Noise reduction method and device of air supply equipment, air supply equipment and storage medium

Abstract

The application discloses a noise reduction method and device of an air supply equipment, the air supply equipment and a storage medium, and belongs to the technical field of noise reduction. The method comprises the following steps: acquiring a first noise signal collected by a feedforward microphone; acquiring a second noise signal collected by a feedback microphone; acquiring the motor speed, air supply speed and ambient temperature of the current environment of the air supply equipment; if the noise intensity of the second noise signal is greater than the intensity threshold value, generating a noise suppression signal based on the first noise signal, the second noise signal, the motor speed, the air supply speed, the ambient temperature and the number of fan blades of the air supply equipment; and outputting the noise suppression signal through the loudspeaker to realize the noise reduction of the air supply equipment. The application combines the motor speed, air supply speed, number of fan blades and ambient temperature of the current environment of the air supply equipment and other factors, and reduces the noise generated in the operation process of the air supply equipment through an active noise reduction technology.

Description

Technical Field

[0001] This application relates to the field of noise reduction technology, and in particular to a noise reduction method, device, air supply equipment, and storage medium for an air supply device. Background Technology

[0002] Active noise cancellation (ANC) is a type of noise reduction technology that, as the name suggests, actively reduces noise. ANC works by targeting the noise source itself, using microphones to collect ambient noise, digitally analyzing it, and reversing the phase of the original noise. This reversed phase is then processed into inverted sound waves, achieving noise cancellation. Currently, ANC is primarily used in headphones. However, for air-purifying devices like air conditioners and fans, due to the complex acoustic environments they operate in, noise reduction is mainly achieved passively through structural design. Summary of the Invention

[0003] This application provides a noise reduction method, apparatus, air supply equipment, and storage medium for air supply equipment, which can solve the noise reduction problem of air supply equipment in related technologies. The technical solution is as follows:

[0004] On one hand, a noise reduction method for an air supply device is provided, characterized in that the air supply device includes a feedforward microphone, a feedback microphone, and a speaker, wherein the feedforward microphone is located inside the air supply device, and the feedback microphone is located outside the air supply device; the method includes:

[0005] Acquire the first noise signal collected by the feedforward microphone;

[0006] Acquire the second noise signal collected by the feedback microphone;

[0007] The motor speed, airflow velocity, and ambient temperature of the air supply equipment are obtained.

[0008] If the noise intensity of the second noise signal is greater than the intensity threshold, a noise suppression signal is generated based on the first noise signal, the second noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades of the air supply device.

[0009] The noise suppression signal is output through the speaker to achieve noise reduction of the air supply device.

[0010] Optionally, generating a noise suppression signal based on the first noise signal, the second noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades of the air supply device includes:

[0011] The first noise signal is segmented, windowed, and time-frequency transformed to obtain multiple frequency domain noise frames;

[0012] Multiple noise suppression frames are determined, and the multiple noise suppression frames correspond one-to-one with the multiple frequency domain noise frames. The corresponding noise suppression frames and frequency domain noise frames have opposite phases, but the same amplitude and frequency.

[0013] Based on the second noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades, the compensation gain corresponding to each frequency within the target frequency range is determined, where the target frequency range refers to the frequency range of the noise signal.

[0014] The noise suppression signal is generated based on the plurality of noise suppression frames and the compensation gain corresponding to each frequency within the target frequency range.

[0015] Optionally, determining the compensation gain corresponding to each frequency within the target frequency range based on the second noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades includes:

[0016] Perform time-frequency transformation on the second noise signal to obtain a frequency domain noise signal;

[0017] If the noise intensity of the target frequency in the frequency domain noise signal is greater than the intensity threshold, then the compensation gain corresponding to the target frequency is determined based on the amplitude corresponding to the target frequency in the frequency domain noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades.

[0018] If the noise intensity at the target frequency in the frequency domain noise signal is not greater than the intensity threshold, then the compensation gain corresponding to the target frequency is determined to be 1;

[0019] Wherein, the target frequency is any frequency within the target frequency range.

[0020] Optionally, the method further includes:

[0021] If the noise intensity of the second noise signal is not greater than the intensity threshold, then the noise suppression signal is generated based on the first noise signal.

[0022] Optionally, generating the noise suppression signal based on the first noise signal includes:

[0023] The first noise signal is segmented, windowed, and time-frequency transformed to obtain multiple frequency domain noise frames;

[0024] Multiple noise suppression frames are determined, and the multiple noise suppression frames correspond one-to-one with the multiple frequency domain noise frames. The corresponding noise suppression frames and frequency domain noise frames have opposite phases, but the same amplitude and frequency.

[0025] The noise suppression signal is generated based on the plurality of noise suppression frames.

[0026] On the other hand, a noise reduction device for an air supply device is provided, the air supply device including a feedforward microphone, a feedback microphone, and a speaker, wherein the feedforward microphone is located inside the air supply device, and the feedback microphone is located outside the air supply device; the device includes:

[0027] The first acquisition module is used to acquire the first noise signal collected by the feedforward microphone;

[0028] The second acquisition module is used to acquire the second noise signal collected by the feedback microphone;

[0029] The third acquisition module is used to acquire the motor speed, airflow speed and ambient temperature of the air supply equipment.

