Active noise reduction device and active noise reduction method

Abstract

The application discloses an active noise reduction device and an active noise reduction method, and relates to the technical field of noise reduction, wherein the active noise reduction device comprises a shell, a first noise reduction assembly, a second noise reduction assembly and a controller, the shell comprises an inner shell and an outer shell, the outer shell is arranged on a wall body and forms an installation cavity with the wall body, the inner shell is accommodated in the installation cavity and arranged on the wall body, a gap is formed between the inner shell and the outer shell, and a sound outlet is formed in the end of the outer shell away from the inner shell; the first noise reduction assembly is installed in the inner shell; the second noise reduction assembly is installed in the outer shell; and the first noise reduction assembly and the second noise reduction assembly are electrically connected with the controller. The first noise reduction assembly and the second noise reduction assembly located on the wall body can be matched to realize noise reduction, the user does not need to wear earphones for a long time, the daily action of the user is not affected, the use is more convenient, noise reduction sound waves are not directly emitted to the ears, and the health of the ears of the user is not affected.

Description

Technical Field

[0001] This invention relates to the field of noise reduction technology, and in particular to an active noise reduction device and an active noise reduction method. Background Technology

[0002] In the process of modern urbanization and industrial development, environmental noise pollution has become an increasingly serious problem. Environmental noise not only affects people's quality of life and health, but also has a wide-ranging and profound negative impact on economic activities. Long-term exposure to high-intensity noise environments, such as traffic noise, industrial noise, and construction site noise, can lead to hearing damage. Studies have shown that continuous exposure to noise levels above 85 decibels significantly increases the risk of hearing loss and noise-induced deafness.

[0003] Existing noise reduction methods typically involve users wearing headphones and achieving noise reduction through passive noise-absorbing structures and active noise cancellation functions on the headphones. However, wearing headphones for extended periods is not only inconvenient for users' daily activities but also affects their ear health. Therefore, existing noise reduction methods suffer from inconvenience and health risks. Summary of the Invention

[0004] The main objective of this invention is to propose an active noise reduction device and method, which aims to solve the problems of inconvenient use and health impact of existing noise reduction methods.

[0005] To achieve the above objectives, the present invention proposes an active noise cancellation device, the active noise cancellation device comprising:

[0006] A housing, comprising an inner shell and an outer shell, wherein the outer shell is disposed on a wall and forms an installation cavity therebetween with the wall, the inner shell is housed within the installation cavity and disposed on the wall, a gap is formed between the inner shell and the outer shell, and a sound outlet is provided at the end of the outer shell away from the inner shell;

[0007] A first noise reduction component is installed inside the inner shell;

[0008] The second noise reduction component is installed inside the housing and is used to acquire noise signals outside the wall and to collect sound.

[0009] The controller is electrically connected to both the first noise reduction component and the second noise reduction component. The controller is used to control the first noise reduction component to generate vibration and to control the second noise reduction component to emit sound waves to reduce the noise signal.

[0010] In one embodiment, the second noise reduction component is used to acquire a noise signal outside the wall and send it to the controller. The controller is used to analyze the noise signal and control the first noise reduction component to emit a vibration opposite in phase to the noise signal to achieve primary noise reduction. The second noise reduction component is used to acquire the remaining noise signal after primary noise reduction and send it to the controller. The controller is used to calculate the remaining noise signal and the noise signal to acquire a secondary noise immunity signal, and control the second noise reduction component to emit a secondary noise immunity wave according to the secondary noise immunity wave signal to achieve secondary noise reduction.

[0011] In one embodiment, the first noise reduction component includes an oscillator electrically connected to the controller and used to generate vibration;

[0012] The second noise reduction component includes a vibration sensor, a sound sensor, and a sound-generating structure. The vibration sensor is located on the side of the housing that contacts the wall and is used to detect the vibration of the wall to obtain the noise signal. The sound sensor is located close to the vibrator and is used to receive the residual noise signal after the noise signal passes through the vibrator. The sound-generating structure is used to emit the secondary noise-resistant wave.

[0013] In one embodiment, the housing includes a connecting portion and a spacer portion. The connecting portion is connected to the wall, and the spacer portion is connected to the connecting portion and spaced apart from the wall to form a mounting cavity with one side open. The vibration sensor is disposed in the connecting portion, and the sound sensor is disposed in the spacer portion.

[0014] In one embodiment, the second noise reduction component further includes a second magnetic attractor disposed in the spacer portion, and the first noise reduction component further includes a first magnetic attractor disposed corresponding to the second magnetic attractor. The second magnetic attractor can attract or de-attract with the first magnetic attractor to correspondingly attach or separate the spacer portion and the inner shell.

