Active noise reduction method, device, apparatus, and computer-readable storage medium

Abstract

The present application relates to an active noise reduction method, apparatus, device, and computer-readable storage medium, which can address the problem of poor active noise reduction effect in car driving scenarios in the prior art. An active noise reduction method includes: establishing a communication connection between a headphone system and a car system, wherein the headphone system includes a headphone noise reduction system, and the car system includes a car noise reduction system; the headphone system obtains driving status information and / or sensor signals of the car system, and performs active noise reduction processing on the headphone noise reduction system based on the driving status information and / or the sensor signals; the car system obtains a headphone error microphone signal or human ear positioning information of the headphone system, and performs active noise reduction processing on the car noise reduction system based on the headphone error microphone signal or the human ear positioning information.

Description

Technical Field

[0001] The present application relates to the field of noise reduction technology, and in particular to an active noise reduction method, apparatus, device, and computer-readable storage medium. Background Art

[0002] As people continue to pursue a higher quality of life, more and more people have higher requirements for active noise reduction functions in car driving scenarios. Active noise reduction functions in car driving scenarios mainly include two aspects: headphone active noise reduction function and car active noise reduction function. As for headphone active noise reduction function, headphones with good active noise reduction effect are generally in-ear headphones or closed-ear headphones. However, car drivers generally cannot wear such headphones because the isolation effect of mid- and high-frequency sounds is too strong, which will filter out effective sound information or some danger warning information. Therefore, in order to avoid the excessive isolation effect of mid- and high-frequency sounds of in-ear headphones or closed-ear headphones, drivers can wear ordinary semi-in-ear headphones or open-ear headphones. However, if such headphones are not optimized for car driving scenarios, the active noise reduction effect is not obvious.

[0003] Active noise cancellation (ANC) in cars targets large sound fields. The complexity of the noise cancellation system and the numerous modes of the spatial sound field make optimal noise cancellation very sensitive to spatial location. This is particularly true due to hardware design limitations. For example, the error microphone in a car's noise cancellation system is typically placed near the headrest, far from the actual position of the human ear. While virtual error microphone technology can theoretically compensate for this, in practice, the ANC effect is less than ideal. Summary of the Invention

[0004] In view of this, embodiments of the present application provide an active noise reduction method, apparatus, device, and computer-readable storage medium to address the problem of poor active noise reduction effect in automobile driving scenarios in the prior art.

[0005] A first aspect of an embodiment of the present application provides an active noise reduction method, including:

[0006] The headphone system establishes a communication connection with the vehicle system, wherein the headphone system includes a headphone noise reduction system and the vehicle system includes a vehicle noise reduction system;

[0007] The headphone system acquires driving state information and / or sensor signals of the automobile system, and performs active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signals, wherein the driving state information includes at least one of driving speed, driving road type, and window opening degree;

[0008] The automobile system obtains an earphone error microphone signal or human ear positioning information of the earphone system, and performs active noise reduction processing on the automobile noise reduction system according to the earphone error microphone signal or the human ear positioning information.

[0009] In one embodiment, performing active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signal includes:

[0010] When the window opening degree is less than or equal to a preset opening degree, determining the headphone noise reduction parameter according to the driving speed and the driving road type;

[0011] When the window opening degree is greater than a preset opening degree, determining the headphone noise reduction parameter according to the window opening degree;

[0012] Active noise reduction processing is performed on the headphone noise reduction system according to the headphone noise reduction parameters.

[0013] In one embodiment, performing active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signal includes:

[0014] Acquiring a plurality of sensor signals at an engine and / or a vehicle suspension system of the vehicle system;

[0015] One or more sensor signals having the highest coherence with the headphone error microphone signal are selected as feedforward input signals of the headphone noise reduction system, and active noise reduction processing is performed on the headphone noise reduction system according to the feedforward input signals.

[0016] In one embodiment, selecting one or more sensor signals having the highest coherence with the headphone error microphone signal as the feedforward input signal of the headphone noise reduction system further includes:

[0017] When selecting the plurality of sensor signals having the highest coherence with the headphone error microphone, establishing a cross-correlation matrix of the plurality of sensor signal combinations, and calculating the condition numbers of the plurality of cross-correlation matrices;

[0018] The sensor signal combination with the lowest condition number of the cross-correlation matrix is ​​selected as the feedforward input signal of the headphone noise reduction system.

[0019] In one embodiment, performing active noise reduction processing on the automobile noise reduction system according to the headphone error microphone signal or the human ear positioning information includes:

[0020] performing active noise reduction processing on the automobile noise reduction system according to the earphone error microphone signal, and detecting a stable state of the automobile noise reduction system;

[0021] When it is detected that the vehicle noise reduction system is in an unstable state, selecting a virtual error microphone closest to the human ear positioning information from a virtual error microphone set, and determining a vehicle noise reduction parameter based on the virtual error microphone, wherein each virtual error microphone in the virtual error microphone set has a different coordinate position relative to the vehicle headrest;

[0022] Active noise reduction processing is performed on the automobile noise reduction system according to the automobile noise reduction parameters.