[0030] The first generation module is used to generate a noise suppression signal based on the first noise signal, the second noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades of the air supply device if the noise intensity of the second noise signal is greater than the intensity threshold.

[0031] The output module is used to output the noise suppression signal through the speaker to achieve noise reduction of the air supply device.

[0032] Optionally, the first generation module includes:

[0033] The first processing submodule is used to perform frame division, windowing and time-frequency transformation on the first noise signal to obtain multiple frequency domain noise frames.

[0034] The first determining submodule is used to determine multiple noise suppression frames, wherein the multiple noise suppression frames correspond one-to-one with the multiple frequency domain noise frames, and the corresponding noise suppression frames and frequency domain noise frames have opposite phases and the same amplitude and frequency.

[0035] The second determining submodule is used to determine the compensation gain corresponding to each frequency within the target frequency range based on the second noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades. The target frequency range refers to the frequency range of the noise signal.

[0036] The first generation submodule is used to generate the noise suppression signal based on the plurality of noise suppression frames and the compensation gain corresponding to each frequency within the target frequency range.

[0037] Optionally, the second determining submodule is specifically used for:

[0038] Perform time-frequency transformation on the second noise signal to obtain a frequency domain noise signal;

[0039] If the noise intensity of the target frequency in the frequency domain noise signal is greater than the intensity threshold, then the compensation gain corresponding to the target frequency is determined based on the amplitude corresponding to the target frequency in the frequency domain noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades.

[0040] If the noise intensity at the target frequency in the frequency domain noise signal is not greater than the intensity threshold, then the compensation gain corresponding to the target frequency is determined to be 1;

[0041] Wherein, the target frequency is any frequency within the target frequency range.

[0042] Optionally, the device further includes:

[0043] The second generation module is used to generate the noise suppression signal based on the first noise signal if the noise intensity of the second noise signal is not greater than the intensity threshold.

[0044] Optionally, the second generation module includes:

[0045] The second processing submodule is used to perform frame division, windowing and time-frequency transformation on the first noise signal to obtain multiple frequency domain noise frames.

[0046] The third determining submodule is used to determine multiple noise suppression frames, which correspond one-to-one with the multiple frequency domain noise frames, and the corresponding noise suppression frames and frequency domain noise frames have opposite phases, the same amplitude and frequency.

[0047] The second generation submodule is used to generate the noise suppression signal based on the plurality of noise suppression frames.

[0048] On the other hand, an air supply device is provided, the air supply device including a memory and a processor, the memory for storing a computer program, and the processor for executing the computer program stored in the memory to implement the steps of the noise reduction method of the air supply device described above.

[0049] On the other hand, a computer-readable storage medium is provided, wherein a computer program is stored therein, and when the computer program is executed by a processor, the steps of the noise reduction method of the air supply device described above are implemented.

[0050] On the other hand, a computer program product containing instructions is provided, which, when run on a computer, cause the computer to perform the steps of the noise reduction method for the air supply device described above.

[0051] The technical solution provided in this application can bring at least the following beneficial effects:

[0052] By acquiring a first noise signal collected by a feedforward microphone, a second noise signal collected by a feedback microphone, the motor speed of the air supply device, the air supply speed, and the ambient temperature, the noise intensity of the second noise signal is compared with an intensity threshold. If the noise intensity of the second noise signal is greater than the intensity threshold, a noise suppression signal is generated based on the first noise signal, the second noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades of the air supply device. This noise suppression signal is then output by a speaker. This method combines the factors that generate noise during the operation of the air supply device with its surrounding environment, applying active noise cancellation technology to the air supply device. This effectively reduces the noise generated during operation, achieving active noise cancellation for the air supply device. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic diagram of the structure of an implementation environment provided in an embodiment of this application;

[0055] Figure 2 This is a flowchart of a noise reduction method for an air supply device provided in an embodiment of this application;

[0056] Figure 3 This is a structural schematic diagram of a noise reduction device for an air supply equipment provided in an embodiment of this application;

[0057] Figure 4 This is a schematic diagram of the structure of an air supply device provided in an embodiment of this application. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0059] Before providing a detailed explanation of the noise reduction method for the air supply equipment provided in the embodiments of this application, the application scenarios and implementation environment involved in the embodiments of this application will be introduced first.

[0060] Active noise cancellation (ADC) is a type of noise reduction technology that, as the name suggests, actively targets and reduces noise. ADC works by addressing the noise source itself, using microphones to collect ambient noise, digitally analyzing it, and reversing the phase of the original noise. This reversed phase is then processed into inverted sound waves, achieving noise cancellation. Based on the microphone's placement, ADC can be categorized into three types: feedforward, feedback, and a combination of both. Currently, ADC is primarily used in headphones. However, for air-purifying devices like fans and air conditioners, due to their large sound field and complex acoustic environments, improper use of ADC might result in noise amplification. Therefore, in related technologies, noise reduction for fans and air conditioners is primarily achieved through passive structural reduction.

[0061] Based on this, the present application provides a noise reduction method for air supply equipment. According to the usage scenario of air supply equipment such as fans and air conditioners, combined with factors such as motor speed, air supply speed, number of fan blades and ambient temperature of the current environment of the air supply equipment, the noise generated during the operation of fans, air conditioners and other equipment is reduced by active noise reduction technology.

