An automotive in-vehicle acoustic zoned active noise reduction system

Abstract

The application discloses a kind of automobile interior acoustic partition type active noise reduction systems, it is related to loudspeaker field, comprising: configuration module is used to dynamically adjust independent acoustic partition boundary according to in-vehicle seating distribution, occupancy state, and is arranged with the pickup unit and directional sound unit with traceability perception function in each partition;Acquisition module is used to acquire each partition noise signal by pickup unit, and synchronously capture noise source characteristic parameter;The application is dynamically adapted to in-vehicle seating distribution and occupancy state, accurately distinguishes the different characteristics of wind noise, road noise, mechanical noise, effectively separates the noise coupling components of each area, strengthens the noise characteristics of exclusive, generates the noise reduction signal that fits noise source and partition characteristics.

Description

Technical Field

[0001] This invention relates to the field of loudspeaker technology, specifically to an in-vehicle acoustic zone active noise cancellation system. Background Technology

[0002] Active noise cancellation uses a microphone to collect ambient noise in real time. After rapid processing by a chip, it generates an anti-phase sound wave with the opposite phase and matching amplitude to the noise. The two sound waves cancel each other out after being superimposed, which can effectively reduce low-frequency noise in the environment. This technology is also used in active noise cancellation in cars to improve the driving experience and quality of car users.

[0003] The invention patent application with application number 202410534088.9 discloses a control system, method and vehicle for an in-vehicle active noise cancellation system. The application aims to solve the problems that "existing noise cancellation technology is not timely in its identification and response is lagging. Due to the sudden change of abnormal vibration, which occurs instantaneously, the system cannot identify and respond in time, resulting in a very low identification rate and inaccurate identification. Because road conditions are not fixed and unpredictable, the sudden vibration waveform has no obvious characteristics, so the system has difficulty in accurately distinguishing abnormal vibration signals, resulting in inaccurate identification".

[0004] However, in the context of active noise cancellation technology in vehicles, most existing technologies treat the in-vehicle environment as a whole, thus ignoring the actual noise needs of users in different seats, and therefore rarely designing in-vehicle zone noise cancellation.

[0005] To address this, we propose an in-vehicle acoustic zone-based active noise cancellation system. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the existing technology, the present invention provides an in-vehicle acoustic zone-based active noise cancellation system, which can effectively solve the problems of the existing technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions;

[0008] This invention discloses an in-vehicle acoustic zone-based active noise cancellation system, comprising:

[0009] The system comprises the following modules: a configuration module for dynamically adjusting the boundaries of independent acoustic zones based on the seating distribution and occupancy status within the vehicle, and deploying sound pickup units and directional sound-emitting units with source-sensing capabilities in each zone; an acquisition module for acquiring noise signals from each zone through the sound pickup units, and simultaneously capturing noise source characteristic parameters; an enhancement module for receiving noise signals and source parameters, separating the noise coupling components of different zones, and enhancing the unique noise characteristics of each zone; a generation module for generating noise-reducing signals that match the noise source and zone characteristics based on the enhanced unique noise characteristics of each zone and the noise source characteristic parameters; a conversion module for adjusting parameters according to the acoustic characteristics of each zone, converting the noise-reducing signal into a noise-reducing electrical signal, and further converting it into an acoustic signal adapted to that zone; and an output module for projecting the acoustic signal to the target zone through the directional sound-emitting units.

[0010] The configuration module is interconnected with a data acquisition module, an enhancement module, and a generation module via a local area network. The data acquisition module, the enhancement module, and the generation module are interconnected via a local area network. The generation module is interconnected with a conversion module via a local area network. The conversion module is interconnected with an output module via a local area network.

[0011] The noise sources include wind noise, road noise, and mechanical noise, and the acoustic characteristics of each zone include space size and material damping.

[0012] Furthermore, when the configuration module dynamically adjusts the boundaries of independent acoustic zones, it constructs a dynamic calculation model for the zone boundaries based on the three-dimensional coordinate information of the seats, the occupancy status of the seats, and the acoustic propagation attenuation characteristics of the in-vehicle space.

[0013] The seat occupancy status is determined based on the seat's built-in pressure sensor, including whether it is occupied or vacant. The spatial coordinates of the partition boundary satisfy the formula:

[0014] ;

[0015] In the formula: is the three-dimensional coordinate vector of any point on the partition boundary; This represents the total number of seats in the vehicle. This is the occupancy status indicator for the i-th seat, where 1 indicates occupancy and 0 indicates vacancy. Let be the three-dimensional coordinate vector of the i-th seat; The acoustic attenuation coefficient of the air medium inside the vehicle; Let (x, y, z) be the straight-line distance from the coordinate point (x, y, z) to the i-th seat. This is the partition boundary expansion coefficient; This is the reference coordinate vector for the interior space of the vehicle.