[0023] In one embodiment, determining the automobile noise reduction parameter according to the virtual error microphone includes:

[0024] Obtaining a transfer function of each virtual error microphone of the virtual error microphone set and a transfer function of a headrest error microphone of the vehicle headrest;

[0025] The vehicle noise reduction parameter is determined according to the transmission functions of the virtual error microphones and the transmission function of the headrest error microphone.

[0026] In one embodiment, after the headset system establishes a communication connection with the vehicle system, the method further includes:

[0027] Detect whether the user's seat is in the driving seat or non-driving seat;

[0028] If the user is in a non-driving position, the car system controls the opening and closing of the car noise reduction system corresponding to the seating position according to the type of the headphone system and the switch status information of the headphone noise reduction system.

[0029] A second aspect of an embodiment of the present application provides an active noise reduction device, including a headphone system and a car system, wherein the headphone system includes a headphone noise reduction system, and the car system includes a car noise reduction system.

[0030] The headphone system establishes a communication connection with the vehicle system to obtain driving status information and / or sensor signals of the vehicle system, and performs active noise reduction processing on the headphone noise reduction system based on the driving status information and / or the sensor signals, wherein the driving status information includes driving speed, driving road type, and window opening degree;

[0031] The automobile system is used to obtain an earphone error microphone signal or human ear positioning information of the earphone system, and perform active noise reduction processing on the automobile noise reduction system according to the earphone error microphone signal or the human ear positioning information.

[0032] A third aspect of an embodiment of the present application provides an active noise reduction device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method described in any one of the first aspects are implemented.

[0033] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any one of the first aspects are implemented.

[0034] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0035] 1. An embodiment of the present application provides a joint active noise reduction mode of a headphone noise reduction system and a car noise reduction system for driving scenarios. After the headphone system and the car system establish a communication connection, the headphone system can perform active noise reduction processing on the headphone noise reduction system by obtaining driving status information and / or sensor signals of the car system, optimize the noise reduction parameters of the headphone noise reduction system, and further improve the noise reduction effect; the car system can perform active noise reduction processing on the car noise reduction system by obtaining the headphone error microphone signal or human ear positioning information of the headphone system, optimize the noise reduction parameters of the car noise reduction system, and achieve better noise reduction effect.

[0036] 2. The headphone system can set the headphone noise reduction parameters corresponding to the optimal noise reduction effect of the headphone noise reduction system based on the vehicle's driving speed, road type and window opening degree, further improving the noise reduction effect of the original noise reduction system of semi-in-ear headphones or open-back headphones in driving scenarios.

[0037] 3. The headphone system can select one or more sensor signals with the highest coherence with the headphone error microphone signal as the feedforward input signal of the headphone noise reduction system, thereby suppressing the noise of the car engine and / or car suspension system and improving the noise reduction depth in the car's specific frequency band.

[0038] 4. The vehicle system can select the virtual error microphone closest to the human ear from the virtual error microphone set based on the actual human ear positioning information, indirectly improving the noise reduction effect at the actual human ear. This ensures a nearly consistent active noise reduction experience for users in different seating positions and different head and ear positions, and effectively solves the problem of reduced noise reduction effect when the same user has different riding postures and different ear positions.

[0039] 5. When the car noise reduction system does not have stability issues such as howling, the car system can directly use the headphone error microphone for adaptive active noise reduction, without the need for virtual error microphones and headrest error microphones, directly improving the noise reduction effect at the actual human ear.

[0040] 6. The vehicle system can control the active noise reduction system in the corresponding area based on the headphone system type and headphone noise reduction system status of the non-driver's user. If the non-driver's user uses in-ear headphones or closed-back headphones with the headphone noise reduction system turned on, the vehicle system will disable the active noise reduction system in the area where the user is located. By reducing the target noise reduction area of ​​the vehicle noise reduction system, the noise reduction effect caused by interference between active noise reduction zones in different areas is reduced, while also increasing the noise reduction bandwidth of the target noise reduction area. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0042] Figure 1 This is a schematic diagram of an implementation flow of an active noise reduction method provided in an embodiment of the present application;

[0043] Figure 2 Schematic diagram of an embodiment of the present application providing active noise reduction for a headphone noise reduction system using a car sensor signal;

[0044] Figure 3 This is a schematic diagram of a structure for actively reducing noise in a car noise reduction system using an earphone error microphone according to an embodiment of the present application;

[0045] Figure 4 This is a schematic diagram of a structure for performing active noise reduction on a car noise reduction system using a virtual error microphone set according to an embodiment of the present application;

[0046] Figure 5 2 is a schematic diagram of an offline debugging phase of performing active noise reduction on a vehicle noise reduction system using a virtual error microphone set according to an embodiment of the present application;

[0047] Figure 6 is a schematic diagram of an actual operation phase of performing active noise reduction on an automobile noise reduction system using a virtual error microphone set provided by an embodiment of the present application;

[0048] Figure 7 Schematic diagram of an active noise reduction device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] In the following description, specific details such as specific system structures and techniques are provided for purposes of illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid obscuring the description of the present application with unnecessary detail.