[0015] In one embodiment, a Bluetooth module is further provided inside the housing. The Bluetooth module is used to communicate with a microphone in the target area and to communicate with the controller. The microphone is used to collect the final noise signal transmitted to the target area after two-stage noise reduction and send it to the controller through the Bluetooth module. The controller calculates the remaining noise signal and the final noise signal to obtain a third-level anti-noise wave signal, and controls the sound-emitting structure to emit a third-level anti-noise wave according to the third-level anti-noise wave signal to achieve three-level noise reduction.

[0016] The present invention also proposes an active noise reduction method, applied to an active noise reduction device, the active noise reduction device comprising:

[0017] A housing, comprising an inner shell and an outer shell, wherein the outer shell is disposed on a wall and forms an installation cavity therebetween with the wall, the inner shell is housed within the installation cavity and disposed on the wall, a gap is formed between the inner shell and the outer shell, and a sound outlet is provided at the end of the outer shell away from the inner shell;

[0018] A first noise reduction component is installed inside the inner shell;

[0019] A second noise reduction component is installed inside the housing;

[0020] The controller, wherein both the first noise reduction component and the second noise reduction component are electrically connected to the controller;

[0021] The active noise reduction method includes the following steps:

[0022] The noise signal outside the wall is obtained through the second noise reduction component;

[0023] The controller controls the first noise reduction component to vibrate and the second noise reduction component to emit sound waves based on the noise signal, so as to reduce the noise signal.

[0024] In one embodiment, the first noise reduction component includes an oscillator electrically connected to the controller;

[0025] The step of the controller controlling the first noise reduction component to emit vibration based on the noise signal includes:

[0026] The controller analyzes the noise signal to obtain the phase of the noise signal;

[0027] The controller controls the oscillator to emit vibrations that are out of phase with the noise signal, thereby achieving first-level noise reduction.

[0028] In one embodiment, the second noise reduction component includes a vibration sensor, a sound sensor, and a sound-generating structure. The vibration sensor is located on the side of the housing that contacts the wall, and the sound sensor is positioned close to the vibrator.

[0029] The step of acquiring the noise signal outside the wall through the second noise reduction component includes:

[0030] The vibration signal of the wall is obtained by the vibration sensor, and then the noise signal outside the wall is obtained.

[0031] The step of the controller controlling the second noise reduction component to emit sound waves includes:

[0032] The controller obtains the remaining noise signal after the noise signal has undergone first-stage noise reduction through the sound sensor;

[0033] The controller calculates the remaining noise signal and the noise signal to obtain a secondary anti-noise wave signal;

[0034] The controller controls the sound-generating structure to emit a secondary noise-reducing wave according to the secondary noise-reducing wave signal, so as to achieve secondary noise reduction.

[0035] In one embodiment, the step of the controller calculating the remaining noise signal and the noise signal to obtain the secondary anti-noise wave signal includes:

[0036] The controller filters the noise signal to obtain the output signal;

[0037] The controller compares the output signal with the remaining noise signal to obtain an error value;

[0038] The controller adjusts the filtering parameters when filtering the noise signal based on the error value.

[0039] Return to the step of the controller filtering the noise signal to obtain the output signal until the error value reaches the preset error value, and use the output signal corresponding to the time when the error value reaches the preset error value as the secondary anti-noise wave signal.

[0040] In one embodiment, a Bluetooth module is disposed within the housing. Following the step of the controller controlling the sound-emitting structure to emit a secondary noise-resistant wave based on the secondary noise-resistant wave signal to achieve secondary noise reduction, the method further includes:

[0041] The final noise signal, after secondary noise reduction, is collected by a microphone in the target area and transmitted to the target area, and then sent to the controller. The microphone is communicatively connected to the Bluetooth module.

[0042] The controller calculates the remaining noise signal and the final noise signal to obtain a level three noise immunity signal;

[0043] The controller controls the sound-generating structure to emit a three-level anti-noise wave according to the three-level anti-noise wave signal, so as to achieve three-level noise reduction.

[0044] In one embodiment, the step of acquiring the final noise signal, after secondary noise reduction, through a microphone in the target area and transmitting it to the target area, and then sending it to the controller, further includes:

[0045] The controller controls the sound-emitting structure to emit standard sound waves toward the target area;

[0046] The controller acquires the standard sound wave through the microphone, obtains the sound wave data of the standard sound wave, and sends it to the controller.