[0016] Furthermore, the noise source characteristic parameters captured by the acquisition module include:

[0017] Wind noise corresponds to turbulence intensity and airflow velocity gradient;

[0018] The vibration acceleration amplitude and vibration frequency spectral density corresponding to road noise;

[0019] The amplitude of harmonic components and the fundamental frequency offset corresponding to mechanical noise;

[0020] When the acquisition module synchronously acquires noise signals and feature parameters through the pickup unit, it uses timestamp alignment logic to ensure that the deviation between the sampling time of the noise signal and the acquisition time of the feature parameters does not exceed a preset time threshold, and the sampling frequency is dynamically adjusted according to the highest frequency component of the noise signal so that the sampling frequency is not lower than a preset multiple of the highest frequency of the noise.

[0021] Furthermore, during the operation phase of the enhancement module, when separating the noise coupling components of different zones, the coupling components are separated and unique features are enhanced by constructing the acoustic modal functions of each zone. The process includes:

[0022] Construct the acoustic modal functions for each partition , where k is the modal order and t is time;

[0023] Based on mode function analysis of mixed noise signals The noise components of each partition are obtained by decomposition. That is, satisfying:

[0024] ;

[0025] In the formula: The total number of acoustic modes in the partition; The modal weighting coefficient is determined by the proportion of the noise amplitude contribution of each partition.

[0026] For each partition of the decomposed noise components Perform spectral enhancement processing:

[0027] First, the characteristic frequency range of the noise in the partition is defined by the noise feature extraction results. Then, the bandpass filtering combined with amplitude modulation is used to process the signal in the characteristic frequency range. The amplitude amplification gain is negatively correlated with the deviation of the characteristic peak value with frequency, and the amplitude attenuation coefficient is positively correlated with the distance of the boundary of the characteristic frequency range with frequency to enhance the unique characteristics of the noise.

[0028] Furthermore, when generating the denoised signal, the generation module constructs a multi-dimensional matching model based on the enhanced unique features of the noise and the noise source feature parameters to generate the denoised signal. :

[0029] ;

[0030] In the formula: This is the amplitude correction coefficient for the noise-reduced signal; This is a noise feature and source matching function; The acoustic impedance of the coordinate point (x, y, z) within the target partition; The acoustic energy loss coefficient is the coordinate point (x, y, z) within the target partition. The phase of the noise-reduced signal; j is the complex unit;

[0031] in, The value range is a preset interval [0.8, 1.2], and its value is positively correlated with the peak amplitude of the original noise in the target partition; ∈[0.3,0.9], its value is positively correlated with the straight-line distance from the coordinate point to the directional sound-emitting unit and the sound absorption performance of the surrounding materials.

[0032] Furthermore, the noise features are matched with the source function. The input is enhanced noise with unique characteristics. With noise source characteristic parameters The output is the matching metric:

[0033] ;

[0034] In the formula: is the weighting coefficient for the q-th type of noise source, where q represents the noise source category identifier, corresponding to wind noise, road noise, and mechanical noise; The characteristic correlation coefficient of the q-th type of noise; Let be the dimension of the feature parameters of the q-th type of noise source; The eigenvalue corresponding to the p-th feature parameter of the q-th type of noise in the enhanced noise unique features; This is the reference value for the p-th characteristic parameter of the q-th noise class; This refers to the actual measured value of the p-th characteristic parameter of the q-th type of noise captured by the acquisition module; This is the standard reference value for the p-th characteristic parameter of the q-th noise; is the source identification factor for the q-th type of noise.

[0035] Furthermore, the parameters adjusted by the conversion module include: the amplitude gain, frequency response characteristics, and phase offset of the noise-reduced electrical signal. ;

[0036] During parameter adjustment, the adjustment range of amplitude gain is determined based on the spatial size in the acoustic characteristics of the zones, and the correction curve of frequency response characteristics is determined based on material damping.

[0037] ;

[0038] In the formula: This is the adjusted amplitude gain; The reference amplitude gain; The spatial volume of the target partition; The preset baseline partition volume; This is the damping effect coefficient; The material damping coefficient for the target partition; This is the adjusted frequency response function; This is the reference frequency response function; This is the frequency attenuation coefficient; The frequency of the noise signal.