[0050] In order to illustrate the technical solution described in this application, specific embodiments are provided below.

[0051] Since in-ear headphones or closed-back headphones with good active noise reduction effects have too strong an isolation effect on mid- and high-frequency sounds, they will filter out effective sound information or danger warning information. Therefore, car drivers cannot wear such headphones. Car drivers can choose to wear ordinary semi-in-ear headphones or open-back headphones. However, if the current semi-in-ear headphones or open-back headphones are not optimized for driving scenarios, the active noise reduction effect is not obvious. In addition, the car noise reduction system needs to be optimized in driving scenarios. Car active noise reduction is complex and there are many spatial sound field modes. The noise reduction effect is very sensitive to spatial position. Currently, due to the limitations of hardware position design, the actual noise reduction effect is not ideal. The noise reduction experience varies greatly due to different seating positions and ear positions.

[0052] Based on the existing problems, the embodiments of the present application provide an active noise reduction method, apparatus, device, and computer-readable storage medium, and propose a combined active noise reduction mode for a headphone noise reduction system and a car noise reduction system in driving scenarios, which can solve the problem of poor noise reduction effects between the headphone noise reduction system and the car noise reduction system in driving scenarios. After the headphone system and the car system are connected in communication, the headphone system can perform active noise reduction processing on the headphone noise reduction system by obtaining driving status information and / or sensor signals from the car system, optimize the noise reduction parameters of the headphone noise reduction system, and further improve the noise reduction effect; the car system can perform active noise reduction processing on the car noise reduction system by obtaining headphone error microphone signals or human ear positioning information from the headphone system, optimize the noise reduction parameters of the car noise reduction system, and achieve better noise reduction effects.

[0053] like Figure 1 As shown, the embodiment of the present application proposes an active noise reduction method, which mainly includes the following steps:

[0054] S101. A headphone system establishes a communication connection with a car system, wherein the headphone system includes a headphone noise reduction system, and the car system includes a car noise reduction system.

[0055] In the embodiments of this application, the headphone system is generally referred to as headphones, and its types generally include in-ear headphones, closed-ear headphones, semi-in-ear headphones, and open-back headphones. The headphone noise reduction system is the part of the headphone system that handles the noise reduction function. Because in-ear headphones and closed-ear headphones have better active noise reduction effects, and car drivers generally cannot wear in-ear headphones and closed-ear headphones, the embodiments of this application mainly perform active noise reduction for semi-in-ear headphones and open-back headphones, which have poor active noise reduction effects and are suitable for driving scenarios.

[0056] An automotive system is typically referred to as an automobile. An automotive noise reduction system is the part of the system that handles the noise reduction function. Currently, active noise reduction is performed using an error microphone in an automotive noise reduction system. However, since the error microphone is placed near the headrest, a considerable distance from the actual human ear, the actual noise reduction effect is poor. The embodiments of this application primarily utilize an error microphone within a headset or a virtual error microphone within the vehicle that is closest to the actual human ear position to enhance the noise reduction effect at the actual ear position, adaptively optimizing the noise reduction experience for different user seating positions and ear positions.

[0057] An embodiment of the present application proposes a joint active noise reduction mode of a headphone noise reduction system and a car noise reduction system. The headphone system establishes a communication connection with the car system, and the headphone system can obtain relevant data information of the car system to optimize the noise reduction performance of the headphone noise reduction system. The car system can obtain relevant data information of the headphone system to optimize the noise reduction performance of the car noise reduction system, thereby improving the noise reduction effect of the headphone system and the car system in driving scenarios.

[0058] S102. The headphone system obtains driving status information and / or sensor signals of the automobile system, and performs active noise reduction processing on the headphone noise reduction system according to the driving status information and / or the sensor signals, where the driving status information includes at least one of driving speed, driving road type, and window opening degree.

[0059] The headphone system establishes a communication connection with the vehicle system, which can be a wireless communication connection such as WiFi, 2.4G, Bluetooth, or UWB. The headphone system uses two combined active noise reduction modes to perform active noise reduction on the headphone noise reduction system. The headphone system can select both or one of the combined active noise reduction modes simultaneously. One combined active noise reduction mode is to obtain driving status information from the vehicle system and perform active noise reduction on the headphone noise reduction system. Specifically, the vehicle system sends driving status information such as the vehicle's current driving speed, the road surface type identified by the vehicle's camera, and the degree of window opening to the headphone system. The headphone system retrieves pre-set corresponding optimal headphone noise reduction parameters based on the driving status information and performs active noise reduction on the headphone noise reduction system. Another combined active noise reduction mode is to obtain sensor signals from the vehicle system and perform active noise reduction on the headphone noise reduction system. Specifically, the vehicle system sends the vehicle's current sensor signal stream to the headphone system. The headphone system selects one or more sensor signal streams with the highest coherence with the headphone error microphone signal as the feedforward input signal of the headphone noise reduction system, and performs adaptive active noise reduction on the headphone noise reduction system.