[0062] Figure 1 This is a schematic diagram of an implementation environment provided in an embodiment of this application. The implementation environment includes a noise suppression controller 101, a feedforward microphone 102, a speed sensor 103, a temperature sensor 104, a wind speed sensor 105, one or more feedback microphones 106 (illustrated as one feedback microphone in the figure), and one or more speakers 107 (illustrated as one speaker in the figure). The noise suppression controller 101 can communicate with the feedforward microphone 102, the speed sensor 103, the temperature sensor 104, the wind speed sensor 105, the feedback microphone 106, and the speaker 107, respectively. This communication connection can be wired or wireless; this embodiment of the application does not limit this.

[0063] The noise suppression controller 101 is used to perform the steps of the noise reduction method for the air supply equipment provided in the embodiments of this application.

[0064] The feedforward microphone 102 is located inside the air supply device and is used to collect the sound signal inside the air supply device during operation and send it to the noise suppression controller 101.

[0065] The speed sensor 103 is used to collect the motor speed of the air supply equipment and send the motor speed to the noise suppression controller 101.

[0066] Temperature sensor 104 is used to collect the ambient temperature of the current environment of the air supply equipment and send the ambient temperature to noise suppression controller 101.

[0067] The wind speed sensor 105 is used to collect the air supply speed of the air supply equipment and send the air supply speed to the noise suppression controller 101.

[0068] The feedback microphone 106 is located on the outside of the air supply device and is used to collect the sound signal from the outside during the operation of the air supply device and send it to the noise suppression controller 101.

[0069] The loudspeaker 107 is used to output a noise suppression signal to reduce noise in the air supply equipment.

[0070] The outer side of the air supply equipment can be understood as the air supply side of the air supply equipment, that is, the side with the air supply direction, while the inner side of the air supply equipment can be understood as the side with the opposite air supply direction.

[0071] It should be noted that the application scenarios and implementation environments described in the embodiments of this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the emergence of new application scenarios and the evolution of implementation environments, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0072] The noise reduction method for the air supply equipment provided in the embodiments of this application will be explained in detail below.

[0073] Figure 2 This is a flowchart illustrating a noise reduction method for an air supply device according to an embodiment of this application. The method is applied to the air supply device. Please refer to... Figure 2 The method includes the following steps.

[0074] Step 201: Acquire the first noise signal collected by the feedforward microphone.

[0075] A first sound signal is acquired by a feedforward microphone. This first sound signal is the sound signal collected inside the air supply device during operation. Since the first sound signal may contain signals that are not noise, the signals that are not noise in the first sound signal are removed to obtain a first noise signal. The first noise signal can also be understood as the noise generated by the air supply device.

[0076] For example, if the air supply device is a fan, the first sound signal of the fan running is acquired by the feedforward microphone. Since the noise signal generated by the fan is generally no greater than 1500Hz, the signal greater than 1500Hz in the first sound signal is removed to obtain the first noise signal.

[0077] It should be noted that the air supply device can be a fan, an air conditioner, or other devices capable of supplying air; this application does not limit this.

[0078] Step 202: Acquire the second noise signal collected by the feedback microphone.

[0079] A second sound signal is acquired by the feedback microphone. This second sound signal is the sound signal collected on the outside during the operation of the air supply device. Since the second sound signal may contain signals that are not noise, the signals that are not noise in the second sound signal are removed to obtain the second noise signal. The second noise signal can also be understood as the noise on the air supply side.

[0080] For example, if the air supply device is a fan, the second sound signal of the fan running is acquired by the feedback microphone. Since the noise signal generated by the fan is generally no greater than 1500Hz, the signal greater than 1500Hz in the second sound signal is removed to obtain the second noise signal.

[0081] It should be noted that the air supply device may have one feedback microphone or multiple feedback microphones installed in different locations; this application embodiment does not limit this.

[0082] Step 203: Obtain the motor speed, airflow speed, and ambient temperature of the air supply equipment.

[0083] The motor speed is measured by a speed sensor. Once the speed sensor measures the motor speed of the air supply device, it sends this speed information to the noise suppression controller. The airflow speed is measured by a wind speed sensor. When the wind speed sensor measures the current airflow speed of the air supply device, it sends this airflow speed information to the noise suppression controller. The ambient temperature is measured by a temperature sensor. When the temperature sensor measures the ambient temperature of the environment in which the air supply device is located, it sends this ambient temperature information to the noise suppression controller. Of course, other sensors can be added to measure other factors that affect the noise of the air supply device, taking into account the current environment.

[0084] It should be noted that the rotation speed sensor can be an analog rotation speed sensor or other types of rotation speed sensors; the wind speed sensor can be a mechanical wind speed sensor or other types of wind speed sensors; and the temperature sensor can be a resistance temperature sensor or other types of temperature sensors. This application does not limit the specific types of temperature sensors.

[0085] Step 204: If the noise intensity of the second noise signal is greater than the intensity threshold, a noise suppression signal is generated based on the first noise signal, the second noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades of the air supply equipment.

