An extractor hood and an intelligent control method thereof

Abstract

The application discloses an extractor hood and an intelligent control method thereof. The extractor hood comprises an air inlet assembly, a fan box body arranged above a ceiling of a kitchen, and a fan arranged in the fan box body. The fan box body is hung to a floor of a top of the kitchen. The fan comprises a volute and an impeller arranged in the volute. The impeller comprises blades. The extractor hood further comprises a microphone array for collecting sound in a channel through which oil fume passes, and a speaker array for emitting inverse sound waves according to a rotating speed of the fan and the sound collected by the microphone array.

Description

Technical Field

[0001] This invention relates to an oil fume purification device, and more particularly to a range hood and an intelligent control method for the range hood. Background Technology

[0002] Range hoods have become an indispensable kitchen appliance in modern homes. Installed above the stove, they quickly remove and exhaust the waste from the stove and the harmful fumes produced during cooking.

[0003] As users become increasingly focused on user experience, range hoods and cooktops are now paying more attention to noise reduction and concealed design during cooking, leading to the popularity of products with ceiling-mounted fan housings in recent years. On one hand, users of ceiling-mounted (split-type) products are generally more sensitive to noise. While these products reduce noise by housing the fan housing within the kitchen ceiling, making the perceived noise level slightly lower than that of a standard integrated range hood, the ceiling primarily isolates high-frequency noise (because higher frequencies have weaker penetration through obstacles), leaving mid-to-low frequencies unisolated. This alters the overall frequency response, resulting in a slightly strange sound compared to standard products. Therefore, some of these products are incorporating active noise cancellation measures to reduce low-frequency noise and further improve the user experience, as disclosed in Chinese patent applications 202220778031.X and 202220778038.1.

[0004] However, range hoods typically use multi-blade centrifugal fans with 48-80 blades, resulting in two key characteristics: 1) a higher blade passing frequency (BPF) compared to ordinary fans (5-18 blades); and 2) noise energy radiated by the impeller shifts towards mid-to-high frequencies, falling within the range most sensitive to human hearing (rather than the low-frequency band below 500Hz, which is easier to reduce with traditional active noise cancellation). Furthermore, traditional broadband noise reduction algorithms cannot accurately capture the harmonic groups generated by these densely packed blades, and the distance between the noise source of a traditional range hood and the human ear is too close, making it difficult for the reverse sound waves to cancel out slightly higher frequency noise. Therefore, ordinary active noise cancellation solutions are often ineffective in kitchen environments.

[0005] Furthermore, the actuators (microphones) used in traditional active noise cancellation are large and occupy valuable fluid channel space. Moreover, as diaphragm structures, they are easily contaminated by oil and require frequent maintenance or cleaning, further increasing the after-sales costs for users. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a range hood that improves noise reduction, provides a more comfortable and convenient cooking experience, and enhances adaptability to different scenarios.

[0007] The second technical problem to be solved by the present invention is to provide an intelligent control method for the above-mentioned range hood.

[0008] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: a range hood, including an air intake component, a fan housing installed above the ceiling of the kitchen and a fan installed inside the fan housing, the fan housing being hung on the floor slab at the top of the kitchen, the fan including a volute and an impeller installed inside the volute, the impeller including blades; The range hood also includes: Microphone array, used to collect sound from the passage through which cooking fumes pass; A loudspeaker array is used to emit antiphase sound waves based on the fan speed and the sound collected by the microphone array.

[0009] By fusing the rotational speed of the ceiling fan with the spatial sound field sampling and signal of a multi-microphone array, the passing frequency of the blades and its third harmonic component can be precisely locked, thereby generating an anti-phase sound wave to drive a speaker array at a specific location, achieving efficient dynamic noise control.

[0010] Furthermore, to achieve spatial distribution acquisition of noise, the microphone array includes a first microphone located at the air inlet of the fan, a second microphone located on the inner wall of the volute, a third microphone located on the inner wall of the fan housing, and a fourth microphone located near the front side of the air inlet assembly as an error microphone.