[0060] In one embodiment, performing active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signal includes:

[0061] When the window opening degree is less than or equal to a preset opening degree, determining the headphone noise reduction parameter according to the driving speed and the driving road type;

[0062] When the window opening degree is greater than a preset opening degree, determining the headphone noise reduction parameter according to the window opening degree;

[0063] Active noise reduction processing is performed on the headphone noise reduction system according to the headphone noise reduction parameters.

[0064] In an embodiment of the present application, the vehicle's driving status information primarily includes driving speed, road surface type, and window opening degree. Driving speed can be specifically divided into multiple speed ranges, for example, four speed ranges: low speed (0-30 km / h), medium-low speed (30-60 km / h), medium-high speed (60-90 km / h), and high speed (greater than 90 km / h). Road surface type can be specifically divided into multiple types, for example, three types: asphalt, cement concrete, and block. The window opening degree can be specifically divided into multiple degrees, for example, four ranges: 1-10% open, 10-20% open, 20-40% open, and 40-100% open. When the window opening degree is less than or equal to a preset opening degree, the window is considered fully closed. The preset window opening degree is set based on actual conditions, for example, less than or equal to 1% can be considered fully closed. Headphone noise reduction parameters can be determined based on driving speed and road surface type.

[0065] When the windows are fully closed, headphone noise reduction parameters are determined based on the vehicle's driving speed and road surface type. For example, speed ranges and road surface types corresponding to different driving speeds are combined into multiple road surface combinations. For example, four speed ranges and three road surface types can be combined into 12 road surface combinations, including (asphalt, medium-low speeds of 30-60 km / h), (cement concrete, high speeds greater than 90 km / h), (block-type, low speeds of 0-30 km / h), and so on. For each road surface combination, a large number of noise sample datasets are collected from the passenger seat in the vehicle using a standard microphone. Different headphone noise reduction parameters are input into a headphone feedback filter to objectively evaluate the optimal noise reduction effect. The optimal headphone noise reduction parameters for the headphone feedback filter corresponding to each road surface combination are stored. In actual driving scenarios, the headphone system determines the corresponding road surface combination based on the speed range and road surface type corresponding to the vehicle's current speed. The stored optimal headphone noise reduction parameters for the headphone feedback filter corresponding to the road surface combination are retrieved to perform active noise reduction processing on the headphone noise reduction system.

[0066] When the window opening degree is greater than a preset opening degree, headphone noise reduction parameters are determined based on the window opening degree. The window opening degree can refer to the opening degree of one or more windows, specifically the window closest to the user's seat, or the opening degree of two windows closer to the user's seat. For example, for the ranges corresponding to different window opening degrees, a large number of noise sample data sets are collected at the closest seat in the vehicle using a standard microphone. Different headphone noise reduction parameters are input into a headphone feedback filter to objectively evaluate the optimal noise reduction effect. The optimal headphone noise reduction parameters for the headphone feedback filter corresponding to each window opening degree range are stored. In actual driving scenarios, the headphone system obtains the corresponding window opening degree range based on the current window opening degree of the vehicle, retrieves the stored optimal headphone noise reduction parameters for the headphone feedback filter corresponding to each window opening degree range, and performs active noise reduction processing on the headphone noise reduction system.

[0067] The headphone system of the embodiment of the present application can set the headphone noise reduction parameters corresponding to the optimal noise reduction effect of the headphone noise reduction system based on driving status information such as the driving speed, driving road type and window opening degree of the automobile system, thereby further improving the noise reduction effect of the original noise reduction system of semi-in-ear headphones or open-ear headphones in driving scenarios.

[0068] In one embodiment, performing active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signal includes:

[0069] Acquiring a plurality of sensor signals at an engine and / or a vehicle suspension system of the vehicle system;

[0070] One or more sensor signals having the highest coherence with the headphone error microphone signal are selected as feedforward input signals of the headphone noise reduction system, and active noise reduction processing is performed on the headphone noise reduction system according to the feedforward input signals.

[0071] like Figure 2 As shown, in the embodiment of the present application, the sensor mainly refers to the automobile sensor installed in the automobile engine and / or automobile suspension system, and the real-time sensor signal stream such as the real-time speed value of the automobile engine and the value of the accelerometer in the automobile suspension system is sent to the headphone system. The headphone system can select one or more sensor signals with the highest coherence with the headphone error microphone as the feedforward input signal of the headphone noise reduction system and input them into the adaptive filter to perform adaptive active noise reduction on the headphone noise reduction system. It is worth noting that when the headphone system performs coherence analysis, the active noise reduction needs to be turned off to obtain the coherence result between the in-ear noise and the automobile sensor signal when active noise reduction is not performed.