[0039] Furthermore, when the output module projects the noise reduction signal through the directional sound unit, it uses adaptive beamforming control to make the main lobe of the noise reduction signal beam point to the center region of the target partition, and the side lobe suppression ratio is not lower than a preset threshold.

[0040] The output module detects acoustic signal feedback in the target zone in real time, and adjusts the emission angle and sound power of the directional sound unit according to the feedback signal, so that the sound pressure amplitude of the noise reduction signal is evenly distributed in the target zone, and the sound pressure amplitude in the non-target zone is lower than the preset sound pressure threshold.

[0041] Compared with the known prior art, the technical solution provided by this invention has the following beneficial effects:

[0042] This invention dynamically adapts to the distribution and occupancy of seats within the vehicle, accurately distinguishing the different characteristics of wind noise, road noise, and mechanical noise. It effectively separates the noise coupling components of each area, enhances specific noise characteristics, and generates noise reduction signals that fit the noise source and zone characteristics. Simultaneously, it adapts to acoustic environments of different space sizes and material damping, projecting the signal directionally to the target area with uniform sound pressure distribution. This significantly reduces the impact on non-target areas. The phase and amplitude of the noise reduction signal are precisely matched with the noise, and it is minimally affected by factors such as temperature, humidity, and spatial morphology, exhibiting strong stability. It can specifically improve the quietness of each area, meeting the personalized noise reduction needs of different passengers and enhancing the driving and riding experience. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0044] Figure 1This is a schematic diagram of a vehicle interior acoustic zone-based active noise cancellation system. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0046] The present invention will be further described below with reference to embodiments.

[0047] Example:

[0048] This embodiment describes an in-vehicle acoustic zone-based active noise cancellation system, such as... Figure 1 As shown, it includes:

[0049] The configuration module is used to dynamically adjust the boundaries of independent acoustic zones according to the distribution and occupancy status of seats in the vehicle, and to deploy pickup units and directional sound units with source sensing function in each zone;

[0050] When the configuration module dynamically adjusts the boundaries of independent acoustic zones, it constructs a dynamic calculation model for the zone boundaries based on the three-dimensional coordinate information of the seats, the occupancy status of the seats, and the acoustic propagation attenuation characteristics of the in-vehicle space.

[0051] The seat occupancy status is determined based on the seat's built-in pressure sensor, including whether it is occupied or vacant. The spatial coordinates of the partition boundary satisfy the formula:

[0052] ;

[0053] In the formula: is the three-dimensional coordinate vector of any point on the partition boundary; This represents the total number of seats in the vehicle. This is the occupancy status indicator for the i-th seat, where 1 indicates occupancy and 0 indicates vacancy. Let be the three-dimensional coordinate vector of the i-th seat; The acoustic attenuation coefficient of the air medium inside the vehicle; Let (x, y, z) be the straight-line distance from the coordinate point (x, y, z) to the i-th seat. This is the partition boundary expansion coefficient; This is the reference coordinate vector for the interior space of the vehicle;

[0054] The above formula combines the actual distribution and occupancy status of seats in the vehicle, takes seat occupancy marks and three-dimensional coordinates as the core calculation basis, and incorporates the acoustic attenuation characteristics of the air medium in the vehicle. It reflects the attenuation law of acoustic propagation through the distance factor, and introduces an expansion coefficient that can adapt to the irregularity of the target partition space and the seat occupancy density. Combined with the spatial reference coordinates preset at the vehicle factory, it realizes the dynamic calculation of the three-dimensional coordinates of the partition boundary, so that the boundary division can not only respond to the real-time changes in seat use, but also conform to the propagation characteristics of the acoustic environment in the vehicle.

[0055] in, The preset value range is 0.01~0.15dB / m. The higher the humidity and the lower the temperature inside the vehicle, the better. The higher the value, the lower the humidity and the higher the temperature inside the car. The smaller the value; The preset value range is [0.8, 1.2]. The higher the irregularity of the target partition space and the greater the seat occupancy density, The larger the value, the more regular the target partition space and the lower the seat occupancy density. The smaller the value; The space parameters are preset from the vehicle's factory settings;

[0056] The acquisition module is used to acquire noise signals from each zone through the pickup unit and simultaneously capture the characteristic parameters of the noise source;

[0057] The noise source characteristic parameters captured by the acquisition module include:

[0058] Wind noise corresponds to turbulence intensity and airflow velocity gradient;

[0059] The vibration acceleration amplitude and vibration frequency spectral density corresponding to road noise;

[0060] The amplitude of harmonic components and the fundamental frequency offset corresponding to mechanical noise;

[0061] When the acquisition module synchronously acquires noise signals and feature parameters through the pickup unit, it uses timestamp alignment logic to ensure that the deviation between the sampling time of the noise signal and the acquisition time of the feature parameters does not exceed a preset time threshold. Furthermore, the sampling frequency is dynamically adjusted according to the highest frequency component of the noise signal to ensure that the sampling frequency is not lower than a preset multiple of the highest noise frequency.

