer function, Sj(n) is an equal intensity acoustic signal 180 ° opposite to the noise source;
step twelve, the equal intensity sound wave signal S1(n)，.....，Sj(n)，.....,SK(n) are respectively transmitted to the K speakers 222;
step thirteen, the error feedback sensor 232 detects the effect, iterates and corrects the adaptive weight coefficient to obtain the final adaptive weight coefficient meeting the requirements and Sj' (n), go to step fourteen;
step fourteen, with Sj' (n) the final equal intensity sound wave signal is correspondingly transmitted to the corresponding speaker 222;
the representation of the three-dimensional noise reduction model is supervised by expressing the cost function of the full band of formula (III) as the mean square error of the error sensor signal,
wherein n is an iterative index through an adaptive algorithm;
Wherein the thirteen steps specifically comprise the following steps of,
step 13.1, presetting errorsThe noise value Γ (n) ═ C of the difference feedback noise sensor, where C is the noise value of the area where the error feedback noise sensor is located, and Γ (n) and [ A (n) -S are determinedj(n)T2]2When [ A (n) -S ] isj(n)T2]2When the value is more than C, the step 13.2 is entered, when the value is [ A (n) -S [)j(n)T2]2When the temperature is less than or equal to C, entering the step 13.4;
step 13.2, mixing w1(k)，......，wg(k)，......，wL(k) Respectively substituting formula (IV) to respectively obtain new w1(k+1)，......，wg(k+1)，......，wLL adaptive weight coefficients of (k +1), μ being a convergence factor, are entered in step 13.3,
w (k +1) ═ w (k) + [ μ r (k) e (k) ] formula (IV);
step 13.3, let w1(k+1)＝w1(k)，......，wg(k+1)＝wg(k)，......，wL(k+1)＝wL(k) Respectively taking the weight vectors of the filter, and entering the step eight;
step 13.4, let Sj(n)＝Sj' (n), proceed to step fourteen.
The value of C of the present invention ranges from-0.001 dB to 0.001 dB.
The adaptive noise reduction control unit 23 of the present invention continuously performs iteration to adjust the weight of adaptive filtering so that the convergence of the whole system tends to a stable state. For example: noise signals are collected at a noise source position in the area where the noise collection sensor 221 is located, the signals are transmitted to the adaptive noise reduction control unit 23 for noise reduction, and then calculation is performed to output signals to drive the loudspeaker 222 so as to eliminate the noise in the area where the loudspeaker 222 is located. The error feedback sensor 232 monitors the sound pressure value of the area where the speaker 222 is located, so that the adaptive noise reduction control unit 23 adjusts the adaptive filtering weight to automatically change the amplitude of the speaker 222.
The adaptive algorithm of the invention adopts a filtering X least mean square algorithm, the advantage of the filtering X least mean square method is that the optimal convergence solution can be realized without solving an inverse matrix and other pre-known parameters, and compared with the standard least mean square algorithm, the algorithm of the adaptive noise reduction control unit 23 is mainly characterized in that a signal processing method which is decomposed into a plurality of sub-bands is adopted and combined with the filtering X least mean square algorithm, the problem of needing a large amount of calculation can be effectively solved, and the noise reduction effect in a three-dimensional space is enhanced. Meanwhile, the calculated amount is in inverse proportion to the number of the sub-bands, so that the stability of the whole system is improved, and the convergence is faster. Moreover, the influence of each transmission channel on the algorithm is strengthened. Another advantage of this algorithm is that it can remove the delay doubt of the signal and enhance the overall noise reduction effect by adding an adaptive weighting algorithm in each subband by filtering X least mean square method and then adjusting the final weighting coefficients via the band pass filter 231.
