Active noise reduction control method, system, device and storage medium for range hood

Abstract

The present disclosure is a method, system, device and storage medium for active noise reduction control of a range hood. The range hood includes an active noise reduction system, characterized in that the active noise reduction control method includes: obtaining a number of output sound waves of the active noise reduction system; determining the sound wave power of the output sound waves; within a first preset time period, if the sound wave power exceeds the power threshold more than the first threshold, it is determined that an unstable state has occurred; if the unstable state occurs, the active noise reduction system is controlled to restart. The present disclosure calculates the sound wave power of the output sound waves by obtaining the output sound waves of a number of active noise reduction systems. The generation of self-oscillation is determined based on the sound wave power and the number of sound waves with excessive power, the unstable state is discovered in time, and the active noise reduction system is paused or restarted in time. Howling is avoided after the unstable state to avoid a bad experience for the user.

Description

Technical Field

[0001] The present disclosure relates to the technical field of household appliances, and in particular to an active noise reduction control method, system, device, and storage medium for a range hood. Background Art

[0002] To optimize the user experience, some range hoods now feature active noise reduction. The basic principle of active noise reduction is that the system uses a microphone to collect noise from the range hood, converts it into analog-to-digital data, and then outputs a sound wave through a speaker. This sound wave can partially offset the noise, achieving a noise reduction effect in a predetermined area.

[0003] However, self-oscillation is an unavoidable problem for active noise cancellation systems. Once self-oscillation occurs within the system, it manifests as a high-frequency "howling" in reality. This is a very unpleasant experience for users. Therefore, ensuring the stability of active noise cancellation systems is a key issue. Current active noise cancellation systems require increased design costs and extensive robustness testing to ensure system stability, or even sacrifice noise cancellation performance to ensure system stability. Summary of the Invention

[0004] The problem to be solved by the present disclosure is to overcome the defect in the prior art of lacking an effective detection method for the stability of an active noise reduction system, and to provide an active noise reduction control method, system, device and storage medium for a range hood.

[0005] The present disclosure solves the above technical problems through the following technical solutions:

[0006] The present disclosure provides an active noise reduction control method for a range hood, the active noise reduction control method comprising:

[0007] Acquiring a number of output sound waves of the active noise reduction system;

[0008] determining the acoustic wave power of the output acoustic wave;

[0009] If, within a first preset time period, the acoustic wave power exceeds the power threshold for a number of times exceeding a first threshold, it is determined that an unstable state has occurred;

[0010] If the unstable state occurs, the active noise reduction system is controlled to restart.

[0011] Preferably, the active noise reduction control method further includes:

[0012] The power threshold is determined according to the current motor speed of the range hood, and the speed is positively correlated with the power threshold.

[0013] Preferably, determining the power threshold according to the current motor speed of the range hood includes:

[0014] Obtaining the current motor speed of the range hood;

[0015] The power threshold value that matches the current motor speed is determined based on the correspondence between the motor speed and the power threshold value.

[0016] Preferably, the active noise reduction control method further includes:

[0017] The power threshold is determined according to the acoustic wave power, and the acoustic wave power is positively correlated with the power threshold.

[0018] Preferably, the calculation formula for determining the power threshold according to the acoustic wave power is:

[0019] T=P+Cδ

[0020] Wherein, T is the power threshold, P is the acoustic wave power in the current time period, C is a positive integer, δ is the standard deviation of the normal distribution, and the calculation formula of δ is:

[0021]

[0022] Where t is time, L is the time window length of the time, y t is the sound wave amplitude at time t.

[0023] Preferably, if the instability state occurs, controlling the active noise reduction system to restart includes:

[0024] If the number of occurrences of the unstable state exceeds a second threshold within a second preset time period, optimizing the noise reduction model of the active noise reduction system;

[0025] The present disclosure also provides an active noise reduction control device for a range hood, comprising:

[0026] A first acquisition module is used to acquire a number of output sound waves of the active noise reduction system;

[0027] A second acquisition module is used to obtain the sound wave power of the output sound wave;

[0028] a determination module, configured to determine that an unstable state has occurred if the acoustic wave power exceeds the power threshold a number of times exceeding a first threshold within a first preset time period;

[0029] The control module is configured to control the active noise reduction system to restart if the unstable state occurs.

[0030] Preferably, the active noise reduction control device further includes:

[0031] The first determining module is configured to determine the power threshold according to a current motor speed of the range hood, wherein the speed is positively correlated with the power threshold.

[0032] Preferably, the first determining module includes:

[0033] an acquiring unit, configured to acquire the current motor speed of the range hood;

[0034] The determining unit is configured to determine a power threshold value that matches the current motor speed based on a correspondence between the motor speed and the power threshold value.