[0062] The enhancement module is used to receive noise signals and source parameters, separate noise coupling components in different zones, and enhance the unique noise characteristics of each zone.

[0063] During the enhancement module's operational phase, when separating noise coupling components from different zones, the process involves constructing acoustic mode functions for each zone to separate the coupling components and enhance unique features. The process includes:

[0064] Construct the acoustic modal functions for each partition , where k is the modal order and t is time;

[0065] Based on mode function analysis of mixed noise signals The noise components of each partition are obtained by decomposition. That is, satisfying:

[0066] ;

[0067] In the formula: The total number of acoustic modes in the partition; The modal weighting coefficient is determined by the proportion of the noise amplitude contribution of each partition.

[0068] The above formula first constructs a dedicated acoustic mode function for each independent acoustic zone. Based on this function, the mixed noise signal inside the vehicle is decomposed. Through the summation and normalization of each mode function, combined with the mode weight coefficient determined according to the proportion of noise amplitude contribution of each zone, the noise components of different zones are accurately separated. This provides a precise noise basis for subsequent signal amplification in the characteristic frequency range of each zone and signal suppression in the non-characteristic frequency range, ensuring the separation of noise coupling components in different zones and the enhancement of the unique noise characteristics of each zone.

[0069] For each partition of the decomposed noise components Perform spectral enhancement processing:

[0070] First, the characteristic frequency range of the noise in the partition is defined by the noise feature extraction results. Then, the bandpass filter combined with amplitude modulation is used for processing. The signal in the characteristic frequency range is applied with an amplitude amplification gain that is negatively correlated with the deviation of the characteristic peak value from the frequency. The signal in the non-characteristic frequency range is applied with an amplitude attenuation coefficient that is positively correlated with the distance of the boundary of the characteristic frequency range from the frequency. The values ​​of the amplification gain and the attenuation coefficient are dynamically adapted based on the acoustic characteristic parameters of the partition. This achieves signal amplification in the characteristic frequency range and signal suppression in the non-characteristic frequency range of the noise in the partition, thereby enhancing the unique characteristics of the noise.

[0071] The generation module is used to generate a noise reduction signal that matches the noise source and partition characteristics based on the unique noise characteristics of each enhanced partition and the noise source characteristic parameters.

[0072] When generating the denoised signal, the generation module constructs a multi-dimensional matching model based on the unique features of the enhanced noise and the noise source feature parameters to generate the denoised signal. :

[0073] ;

[0074] In the formula: This is the amplitude correction coefficient for the noise-reduced signal; This is a noise feature and source matching function; The acoustic impedance of the coordinate point (x, y, z) within the target partition; The acoustic energy loss coefficient is the coordinate point (x, y, z) within the target partition. The phase of the noise-reduced signal is opposite to the phase of the corresponding partition noise signal, and the deviation does not exceed a preset phase threshold; j is a complex number unit.

[0075] The above formula takes the unique characteristics of enhanced noise and the characteristic parameters of noise source as the core, quantifies the correlation between the two through a special matching function, introduces an amplitude correction coefficient that is positively correlated with the peak amplitude of the original noise in the target zone, and takes into account the distance from different coordinate points in the target zone to the directional sound-emitting unit and the sound absorption performance of the surrounding materials. The amplitude of the noise reduction signal is adjusted by acoustic impedance and acoustic energy loss coefficient. Then, by setting a phase parameter that is opposite to the phase of the noise signal of the corresponding zone and the deviation is controlled within a reasonable range, the generated noise reduction signal can accurately match the noise situation of the target zone in terms of amplitude, phase and other aspects, thereby greatly improving the targeting and effectiveness of the noise reduction effect.