[0011] Furthermore, the loudspeaker includes a first loudspeaker disposed at the air inlet of the fan, a second loudspeaker disposed on the inner wall of the volute, a third loudspeaker disposed on the inner wall of the fan housing, and a fourth loudspeaker disposed at the air outlet of the fan. This effectively solves the noise reduction problem of split-type range hoods caused by standing waves in the ceiling cavity, sound transmission through ducts, and dense harmonics from multi-blade centrifugal fans.

[0012] Furthermore, each speaker is a piezoresistive ceramic speaker. This type of speaker has no diaphragm, is small in size, highly efficient, and does not easily accumulate oil, making it especially suitable for range hoods.

[0013] Preferably, the first speaker, the second speaker, the third speaker and the fourth speaker each have at least two.

[0014] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: an intelligent control method for a range hood, using the range hood described above, characterized in that: the range hood further includes a controller, the controller being electrically connected to a fan, a microphone array, and a speaker array respectively; the intelligent control method includes the following steps: 1) The range hood is started, and the fan runs at a preset speed, proceeding to step 2); 2) Rotational speed signal acquisition: The controller acquires the current rotational speed signal of the fan. ; 3) Calculate the blade passing frequency : in, The number of leaves; 4) Order selection and harmonic frequency generation:

[0015] in, =4; 5) Multi-microphone sound pressure signal acquisition and fusion: The following time delay compensation formula is used: Fusion computing:

[0016] in, This represents the distance of each microphone from its corresponding sound source. This refers to the system's real-time uptime. It is an integral variable; 6) Adaptive cancellation implementation: The result obtained in step 5) The signal is processed in four channels according to its order, and after bandpass filtering, the amplitude is achieved separately. Detection and phase Detection:

[0017] This generates an antiphase wave: ; 7) Loudspeaker array drive position coordination strategy: After the inverting wave is converted from digital to analog and amplified, it is transmitted to the loudspeaker array. The driving signal for the first loudspeaker is... The driving signal for the second speaker is The driving signal for the third speaker is The driving signal for the fourth speaker is .

[0018] By combining fan speed with spatial sound field sampling and signal fusion technology using a multi-microphone array, the passing frequency of the blades and its third harmonic component are accurately locked. Four sets of parallel narrowband trackers are used to generate anti-phase sound waves, which drive the speakers at specific locations to achieve noise cancellation. This solves the noise reduction problem caused by standing waves in the ceiling cavity, sound transmission in the duct, and dense harmonics of multi-blade fans in split range hoods, achieving efficient dynamic noise control with a noise reduction of 12-15 dB(A).

[0019] Preferably, in step 6), The passband of the channel corresponding to =1 is... ±5Hz , The passband of the channel corresponding to =2 is... ±5Hz , The passband of the channel corresponding to =3 is... ±5Hz , =4 corresponds to the passband of the channel. ±5Hz .

[0020] Preferably, to achieve noise reduction effect feedback, step 8) multi-channel detection correction of the error microphone is also included: 8.1) Error signal separation: The signal e(t) from the fourth microphone is passed through four parallel bandpass filters to obtain the error signal for each frequency component. ; judge If all parameters are less than the threshold, then if so, keep the current parameters and return to step 5); otherwise, proceed to step 8.2). The threshold range is 0.005~0.03 Pa. 2 ; 8.2) Independent adaptive adjustment strategy for each channel parameter

[0021] For each channel ( =1,2,3,4), perform amplitude and phase adjustments, with the adjustment objective being to minimize... : 8.2.1) Amplitude Adjustment Logic The update rules are as follows: in, For the convergence step size of the amplitude update, For a pre-set energy threshold, For amplitude adjustment steps, For symbolic functions: ; 8.2.2) Phase Adjustment Logic For error signals and reverse sound waves Find the coherence coefficient : The update rules are as follows: in, The convergence factor for phase updates. For phase adjustment steps; After adjustment, return to step 6).