[0072] In one embodiment, selecting one or more of the sensor signals with the highest coherence with the headphone error microphone signal as the feedforward input signal of the headphone noise reduction system includes:

[0073] When selecting multiple sensor signals with the highest coherence with the headphone error microphone, establish a cross-correlation matrix of multiple combinations of the sensor signals, and calculate the condition number of the multiple cross-correlation matrices;

[0074] Select the combination of sensor signals with the lowest condition number of the cross-correlation matrix as the feedforward input signal of the headphone noise reduction system.

[0075] After selecting K (K>1) sensor signals according to coherence analysis, it is also possible to further select S (S<K) combinations of sensor signals with more independent orthogonality as the feedforward input signal for headphone adaptive active noise reduction. Specifically, first, establish a cross-correlation matrix R of K different combinations of sensor signals. For example, there are sensors numbered 1-k, and the cross-correlation matrix R can be expressed as [[R11, R12…R1k], [R21, R22…R2k], …, [Rk1, Rk2…Rkk]], where Rij represents the cross-correlation matrix between the i-th sensor and the j-th sensor. Then, calculate the condition number of the cross-correlation matrix respectively, and select the combination of sensor signals with the lowest condition number of the cross-correlation matrix as the feedforward input signal. Because a high condition number of the cross-correlation matrix means that the matrix is ill-conditioned, and the convergence speed of using such sensor signals for active noise reduction is slow or unable to converge, so it is necessary to select the combination of sensor signals with the lowest condition number of the cross-correlation matrix.

[0076] Because the computational complexity of this method is relatively high, when it is not suitable for real-time operation due to hardware reasons, it is also possible to calculate the condition numbers of the cross-correlation matrices of all sensor combinations during the offline debugging stage. After selecting K (K>1) sensor signals according to coherence analysis, compare the condition numbers of the cross-correlation matrices of S (S<K) combinations of different sensor combinations among them, and select the combination of S (S<K) sensor signal sources with the lowest condition number as the feedforward input signal of the headphone noise reduction system, and input it into the LMS adaptive feedforward filter to achieve the adaptive active noise reduction of the headphone noise reduction system.

[0077] The headphone system of the embodiment of the present application can select one or more sensor signals with the highest coherence with the headphone error microphone signal, and can further select a more independent and orthogonal combination of sensor signals as the feedforward input signal for adaptive noise reduction, realizing the suppression of automobile engine or automobile suspension noise and improving the noise reduction depth in special frequency bands of the automobile.

[0078] S103: The automobile system obtains an earphone error microphone signal or human ear positioning information of the earphone system, and performs active noise reduction processing on the automobile noise reduction system according to the earphone error microphone signal or the human ear positioning information.

[0079] In one embodiment, performing active noise reduction processing on the automobile noise reduction system according to the headphone error microphone signal or the human ear positioning information includes:

[0080] performing active noise reduction processing on the automobile noise reduction system according to the earphone error microphone signal, and detecting a stable state of the automobile noise reduction system;

[0081] When it is detected that the vehicle noise reduction system is in an unstable state, selecting a virtual error microphone closest to the human ear positioning information from a virtual error microphone set, and determining a vehicle noise reduction parameter based on the virtual error microphone, wherein each virtual error microphone in the virtual error microphone set has a different coordinate position relative to the vehicle headrest;

[0082] Active noise reduction processing is performed on the automobile noise reduction system according to the automobile noise reduction parameters.

[0083] In the embodiment of the present application, the error microphone is a component of the active noise reduction system, such as Figure 4 As shown, the headrest error microphone is the error microphone of a conventional car noise reduction system, and the headphone error microphone is the error microphone of a conventional headphone noise reduction system. After the car system and the headphone system establish a communication connection, the car system mainly uses two joint active noise reduction modes to actively reduce the noise of the car noise reduction system. One of the joint active noise reduction modes is: Figure 3 As shown, the headphone system sends the headphone error microphone signal to the car system. The car system directly uses the headphone error microphone signal and the car speaker to perform adaptive active noise reduction on the car noise reduction system, which can directly improve the active noise reduction effect at the human ear. Another joint active noise reduction mode is: Figure 4 As shown in the figure, when the car noise reduction system is in an unstable state, a set of virtual error microphones with different coordinate positions relative to the headrest are set in the car, and the actual ear positioning information of the current earphones is obtained. The best virtual error microphone and corresponding parameters are selected from the virtual error microphone set based on the ear positioning information to perform adaptive active noise reduction on the car noise reduction system.

[0084] It is worth noting that when the active noise reduction functions of the headphone noise reduction system and the car noise reduction system are not turned on, when the headphone error microphone recording analysis identifies that the noise spectrum belongs to strong low frequency, the system starts by default and prioritizes the use of the headphone error microphone signal to actively reduce the noise of the car noise reduction system in a combined active noise reduction mode. Because this mode has higher requirements for delay control and has certain requirements for the headphone wearing position and the passenger seating position, there is a risk of howling. When stability issues such as howling are detected in real time, the system automatically switches to a combined active noise reduction mode that uses human ear positioning information to actively reduce the noise of the car noise reduction system. By switching between the two combined active noise reduction modes, the noise reduction performance and stability of the car noise reduction system can be guaranteed.