[0047] The controller adjusts the filtering parameters based on the acoustic wave data to normalize the microphone.

[0048] In one embodiment, the step of acquiring the vibration signal of the wall through the vibration sensor, and then acquiring the noise signal outside the wall, includes:

[0049] The controller controls the vibration sensor to acquire the vibration signal of the wall;

[0050] The controller removes low-amplitude vibrations from the vibration signal using an amplitude high-pass filter to obtain the noise signal.

[0051] The technical solution of this invention acquires noise signals from outside the wall through a second noise reduction component, and controls a first noise reduction component to vibrate at the wall via a controller, thereby canceling out some of the noise in the noise signal with the vibration. Then, the second noise reduction component acquires the sound after it passes through the wall, and the controller controls the second noise reduction component to emit sound waves to neutralize the noise after vibration cancellation, thus eliminating most of the external noise. This application cancels out most of the noise outside the wall by setting an inner shell at the wall and the first noise reduction component vibrating to cancel out noise, and then neutralizing the noise by emitting sound waves via the second noise reduction component, thereby making the indoor environment quieter and avoiding the various drawbacks of prolonged exposure to noisy environments. This application achieves noise reduction through external noise reduction means, eliminating the need for users to wear headphones for extended periods, not affecting users' daily activities, making it more convenient to use, and not directly emitting noise reduction waves to the ears, thus not affecting the user's ear health. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0053] Figure 1 This is a schematic diagram of an embodiment of the active noise reduction device provided by the present invention;

[0054] Figure 2 This is a flowchart of an embodiment of the active noise reduction method provided by the present invention;

[0055] Figure 3A flowchart of another embodiment of the active noise reduction method provided by the present invention;

[0056] Figure 4 A detailed flowchart of step S230a of the active noise reduction method provided by the present invention;

[0057] Figure 5 A detailed flowchart of step S232a of the active noise reduction method provided by the present invention.

[0058] Explanation of icon numbers:

[0059] 100. Active noise reduction device; 1. Housing; 11. Inner shell; 12. Outer shell; 121. Sound outlet; 122. Connecting part; 123. Spacing part; 13. Mounting cavity; 14. Gap; 2. First noise reduction component; 21. Vibrator; 22. First magnetic suction component; 3. Second noise reduction component; 31. Vibration sensor; 32. Sound sensor; 33. Sound generation structure; 4. Controller.

[0060] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0062] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0063] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0064] Existing noise reduction methods typically involve users wearing headphones and achieving noise reduction through passive noise-absorbing structures and active noise cancellation functions on the headphones. However, wearing headphones for extended periods is not only inconvenient for users' daily activities but also affects their ear health. Therefore, existing noise reduction methods suffer from inconvenience and health risks.

[0065] To address the above problems, the present invention proposes an active noise reduction device 100.

[0066] Please see Figure 1 In one embodiment of the present invention, the active noise reduction device 100 includes a housing 1, a first noise reduction component 2, a second noise reduction component 3, and a controller 4. The housing 1 includes an inner shell 11 and an outer shell 12. The outer shell 12 is disposed on a wall and forms an installation cavity 13 with the wall. The inner shell 11 is housed in the installation cavity 13 and disposed on the wall. A gap 14 is formed between the inner shell 11 and the outer shell 12. A sound outlet 121 is provided at the end of the outer shell 12 away from the inner shell 11. The first noise reduction component 2 is installed in the inner shell 11. The second noise reduction component 3 is installed in the outer shell 12. The second noise reduction component 3 is used to acquire noise signals outside the wall and to collect sound. Both the first noise reduction component 2 and the second noise reduction component 3 are electrically connected to the controller 4. The controller 4 is used to control the first noise reduction component 2 to generate vibration and to control the second noise reduction component 3 to emit sound waves to reduce noise signals.

[0067] The technical solution of this invention acquires noise signals from outside the wall through a second noise reduction component 3, and controls a first noise reduction component 2 to vibrate at the wall through a controller 4, thereby canceling out some of the noise in the noise signal with the vibration. Then, the second noise reduction component 3 acquires the sound after passing through the wall, and the controller 4 controls the second noise reduction component 3 to emit sound waves to neutralize the noise after vibration cancellation, thus eliminating most of the external noise. This application cancels out most of the noise outside the wall by setting an inner shell 11 at the wall and the first noise reduction component 2 to vibrate, and then neutralizes the noise by emitting sound waves through the second noise reduction component 3, thereby making the indoor environment quieter and avoiding the various drawbacks of prolonged exposure to noise. This application achieves noise reduction through external noise reduction means, eliminating the need for users to wear headphones for extended periods, not affecting users' daily activities, making it more convenient to use, and not directly emitting noise reduction waves to the ears, thus not affecting the user's ear health.