[0076] in, The value range is a preset interval [0.8, 1.2], and its value is positively correlated with the peak amplitude of the original noise in the target partition; ∈[0.3,0.9], its value is positively correlated with the straight-line distance from the coordinate point to the directional sound-emitting unit and the sound absorption performance of the surrounding materials;

[0077] Noise characteristics and source matching function The input is enhanced noise with unique characteristics. With noise source characteristic parameters The output is the matching metric:

[0078] ;

[0079] In the formula: is the weighting coefficient for the q-th type of noise source, where q represents the noise source category identifier, corresponding to wind noise, road noise, and mechanical noise; The characteristic correlation coefficient of the q-th type of noise; Let be the dimension of the feature parameters of the q-th type of noise source; The eigenvalue corresponding to the p-th feature parameter of the q-th type of noise in the enhanced noise unique features; This is the reference value for the p-th characteristic parameter of the q-th noise class; This refers to the actual measured value of the p-th characteristic parameter of the q-th type of noise captured by the acquisition module; This is the standard reference value for the p-th characteristic parameter of the q-th noise; is the source identification factor for the q-th type of noise;

[0080] The above formula defines the corresponding characteristic parameter dimensions for three different noise sources: wind noise, road noise, and mechanical noise. It calculates the characteristic values ​​of each dimension in the enhanced noise unique features by comparing them with the corresponding benchmark reference values, and the actual measured values ​​of the noise source characteristic parameters collected by the sampled samples with the standard reference values. Then, it introduces weight coefficients that reflect the importance of various noises, feature correlation coefficients that characterize the closeness of feature correlation, and source identification factors that are related to the proportion of various noise intensities under the current working conditions. The matching degree between noise features and sources is comprehensively quantified from multiple dimensions, providing quantitative data support for the accurate generation of subsequent noise reduction signals.

[0081] in, The degree of inherent correlation between the unique features of the enhanced noise and the characteristics of this type of noise source is characterized by obtaining a fixed range of values ​​through training with a large number of noise samples; ∈(0,2], which is positively correlated with the intensity proportion of this type of noise under the current operating conditions;

[0082] about Wind noise =2, corresponding to turbulence fluctuation intensity and airflow velocity gradient; road noise =2, corresponding to vibration acceleration amplitude and vibration frequency spectral density; mechanical noise =2, corresponding to harmonic component amplitude and fundamental frequency offset;

[0083] The conversion module is used to adjust parameters according to the acoustic characteristics of each zone, convert the noise-reduced signal into a noise-reduced electrical signal, and further convert it into an acoustic signal adapted to that zone.

[0084] The parameters adjusted by the conversion module include: the amplitude gain of the noise-reduced electrical signal, frequency response characteristics, and phase offset. ;

[0085] During parameter adjustment, the adjustment range of amplitude gain is determined based on the spatial size in the acoustic characteristics of the zones, and the correction curve of frequency response characteristics is determined based on material damping.

[0086] ;

[0087] In the formula: This is the adjusted amplitude gain; The reference amplitude gain; The spatial volume of the target partition; The preset baseline partition volume; This is the damping effect coefficient; The material damping coefficient for the target partition; This is the adjusted frequency response function; This is the reference frequency response function; This is the frequency attenuation coefficient; The frequency of the noise signal;

[0088] Among them, phase offset Acoustic propagation delay calculation based on partition boundaries;

[0089] The above formula sets adjustment logic for the amplitude gain and frequency response characteristics of the noise reduction electrical signal. The amplitude gain is based on the reference gain, combined with the volume ratio of the target partition and the preset reference partition, and incorporates the damping influence factor that varies with the material damping coefficient to ensure that the gain is adapted to the size of the partition space. The frequency response characteristics are based on the reference response function calibrated in advance through acoustic simulation modeling. A frequency attenuation coefficient related to the material damping coefficient of the target partition and the frequency of the noise signal is introduced to correct the reference function, so that the adjusted electrical signal can accurately match the size of the target partition space and the material damping characteristics in terms of amplitude and frequency response, laying the foundation for further acoustic signal conversion of the system.

[0090] in, The preset value range is [0.3, 0.8]. Its value increases with the increase of the damping coefficient of the target partition material and decreases with the decrease of the damping coefficient of the target partition material. The preset value range is [0.002, 0.015]. Its value increases with the increase of noise signal frequency and decreases with the increase of target partition material damping coefficient. Based on the spatial size and material damping of the target partition, combined with the inherent acoustic parameters of the directional sound generation unit and the preset noise reduction frequency coverage of the system, the acoustic simulation model is used to pre-calibrate and determine the target partition.

[0091] The output module is used to project acoustic signals to the target area through the directional sound unit;

[0092] When the output module projects the noise reduction signal through the directional sound unit, it uses adaptive beamforming control to make the main lobe of the noise reduction signal beam point to the center region of the target area, and the side lobe suppression ratio is not lower than the preset threshold.

[0093] The output module detects acoustic signal feedback in the target zone in real time, and adjusts the emission angle and sound power of the directional sound unit according to the feedback signal, so that the sound pressure amplitude of the noise reduction signal is evenly distributed in the target zone, and the sound pressure amplitude in the non-target zone is lower than the preset sound pressure threshold.