[0085] In one embodiment, determining the automobile noise reduction parameter according to the virtual error microphone includes:

[0086] Obtaining a transfer function of each virtual error microphone of the virtual error microphone set and a transfer function of a headrest error microphone of the vehicle headrest;

[0087] The vehicle noise reduction parameter is determined according to the transmission functions of the virtual error microphones and the transmission function of the headrest error microphone.

[0088] When the car's noise reduction system is detected to be unstable, such as whistling, the car system switches to another combined active noise reduction mode. Conventional in-vehicle LMS adaptive feedback active noise reduction uses an error microphone on the headrest to optimize the active noise reduction effect of the car's speakers playing out-of-phase sounds. However, the headrest error microphone is significantly away from the actual human ear position, so the embodiment of the present application compensates for this by providing a virtual error microphone. Specifically, a set of virtual error microphones with multiple different coordinate positions is provided relative to the car's headrest, and the virtual error microphone closest to the actual human ear position is selected from the set as the feedback microphone.

[0089] During the offline debugging phase, an onboard active noise reduction adaptive filter 2 is added to the original onboard active noise reduction adaptive filter 1. The filter coefficient D of the added LMS adaptive filter 2 is used to remember the headrest microphone signal state when the error microphone at the real human ear position has the best active noise reduction effect. Then, during the actual operation phase, the error microphone at the real human ear position and the adaptive algorithm part of the onboard active noise reduction adaptive filter 2 are removed, and the filter coefficient D is directly called to simulate the influence of the microphone at the real human ear position on the system. Specifically, Figure 5 As shown, in the offline debugging stage of the embodiment of the present application, the vehicle-mounted active noise reduction adaptive filter 1 is based on the transfer functions SV1…SV corresponding to the virtual error microphones 1…i…n at multiple different coordinate positions of the car horn. i …SVn (In which, the virtual error microphone i is a real error microphone that exists and is connected to the car noise reduction system to simulate the real human ear position during the offline debugging stage), as well as the transfer function ST from the car speaker to the headrest error microphone. The virtual error microphones 1...i...n are iterated separately with the best noise reduction effect as the iteration target. When the iteration of the on-board active noise reduction adaptive filter 1 is completed, the added on-board active noise reduction adaptive filter 2 stores the iteration coefficients D1...Di...Dn when the active noise reduction effect of each virtual error microphone is the best, and generates the filter coefficient D of the adaptive filter 2 accordingly. The filter coefficient D corresponding to each virtual microphone can be a filter coefficient of any specified order, such as 128th order. The filter coefficient D remembers the corresponding headrest error microphone signal state when the active noise reduction effect of the error microphone at the real human ear position is the best, so it also reflects the transfer function SV1...SV of the current virtual microphone position. i …SV n The impact of the difference in transfer function ST of the headrest error microphone position on the overall active noise cancellation.

[0090] In the actual operation stage of the embodiment of the present application, the human ear positioning information can be obtained through various means such as ultrasonic ranging. For example, an ultrasonic pulse can be emitted by the headphone speaker, and the pulse can be received by microphones set at different positions on the car. For example, four microphones are set at different positions, and the ultrasonic distances L1, L2, L3, and L4 of the four microphones are calculated. Finally, with each microphone as the center of the sphere, spheres with radii of L1, L2, L3, and L4 are made respectively. The intersection of the four spheres is the current position of the human ear. The headphone speaker position calculated above can be directly used as the current position of the human ear wearing the headphones, or it can be further deduced from the position of the ear canal entrance based on the structural characteristics and size of the semi-open or open headphones currently worn, as the current position of the human ear wearing the headphones.

[0091] like Figure 6As shown in the figure, after obtaining ear location information, a virtual error microphone i closest to the current ear position is selected from the virtual error microphone set. Based on the iteration coefficients D1…Di…Dn corresponding to each virtual error microphone 1…i…n stored during the offline debugging phase, the filter coefficients D corresponding to the iteration coefficients Di stored in the vehicle-mounted active noise reduction adaptive filter 2 are called. The adaptive algorithm portion of the vehicle-mounted active noise reduction adaptive filter 2 during the offline debugging phase is eliminated, and filtering is performed directly using the stored filter coefficients D. The output residual is provided as feedback information to the vehicle-mounted active noise reduction adaptive filter 1. In this way, the vehicle-mounted active noise reduction adaptive filter 1 does not traditionally use the headrest error microphone as feedback signal, but instead uses a virtual error microphone closest to the ear of the wearer of headphones as feedback signal. This allows for more accurate optimization of the actual active noise reduction experience for different users in the car, overcoming the drawbacks of significant differences in active noise reduction due to seat adjustments, as well as different upper body heights, forward tilt angles, and relative head positions. The above process can also continuously update the ear position, improving the in-vehicle active noise reduction effect caused by changes in the sitting posture of the same person.