[0086] Since the noise reduction process of the air supply equipment is a continuous cycle, aiming to achieve a balance between the noise generated by the air supply equipment and noise suppression, that is, after noise suppression in the previous cycle, the current cycle will continue to collect a second noise signal to determine whether the noise intensity is greater than the intensity threshold. Therefore, the second noise signal obtained in step 202 above may be a noise signal that has already been suppressed in the previous cycle. If the noise intensity of the second noise signal is greater than the intensity threshold, it indicates that the noise of the air supply equipment is still too high during operation. The environment and factors of the air supply equipment will affect the noise reduction effect. Therefore, this embodiment of the application considers motor speed, air supply speed, ambient temperature and number of fan blades, and generates a noise suppression signal based on the first noise signal, the second noise signal, motor speed, air supply speed, ambient temperature and number of fan blades of the air supply equipment.

[0087] The noise intensity of the second noise signal can be characterized by its maximum amplitude. Specifically, if the maximum amplitude of the second noise signal is greater than an intensity threshold, the noise intensity of the second noise signal is greater than that threshold. This intensity threshold is used to indicate whether the noise is excessive during the operation of the air supply equipment. This intensity threshold can be set according to actual needs, and this embodiment does not limit its setting.

[0088] In some embodiments, the noise suppression signal can be generated according to the following steps (1)-(4).

[0089] (1) The first noise signal is framed, windowed and time-frequency transformed to obtain multiple frequency domain noise frames.

[0090] First, the first noise signal is divided into frames to obtain multiple noise frames. The characteristics of each noise frame remain basically unchanged. Then, each noise frame is windowed to obtain windowed noise frames. Time-frequency transformation is performed on each windowed noise frame to transform each noise frame from the time domain to the frequency domain, thereby obtaining multiple frequency domain noise frames.

[0091] Framing and windowing are both preprocessing stages for extracting features from noise signals. Noise processing requires a stationary input signal, so the entire noise signal needs to be framed, meaning it's divided into many segments. Simply put, a noise signal as a whole is not stationary, but locally it can be considered stationary. After framing the noise signal, because there are discontinuities at the beginning and end of each frame, the more frames there are, the greater the error compared to the original noise signal. Windowing is used to solve this problem and prevent spectral leakage, making the framed noise signal more continuous, so that each frame exhibits the characteristics of a periodic function.

[0092] After framing and windowing the noise signal, it needs to be transformed in a time-frequency manner to facilitate subsequent processing. For example, the noise signal can be transformed from the time domain to the frequency domain using Fourier transform, or other methods can be used to transform the noise signal from the time domain to the frequency domain. This application does not limit the specific methods used in this embodiment.

[0093] As an example, taking one of the multiple frequency domain noise frames as an example, the frequency domain noise frame can be represented by the following formula (1);

[0094]

[0095] In formula (1) above, F0(ω) represents the frequency domain noise frame, A represents the amplitude of the frequency domain noise frame, ω represents the frequency, and x is the independent variable. This represents the phase of the frequency domain noise frame. Similarly, other frequency domain noise frames can also be represented using the same method.

[0096] (2) Determine multiple noise suppression frames, each of which corresponds to a frequency domain noise frame, and the corresponding noise suppression frames and frequency domain noise frames have opposite phases, the same amplitude and frequency.

[0097] As an example, since the corresponding noise suppression frames and frequency domain noise frames have opposite phases and the same amplitude and frequency, the noise suppression frame corresponding to the frequency domain noise frame represented by formula (1) can be represented by the following formula (2);

[0098]

[0099] In formula (2) above, F1(ω) represents the noise-suppressed frame, A represents the amplitude of the noise-suppressed frame, ω represents the frequency, and x is the independent variable. This represents the phase of the noise-suppressed frame. Similarly, other noise-suppressed frames can also be represented using the same method.

[0100] (3) Based on the second noise signal, motor speed, air supply speed, ambient temperature and number of fan blades, determine the compensation gain corresponding to each frequency within the target frequency range. The target frequency range refers to the frequency range in which the noise signal is located.

[0101] In some embodiments, the second noise signal is subjected to time-frequency transformation to obtain a frequency domain noise signal. If the noise intensity of the target frequency in the frequency domain noise signal is greater than the intensity threshold, the compensation gain corresponding to the target frequency is determined based on the amplitude, motor speed, air supply speed, ambient temperature and number of fan blades corresponding to the target frequency in the frequency domain noise signal. If the noise intensity of the target frequency in the frequency domain noise signal is not greater than the intensity threshold, the compensation gain corresponding to the target frequency is determined to be 1. The target frequency is any frequency within the target frequency range.

[0102] Based on the above description, the second noise signal can be time-frequency transformed by Fourier transform, or other methods can be used to perform time-frequency transformation on the second noise. This application does not limit the specific methods used.

[0103] Similarly, the noise intensity at a target frequency in a frequency-domain noise signal can be characterized by the amplitude of that target frequency. That is, if the amplitude corresponding to the target frequency in the frequency-domain noise signal is greater than the intensity threshold, then the noise intensity at the target frequency in the frequency-domain noise signal is greater than the intensity threshold. If the amplitude corresponding to the target frequency in the frequency-domain noise signal is not greater than the intensity threshold, then the noise intensity at the target frequency in the frequency-domain noise signal is not greater than the intensity threshold.