[0094] The noise sources include wind noise, road noise, and mechanical noise, and the acoustic characteristics of each zone include space size and material damping.

[0095] The configuration module is interconnected with the acquisition module, enhancement module, and generation module via a local area network. The acquisition module, enhancement module, and generation module are interconnected via a local area network. The generation module is interconnected with the conversion module via a local area network. The conversion module is interconnected with the output module via a local area network.

[0096] In this embodiment, the configuration module dynamically adjusts the boundaries of independent acoustic zones based on the seating distribution and occupancy status within the vehicle. Each zone is equipped with a sound pickup unit and a directional sound-emitting unit with source-finding capabilities. The acquisition module, operating downstream, collects noise signals from each zone through the sound pickup units, simultaneously capturing noise source characteristic parameters. The enhancement module further receives the noise signals and source-finding parameters, separates the noise coupling components of different zones, and enhances the unique noise characteristics of each zone. The generation module then generates a noise-reducing signal matching the noise source and zone characteristics based on the enhanced unique noise characteristics and noise source characteristic parameters of each zone. The conversion module adjusts parameters according to the acoustic characteristics of each zone, converting the noise-reducing electrical signal into an acoustic signal adapted to that zone. Finally, the output module projects the adapted noise-reducing signal to the target zone through the directional sound-emitting unit.

[0097] In the above embodiments, the system can adapt to the distribution and occupancy status of seats in the vehicle, accurately capture the different characteristics of wind noise, road noise, and mechanical noise, separate the noise coupling components of the zones, generate noise reduction signals that fit the acoustic characteristics of the zones and project them in a directional manner, so that the noise reduction effect in the target area is uniform and does not interfere with non-target areas, effectively suppressing various types of noise and effectively improving the acoustic comfort and driving experience of drivers and passengers.

[0098] Application example:

[0099] A five-seater family sedan is equipped with this zoned noise reduction system. When the vehicle is in motion, the system first operates through the configuration module. The pressure sensors built into the seats detect that the driver's seat, front passenger seat, and the middle and right rear seats are occupied, while the left rear seat is vacant. Combining the three-dimensional coordinate information of each seat with the acoustic propagation attenuation characteristics of the vehicle's interior space, and taking into account the acoustic attenuation coefficient determined by the current high humidity and low temperature inside the vehicle, as well as the zone boundary expansion coefficient set due to the higher occupancy density and slightly higher irregularity of the rear seats, the system ultimately determines two independent acoustic zones: the driver's seat, the front passenger seat, and the rear seats. The boundaries of each zone precisely match the corresponding seat area.

[0100] The acquisition module then starts up and synchronously acquires noise signals and noise source characteristic parameters through the pickup units deployed in each zone: the turbulence pulsation intensity and airflow velocity gradient corresponding to wind noise, the vibration acceleration amplitude and vibration frequency spectral density corresponding to road noise, and the harmonic component amplitude and fundamental frequency offset corresponding to mechanical noise are all accurately captured. The deviation between the sampling time and the acquisition time is controlled within 0.001 seconds, and the sampling frequency is dynamically adjusted to 4 times the highest noise frequency.

[0101] After receiving the relevant signals and parameters, the enhancement module constructs the acoustic mode functions of each zone, separates the noise coupling components of different zones, and then performs spectrum enhancement processing by combining bandpass filtering with amplitude modulation to amplify the signals in the characteristic frequency range of each zone's noise and suppress signals in the non-characteristic frequency range, thus successfully enhancing the unique characteristics of the noise in each zone.

[0102] The generation module constructs a multi-dimensional matching model based on the unique characteristics of the enhanced noise and the characteristic parameters of the noise source, generating noise reduction signals adapted to each zone. The noise reduction signal is out of phase with the corresponding zone noise signal, and the phase deviation does not exceed a preset value. The noise reduction signal amplitude correction coefficient is determined to be 1.0 based on the original noise peak value, and the acoustic energy loss coefficient is adapted to be between 0.5 and 0.8 according to the distance from each coordinate point to the directional sound-emitting unit and the sound absorption performance of the surrounding materials.

[0103] The conversion module adjusts parameters according to the acoustic characteristics of each zone: the amplitude gain of the driver's seat zone is adjusted to 1.1 times the reference value due to the ratio of the space volume to the reference volume; combined with the material damping coefficient of each zone, the frequency response characteristic correction curve is determined, the frequency attenuation coefficient is set according to the current noise frequency and the material damping coefficient, and the phase offset is precisely adjusted to convert the noise reduction electrical signal into an acoustic signal adapted to each zone.