[0022] Preferably, the controller includes an FPGA.

[0023] Compared with the prior art, the advantages of the present invention are: by fusing the rotation speed of the ceiling fan with the spatial sound field sampling and signal of the multi-microphone array, the passing frequency of the blades and its third harmonic component can be accurately locked, thereby generating an anti-phase sound wave to drive the speaker array at a specific location, thus achieving efficient dynamic noise control. Attached Figure Description

[0024] Figure 1 This is a front view of the range hood in use after installation, according to an embodiment of the present invention.

[0025] Figure 2 This is a side view of the range hood in its installed and usable state according to an embodiment of the present invention;

[0026] Figure 3 This is a cross-sectional side view of a range hood according to an embodiment of the present invention;

[0027] Figure 4 This is a sectional side view of the fan and fan housing of the range hood according to an embodiment of the present invention;

[0028] Figure 5 This is a hardware principle block diagram of a range hood according to an embodiment of the present invention;

[0029] Figure 6 This is a flowchart of the active noise reduction control method for a range hood according to an embodiment of the present invention;

[0030] Figure 7 This is a flowchart illustrating the adaptive cancellation implementation in the active noise reduction method for a range hood according to an embodiment of the present invention.

[0031] Figure 8 This is a flowchart illustrating the error microphone detection and correction process in the active noise reduction method for a range hood according to an embodiment of the present invention. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Since the embodiments disclosed in this invention can be arranged in different directions, these terms indicating direction are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined with "first" and "second" may explicitly or implicitly include one or more of such features.

[0034] See Figures 1-4 A range hood includes an air inlet assembly 1, a fan housing 2 mounted above a ceiling 100 in the kitchen, a fan 3 housed within the fan housing 2, a connecting pipe 4 connecting the air inlet assembly 1 and the fan housing 2, and an air outlet mask 5 located at the air outlet of the fan 3. The air inlet assembly 1 includes a smoke inlet 11. The air inlet assembly 1 can be flush with a wall cabinet 200 below the ceiling 100, can be exposed below the wall cabinet 200, or can only be exposed below the wall cabinet 200 during operation. The connecting pipe 4 can be a flexible hose to allow adjustment of the position of the fan housing 2 and the air inlet assembly 1 during installation. The fan 3 includes a volute 31, an impeller 32 housed within the volute 31, and a motor 33 for driving the impeller 32. The impeller 32 includes multiple blades 321.

[0035] The fan housing 2 is hung on the floor slab 300 at the top of the room. It is fixed to the fan housing 2 and the floor slab 300 respectively by hooks, thereby achieving the hanging. How to hoist it is the prior art in this field, and will not be described in detail here. For example, please refer to the applicant's Chinese patent application number 202221537478.4.

[0036] The range hood also includes a microphone array and a speaker array, both of which are distributed. The microphone array is used to collect sound within the passageway through which cooking fumes pass, and includes a first microphone 61 located at the air inlet of the fan 3, a second microphone 62 located on the inner wall of the volute 31, a third microphone 63 located on the inner wall of the fan housing 2, and a fourth microphone 64 located near the user's ear on the front side of the air intake assembly 1. The first microphone 61 can be located at the air inlet of the fan 3 (such as on the collector of the fan 3), the third microphone 63 is located on the top inner wall of the fan housing 2, preferably at the center, and the second microphone 62 is located on the bottom inner wall of the volute 31. The fourth microphone 64 can be located within the panel assembly 11 at the bottom of the front end of the air intake assembly 1. This panel assembly 11 is a control panel typically used for button control, and it serves as an error microphone. Thus, the four microphones form a spatial acquisition layout.