[0104] If the noise intensity at the target frequency in the frequency domain noise signal exceeds the intensity threshold, it indicates that the noise at the target frequency outside the air supply equipment is too high, and the noise signal at the target frequency is not in balance with the noise suppression signal. Therefore, the compensation gain corresponding to the target frequency is determined using the second noise signal, motor speed, air supply speed, ambient temperature, and number of fan blades, and noise suppression is compensated using this compensation gain. If the noise intensity at the target frequency in the frequency domain noise signal is not greater than the intensity threshold, it indicates that the noise at the target frequency outside the air supply equipment is not high, and the noise signal at the target frequency is in balance with the noise suppression signal. Therefore, the compensation gain corresponding to the target frequency is set to 1, that is, the noise suppression situation at the target frequency is the same as that in the previous cycle.

[0105] As an example, based on the amplitude corresponding to the target frequency in the frequency domain noise signal, the motor speed of the air supply equipment, the air supply speed, the ambient temperature and the number of fan blades, the compensation gain corresponding to the target frequency is determined according to the following formula (3);

[0106]

[0107] Where g represents the compensation gain corresponding to the target frequency, A1 represents the amplitude corresponding to the target frequency in the frequency domain noise signal, v represents the air supply speed of the air supply device, p represents the ambient temperature of the air supply device, i represents the number of fan blades of the air supply device, r represents the motor speed of the air supply device, and α and β are compensation coefficients, which can be adjusted accordingly according to the noise reduction effect. This application embodiment does not limit them.

[0108] (4) Generate a noise suppression signal based on multiple noise suppression frames and the compensation gain corresponding to each frequency within the target frequency range.

[0109] Based on the compensation gain corresponding to each frequency, multiple noise suppression frames are compensated to obtain multiple compensated noise suppression frames. These multiple compensated noise suppression frames are then synthesized to obtain a noise suppression signal in the frequency domain. Finally, an inverse time-frequency transform is performed on the noise suppression signal in the frequency domain to obtain a noise suppression signal in the time domain.

[0110] It should be noted that the inverse time-frequency transformation of the noise suppression signal in the frequency domain can be performed by using the inverse Fourier transform, or other methods can be used for the inverse time-frequency transformation. This application does not limit the specific methods used in this embodiment.

[0111] As an example, based on the compensation gain, the noise-suppressed frame represented by formula (2) is compensated according to the following formula (4);

[0112]

[0113] Where F2(ω) represents the compensated noise-suppressed frame, and g represents the compensation gain corresponding to a certain frequency. Similarly, other noise-suppressed frames can also be compensated according to the above formula (4).

[0114] As an example, a noise suppression signal in the frequency domain is generated according to the following formula (5), which is a noise suppression signal at all frequencies;

[0115] F(ω)=∫F2(ω) (5)

[0116] Where F(ω) represents the noise suppression signal in the frequency domain, and F2(ω) represents the compensated noise suppression frame.

[0117] As an example, according to the following formula (6), the noise suppression signal in the frequency domain is subjected to inverse time-frequency transformation through inverse Fourier transform to obtain the noise suppression signal in the time domain;

[0118]

[0119] Where f(t) represents the noise suppression signal in the time domain, F(ω) represents the noise suppression signal in the frequency domain, ω represents the frequency, and t represents the time.

[0120] In other embodiments, if the noise intensity of the second noise signal is not greater than the intensity threshold, a noise suppression signal is generated based on the first noise signal. That is, if the noise intensity of the second noise signal is not greater than the intensity threshold, it indicates that the current noise is relatively low, and there is no need to determine the compensation gain; the noise suppression signal is simply generated based on the first noise signal. In other words, the noise suppression signal is obtained by inverting the first noise signal.

[0121] As an example, the first noise signal is segmented, windowed, and subjected to time-frequency transformation to obtain multiple frequency domain noise frames; multiple noise suppression frames are determined, with each noise suppression frame corresponding to one of the multiple frequency domain noise frames, and the corresponding noise suppression frames and frequency domain noise frames have opposite phases, the same amplitude, and the same frequency; based on the multiple noise suppression frames, a noise suppression signal is generated.

[0122] The process of generating a noise suppression signal based on multiple noise suppression frames is as follows: the multiple noise suppression frames are synthesized to obtain a noise suppression signal in the frequency domain, and the noise suppression signal in the frequency domain is subjected to an inverse time-frequency transform to obtain a noise suppression signal in the time domain.

[0123] As an example, based on the noise suppression frame represented by formula (2), the noise suppression signal in the frequency domain can be generated according to the following formula (7);

[0124] F(ω)=∫F1(ω) (7)

[0125] Where F(ω) represents the noise suppression signal in the frequency domain, and F1(ω) represents the noise suppression frame.

[0126] The process of performing time-frequency inverse transformation on the noise suppression signal in the frequency domain to obtain the noise suppression signal in the time domain can be referred to the relevant content of the above formula (6). Moreover, the other implementation processes are the same as those in the above implementation process. Please refer to the relevant content in the above text. It will not be repeated here.

[0127] Step 205: Output the noise suppression signal through the speaker to achieve noise reduction of the air supply device.

[0128] After generating the time-domain noise suppression signal, the noise suppression signal is output through a loudspeaker to achieve noise reduction of the air supply equipment.