[0068] Specifically, the second noise reduction component 3 is used to acquire the noise signal outside the wall and send it to the controller 4. The controller 4 is used to analyze the noise signal and control the first noise reduction component 2 to emit vibrations opposite to the phase of the noise signal to achieve first-level noise reduction. The second noise reduction component 3 is used to acquire the remaining noise signal after the first-level noise reduction and send it to the controller 4. The controller 4 calculates the remaining noise signal and the noise signal to acquire the second-level anti-noise wave signal, and controls the second noise reduction component 3 to emit the second-level anti-noise wave according to the second-level anti-noise wave signal to achieve second-level noise reduction.

[0069] Noise signals from outside the wall are acquired by the second noise reduction component 3, and the first noise reduction component 2 is controlled by the controller 4 to emit vibrations at the wall that are opposite in phase to the noise signal. This causes some of the noise in the noise signal to cancel out with the vibration, completing the first stage of noise reduction. Then, the second noise reduction component 3 acquires the remaining noise signal after passing through the wall and undergoing the first stage of noise reduction. The remaining noise signal and the noise signal are calculated to obtain the second stage of anti-noise wave signal. The second noise reduction component 3 then emits the second stage of anti-noise wave to further neutralize the noise in the remaining noise signal, thus achieving the second stage of noise reduction and eliminating most of the external noise. By setting the inner shell 11 and the first noise reduction component 2 at the wall for the first stage of noise reduction, and then emitting the second stage of anti-noise wave through the second noise reduction component 3 for the second stage of noise reduction, most of the noise outside the wall is canceled out. This graded noise reduction can improve the noise reduction effect. At the same time, the second stage of anti-noise wave generated based on the remaining noise signal can avoid the anti-noise wave affecting the indoor sound. Graded noise reduction is more flexible and applicable to different situations.

[0070] Specifically, the first noise reduction component 2 includes an oscillator 21, which is electrically connected to the controller 4 and used to generate vibration; the second noise reduction component 3 includes a vibration sensor 31, a sound sensor 32, and a sound-generating structure 33. The vibration sensor 31 is located on the side of the housing 12 that contacts the wall and is used to detect the vibration of the wall to obtain a noise signal. The sound sensor 32 is set close to the oscillator 21 and is used to receive the residual noise signal after the noise signal passes through the oscillator 21. The sound-generating structure 33 is used to emit a secondary anti-noise wave.

[0071] Vibration sensor 31 is located on the side of housing 12 that contacts the wall, allowing it to directly sense the wall's vibration and obtain noise signals more accurately. Vibrator 21 generates vibrations of opposite phase to the wall to neutralize the wall's vibration, thus achieving noise reduction. Sound sensor 32 is positioned close to vibrator 21, enabling precise detection of residual noise signals passing through vibrator 21, improving detection accuracy and resulting in better noise neutralization by the secondary noise-resistant wave. Sound sensor 32 can be a microphone from the prior art, and sound-generating structure 33 can be a loudspeaker or horn from the prior art.

[0072] In one embodiment, the outer casing 12 includes a connecting portion 122 and a spacer portion 123. The connecting portion 122 is connected to the wall, and the spacer portion 123 is connected to the connecting portion 122 and spaced apart from the wall to form a mounting cavity 13 with one side open. A vibration sensor 31 is installed in the connecting portion 122, and a sound sensor 32 is installed in the spacer portion 123. The outer casing 12 is connected to the wall only by the connecting portion 122, with the other side spaced apart from the wall to form an opening. This reduces the impact of wall vibrations transmitted to the outer casing 12 on the sound sensor 32 in the spacer portion 123. The sound sensor 32 is preferably located at the end of the spacer portion 123 away from the connecting portion 122 to minimize the impact of wall vibrations. Furthermore, this facilitates the installation of the inner casing 11 into the mounting cavity 13, reducing assembly difficulty.

[0073] Furthermore, the second noise reduction component 3 also includes a second magnetic attractor disposed in the spacer portion 123, and the first noise reduction component 2 also includes a first magnetic attractor 22 disposed corresponding to the second magnetic attractor. The second magnetic attractor 21 can be attracted to or de-attracted from the second magnetic attractor to attach or separate the spacer portion 123 and the inner shell 11 accordingly.