[0037] The speaker array is used to emit sound that is out of phase with the noise collected by the microphone array to cancel it out. It includes a first speaker 71 located at the air inlet of the fan 3, a second speaker 72 located on the inner wall of the volute 31, a third speaker 73 located on the inner wall of the fan housing 2, and a fourth speaker 74 located at the air outlet of the fan 3. The first speaker 71 can be arranged adjacent to the first microphone 61 to cancel direct start-up noise. The third speaker 73 can also be located on the top inner wall of the fan housing 2 to disrupt cavity standing waves. The second speaker 72 is arranged adjacent to the second microphone 62 to suppress 2nd / 3rd harmonic vibrations. The fourth speaker 74 can be located at the air outlet of the fan 3 or inside the air outlet mask 5 to block noise transmission. The first speaker 71, second speaker 72, third speaker 73, and fourth speaker 74 can each be a speaker array, meaning there can be at least two of each. In this embodiment, the first speaker 71 has 6 pieces, the second speaker 72 has 4 pieces (installed in the four quadrants of the volute 31 respectively), the third speaker 73 has 4 pieces (installed in the four corners of the fan housing 2), and the fourth speaker 74 has 2 pieces.

[0038] The preferred loudspeakers are piezoresistive ceramic loudspeakers. These loudspeakers do not have traditional voice coils, magnets, or paper cones. They have a relatively simple structure, are shock-resistant and drop-resistant, small in size, highly efficient, and do not easily accumulate oil (dirt does not affect operation and can be compensated for by error).

[0039] See Figure 2 and Figure 5The range hood also includes a controller 8, which can be a standalone FPGA (Field Programmable Gate Array) or an integration of a conventional controller and an FPGA. Controller 8 receives the rotational speed signal from the fan 3. The PSMS or BLDC motor drive module commonly used in range hoods typically has its own rotational speed information, so this information can be directly acquired. This signal provides the fundamental frequency characteristics of the range hood's aerodynamic noise. If the motor itself does not have this information, existing methods can be used to detect the motor speed, such as the back EMF method or using an encoder; these are conventional technologies and will not be elaborated upon here. Controller 8 is also electrically connected to both the microphone array and the speaker array, receiving signals collected by the microphone array, calculating them, and outputting control signals to control the speaker array to perform corresponding actions.

[0040] Specifically, the intelligent control method for active noise reduction of the range hood of the present invention is described in [reference needed]. Figure 6 It includes the following steps:

[0041] 1) The range hood starts, and the fan 3 runs at the preset speed. It is determined whether the user has selected intelligent monitoring. If yes, proceed to step 2); if no, enter manual mode. This judgment can also be skipped and the process can proceed directly to step 2.

[0042] 2) Rotational speed signal acquisition: Acquire the current rotational speed signal n of fan 3;

[0043] 3) Calculate the blade passing frequency (Noise source modeling):

[0044] Blade passing frequency Discrete noise is generated by the periodic cutting of the airflow by the blades 321 of impeller 32: in, The number of blades 321 refers to the number of blades 321. The fan 3 of a range hood is typically a multi-blade centrifugal fan, with 48-80 blades in total. , hour, This frequency is a frequency band that is sensitive to human hearing.

[0045] This leads to two key characteristics: 1) the frequency of blade passage. The noise levels are higher than those of ordinary fans (5-18 blades); 2) the noise energy shifts to mid-to-high frequencies and falls within the range that is most sensitive to human hearing (rather than the low-frequency band below 500Hz, which is easier to reduce with traditional dominant noise reduction methods). These two characteristics cause ordinary dominant noise reduction schemes to fail because: ① traditional broadband noise reduction algorithms cannot accurately capture such dense harmonic groups; ② the distance between the noise source of a traditional range hood fan and the human ear is too close, making it difficult for the reverse sound waves to cancel out slightly higher frequency noise.

[0046] In this embodiment: ① Tracking based on rotational speed can directly lock the characteristic frequency of the noise source; ② The noise source of the split / ceiling-mounted fan is farther away from the user, and the reverse sound wave is more likely to cancel the slightly higher frequency band.