[0129] Based on the above description, the noise reduction process of the air supply equipment is a continuous cycle in order to pursue a balance between the noise generated by the air supply equipment and the noise suppression. Therefore, after outputting the noise suppression signal in step 205, it can return to step 201 again until the noise intensity of the second noise signal collected by the feedback microphone is not greater than the intensity threshold, and then the noise reduction of the air supply equipment is completed.

[0130] It should be noted that the number of speakers can be adjusted according to the actual situation. That is, the number of speakers can be one or more, and the noise suppression signal can be output by one speaker or by multiple speakers. This application embodiment does not limit this.

[0131] The methods provided in the embodiments of this application will now be described again in a cyclical manner.

[0132] In the first loop, a first noise signal is acquired via a feedforward microphone, inverted to obtain a noise suppression signal, and output through a speaker. In the second loop, the first noise signal is acquired via the feedforward microphone, and a second noise signal (which has already been suppressed in the first loop) is acquired via a feedback microphone. If the noise intensity of the second noise signal exceeds a threshold, a noise suppression signal is generated based on the first noise signal, the second noise signal, motor speed, airflow velocity, ambient temperature, and the number of fan blades in the air supply equipment, and output through a speaker. The third and subsequent loops are similar to the second loop, until the noise intensity of the second noise signal is no greater than the threshold, indicating that a balance has been reached between the noise generated by the air supply equipment and noise suppression.

[0133] This embodiment of the application acquires a first noise signal collected by a feedforward microphone and a second noise signal collected by a feedback microphone. The noise intensity of the second noise signal is compared with an intensity threshold. If the noise intensity of the second noise signal is greater than the intensity threshold, a compensation gain is calculated based on the motor speed of the air supply device, the airflow speed, the ambient temperature, and the number of fan blades of the air supply device. A noise suppression signal is then generated and output by a speaker. This process continues until the noise intensity of the second noise signal collected by the feedback microphone is no greater than the intensity threshold. This indicates that a balance has been reached between the noise generated by the air supply device and noise suppression, and the noise reduction effect is currently good. The above method combines the factors that generate noise during the operation of the air supply device with its surrounding environment, applying active noise reduction technology to the air supply device. This effectively reduces the noise generated during operation, achieving active noise reduction for the air supply device.

[0134] Figure 3This is a schematic diagram of the structure of a noise reduction device for an air supply equipment according to an embodiment of this application. The noise reduction device can be implemented by software, hardware, or a combination of both, and can be part or all of the air supply equipment. Please refer to... Figure 3 The device includes: a first acquisition module 301, a second acquisition module 302, a third acquisition module 303, a first generation module 304, and an output module 305.

[0135] The first acquisition module 301 is used to acquire the first noise signal collected by the feedforward microphone;

[0136] The second acquisition module 302 is used to acquire the second noise signal collected by the feedback microphone;

[0137] The third acquisition module 303 is used to acquire the motor speed, airflow speed and ambient temperature of the air supply equipment.

[0138] The first generation module 304 is used to generate a noise suppression signal based on the first noise signal, the second noise signal, the motor speed, the air supply speed, the ambient temperature and the number of fan blades of the air supply device if the noise intensity of the second noise signal is greater than the intensity threshold.

[0139] Output module 305 is used to output a noise suppression signal through a speaker to achieve noise reduction of the air supply equipment.

[0140] Optionally, the first generation module 304 includes:

[0141] The first processing submodule is used to perform framing, windowing and time-frequency transformation on the first noise signal to obtain multiple frequency domain noise frames.

[0142] The first determining submodule is used to determine multiple noise suppression frames, which correspond one-to-one with multiple frequency domain noise frames, and the corresponding noise suppression frames and frequency domain noise frames have opposite phases and the same amplitude and frequency.

[0143] The second determining submodule is used to determine the compensation gain corresponding to each frequency within the target frequency range based on the second noise signal, motor speed, air supply speed, ambient temperature and number of fan blades. The target frequency range refers to the frequency range of the noise signal.

[0144] The first generation submodule is used to generate a noise suppression signal based on the multiple noise suppression frames and the compensation gain corresponding to each frequency within the target frequency range.

[0145] Optionally, the second determining submodule is specifically used for:

[0146] The second noise signal is transformed by time and frequency to obtain the frequency domain noise signal;

[0147] If the noise intensity of the target frequency in the frequency domain noise signal is greater than the intensity threshold, then the compensation gain corresponding to the target frequency is determined based on the amplitude, motor speed, air supply speed, ambient temperature and number of fan blades corresponding to the target frequency in the frequency domain noise signal.

[0148] If the noise intensity at the target frequency in the frequency domain noise signal is not greater than the intensity threshold, then the compensation gain corresponding to the target frequency is determined to be 1.

[0149] The target frequency is any frequency within the target frequency range.

[0150] Optionally, the device further includes:

[0151] The second generation module is used to generate a noise suppression signal based on the first noise signal if the noise intensity of the second noise signal is not greater than the intensity threshold.

[0152] Optionally, the second generation module includes:

[0153] The second processing submodule is used to perform framing, windowing and time-frequency transformation on the first noise signal to obtain multiple frequency domain noise frames.

[0154] The third determining submodule is used to determine multiple noise suppression frames, which correspond one-to-one with multiple frequency domain noise frames, and the corresponding noise suppression frames and frequency domain noise frames have opposite phases and the same amplitude and frequency.