[0035] Preferably, the active noise reduction control device further includes:

[0036] The second determining module is configured to determine the power threshold according to the acoustic wave power, where the acoustic wave power is positively correlated with the power threshold.

[0037] The formula for determining the power threshold according to the acoustic wave power is:

[0038] T=P+Cδ

[0039] Wherein, T is the power threshold, P is the acoustic wave power in the current time period, C is a positive integer, δ is the standard deviation of the normal distribution, and the calculation formula of δ is:

[0040]

[0041] Where t is time, L is the time window length of the time, y t is the sound wave amplitude at time t.

[0042] Preferably, the control module includes:

[0043] an optimization unit, configured to optimize a noise reduction model of the active noise reduction system if the number of occurrences of the unstable state exceeds a second threshold within a second preset time period;

[0044] A restart unit is used to restart the active noise reduction system.

[0045] The present disclosure also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and used to run on the processor, wherein the processor implements the aforementioned active noise reduction control method for the range hood when executing the computer program.

[0046] The present disclosure also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the aforementioned active noise reduction control method for a range hood.

[0047] On the basis of conforming to the common sense in this field, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0048] The positive progress of this disclosure lies in: by obtaining the output sound waves of several active noise reduction systems and calculating the sound wave power of the output sound waves, the occurrence of self-oscillation is determined based on the sound wave power and the number of sound waves with excessive sound wave power, and instability is promptly detected, allowing the active noise reduction system to be paused or restarted in a timely manner. This prevents the occurrence of howling after instability, thereby preventing a negative user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 A flowchart of an active noise reduction control method for a range hood provided by an exemplary embodiment of the present invention;

[0050] Figure 2 A schematic diagram of a module of an active noise reduction control device for a range hood provided by an exemplary embodiment of the present invention;

[0051] Figure 3 The present invention provides a schematic structural diagram of an electronic device according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0052] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0053] Active noise reduction works by using sound waves to cancel out noise. This typically involves placing a microphone near the noise source to pick up the noise signal. This analog signal is then transmitted to the chip via a feedforward amplifier. After analog-to-digital conversion, the chip's processing unit calculates the reference signal to produce an output sound wave. This output sound wave undergoes digital-to-analog conversion and is output through a speaker, ultimately achieving noise reduction in the desired area.

[0054] Active noise reduction for range hoods is generally aimed at the noise generated by the rotation of the motor. Since the range hood motor maintains a certain power when rotating, the noise it generates is also approximately stable. Correspondingly, the output sound waves output by the active noise reduction system to offset the noise should also be stable. Through testing, it was found that under normal circumstances, the frequency of the output sound waves within a certain period of time will remain within a stable range. However, when the active noise reduction system produces self-excited oscillations, the frequency of the output sound waves will increase significantly. Based on this feature, the following active noise reduction control method is designed to control the active noise reduction system.

[0055] This embodiment provides an active noise reduction control method for a range hood, wherein the range hood includes an active noise reduction system. Figure 1 , active noise reduction control methods include:

[0056] Step 101: Obtain output sound waves of several active noise reduction systems.

[0057] To achieve active noise reduction, the speaker emits output sound waves to offset the noise generated by the range hood motor. In this step, several output sound waves are needed to prepare for the next step.

[0058] Step 102: Determine the sound wave power of the output sound wave.

[0059] In this step, the sound wave power of the output sound wave can be determined by outputting the sound wave.

[0060] The calculation formula can be:

[0061]

[0062] Among them, P is the sound wave power of the output sound wave, t is time, L is the time window length, y t is the sound wave amplitude at time t.

[0063] Step 103: within a first preset time period, if the number of times that the acoustic wave power exceeds the power threshold exceeds a first threshold, it is determined that an unstable state has occurred.

[0064] This step determines whether the range hood's active noise reduction system has experienced instability. This instability is determined by monitoring the number of times the output sound wave power exceeds a pre-set power threshold within a certain time period. Preferably, within a first preset time period, the number of times the sound wave power exceeds the power threshold exceeds a first threshold. If so, instability is determined. In this step, the first preset time period, power threshold, and first threshold can all be set based on actual needs.

[0065] Step 104: If an unstable state occurs, the active noise reduction system is controlled to restart.

[0066] In this step, if an instability occurs, control of the active noise reduction system is triggered, preferably restarting the system. The occurrence of an instability can cause howling, and the instability can occur suddenly or gradually. Therefore, if an instability is detected, the active noise reduction system must be immediately intervened and controlled. This control method can be to restart the active noise reduction system. Before the restart process, the active noise reduction system can be paused and then restarted according to the current situation.