[0047] 4) Order selection and harmonic frequency generation (noise energy distribution modeling):

[0048] Noise spectrum characteristics:

[0049] The highest harmonic order considered in the analysis is 4 in this embodiment, because, as shown in Table 1 below:

[0050]

[0051] Table 1: Basis for Selecting Harmonic Order

[0052] Therefore, it can be seen that taking the first four harmonics can cover >90% of the noise energy, so in this embodiment... =4.

[0053] 5) Multi-microphone sound pressure signal acquisition and fusion:

[0054] The following time delay compensation formula is used:

[0055] Fusion computing:

[0056] in The distances of each microphone from its corresponding sound source are shown in Table 2 below:

[0057]

[0058] Table 2: Microphone Locations and relation

[0059] 6) Adaptive cancellation implementation (four-channel parallel anti-phase wave generation):

[0060] Combination Figure 7 The result obtained in step 5) Processed in four channels according to order. The signal passes through channel 1. , representing fundamental frequency noise, the passband of the bandpass filter is ±5Hz The signal passes through channel 2. , representing the second harmonic, the passband of the bandpass filter is ±5Hz The signal passes through channel 3. , representing the third harmonic, the passband of the bandpass filter is ±5Hz The signal passes through channel 4. , representing the fourth harmonic, the passband of the bandpass filter is ±5Hz;

[0061] Thus, the amplitude is achieved respectively. Detection and phase Detection:

[0062]

[0063] in, It is an integral variable, representing a continuous independent variable in the time dimension, representing the flow of time from the initial moment to the current moment, in seconds, with a range of values: ∈ [t - T, t];

[0064] The amplitude can be calculated by the square root operation circuit of the integrator built into the FPGA of controller 8, and the phase can be calculated by the Hilbert converter of the FPGA.

[0065] This generates an antiphase wave: ,in, The system's real-time running time, in seconds, represents the continuous timeline of sound wave generation.

[0066] 7) Loudspeaker array drive position coordination strategy:

[0067] The FPGA transmits the inverted wave signal to the speaker array through a four-channel DAC and a high-voltage operational amplifier. The first speaker array 71 corresponds to high-voltage operational amplifier 1, the second speaker array 72 corresponds to high-voltage operational amplifier 2, the third speaker array 73 corresponds to high-voltage operational amplifier 3, and the fourth speaker array 74 corresponds to high-voltage operational amplifier 4.

[0068] The first loudspeaker array 71, driven by the following signal. The second loudspeaker array is 72, and the drive signal is... The third speaker array is 73, and the drive signal is... The fourth speaker array is 74, and the drive signal is... .

[0069] 8) Multi-channel detection correction for error microphones:

[0070] The error microphone, also known as the fourth microphone 64, is located close to the user. The residual noise signal e(t) it acquires contains all frequency components. Therefore, the residual quantities of the four target frequency components can be separated from e(t) as needed, and then the four channels can be iteratively adjusted based on these residual quantities. and Four target frequencies ( ~ The frequency interval is significant (>300Hz), and frequency isolation can be achieved through narrowband filtering;

[0071] 8.1) Error signal separation (frequency domain decomposition)

[0072] The error microphone signal e(t) passes through four parallel bandpass filters (corresponding to...). ±5Hz ±5Hz ±5Hz ±5Hz) is used to obtain the error signal (residual quantity) at each frequency component. ;

[0073] judge If all parameters are less than the threshold, then if so, keep the current parameters and return to step 5); otherwise, proceed to step 8.2). The preferred range for the threshold is 0.005~0.03 Pa. 2 A more preferred value is 0.01 Pa. 2 Experiments have shown that when the residual energy is 0.03, the noise is noticeably present; when the residual energy is 0.01, the noise is barely noticeable; and when the residual energy is 0.005, it is completely silent. Further reduction results in low marginal benefits.