[0074] The second magnetic component is an electromagnet, and a switch can be set on the outer casing 12 to control the magnetic direction of the second magnetic component, thereby adjusting whether the second magnetic component generates an attractive force or a repulsive force on the first magnetic component 22. Specifically, the magnetic direction of the second magnetic component can be adjusted by changing the direction of the current. When not in use, the second magnetic component generates an attractive force on the first magnetic component 22, making the outer casing 12 and the inner casing 11 press tightly together, preventing dust and other particles from entering the gap 14 between the outer casing 12 and the inner casing 11. When in use, the vibrator 21 inside the inner casing 11 vibrates, at which time the second magnetic component generates a repulsive force on the first magnetic component 22, causing the outer casing 12 and the inner casing 11 to separate, preventing the vibration emitted by the vibrator 21 from causing the outer casing 12 to vibrate and affecting the sound sensor 32 and the vibration sensor 31, thereby improving the noise reduction effect.

[0075] In one embodiment, a Bluetooth module is also provided inside the housing 12. The Bluetooth module is used to communicate with the microphone in the target area and to communicate with the controller 4. The microphone is used to collect the final noise signal transmitted to the target area after secondary noise reduction and send it to the controller 4 through the Bluetooth module. The controller 4 calculates the remaining noise signal and the final noise signal to obtain the third-level anti-noise wave signal, and controls the sound-emitting structure 33 to emit the third-level anti-noise wave according to the third-level anti-noise wave signal to achieve third-level noise reduction.

[0076] The target area is the area where the user is located. The microphone in the target area can be a smart device with Bluetooth functionality and a microphone on the user's body. The microphone collects the final noise signal received in the target area after two levels of noise reduction and sends it to the Bluetooth module via Bluetooth. The Bluetooth module sends the final noise signal to the controller 4. After the controller 4 calculates the third-level anti-noise wave signal, it controls the sound-emitting structure 33 to emit the third-level anti-noise wave. If the smart device on the user's body has a speaker, the third-level anti-noise wave signal can also be sent to the smart device and emitted through the speaker of the smart device. The third-level anti-noise wave is calculated based on the feedback from the user end, which further improves the cancellation of noise signals and enhances the anti-noise effect.

[0077] Please combine Figure 1 and Figure 2The present invention also provides an active noise cancellation method applied to an active noise cancellation device 100. The active noise cancellation device 100 includes a housing 1, a first noise cancellation component 2, a second noise cancellation component 3, and a controller 4. The housing 1 includes an inner shell 11 and an outer shell 12. The outer shell 12 is disposed in a wall and forms an installation cavity 13 with the wall. The inner shell 11 is housed in the installation cavity 13 and disposed in the wall. A gap 14 is formed between the inner shell 11 and the outer shell 12. A sound outlet 121 is provided at the end of the outer shell 12 away from the inner shell 11. The first noise cancellation component 2 is installed in the inner shell 11. The second noise cancellation component 3 is installed in the outer shell 12. Both the first noise cancellation component 2 and the second noise cancellation component 3 are electrically connected to the controller 4.

[0078] The active noise reduction method includes the following steps:

[0079] S100: Obtain noise signals from outside the wall through the second noise reduction component;

[0080] The active noise reduction devices in this active noise reduction method are all installed indoors. Therefore, the noise signal obtained outside the wall represents the outdoor noise signal. It is not that the noise signal can only be obtained directly from the wall. The noise signal can be obtained through window glass, door or wall, etc.

[0081] S200: The controller controls the first noise reduction component to vibrate and the second noise reduction component to emit sound waves according to the noise signal, so as to reduce the noise signal.

[0082] The technical solution of this invention acquires noise signals from outside the wall through a second noise reduction component 3, and controls a first noise reduction component 2 to vibrate at the wall through a controller 4, thereby canceling out some of the noise in the noise signal with the vibration. Then, the second noise reduction component 3 acquires the sound after passing through the wall, and the controller 4 controls the second noise reduction component 3 to emit sound waves to neutralize the noise after vibration cancellation, thus eliminating most of the external noise. This application cancels out most of the noise outside the wall by setting an inner shell 11 at the wall and the first noise reduction component 2 to vibrate, and then neutralizes the noise by emitting sound waves through the second noise reduction component 3, thereby making the indoor environment quieter and avoiding the various drawbacks of prolonged exposure to noise. This application achieves noise reduction through external noise reduction means, eliminating the need for users to wear headphones for extended periods, not affecting users' daily activities, making it more convenient to use, and not directly emitting noise reduction waves to the ears, thus not affecting the user's ear health.