[0104] Finally, the output module uses a directional sound unit and adaptive beamforming control to project the noise-reducing signal to the target zones. The main lobe of the sound beam is precisely pointed to the center area of ​​each zone, and the side lobe suppression ratio is no less than 30dB. The system monitors the acoustic signal feedback of each zone in real time and dynamically adjusts the emission angle and sound power of the directional sound unit to ensure that the sound pressure amplitude of the noise-reducing signal is evenly distributed in the target zones, and the sound pressure amplitude in non-target zones is lower than the preset threshold of 0.01Pa. This effectively reduces wind noise, road noise, and mechanical noise in each occupied zone, improving the acoustic comfort of drivers and passengers.

[0105] In summary, the system in the above embodiments dynamically adapts to the distribution and occupancy status of seats in the vehicle, accurately distinguishes the different characteristics of wind noise, road noise, and mechanical noise, effectively separates the noise coupling components of each area, enhances the specific noise characteristics, and generates noise reduction signals that fit the noise source and zoning characteristics. At the same time, it adapts to acoustic environments of different space sizes and material damping, projects the signal directionally to the target area with uniform sound pressure distribution, significantly reduces the impact on non-target areas, and accurately matches the phase and amplitude of the noise reduction signal with the noise. Overall, it is less affected by factors such as temperature, humidity, and spatial shape, has strong stability, and can specifically improve the quietness of each area, meet the personalized noise reduction needs of different passengers, and improve the driving and riding experience.

[0106] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vehicle interior acoustic zone-based active noise cancellation system, characterized in that, include: The configuration module is used to dynamically adjust the boundaries of independent acoustic zones according to the distribution and occupancy status of seats in the vehicle, and to deploy pickup units and directional sound units with source sensing function in each zone; The acquisition module is used to acquire noise signals from each zone through the pickup unit and simultaneously capture the characteristic parameters of the noise source; The enhancement module is used to receive noise signals and source parameters, separate noise coupling components in different zones, and enhance the unique noise characteristics of each zone. The generation module is used to generate a noise reduction signal that matches the noise source and partition characteristics based on the unique noise characteristics of each enhanced partition and the noise source characteristic parameters. The conversion module is used to adjust parameters according to the acoustic characteristics of each zone, convert the noise-reduced signal into a noise-reduced electrical signal, and further convert it into an acoustic signal adapted to that zone. The output module is used to project acoustic signals to the target area through the directional sound unit; The noise sources include wind noise, road noise, and mechanical noise, and the acoustic characteristics of each zone include space size and material damping.

2. The automotive in-vehicle acoustic zone-based active noise cancellation system according to claim 1, characterized in that, When the configuration module dynamically adjusts the boundaries of independent acoustic zones, it constructs a dynamic calculation model for the zone boundaries based on the three-dimensional coordinate information of the seats, the occupancy status of the seats, and the acoustic propagation attenuation characteristics of the in-vehicle space. The seat occupancy status is determined based on the seat's built-in pressure sensor, including whether it is occupied or vacant. The spatial coordinates of the partition boundary satisfy the formula: ； In the formula: is the three-dimensional coordinate vector of any point on the partition boundary; This represents the total number of seats in the vehicle. This is the occupancy status indicator for the i-th seat, where 1 indicates occupancy and 0 indicates vacancy. Let be the three-dimensional coordinate vector of the i-th seat; The acoustic attenuation coefficient of the air medium inside the vehicle; Let (x, y, z) be the straight-line distance from the coordinate point (x, y, z) to the i-th seat. This is the partition boundary expansion coefficient; This is the reference coordinate vector for the interior space of the vehicle.

3. The automotive in-vehicle acoustic zone-based active noise cancellation system according to claim 1, characterized in that, The noise source characteristic parameters captured by the acquisition module include: Wind noise corresponds to turbulence intensity and airflow velocity gradient; The vibration acceleration amplitude and vibration frequency spectral density corresponding to road noise; The amplitude of harmonic components and the fundamental frequency offset corresponding to mechanical noise; When the acquisition module synchronously acquires noise signals and feature parameters through the pickup unit, it uses timestamp alignment logic to ensure that the deviation between the sampling time of the noise signal and the acquisition time of the feature parameters does not exceed a preset time threshold, and the sampling frequency is dynamically adjusted according to the highest frequency component of the noise signal so that the sampling frequency is not lower than a preset multiple of the highest frequency of the noise.