[0092] In one embodiment, after the earphone system establishes a communication connection with the vehicle system, the method further includes:

[0093] Determine whether the user's seat is in the driving seat or non-driving seat;

[0094] If the user is in a non-driving position, the car system controls the opening and closing of the car noise reduction system corresponding to the seating position according to the type of the headphone system and the switch status information of the headphone noise reduction system.

[0095] The embodiment of the present application can set different car noise reduction systems for areas corresponding to different seating positions. When there are multiple users in the car, it detects whether the user's seating position is the driving seat or the non-driving seat. When the user is in the driving seat, the combined active noise reduction mode described in the embodiment of the present application is used for the driving seat; when the user is in the non-driving seat, the car noise reduction system corresponding to the seating position is turned on or off according to the type of the user's headphone system and the switch status information of the headphone noise reduction system. For example, when the user is in the non-driving seat, the headphone system type is semi-in-ear headphones or open-ear headphones, and the headphone noise reduction system is turned on, the combined active noise reduction mode described in the embodiment of the present application can be used to turn on the car noise reduction system corresponding to the seating position; when the user's headphone system type is in-ear headphones or closed-ear headphones, and the headphone noise reduction system is turned on, the car noise reduction system corresponding to the user's seating position is turned off. The embodiment of the present application reduces the target noise reduction space range of the car noise reduction system, reduces the interference of active noise reduction in different partitions, and thus reduces the noise reduction effect, while increasing the noise reduction bandwidth of the target noise reduction space.

[0096] A second aspect of an embodiment of the present application provides an active noise reduction device, including a headphone system and a car system, wherein the headphone system includes a headphone noise reduction system, and the car system includes a car noise reduction system.

[0097] The headphone system establishes a communication connection with the vehicle system to obtain driving status information and / or sensor signals of the vehicle system, and performs active noise reduction processing on the headphone noise reduction system based on the driving status information and / or the sensor signals, wherein the driving status information includes driving speed, driving road type, and window opening degree;

[0098] The automobile system is used to obtain an earphone error microphone signal or human ear positioning information of the earphone system, and perform active noise reduction processing on the automobile noise reduction system according to the earphone error microphone signal or the human ear positioning information.

[0099] In one embodiment, performing active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signal includes:

[0100] When the window opening degree is less than or equal to a preset opening degree, determining the headphone noise reduction parameter according to the driving speed and the driving road type;

[0101] When the window opening degree is greater than a preset opening degree, determining the headphone noise reduction parameter according to the window opening degree;

[0102] Active noise reduction processing is performed on the headphone noise reduction system according to the headphone noise reduction parameters.

[0103] In one embodiment, performing active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signal includes:

[0104] Acquiring a plurality of sensor signals at an engine or a suspension of the vehicle system;

[0105] One or more sensor signals having the highest coherence with the headphone error microphone signal are selected as feedforward input signals of the headphone noise reduction system, and active noise reduction processing is performed on the headphone noise reduction system according to the feedforward input signals.

[0106] In one embodiment, selecting one or more sensor signals having the highest coherence with the headphone error microphone signal as feedforward input signals of the headphone noise reduction system includes:

[0107] When selecting the plurality of sensor signals having the highest coherence with the headphone error microphone, establishing a cross-correlation matrix of the plurality of sensor signal combinations, and calculating the condition numbers of the plurality of cross-correlation matrices;

[0108] The sensor signal combination with the lowest condition number of the cross-correlation matrix is ​​selected as the feedforward input signal of the headphone noise reduction system.

[0109] In one embodiment, performing active noise reduction processing on the automobile noise reduction system according to the headphone error microphone signal or the human ear positioning information includes:

[0110] determining a car noise reduction parameter according to the headphone error microphone signal to perform active noise reduction processing on the car noise reduction system, and detecting a stable state of the car noise reduction system;

[0111] When it is detected that the vehicle noise reduction system is in an unstable state, selecting a virtual error microphone closest to the human ear positioning information from a virtual error microphone set, and determining a vehicle noise reduction parameter based on the virtual error microphone, wherein each virtual error microphone in the virtual error microphone set has a different coordinate position relative to the vehicle headrest;

[0112] Active noise reduction processing is performed on the automobile noise reduction system according to the automobile noise reduction parameters.

[0113] In one embodiment, determining the automobile noise reduction parameter according to the virtual error microphone includes:

[0114] Obtaining a transfer function of each virtual error microphone of the virtual error microphone set and a transfer function of a headrest error microphone of the vehicle headrest;

[0115] The vehicle noise reduction parameter is determined according to the transmission functions of the virtual error microphones and the transmission function of the headrest error microphone.