[0083] Please see Figure 3 In another embodiment, the first noise reduction component includes an oscillator electrically connected to a controller; the active noise reduction method includes the following steps:

[0084] S100a: Obtain noise signals from outside the wall through the second noise reduction component;

[0085] S210a: The controller analyzes the noise signal to obtain the phase of the noise signal;

[0086] S220a: The controller controls the oscillator to emit vibrations that are opposite in phase to the noise signal, so as to achieve first-level noise reduction;

[0087] S230a: The controller controls the second noise reduction component to emit sound waves according to the noise signal in order to reduce the noise signal.

[0088] As is understandable, sound is essentially vibration. Therefore, by analyzing the phase of a noise signal and controlling a vibrating structure to emit vibrations with the opposite phase, some of the noise can be canceled out. Typically, the vibrating structure is installed in the wall, glass, or door, or other parts that receive the noise signal.

[0089] Please see Figure 4 Furthermore, the second noise reduction component includes a vibration sensor, a sound sensor, and a sound-generating structure. The vibration sensor is located on the side of the housing that contacts the wall, and the sound sensor is positioned close to the vibrator.

[0090] Step S100a includes:

[0091] S110a: The vibration signal of the wall is obtained through the vibration sensor, and then the noise signal outside the wall is obtained;

[0092] Step S230a includes:

[0093] S231a: The controller obtains the remaining noise signal after the noise signal has undergone first-stage noise reduction through the sound sensor;

[0094] The residual noise signal is obtained by collecting the sound signal that passes through the wall and undergoes primary noise reduction.

[0095] S232a: The controller calculates the remaining noise signal and the noise signal to obtain a secondary anti-noise wave signal;

[0096] Specifically, the calculation can be performed using the LMS algorithm, which is a mature adaptive algorithm in the existing technology. The LMS algorithm can make the headphone noise-canceling wave signal converge to the residual noise signal, so that the secondary noise-canceling wave has the best cancellation effect on the residual noise signal.

[0097] S233a: The controller controls the sound-generating structure to emit a secondary noise-reducing wave according to the secondary noise-reducing wave signal, so as to achieve secondary noise reduction.

[0098] Graded noise reduction can improve the noise reduction effect, and the secondary anti-noise wave generated based on the residual noise signal can avoid the anti-noise wave from affecting the indoor sound. Graded noise reduction is more flexible and applicable to different situations.

[0099] Please see Figure 5 In one embodiment, step S232a includes:

[0100] S2321a: The controller filters the noise signal to obtain an output signal;

[0101] S2322a: The controller compares the output signal with the residual noise signal to obtain an error value;

[0102] S2323a: The controller adjusts the filtering parameters when filtering the noise signal according to the error value;

[0103] S2324a: Return to step S2321a until the error value reaches the preset error value, and use the output signal corresponding to the error value reaching the preset error value as the secondary anti-noise wave signal.

[0104] Understandably, the preset error value is selected as the minimum error value in a certain number of adjustment processes. Filtering can be performed using an adaptive filter. The adaptive filter can adjust the filter parameters and structure in real time according to the time-varying statistical characteristics of the input signal using the LMS (Least Mean Square) adaptive algorithm. The coefficients of the adaptive filter can automatically and continuously adapt to the input signal. In practical applications, the adaptive filter first continuously corrects its own filter coefficients according to the characteristics of the noise signal to minimize the error value, thereby making the output secondary anti-noise wave signal have the best cancellation effect on the remaining noise signal and improving the noise reduction effect.

[0105] Furthermore, a Bluetooth module is provided inside the casing, and the process after step S233a also includes:

[0106] S234a: The final noise signal transmitted to the target area after secondary noise reduction is collected by the microphone in the target area and sent to the controller, wherein the microphone is communicatively connected to the Bluetooth module;

[0107] The target area is the area where the noise reduction effect needs to be tested. The final noise signal transmitted to the target area is collected by sound acquisition devices such as microphones.

[0108] S235a: The controller calculates the remaining noise signal and the final noise signal to obtain a level three noise immunity signal;

[0109] The third-level noise immunity signal was obtained by calculating the same method as the second-level noise immunity signal;

[0110] S236a: The controller controls the sound-generating structure to emit a three-level anti-noise wave according to the three-level anti-noise wave signal, so as to achieve three-level noise reduction.

[0111] Specifically, the target area is the area where the user is located. The final noise signal received in the target area after two-stage noise reduction is collected. Then, the third-level anti-noise wave signal is calculated by an adaptive filter and LMS algorithm, and the third-level anti-noise wave is emitted. If the user's smart device has a speaker, the third-level anti-noise wave signal can also be sent to the smart device and emitted through the speaker of the smart device. The third-level anti-noise wave is calculated based on the feedback from the user, which further improves the cancellation of noise signals and enhances the anti-noise effect.