4. The automotive in-vehicle acoustic zone-based active noise cancellation system according to claim 1, characterized in that, During the operation phase of the enhancement module, when separating the noise coupling components of different zones, the coupling components are separated and unique features are enhanced by constructing the acoustic mode functions of each zone. The process includes: Construct the acoustic modal functions for each partition , where k is the modal order and t is time; Based on mode function analysis of mixed noise signals The noise components of each partition are obtained by decomposition. That is, satisfying: ； In the formula: The total number of acoustic modes in the partition; The modal weighting coefficient is determined by the proportion of the noise amplitude contribution of each partition. For each partition of the decomposed noise components Perform spectral enhancement processing: First, the characteristic frequency range of the noise in the partition is defined by the noise feature extraction results. Then, the bandpass filtering combined with amplitude modulation is used to process the noise. The signal in the characteristic frequency range is given an amplitude amplification gain that is negatively correlated with the deviation of the characteristic peak value from the frequency. The signal in the non-characteristic frequency range is given an amplitude attenuation coefficient that is positively correlated with the distance between the frequency and the boundary of the characteristic frequency range, so as to enhance the unique characteristics of the noise.

5. The automotive in-vehicle acoustic zone-based active noise cancellation system according to claim 1, characterized in that, When generating a denoised signal, the generation module constructs a multi-dimensional matching model based on the enhanced noise's unique characteristics and the noise source's characteristic parameters to generate the denoised signal. : ； In the formula: This is the amplitude correction coefficient for the noise-reduced signal; This is a noise feature and source matching function; The acoustic impedance of the coordinate point (x, y, z) within the target partition; The acoustic energy loss coefficient is the coordinate point (x, y, z) within the target partition. The phase of the noise-reduced signal; j is the complex unit; in, The value range is a preset interval [0.8, 1.2], and its value is positively correlated with the peak amplitude of the original noise in the target partition; ∈[0.3,0.9], its value is positively correlated with the straight-line distance from the coordinate point to the directional sound-emitting unit and the sound absorption performance of the surrounding materials.

6. The automotive in-vehicle acoustic zone-based active noise cancellation system according to claim 5, characterized in that, The noise feature and source matching function The input is enhanced noise with unique characteristics. With noise source characteristic parameters The output is the matching metric: ； In the formula: is the weighting coefficient for the q-th type of noise source, where q represents the noise source category identifier, corresponding to wind noise, road noise, and mechanical noise; The characteristic correlation coefficient of the q-th type of noise; Let be the dimension of the feature parameters of the q-th type of noise source; The eigenvalue corresponding to the p-th feature parameter of the q-th type of noise in the enhanced noise unique features; This is the reference value for the p-th characteristic parameter of the q-th noise class; This refers to the actual measured value of the p-th characteristic parameter of the q-th type of noise captured by the acquisition module; This is the standard reference value for the p-th characteristic parameter of the q-th noise; is the source identification factor for the q-th type of noise.

7. The automotive in-vehicle acoustic zone-based active noise cancellation system according to claim 1, characterized in that, The parameters adjusted by the conversion module include: the amplitude gain of the noise-reduced electrical signal, frequency response characteristics, and phase offset. ; During parameter adjustment, the adjustment range of amplitude gain is determined based on the spatial size in the acoustic characteristics of the zones, and the correction curve of frequency response characteristics is determined based on material damping. ； In the formula: This is the adjusted amplitude gain; The reference amplitude gain; The spatial volume of the target partition; The preset baseline partition volume; This is the damping effect coefficient; The material damping coefficient for the target partition; This is the adjusted frequency response function; This is the reference frequency response function; This is the frequency attenuation coefficient; The frequency of the noise signal.

8. The automotive in-vehicle acoustic zone-based active noise cancellation system according to claim 1, characterized in that, When the output module projects the noise reduction signal through the directional sound unit, it uses adaptive beamforming control to make the main lobe of the noise reduction signal beam point to the center region of the target area, and the side lobe suppression ratio is not lower than a preset threshold. The output module detects acoustic signal feedback in the target zone in real time, and adjusts the emission angle and sound power of the directional sound unit according to the feedback signal, so that the sound pressure amplitude of the noise reduction signal is evenly distributed in the target zone, and the sound pressure amplitude in the non-target zone is lower than the preset sound pressure threshold.

9. The automotive in-vehicle acoustic zone-based active noise cancellation system according to claim 1, characterized in that, The configuration module is interconnected with a data acquisition module, an enhancement module, and a generation module via a local area network. The data acquisition module, the enhancement module, and the generation module are interconnected via a local area network. The generation module is interconnected with a conversion module via a local area network. The conversion module is interconnected with an output module via a local area network.

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