[0074] 8.2) Independent adaptive adjustment strategy for each channel parameter

[0075] For each channel ( =1,2,3,4): The adjustment objective is to minimize the residual noise energy of this frequency component, i.e., minimize... These include amplitude adjustment and phase adjustment, respectively: It is an integral variable, representing a continuous independent variable in the time dimension, representing the flow of time from the initial moment to the current moment, in seconds, with a range of values: ∈ [t- T, t];

[0076] 8.2.1) Amplitude Adjustment Logic

[0077] The update rules are as follows:

[0078] in, To achieve convergence, a step size of 0.1 is preferred. A pre-set energy threshold, compared with the current energy participating The preferred value for the difference is 0.01 Pa. 2 , For amplitude adjustment steps, a preferred value is 0.02. , For symbolic functions: ;

[0079] 8.2.2) Phase Adjustment Logic

[0080] Adjustment basis: Error signal (residual quantity) and reverse sound waves Find the coherence coefficient :

[0081] Update rules:

[0082] in, The convergence factor is preferably 0.05. For phase adjustment steps, a preferred step size is 2°;

[0083] After adjustment, return to step 6).

[0084] In the above method, the first microphone 61, the second microphone 62, and the third microphone 63 are all "noise source monitoring microphones" used to capture the original characteristics of the noise source (such as direct aerodynamic noise, structural vibration noise, and cavity standing waves); while the fourth microphone 64 is an "effect evaluation microphone" used to monitor the residual noise actually heard by the user (i.e., the final sound after the noise has passed through the ceiling, pipes, and air), which can compensate for the loss of environmental transmission: the noise will go through cavity reflection, pipe attenuation, and air absorption in the path from the fan source to the user's ear, which will cause changes in the noise characteristics (amplitude and phase). The presence of the fourth microphone 64 can directly perceive these changes, ensuring that the noise reduction effect is consistent with the user experience. As a closed-loop feedback signal, it is used to verify whether "the anti-phase wave effectively cancels the noise at the user's location".

[0085] The core value of the fourth microphone 64 lies in achieving dual-loop control of "feedforward prediction + feedback correction", the specific significance of which is as follows:

[0086] 1. Addressing the source-user path discrepancy: The first three microphones (air inlet, volute, and fan housing) can accurately capture the characteristics of the noise source, but they cannot predict changes in noise during transmission (such as phase shifts caused by cavity standing waves and amplitude drops caused by pipe attenuation). The fourth microphone 64 compensates for this discrepancy by feeding back the actual noise at the user's location.

[0087] 2. Ensuring Noise Reduction in the "High-Frequency Band": This invention targets the mid-to-high frequency harmonics (such as 1625Hz BPF) of multi-blade centrifugal fans. This type of noise has a short wavelength (approximately 0.2m), and the cancellation effect of the anti-phase wave requires extremely high accuracy in phase and amplitude. The closed-loop adjustment of the fourth microphone 64 can correct these parameters in real time, ensuring that the anti-phase wave is precisely out of phase with the noise source signal at the user's position (phase difference 180°±5°).

[0088] 3. Adapting to "Dynamic Scene" Changes: During cooking, the fan speed changes with the amount of oil fumes (e.g., the speed increases during stir-frying), causing changes in the BPF and its harmonic frequencies. The fourth microphone 64 can monitor the residual noise caused by this change in real time and adjust the frequency, amplitude, and phase of the antiphase wave to achieve "dynamic noise reduction".

[0089] Compared with conventional methods, the method of the present invention has the following advantages:

[0090]

Claims

1. A range hood, comprising an air intake assembly (1), a fan housing (2) disposed above a ceiling (100) in a kitchen, and a fan (3) disposed within the fan housing (2), wherein the fan housing (2) is suspended from the floor slab (300) at the top of the kitchen interior, and the fan (3) comprises a volute (31) and an impeller (32) disposed within the volute (31), wherein the impeller (32) comprises blades (321); Its features are: The range hood also includes: Microphone array, used to collect sound from the passage through which cooking fumes pass; A loudspeaker array is used to emit antiphase sound waves based on the rotational speed of the fan (3) and the sound collected by the microphone array.