[0155] The second generation submodule is used to generate a noise suppression signal based on the multiple noise suppression frames.

[0156] In this embodiment, a first noise signal collected by a feedforward microphone and a second noise signal collected by a feedback microphone are acquired. The noise intensity of the second noise signal is compared with an intensity threshold. If the noise intensity of the second noise signal is greater than the intensity threshold, a compensation gain is calculated based on the motor speed of the air supply device, the air supply speed, the ambient temperature, and the number of fan blades of the air supply device. A noise suppression signal is then generated and output by a speaker. This process continues until the noise intensity of the second noise signal collected by the feedback microphone is no greater than the intensity threshold. This indicates that the noise generated by the air supply device and the noise suppression have reached a balance, and the noise reduction effect is good. The above method combines the factors that generate noise during the operation of the air supply device with its environment, applying active noise reduction technology to the air supply device. This effectively reduces the noise generated during the operation of the air supply device, achieving active noise reduction for the air supply device.

[0157] It should be noted that the noise reduction device for the air supply equipment provided in the above embodiments is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the noise reduction device for the air supply equipment provided in the above embodiments and the noise reduction method embodiments for the air supply equipment belong to the same concept, and the specific implementation process can be found in the method embodiments, which will not be repeated here.

[0158] Figure 4 This is a structural block diagram of an air supply device 400 provided in an embodiment of this application. The air supply device 400 can be any device with air supply function, such as an air conditioner or a fan.

[0159] Typically, the air supply device 400 includes: a processor 401, a memory 402, a peripheral device interface 403, and peripheral devices: a feedforward microphone 404, a feedback microphone 405, a speed sensor 406, a temperature sensor 407, a wind speed sensor 408, and a speaker 409. The processor 401, the memory 402, and the peripheral device interface 403 can be connected via a bus or signal line, and each peripheral device can be connected to the peripheral device interface 403 via a bus, signal line, or circuit board.

[0160] Processor 401 may include one or more processing cores, such as a quad-core processor, an octa-core processor, etc. Processor 401 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field Programmable Gate Array), and PLA (Programmable Logic Array). Processor 401 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 401 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, processor 401 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0161] The memory 402 may include one or more computer-readable storage media, which may be non-transitory. The memory 402 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory 402 are used to store at least one instruction, which is executed by the processor 401 to implement the noise reduction method of the air supply device provided in the method embodiments of this application.

[0162] Peripheral device interface 403 can be used to connect at least one I / O (Input / Output) related peripheral device to processor 401 and memory 402. In some embodiments, processor 401, memory 402 and peripheral device interface 403 are integrated on the same chip or circuit board; in some other embodiments, any one or two of processor 401, memory 402 and peripheral device interface 403 can be implemented on separate chips or circuit boards, which is not limited in this embodiment.

[0163] The feedforward microphone 404 and feedback microphone 405 are used to collect sound waves from the user and the environment, and convert the sound waves into electrical signals that are input to the processor 401 for processing. For noise reduction purposes, there can be multiple feedback microphones 405, which are respectively set in different parts of the air supply device 400. The feedforward microphone 404 and feedback microphone 405 can be array microphones or omnidirectional acquisition microphones.

[0164] The speed sensor 406 can be any of the following speed sensors: photoelectric speed sensor, variable reluctance speed sensor, capacitive speed sensor, or Hall effect speed sensor, used to measure speed and convert speed into a usable output signal.

[0165] Temperature sensor 407 can be any of the following temperature sensors: thermocouple temperature sensor, thermistor temperature sensor, resistance temperature sensor, or integrated temperature sensor, used to sense temperature and convert it into a usable output signal.

[0166] The wind speed sensor 408 can be any of the following wind speed sensors: propeller-type wind speed sensor, cup wind speed sensor, thermal wind speed sensor, or pitot tube wind speed sensor, used to measure wind speed and convert it into a usable output signal.

[0167] The speaker 409 is used to convert electrical signals from the processor 401 into sound waves. The speaker can be a traditional diaphragm speaker or a piezoelectric ceramic speaker. When the speaker is a piezoelectric ceramic speaker, it can convert electrical signals not only into sound waves that humans can hear, but also into sound waves that humans cannot hear for purposes such as distance measurement.

[0168] Those skilled in the art will understand that Figure 4 The structure shown does not constitute a limitation on the air supply device 400, and may include more or fewer components than shown, or combine certain components, or use different component arrangements.

[0169] In some embodiments, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps of the noise reduction method for the air supply device described above. For example, the computer-readable storage medium may be a ROM, RAM, CD-ROM, magnetic tape, floppy disk, or optical data storage device.

[0170] It is worth noting that the computer-readable storage medium mentioned in the embodiments of this application can be a non-volatile storage medium, in other words, it can be a non-transient storage medium.

[0171] It should be understood that all or part of the steps of the above embodiments can be implemented by software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented wholly or partially in the form of a computer program product. The computer program product includes one or more computer instructions. The computer instructions can be stored in the above-described computer-readable storage medium.

[0172] That is, in some embodiments, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to perform the steps of the noise reduction method of the air supply device described above.