In a closed three-dimensional space, such as a space with a length, a width and a height of L, W, H, the N-th order acoustic mode function can be expressed as
Wherein N is1、N2And N3Is the acoustic mode number along the rectangular coordinate X, Y, Z. In practical applications, such as three-dimensional space noise reduction systems of air ducts of cigarette making machines, the noise frequency domain distribution of the cigarette making machines is broadband noise from 200Hz to 2000Hz, and line spectrum noise generated by some fans and noise caused by vibration.
In the prior art, only the active noise reduction technology for eliminating low-order sound modes such as the typical noise reduction technology of less than 500Hz or less than 1000Hz is focused, but the noise frequency of the existing cigarette making machine is more than 1000Hz, and the noise power of the existing cigarette making machine which needs to be effectively reduced cannot meet the noise reduction strategy of the existing cigarette making machine. For a three-dimensional sound field which is completely or partially surrounded by a space where an air duct or an air draft assembly 12 of a cigarette machine is located, and the amplitude of a noise source mode and the mode coefficient of a loudspeaker 222 sound production are used for three-dimensional noise reduction, the core technology for actively reducing the noise is the unknown number, and the two unknown numbers are closely related to the peripheral structure, the geometric shape and the sound source characteristics of the noise. Therefore, the noise hologram information is quickly and effectively established by an equivalent source method, namely the amplitude and the phase of the noise source are recorded by the interference principle of the sound wave. Based on the effective and accurate estimation of the space noise and the free space noise radiation, the sound field signal can be simulated quickly and accurately to eliminate the calculation of the noise in the smoke ventilator. The method can adapt to solving the high-order acoustic mode, can improve the frequency domain of noise reduction to 2000Hz, solves the problem that some frequency bands cannot be achieved in the existing active noise reduction technology, and breaks through the limitation that the active noise reduction can only reduce the noise within 1000 Hz.
The noise reduction method of the range hood with the noise reduction device has the advantages that after the signals are decomposed into sub-band signals, the signals are used for accelerating convergence on an algorithm, the dynamic domain of the frequency spectrum of the signals on the sub-bands is greatly reduced relative to the original signals, and meanwhile, the reduction rate of calculated amount is in direct proportion to the number of the sub-bands, so that the signals are decomposed and then used in a filtering X least mean square algorithm.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the protection scope of the present invention, and although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims (9)
1. The utility model provides a lampblack absorber of device of making an uproar falls in area which characterized in that: the smoke machine is provided with a smoke machine main body and a three-dimensional space sound field noise reduction device for actively reducing noise, wherein the three-dimensional space sound field noise reduction device is assembled in the smoke machine main body;
the range hood main body is provided with a range hood main board for controlling the operation of the range hood, and the range hood main board is electrically connected with the three-dimensional space sound field noise reduction device;
the method comprises the following steps that a cigarette machine main board detects the working state of a cigarette machine main body, when the working state is higher than a threshold value, the cigarette machine main board transmits an indication signal to a three-dimensional space sound field noise reduction device, and the three-dimensional space sound field noise reduction device receives the indication signal and starts noise reduction work;
decomposing the noise signal into a plurality of sub-band signals, converting to obtain a weight vector of a band-pass filter, converting the weight vector of the band-pass filter to generate a corresponding loudspeaker sound field, transmitting the equal-intensity sound wave signal to a corresponding loudspeaker, and offsetting or counteracting the noise sound wave generated by the range hood through the sound wave generated by the corresponding loudspeaker to realize noise reduction;
a method of noise reduction comprising the steps of:
determining and fixing the positions of A noise acquisition sensors, Q error feedback sensors and K loudspeakers;
step two, determining a transfer function T from an initial noise source to a noise acquisition sensor1Transfer function T of loudspeaker to target noise reduction space2And transfer function T of noise collection sensor to target noise reduction space3；