[0112] Furthermore, the procedure prior to step S234a includes:

[0113] S2331a: The controller controls the sound-emitting structure to emit standard sound waves toward the target area;

[0114] S2332a: The controller acquires the standard sound wave through the microphone, obtains the sound wave data of the standard sound wave, and sends it to the controller;

[0115] S2333a: The controller adjusts the filtering parameters according to the sound wave data to normalize the microphone.

[0116] As mentioned earlier, the target area is the area where the user is located. Standard sound waves are collected by a smart device with a microphone on the user. Since the microphones on different smart devices are different, they emit standard sound waves with a fixed frequency. Then, the sound wave data received by the microphone is compared with the standard sound wave data to obtain the influence of the microphone's quality on the received sound. The filtering parameters are then adjusted based on this influence. Specifically, the LMS adaptive algorithm is weighted and calibrated according to the influence parameters of the microphone's quality to eliminate the influence of the microphone on the final noise signal, improve the accuracy of the final noise signal, and thus improve the accuracy of the level 3 noise rejection wave and improve the anti-smuggling effect.

[0117] In one embodiment, step S110a includes:

[0118] S111a: The controller controls the vibration sensor to acquire the vibration signal of the wall;

[0119] When external noise is transmitted to the wall, it will cause the wall to vibrate. Therefore, noise data can be obtained by detecting the vibration signal of the wall.

[0120] S112a: The controller removes low-amplitude vibrations from the vibration signal using an amplitude high-pass filter to obtain the noise signal.

[0121] By using high-pass amplitude filtering to remove low-amplitude vibrations in the space, vibrations generated by indoor sounds are filtered out, ensuring that the acquired noise signals are all high-frequency noise obtained from the noisy external environment, thus improving the accuracy of noise interference and the noise reduction effect.

[0122] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An active noise reduction device, characterized in that, The active noise reduction device includes: A housing, comprising an inner shell and an outer shell, wherein the outer shell is disposed on a wall and forms an installation cavity therebetween with the wall, the inner shell is housed within the installation cavity and disposed on the wall, a gap is formed between the inner shell and the outer shell, and a sound outlet is provided at the end of the outer shell away from the inner shell; A first noise reduction component is installed inside the inner shell; The second noise reduction component is installed inside the housing and is used to acquire noise signals outside the wall and to collect sound. The controller is electrically connected to both the first noise reduction component and the second noise reduction component. The controller is used to control the first noise reduction component to generate vibration and to control the second noise reduction component to emit sound waves to reduce the noise signal. The second noise reduction component is used to acquire noise signals outside the wall and send them to the controller. The controller is used to analyze the noise signals and control the first noise reduction component to emit vibrations opposite to the phase of the noise signals to achieve first-level noise reduction. The second noise reduction component is used to acquire the remaining noise signals after the first-level noise reduction and send them to the controller. The controller is used to calculate the remaining noise signals and the noise signals to acquire a second-level anti-noise wave signal, and control the second noise reduction component to emit a second-level anti-noise wave based on the second-level anti-noise wave signal to achieve second-level noise reduction. The housing also includes a Bluetooth module, which communicates with a microphone in the target area and with the controller. The microphone collects the final noise signal transmitted to the target area after secondary noise reduction and sends it to the controller via the Bluetooth module. The controller calculates the remaining noise signal and the final noise signal to obtain a third-level anti-noise wave signal, and controls the second noise reduction component to emit a third-level anti-noise wave based on the third-level anti-noise wave signal to achieve third-level noise reduction.

2. The active noise cancellation device as described in claim 1, characterized in that, The first noise reduction component includes an oscillator, which is electrically connected to the controller and used to generate vibration; The second noise reduction component includes a vibration sensor, a sound sensor, and a sound-generating structure. The vibration sensor is located on the side of the housing that contacts the wall and is used to detect the vibration of the wall to obtain the noise signal. The sound sensor is located close to the vibrator and is used to receive the residual noise signal after the noise signal passes through the vibrator. The sound-generating structure is used to emit the secondary noise-resistant wave.

3. The active noise cancellation device as described in claim 2, characterized in that, The housing includes a connecting part and a spacer part. The connecting part is connected to the wall, and the spacer part is connected to the connecting part and spaced apart from the wall to form a mounting cavity with one side open. The vibration sensor is disposed in the connecting part, and the sound sensor is disposed in the spacer part.