[0116] In one embodiment, after the earphone system establishes a communication connection with the vehicle system, the method further includes:

[0117] Determine whether the user's seat is in the driving seat or non-driving seat;

[0118] If the user is in a non-driving position, the car system controls the opening and closing of the car noise reduction system corresponding to the seating position according to the type of the headphone system and the switch status information of the headphone noise reduction system.

[0119] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0120] like Figure 7 As shown, a third aspect of an embodiment of the present application provides an active noise reduction device, including a memory 71, a processor 72, and a computer program 72 stored in the memory 71 and executable on the processor 70, wherein the processor 71 implements the steps of the method described in any one of the first aspects when executing the computer program 72.

[0121] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any one of the first aspects are implemented.

[0122] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0123] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0124] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0125] In the embodiments provided in this application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0126] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0127] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0128] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the process in the above-mentioned embodiment method, and can also be completed by hardware related to computer program instructions. The computer program can be stored in a computer-readable storage medium, and when the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0129] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. An active noise reduction method, characterized in that: include: The headphone system establishes a communication connection with the vehicle system, wherein the headphone system includes a headphone noise reduction system and the vehicle system includes a vehicle noise reduction system; The headphone system acquires driving state information and / or sensor signals of the automobile system, and performs active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signals, wherein the driving state information includes at least one of driving speed, driving road type, and window opening degree; The automobile system obtains an earphone error microphone signal or human ear positioning information of the earphone system, and performs active noise reduction processing on the automobile noise reduction system according to the earphone error microphone signal or the human ear positioning information.

2. The active noise reduction method according to claim 1, wherein: The performing active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signal includes: When the window opening degree is less than or equal to a preset opening degree, determining the headphone noise reduction parameter according to the driving speed and the driving road type; When the window opening degree is greater than a preset opening degree, determining the headphone noise reduction parameter according to the window opening degree; Active noise reduction processing is performed on the headphone noise reduction system according to the headphone noise reduction parameters.

3. The active noise reduction method according to claim 1, wherein: The performing active noise reduction processing on the headphone noise reduction system according to the driving state information and / or the sensor signal includes: Acquiring a plurality of sensor signals at an engine and / or a vehicle suspension system of the vehicle system; One or more sensor signals having the highest coherence with the headphone error microphone signal are selected as feedforward input signals of the headphone noise reduction system, and active noise reduction processing is performed on the headphone noise reduction system according to the feedforward input signals.

4. The active noise reduction method according to claim 3, characterized in that: The selecting one or more sensor signals having the highest coherence with the headphone error microphone signal as the feedforward input signal of the headphone noise reduction system includes: When selecting the plurality of sensor signals having the highest coherence with the headphone error microphone, establishing a cross-correlation matrix of the plurality of sensor signal combinations, and calculating the condition numbers of the plurality of cross-correlation matrices; The sensor signal combination with the lowest condition number of the cross-correlation matrix is ​​selected as the feedforward input signal of the headphone noise reduction system.

5. The active noise reduction method according to claim 1, wherein: Active noise reduction processing is performed on the automobile noise reduction system according to the earphone error microphone signal or the human ear positioning information, including: performing active noise reduction processing on the automobile noise reduction system according to the earphone error microphone signal, and detecting a stable state of the automobile noise reduction system; When it is detected that the vehicle noise reduction system is in an unstable state, selecting a virtual error microphone closest to the human ear positioning information from a virtual error microphone set, and determining a vehicle noise reduction parameter based on the virtual error microphone, wherein each virtual error microphone in the virtual error microphone set has a different coordinate position relative to the vehicle headrest; Active noise reduction processing is performed on the automobile noise reduction system according to the automobile noise reduction parameters.

6. The active noise reduction method according to claim 5, characterized in that: The determining of the automobile noise reduction parameter according to the virtual error microphone includes: Obtaining a transfer function of each virtual error microphone of the virtual error microphone set and a transfer function of a headrest error microphone of the vehicle headrest; The vehicle noise reduction parameter is determined according to the transmission functions of the virtual error microphones and the transmission function of the headrest error microphone.

7. The active noise reduction method according to claim 1, characterized in that: After the earphone system establishes a communication connection with the vehicle system, the method further includes: Detect whether the user's seat is in the driving seat or non-driving seat; If the user is in a non-driving position, the car system controls the opening and closing of the car noise reduction system corresponding to the seating position according to the type of the headphone system and the switch status information of the headphone noise reduction system.

8. An active noise reduction device, characterized in that: The invention comprises an earphone system and a car system, wherein the earphone system comprises an earphone noise reduction system, and the car system comprises a car noise reduction system. The headphone system establishes a communication connection with the vehicle system to obtain driving status information and / or sensor signals of the vehicle system, and performs active noise reduction processing on the headphone noise reduction system based on the driving status information and / or the sensor signals, wherein the driving status information includes driving speed, driving road type, and window opening degree; The automobile system is used to obtain an earphone error microphone signal or human ear positioning information of the earphone system, and perform active noise reduction processing on the automobile noise reduction system according to the earphone error microphone signal or the human ear positioning information.

9. An active noise reduction device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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