[0067] In one embodiment, step 104 includes: if the number of occurrences of the instability state exceeds a second threshold within a second preset time period, optimizing the noise reduction model of the active noise reduction system and restarting the active noise reduction system.

[0068] This step is to make the noise reduction model of the active noise reduction system better adapt to the current noise environment and avoid the occurrence of misjudgment. Because if an unstable state occurs, it means that the current noise reduction model cannot perform noise reduction well, so it needs to be replaced. After the optimized noise reduction model is imported into the noise reduction system, noise reduction can be performed better. It should be clear that individual occasional conditions will also lead to the occurrence of an unstable state. The cause of the unstable state is not a problem with the noise reduction system itself. Therefore, a second threshold is set here. Only when the number of occurrences of the unstable state exceeds a certain number can it be determined whether an unstable state has occurred, thereby avoiding the occurrence of misjudgment. In one embodiment, the active noise reduction control method also includes:

[0069] The power threshold is determined according to the current motor speed of the range hood, and the speed is positively correlated with the power threshold.

[0070] In this step, the power threshold can be adjusted based on the motor speed. When the range hood motor speed is high, it generates louder noise, and thus the sound wave power of the output sound wave increases. Consequently, the sound wave power threshold of the output sound wave also increases accordingly. Similarly, when the range hood motor speed is low, the sound wave power threshold of the output sound wave also decreases accordingly.

[0071] In one embodiment, this step includes:

[0072] Get the current motor speed of the range hood. Based on the correspondence between motor speed and power threshold, determine the power threshold that matches the current motor speed.

[0073] In this step, the correspondence between motor speed and power threshold can be obtained based on experimental data, for example, by training the experimental data through machine learning or deep learning. Alternatively, a function corresponding to motor speed and power threshold can be pre-set based on actual needs. This power threshold can limit the output sound wave power to a reasonable range.

[0074] In one embodiment, the active noise reduction control method further includes: determining a power threshold according to the sound wave power, where the sound wave power is positively correlated with the power threshold.

[0075] The formula for determining the power threshold based on the acoustic wave power is:

[0076] T=P+Cδ

[0077] Where T is the power threshold, P is the acoustic power in the current time period, C is a positive integer, and δ is the standard deviation of the normal distribution. The calculation formula for δ is:

[0078]

[0079] Among them, t is time, L is the time window length, yt is the sound wave amplitude at time t.

[0080] If the value of C is 3, it means that 99.73% of the instantaneous sound wave power falls within the interval (P-3δ, P+3δ). At this time, the probability of the sound wave power exceeding the power threshold T is extremely low. Similarly, it can be considered that when the sound wave power exceeds the power threshold T, it indicates that the active noise reduction system is about to become unstable.

[0081] To help you understand the above steps, here is a specific example:

[0082] First, the active noise reduction system's output sound waves are monitored. When the range hood motor begins to rotate, it generates noise. The active noise reduction system collects the ambient noise through a sound pickup device. Preferably, the sound pickup device utilizes a microphone. This noise is converted into a digital signal and processed by a computing unit. After calculation, the sound power of the current sound output is determined. It is important to note that range hoods typically have multiple gears, and different gears correspond to different motor speeds. Therefore, to accommodate the noise generated by different speeds, the active noise reduction system's output sound waves should also vary to suit different scenarios. Therefore, to determine the occurrence of an unstable state, different power thresholds for the output sound wave power are set for each gear. If the output sound wave power exceeds the power threshold a certain number of times within a certain period of time, an unstable state is determined. For example, the condition for determining an unstable state is set to be that the output sound wave power exceeds the power threshold twice within 0.5 seconds, i.e., the first threshold is 2. If the actual situation is that the acoustic power of the sound wave output per 0.5 seconds exceeds the power threshold five times, it can be determined that the first threshold has been exceeded, i.e., an unstable state has occurred. Alternatively, if the actual situation is that the acoustic power of the sound wave output per second exceeds the power threshold six times, i.e., the acoustic power of the sound wave output per 0.5 seconds exceeds the power threshold three times on average, it can also be determined that the first threshold has been exceeded, and an unstable state has occurred. Here, the power threshold and the first threshold can be set according to actual conditions.

[0083] Regarding the means for setting the power threshold, optionally, the setting means includes:

[0084] 1) Pre-set: Since the range hood gears correspond to different motor speeds, the motor speed is positively correlated with the noise power, the noise power is positively correlated with the power of the output sound wave, and the power of the output sound wave is positively correlated with the power threshold. Therefore, it can be concluded that there is a mapping relationship between the range hood gear and the power threshold. Therefore, when the user uses the corresponding gear of the range hood, the power threshold corresponding to the gear is also determined. In specific practice, multiple sets of experimental data on the range hood gear and power threshold can be sampled and fitted using methods such as machine learning or deep learning to obtain a mapping function between the gear and the power threshold.