[0173] It should be understood that "at least one" as mentioned herein refers to one or more, and "multiple" refers to two or more. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. In addition, in order to clearly describe the technical solutions of the embodiments of this application, the terms "first," "second," etc., are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and the terms "first," "second," etc., are not necessarily different.

[0174] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, data stored, data displayed, etc.) and signals involved in the embodiments of this application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0175] The above descriptions are embodiments provided in this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for noise reduction in an air supply device, characterized in that, The air supply device includes a feedforward microphone, a feedback microphone, and a speaker. The feedforward microphone is located inside the air supply device, and the feedback microphone is located outside the air supply device. The method includes: Acquire the first noise signal collected by the feedforward microphone; Acquire the second noise signal collected by the feedback microphone; The motor speed, airflow velocity, and ambient temperature of the air supply equipment are obtained. If the noise intensity of the second noise signal is greater than the intensity threshold, then the first noise signal is subjected to framing, windowing, and time-frequency transformation to obtain multiple frequency domain noise frames; Multiple noise suppression frames are determined, and the multiple noise suppression frames correspond one-to-one with the multiple frequency domain noise frames. The corresponding noise suppression frames and frequency domain noise frames have opposite phases, but the same amplitude and frequency. Perform time-frequency transformation on the second noise signal to obtain a frequency domain noise signal; If the noise intensity at the target frequency in the frequency domain noise signal is greater than the intensity threshold, then based on the amplitude corresponding to the target frequency in the frequency domain noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades, according to the formula... Determine the compensation gain corresponding to the target frequency; where g represents the compensation gain corresponding to the target frequency, A1 represents the amplitude corresponding to the target frequency in the frequency domain noise signal, v represents the airflow speed of the air supply device, p represents the ambient temperature of the current air supply device, i represents the number of fan blades of the air supply device, r represents the motor speed of the air supply device, and α and β are compensation coefficients; if the noise intensity of the target frequency in the frequency domain noise signal is not greater than the intensity threshold, then determine the compensation gain corresponding to the target frequency as 1, where the target frequency is any frequency within the target frequency range, and the target frequency range refers to the frequency range of the noise signal; A noise suppression signal is generated based on the plurality of noise suppression frames and the compensation gain corresponding to each frequency within the target frequency range; The noise suppression signal is output through the speaker to achieve noise reduction of the air supply device.

2. The method as described in claim 1, characterized in that, The method further includes: If the noise intensity of the second noise signal is not greater than the intensity threshold, then the noise suppression signal is generated based on the first noise signal.

3. The method as described in claim 2, characterized in that, The step of generating the noise suppression signal based on the first noise signal includes: The first noise signal is segmented, windowed, and time-frequency transformed to obtain multiple frequency domain noise frames; Multiple noise suppression frames are determined, and the multiple noise suppression frames correspond one-to-one with the multiple frequency domain noise frames. The corresponding noise suppression frames and frequency domain noise frames have opposite phases, but the same amplitude and frequency. The noise suppression signal is generated based on the plurality of noise suppression frames.

4. A noise reduction device for an air supply equipment, characterized in that, The air supply device includes a feedforward microphone, a feedback microphone, and a speaker. The feedforward microphone is located inside the air supply device, and the feedback microphone is located outside the air supply device. The device includes: The first acquisition module is used to acquire the first noise signal collected by the feedforward microphone; The second acquisition module is used to acquire the second noise signal collected by the feedback microphone; The third acquisition module is used to acquire the motor speed, airflow speed and ambient temperature of the air supply equipment. The first generation module is configured to: if the noise intensity of the second noise signal is greater than an intensity threshold, perform framing, windowing, and time-frequency transformation on the first noise signal to obtain multiple frequency domain noise frames; determine multiple noise suppression frames, wherein each noise suppression frame corresponds one-to-one with the multiple frequency domain noise frames, and the corresponding noise suppression frames and frequency domain noise frames have opposite phases, the same amplitude, and the same frequency; perform time-frequency transformation on the second noise signal to obtain a frequency domain noise signal; if the noise intensity at a target frequency in the frequency domain noise signal is greater than the intensity threshold, then, based on the amplitude corresponding to the target frequency in the frequency domain noise signal, the motor speed, the air supply speed, the ambient temperature, and the number of fan blades, according to the formula... Determine the compensation gain corresponding to the target frequency; where g represents the compensation gain corresponding to the target frequency, A1 represents the amplitude corresponding to the target frequency in the frequency domain noise signal, v represents the airflow speed of the air supply device, p represents the ambient temperature of the current air supply device, i represents the number of fan blades of the air supply device, r represents the motor speed of the air supply device, and α and β are compensation coefficients; if the noise intensity of the target frequency in the frequency domain noise signal is not greater than the intensity threshold, then determine the compensation gain corresponding to the target frequency as 1, where the target frequency is any frequency within the target frequency range, and the target frequency range refers to the frequency range of the noise signal; generate a noise suppression signal based on the multiple noise suppression frames and the compensation gain corresponding to each frequency within the target frequency range; The output module is used to output the noise suppression signal through the speaker to achieve noise reduction of the air supply device.

5. An air supply device, characterized in that, The air supply device includes a memory and a processor. The memory is used to store computer programs, and the processor is used to execute the computer programs stored in the memory to implement the steps of the method according to any one of claims 1-3.

6. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the steps of the method described in any one of claims 1-3.

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