4. The active noise cancellation device as described in claim 3, characterized in that, The second noise reduction component further includes a second magnetic attractor disposed in the spacer portion, and the first noise reduction component further includes a first magnetic attractor disposed corresponding to the second magnetic attractor. The second magnetic attractor can attract or de-attract with the first magnetic attractor to correspondingly attach or separate the spacer portion and the inner shell.

5. An active noise reduction method, characterized in that, Applied to an active noise cancellation device, the active noise cancellation device comprising: A housing, comprising an inner shell and an outer shell, wherein the outer shell is disposed on a wall and forms an installation cavity therebetween with the wall, the inner shell is housed within the installation cavity and disposed on the wall, a gap is formed between the inner shell and the outer shell, and a sound outlet is provided at the end of the outer shell away from the inner shell; A first noise reduction component is installed inside the inner shell; A second noise reduction component is installed inside the housing; The controller, wherein both the first noise reduction component and the second noise reduction component are electrically connected to the controller; The active noise reduction method includes the following steps: The noise signal outside the wall is obtained through the second noise reduction component; The controller controls the first noise reduction component to vibrate and the second noise reduction component to emit sound waves based on the noise signal, so as to reduce the noise signal.

6. The active noise reduction method as described in claim 5, characterized in that, The first noise reduction component includes an oscillator, which is electrically connected to the controller; The step of the controller controlling the first noise reduction component to emit vibration based on the noise signal includes: The controller analyzes the noise signal to obtain the phase of the noise signal; The controller controls the oscillator to emit vibrations that are out of phase with the noise signal, thereby achieving first-level noise reduction.

7. The active noise reduction method as described in claim 6, characterized in that, The second noise reduction component includes a vibration sensor, a sound sensor, and a sound-generating structure. The vibration sensor is located on the side of the housing that contacts the wall, and the sound sensor is positioned close to the vibrator. The step of acquiring the noise signal outside the wall through the second noise reduction component includes: The vibration signal of the wall is obtained by the vibration sensor, and then the noise signal outside the wall is obtained. The step of the controller controlling the second noise reduction component to emit sound waves includes: The controller obtains the remaining noise signal after the noise signal has undergone first-stage noise reduction through the sound sensor; The controller calculates the remaining noise signal and the noise signal to obtain a secondary anti-noise wave signal; The controller controls the sound-generating structure to emit a secondary noise-reducing wave according to the secondary noise-reducing wave signal, so as to achieve secondary noise reduction.

8. The active noise reduction method as described in claim 7, characterized in that, The step of the controller calculating the remaining noise signal and the noise signal to obtain the secondary anti-noise wave signal includes: The controller filters the noise signal to obtain the output signal; The controller compares the output signal with the remaining noise signal to obtain an error value; The controller adjusts the filtering parameters when filtering the noise signal based on the error value. Return to the step of the controller filtering the noise signal to obtain the output signal until the error value reaches the preset error value, and use the output signal corresponding to the time when the error value reaches the preset error value as the secondary anti-noise wave signal.

9. The active noise reduction method as described in claim 8, characterized in that, The housing contains a Bluetooth module. Following the step of the controller controlling the sound-generating structure to emit a secondary noise-reducing wave based on the secondary noise-reducing wave signal to achieve secondary noise reduction, the system further includes: The final noise signal, after secondary noise reduction, is collected by a microphone in the target area and transmitted to the target area, and then sent to the controller. The microphone is communicatively connected to the Bluetooth module. The controller calculates the remaining noise signal and the final noise signal to obtain a level three noise immunity signal; The controller controls the sound-generating structure to emit a three-level anti-noise wave according to the three-level anti-noise wave signal, so as to achieve three-level noise reduction.

10. The active noise reduction method as described in claim 9, characterized in that, Before the step of acquiring the final noise signal, after secondary noise reduction, through the microphone in the target area and transmitting it to the controller, the following steps are included: The controller controls the sound-emitting structure to emit standard sound waves toward the target area; The controller acquires the standard sound wave through the microphone, obtains the sound wave data of the standard sound wave, and sends it to the controller. The controller adjusts the filtering parameters based on the acoustic wave data to normalize the microphone.

11. The active noise reduction method as described in claim 7, characterized in that, The step of acquiring the vibration signal of the wall through the vibration sensor, and then acquiring the noise signal outside the wall, includes: The controller controls the vibration sensor to acquire the vibration signal of the wall; The controller removes low-amplitude vibrations from the vibration signal using an amplitude high-pass filter to obtain the noise signal.

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