2. The range hood according to claim 1, characterized in that: The microphone array includes a first microphone (61) located at the air inlet of the fan (3), a second microphone (62) located on the inner wall of the volute (31), a third microphone (63) located on the inner wall of the fan housing (2), and a fourth microphone (64) located near the front of the air inlet assembly (1) as an error microphone.

3. The range hood according to claim 2, characterized in that: The loudspeakers include a first loudspeaker (71) installed at the air inlet of the fan (3), a second loudspeaker (72) installed on the inner wall of the volute (31), a third loudspeaker (73) installed on the inner wall of the fan housing (2), and a fourth loudspeaker (74) installed at the air outlet of the fan (3).

4. The range hood according to claim 3, characterized in that: Each speaker is a piezoresistive ceramic speaker.

5. The range hood according to claim 3, characterized in that: The first speaker (71), the second speaker (72), the third speaker (73) and the fourth speaker (74) each have at least two.

6. A smart control method for a range hood, using a range hood as described in any one of claims 3 to 5, characterized in that: The range hood also includes a controller (8), which is electrically connected to the fan (3), microphone array, and speaker array respectively; the intelligent control method includes the following steps: 1) The range hood is started, and the fan (3) runs at the preset speed, proceeding to step 2); 2) Rotational speed signal acquisition: The controller (8) acquires the rotational speed signal of the current fan (3). ; 3) Calculate the blade passing frequency : in, The number of leaves (321); 4) Order selection and harmonic frequency generation: in, =4; 5) Multi-microphone sound pressure signal acquisition and fusion: The following time delay compensation formula is used: Fusion computing: in, This represents the distance of each microphone from its corresponding sound source. This refers to the system's real-time uptime. It is an integral variable; 6) Adaptive cancellation implementation: The result obtained in step 5) The signal is processed in four channels according to its order, and after bandpass filtering, the amplitude is achieved separately. Detection and phase Detection: This generates an antiphase wave: ; 7) Loudspeaker array drive position coordination strategy: After the inverting wave is converted from digital to analog and amplified, it is transmitted to the loudspeaker array. The driving signal of the first loudspeaker (71) is... The driving signal for the second speaker (72) is The driving signal for the third speaker (73) is The driving signal for the fourth speaker (74) is .

7. The intelligent control method for a range hood according to claim 6, characterized in that: In step 6), The passband of the channel corresponding to =1 is... ±5Hz , The passband of the channel corresponding to =2 is... ±5Hz , The passband of the channel corresponding to =3 is... ±5Hz , =4 corresponds to the passband of the channel. ±5Hz .

8. The intelligent control method for a range hood according to claim 6 or 7, characterized in that: It also includes step 8) multi-channel detection correction for the error microphone: 8.1) Error signal separation: The signal e(t) from the fourth microphone (64) is passed through four parallel bandpass filters to obtain the error signal for each frequency component. ; judge If all parameters are less than the threshold, then if so, keep the current parameters and return to step 5); otherwise, proceed to step 8.2). The threshold range is 0.005~0.03 Pa. 2 ; 8.2) Independent adaptive adjustment strategy for each channel parameter For each channel ( =1,2,3,4), perform amplitude and phase adjustments, with the adjustment objective being to minimize... : 8.2.1) Amplitude Adjustment Logic The update rules are as follows: in, For the convergence step size of the amplitude update, For a pre-set energy threshold, For amplitude adjustment steps, For symbolic functions: ; 8.2.2) Phase Adjustment Logic For error signals and reverse sound waves Find the coherence coefficient : The update rules are as follows: in, The convergence factor for phase updates, For phase adjustment steps; After adjustment, return to step 6).

9. The intelligent control method for a range hood according to claim 6, characterized in that: The controller (8) includes an FPGA.

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