Step three, respectively collecting the noise collection sensor signals of the regions in which the A noise collection sensors are positioned in the space of the smoke machine, specifically R1(n)，......，Ri(n),......,RA(n), i is more than or equal to 4 and less than or equal to A, i is a positive integer,
q error feedback noise sensors collect signals of the error feedback sensors respectively in the areas, specifically epsilon1(n)，......,εv(n),......,εQ(n), v is more than or equal to 1 and less than or equal to Q, and v and Q are positive integers;
step four, converting the noise acquisition sensor signals collected by the A noise acquisition sensors obtained in the step three into R (n) ═ R1(n)......Ri(n).......RA(n)]After Q noise acquisition sensors are corrected, the signal of the error return sensor is converted into epsilon (n) ═ epsilon1(n)......εv(n)......εQ(n)]；
Step five, correcting R (n) in step four into R (n) through the formula (I)
Step six, the D band-pass filters of the three-dimensional space noise reduction control unit enable the D band-pass filters obtained in the step five
The corresponding decomposition into L subbands: r is1(k)，......，rg(k)，......，rL(k) And D, obtaining the product of the step four. The corresponding decomposition into L subbands: e.g. of the type1(k)，......，eg(k)，......，eL(k) L is more than or equal to g and more than or equal to 2, and L and g are positive integers;
step seven, the sub-band r obtained in the step six is used1(k)，......，rg(k)，......，rL(k) And e1(k)，......，eg(k)，......，eL(k) Calculating adaptive weight coefficients w of L subbands by filtering X least mean square1(k)，......，wg(k)，......，wL(k) W (K) is a matrix of K × A × D, r (K) is Q × (A × K × D), e (K) is a matrix of Q × D;
step eight, the L sub-bands of the D band-pass filters are subjected to self-adaptive weight coefficients w1(k)，......，wg(k)，......，wL(k) Performing fast Fourier transform to convert into L × Z frequency bands, wherein Z is a matrix of K × A × D;
step nine, superposing the L multiplied by Z frequency bands obtained in the step eight by a frequency superposition method to form a unique A multiplied by K matrix signal frequency;
step ten, carrying out Fourier inverse transformation solution on the frequency of the A multiplied by K matrix signal obtained in the step nine to obtain a weight vector W of the band-pass filterij(n), wherein j is more than or equal to 1 and less than or equal to K, and i is more than or equal to 4 and less than or equal to A;
step eleven, obtaining the weight vector W of the band-pass filter in the step elevenij(n) converting to generate K loudspeaker sound fields, wherein the K loudspeaker sound fields respectively correspond to S1(n)，.....，Sj(n)，.....,SK(n), wherein j is more than or equal to 1 and less than or equal to K, and acquiring an initial noise source R through a noise sensor according to a formula (II)i(n) and the bandpass filter weight vector Wji(n) to estimate the final noise field S of the j-th loudspeaker output signalj(n)，
Wherein the content of the first and second substances,
is Wij(n) a transpose of the matrix,
is Ri(n) by T2Transposed matrix after transfer function, Sj(n) is an equal intensity acoustic signal 180 ° opposite to the noise source;
step twelve, the equal intensity sound wave signal S1(n)，.....，Sj(n)，.....,SK(n) transmitting to the K loudspeakers respectively;
step thirteen, the error is transmitted back to the sensor detection effect, iteration is carried out and the self-adaptive weight coefficient is corrected, the final self-adaptive weight coefficient meeting the requirements is obtained, and S is obtainedj' (n), go to step fourteen;
step fourteen, with Sj' (n) the final equal-intensity sound wave signals are correspondingly transmitted to corresponding loudspeakers;
the representation of the three-dimensional noise reduction model is supervised by expressing the cost function of the full band of formula (III) as the mean square error of the error sensor signal,
wherein n is an iterative index through an adaptive algorithm;
the above-mentioned
Wherein epsilonv(n)＝A(n)+Sj(n)·T2Wherein A (n) is the final noise field formed by the initial noise source after transmission through the interior space of the cigarette machine;
the step thirteen concretely comprises the following steps of,
in the step 13.1, the step of the method,presetting a noise value gamma (n) of the error feedback noise sensor as C, wherein C is the noise value of the area where the error feedback noise sensor is detected, and judging gamma (n) and [ A (n) -Sj(n)T2]2When [ A (n) -S ] isj(n)T2]2When the value is more than C, the step 13.2 is entered, when the value is [ A (n) -S [)j(n)T2]2When the temperature is less than or equal to C, entering the step 13.4;
step 13.2, mixing w1(k)，......，wg(k)，......，wL(k) Respectively substituting formula (IV) to respectively obtain new w1(k+1)，......，wg(k+1)，......，wLL adaptive weight coefficients of (k +1), μ being a convergence factor, are entered in step 13.3,
w (k +1) ═ w (k) + [ μ r (k) e (k) ] formula (IV);
step 13.3, let w1(k+1)＝w1(k)，......，wg(k+1)＝wg(k)，......，wL(k+1)＝wL(k) Respectively taking the weight vectors of the filter, and entering the step eight;
step 13.4, let Sj(n)＝Sj' (n), go to step fourteen;
the C value ranges from-0.001 dB to 0.001 dB.