[0085] 2) Real-time dynamic determination: Since the motor operates at a stable power level, the noise is relatively stable, so the output sound wave is also in a stable state under normal noise reduction conditions. Since the amplitude of the range hood noise is approximately normally distributed, based on the normal distribution model, the appropriate power threshold can be determined based on the output sound wave. The power threshold calculation expression is as follows:

[0086] T=P+Cδ

[0087] Where T is the power threshold, P is the acoustic power in the current time period, C is a positive integer, and δ is the standard deviation of the normal distribution. The calculation formula for δ is:

[0088]

[0089] Among them, t is time, L is the time window length, y t is the sound wave amplitude at time t.

[0090] Then, when the active noise reduction system is detected to be unstable, the system is first reset, which includes deleting the historical noise data and output sound wave data. The number of occurrences of the unstable state is counted by 1, and the active noise reduction system is then restarted. When the count exceeds the second threshold, it indicates that the current noise reduction model does not match the current noise environment, and the active noise reduction needs to be turned off and recalibrated. The noise reduction model calibration process is as follows:

[0091] 1) The loudspeaker emits an output sound wave, and the reference microphone and error microphone simultaneously pick up white noise signals. Based on Wiener filtering, the secondary path model and acoustic feedback path model are calculated respectively.

[0092] 2) Turn on the range hood, and the reference microphone and error microphone simultaneously pick up the noise signal. The noise reduction model is calculated based on the Wiener filter.

[0093] This noise reduction model is used to calculate the output sound waves based on noise data. When recalibrating the noise reduction model, the noise data needs to be resampled and uploaded to the cloud for training to recalibrate the noise reduction model. Once the noise reduction model training is complete, it is downloaded from the cloud to the range hood active noise reduction system to achieve noise reduction. Additionally, if the time interval between consecutive counts exceeds a certain time, indicating that the current noise reduction model is adaptable to the current noise environment, the count is reset to zero and restarted.

[0094] Reference Figure 2 , is a module diagram of an active noise reduction control system for a range hood provided by an exemplary embodiment of the present disclosure, the system includes the following modules:

[0095] The present disclosure also provides an active noise reduction control device for a range hood, comprising:

[0096] A first acquisition module 21 is used to acquire output sound waves of several active noise reduction systems;

[0097] A second acquisition module 22 is used to obtain the sound wave power of the output sound wave;

[0098] The determination module 23 is configured to determine that an unstable state has occurred if the acoustic wave power exceeds the power threshold for a number of times exceeding a first threshold within a first preset time period;

[0099] The control module 24 is configured to control the active noise reduction system to restart if an unstable state occurs.

[0100] Optionally, the active noise reduction control device further includes:

[0101] The first determining module is used to determine a power threshold according to a current motor speed of the range hood, where the speed is positively correlated with the power threshold.

[0102] Optionally, the first determining module includes:

[0103] An acquisition unit, used to obtain the current motor speed of the range hood;

[0104] The determining unit is used to determine the power threshold that matches the current motor speed based on the corresponding relationship between the motor speed and the power threshold.

[0105] Optionally, the active noise reduction control device further includes:

[0106] The second determining module is configured to determine a power threshold according to the acoustic wave power, where the acoustic wave power is positively correlated with the power threshold.

[0107] The formula for determining the power threshold based on the acoustic wave power is:

[0108] T=P+Cδ

[0109] Where T is the power threshold, P is the acoustic power in the current time period, C is a positive integer, and δ is the standard deviation of the normal distribution. The calculation formula for δ is:

[0110]

[0111] Among them, t is time, L is the time window length, y t is the sound wave amplitude at time t.

[0112] Optionally, the control module includes:

[0113] an optimization unit, configured to optimize a noise reduction model of the active noise reduction system if the number of occurrences of the instability state exceeds a second threshold within a second preset time period;

[0114] Restart unit, used to restart the active noise reduction system.

[0115] Figure 3 This is a schematic diagram of the structure of an electronic device provided in this embodiment. The electronic device includes a memory, a processor, and a computer program stored in the memory and configured to run on the processor. When the processor executes the program, the active noise reduction control method for a range hood provided in any of the above embodiments is implemented. Figure 3 The electronic device 300 shown is merely an example and should not limit the functions and scope of use of the embodiments of the present invention.

[0116] Reference Figure 3 The electronic device 300 may be a general-purpose computing device, such as a server device. Components of the electronic device 300 may include, but are not limited to, the at least one processor 301, the at least one memory 302, and a bus 303 connecting various system components (including the memory 302 and the processor 301).

[0117] The bus 303 includes a data bus, an address bus, and a control bus.

[0118] The memory 302 may include a volatile memory, such as a random access memory (RAM) 321 and / or a cache memory 322 , and may further include a read-only memory (ROM) 323 .

[0119] The memory 302 may also include a program / utility 325 having a set (at least one) of program modules 324, such program modules 324 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0120] The processor 301 executes various functional applications and data processing by running the computer program stored in the memory 302, such as the active noise reduction control method for the range hood according to embodiment 1 of the present invention.

[0121] The electronic device 300 can also communicate with one or more external devices 304 (e.g., a keyboard, pointing device, etc.). This communication can occur via an input / output (I / O) interface 305. Furthermore, the model-generating device 300 can also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) via a network adapter 306. As shown, the network adapter 306 communicates with other modules of the model-generating device 300 via a bus 303. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the model-generating device 300, including but not limited to microcode, device drivers, redundant processors, external disk drive arrays, RAID (RAID) systems, tape drives, and data backup storage systems.

[0122] It should be noted that although several units / modules or sub-units / modules of the electronic device are mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more units / modules described above may be embodied in a single unit / module. Conversely, the features and functions of a single unit / module described above may be further divided and embodied by multiple units / modules.

[0123] This embodiment further provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the active noise reduction control method for the range hood provided in any of the above embodiments is implemented.

[0124] The readable storage medium may include, but is not limited to, a portable disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0125] In a possible implementation, the present invention can also be implemented in the form of a program product, which includes program code. When the program product is run on a terminal device, the program code is used to enable the terminal device to execute the active noise reduction control method for the range hood provided in any of the above embodiments.

[0126] The program code for executing the present invention may be written in any combination of one or more programming languages, and may be executed entirely on the user device, partially on the user device, as an independent software package, partially on the user device and partially on a remote device, or entirely on the remote device.

[0127] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of the present invention.

Claims

1. A range hood active noise reduction control method, wherein the range hood includes an active noise reduction system, characterized in that: The active noise reduction control method includes: Acquiring a number of output sound waves of the active noise reduction system; determining the acoustic wave power of the output acoustic wave; Within a first preset time period, if the acoustic wave power exceeds a power threshold for a number of times exceeding a first threshold, it is determined that an unstable state has occurred; the power threshold is determined based on a current motor speed of the range hood, and the speed is positively correlated with the power threshold; or, the power threshold is determined based on the acoustic wave power, and the acoustic wave power is positively correlated with the power threshold; If the unstable state occurs, the active noise reduction system is controlled to restart.

2. The active noise reduction control method for a range hood according to claim 1, characterized in that: The active noise reduction control method further includes: Obtaining the current motor speed of the range hood; The power threshold value that matches the current motor speed is determined based on the correspondence between the motor speed and the power threshold value.

3. The active noise reduction control method for a range hood according to claim 1, characterized in that: The calculation formula for determining the power threshold according to the acoustic wave power is: Wherein, T is the power threshold, P is the sound wave power in the current time period, and C is a positive integer. is the standard deviation of the normal distribution, The calculation formula is: Wherein, t is time, L is the time window length of the time, is the sound wave amplitude at time t.

4. The active noise reduction control method for a range hood according to claim 1, characterized in that: If the instability state occurs, controlling the active noise reduction system to restart includes: If the number of occurrences of the unstable state exceeds a second threshold within a second preset time period, optimizing the noise reduction model of the active noise reduction system; The active noise reduction system is restarted.

5. An active noise reduction control system for a range hood, characterized in that: The active noise reduction control system includes: A first acquisition module is used to acquire output sound waves of several active noise reduction systems; A second acquisition module is used to obtain the sound wave power of the output sound wave; a determination module, configured to determine that an unstable state has occurred if the number of times the sound wave power exceeds a power threshold exceeds a first threshold within a first preset time period; the power threshold is determined based on a current motor speed of the range hood, the speed being positively correlated with the power threshold; or the power threshold is determined based on the sound wave power, the sound wave power being positively correlated with the power threshold; The control module is configured to control the active noise reduction system to restart if the unstable state occurs.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and configured to run on the processor, wherein: When the processor executes the computer program, the active noise reduction control method for the range hood according to any one of claims 1 to 4 is implemented.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the active noise reduction control method for the range hood according to any one of claims 1 to 4 is implemented.

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