2. A range hood with a noise reducer as set forth in claim 1, wherein: the range hood main body is also provided with an air draft assembly, and the air draft assembly is assembled inside the range hood main body;
the cigarette machine mainboard detects the rotational speed of convulsions subassembly, and when the rotational speed of convulsions subassembly was higher than first threshold value, cigarette machine mainboard transmission pilot signal falls the device of making an uproar to three-dimensional space sound field, and the three-dimensional space sound field falls the device of making an uproar and receives pilot signal and begin to fall the work of making an uproar.
3. A range hood with a noise reducer as set forth in claim 2, wherein: the cigarette machine main body is also provided with a rectifying plate which is assembled on the cigarette machine main body;
the cigarette machine mainboard detects the flexible length of rectifying plate, and when the flexible length of rectifying plate was higher than the second threshold value, cigarette machine mainboard transmission instruction signal extremely, the work of making an uproar is fallen in three-dimensional space sound field noise reduction device receipt instruction signal and beginning to fall.
4. A range hood with a noise reducer according to claim 3, wherein: the first threshold value is 100-10000 rpm/min;
the second threshold value is 0-30 cm.
5. A range hood with a noise reducer according to claim 3, wherein: the first threshold value is 800-2000 rpm/min;
the second threshold value is 2-5 cm.
6. A range hood with a noise reducer according to any one of claims 2 to 5, wherein: the three-dimensional space sound field noise reduction device is provided with a three-dimensional space sound field noise reduction unit and a self-adaptive noise reduction control unit, the self-adaptive noise reduction control unit is electrically connected with the three-dimensional space sound field noise reduction unit, and the three-dimensional space sound field noise reduction unit and the self-adaptive noise reduction control unit are respectively assembled on the cigarette machine main body;
the three-dimensional space sound field noise reduction unit is provided with a noise collection sensor, a loudspeaker and an acoustic resonator, the loudspeaker is installed inside the acoustic resonator, the acoustic resonator is fixedly assembled below an air draft assembly of the cigarette machine main body, the noise collection sensor is fixedly installed on the air draft assembly, and the noise collection sensor and the loudspeaker are respectively and electrically connected with the self-adaptive noise reduction control unit;
the self-adaptive noise reduction control unit is arranged as a band-pass filter, the band-pass filter is assembled in the cigarette machine main body, and the noise acquisition sensor and the loudspeaker are respectively and electrically connected with the band-pass filter;
the band-pass filter receives an indication signal of a main board of the range hood and starts to reduce noise;
the cigarette machine main body is provided with a low-damping air box for reducing broadband vibration, and the low-damping air box is assembled in the cigarette machine main body;
the low-damping air bellow is provided with a plurality of air bellow plates and a noise filtering device, the air bellow plates are spliced into a three-dimensional structure, and the noise filtering device is assembled on the inner surface of the air bellow plates;
the air draft assembly is positioned inside a full-surrounding structure formed by a filter screen of the air inlet and the low-damping air box; or
The air draft assembly is positioned in a semi-enclosed structure which is composed of low-damping bellows and at least has two completely opened structural surfaces;
the air draft assembly is provided with a wind wheel, a volute and air guide hoods for guiding airflow to enter two sides of the wind wheel, the air guide hoods and the wind wheel are fixedly installed on the volute, the wind wheel is assembled inside the volute, and the volute is fixedly assembled inside the low-damping air box.
7. A range hood with a noise reducer according to claim 6, wherein: the self-adaptive noise reduction control unit is also provided with an error return sensor which is fixedly arranged in the smoke machine main body and is positioned below the low-damping air box, and the error return sensor is electrically connected with the band-pass filter;
the error return sensor is located below the speaker.
8. A range hood with a noise reducer according to claim 7, wherein: k loudspeakers and acoustic resonance boxes are arranged, wherein K is more than or equal to 1 and is a positive integer, and the loudspeakers and the acoustic resonance boxes are in one-to-one correspondence;
the acoustic resonance box is fixedly assembled on the flow guide cover and suspended at the bottom of the low-damping air box;
the cone or the diaphragm of the loudspeaker faces the air inlet of the main body of the cigarette making machine, and is parallel to the air inlet or forms an included angle β with the air inlet, and β is not more than 60 degrees;
the noise acquisition sensors are fixed on the air guide sleeve, A is more than or equal to 4, A is a positive integer and is more than or equal to K;
the error feedback sensors are provided with Q numbers, Q is a positive integer and is more than or equal to 1;
the noise acquisition sensor is positioned above the loudspeaker;
d band-pass filters are arranged, and D is a positive integer;
the noise filtering device is a low-damping noise filtering plate;
the low-damping noise filter plate is provided with a panel main body and a reinforcing structure, wherein the panel main body is distributed with a plurality of through holes for eliminating noise, and the reinforcing structure is fixed on the panel main body;
the reinforcing structure is at least one of reinforcing ribs, rivets, guide edges, fixing frames, grooves or convex hulls;
the noise filtering device is provided with a sound absorbing part which is assembled between the low-damping noise filtering plate and the wall surface of the low-damping air box;
the outer surface of the low-damping air box is provided with a foam board, an asphalt board or a rubber board;
the noise reduction frequency range of the three-dimensional space sound field noise reduction device is 100 Hz-2000 Hz.
9. A noise reduction method of a range hood with a noise reduction device is characterized in that: the noise reduction method of the range hood of claim 8.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2018101919149 | 2018-03-08 | ||
| CN201810191914 | 2018-03-08 |
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| Publication Number | Publication Date |
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| CN108954442A CN108954442A (en) | 2018-12-07 |
| CN108954442B true CN108954442B (en) | 2020-06-09 |
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| CN201810772839.5A Active CN108731073B (en) | 2018-03-08 | 2018-07-14 | Lampblack absorber with lampblack separation device and noise reduction method |
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| CN109994099A (en) * | 2019-03-18 | 2019-07-09 | 佛山市云米电器科技有限公司 | A kind of bedroom active noise reducing device and the bedroom with the active noise reducing device |
| CN110516341B (en) * | 2019-08-21 | 2024-01-23 | 西北工业大学 | Noise reduction method for additional damping of gearbox based on modal strain energy |
| TWI790597B (en) | 2020-05-21 | 2023-01-21 | 佳音醫療器材股份有限公司 | Device for alleviating obstructive sleep apnea |
| CN111536569B (en) * | 2020-06-11 | 2021-06-29 | 珠海格力电器股份有限公司 | Range hood control method and device, range hood and readable storage medium |
| CN111899712B (en) * | 2020-08-13 | 2024-03-22 | 珠海格力电器股份有限公司 | Active noise reduction device and method for smoke exhaust ventilator |
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