Vehicle exterior sound prompting method, device and equipment and computer readable storage medium

Abstract

This invention discloses a method, apparatus, device, and computer-readable storage medium for external sound alerts. The method is applied to a vehicle, with at least two microphones installed around the vehicle's exterior and at least two speakers installed inside. The method includes: acquiring ambient sound signals collected by each microphone; extracting a target sound signal from the ambient sound signals and locating the sound source direction of the target sound signal based on the at least two microphones; acquiring playback parameter values ​​for each speaker to simulate the sound source direction; and controlling each speaker to play the target sound signal according to its corresponding playback parameter values. This invention provides an external sound alert solution that, without affecting the vehicle's NVH performance, ensures that the driver can accurately identify external sounds, enabling timely countermeasures and elimination of safety hazards.

Description

Technical Field

[0001] This invention relates to the field of signal processing technology, and in particular to a method, apparatus, device, and computer-readable storage medium for external vehicle sound prompts. Background Technology

[0002] In recent years, people have placed increasingly higher demands on vehicle driving comfort. Manufacturers have invested heavily in research and optimization of NVH (Noise, Vibration, and Harshness), resulting in a rapid improvement in vehicle NVH performance. However, this improvement in NVH performance has also led to drivers being unable to accurately and promptly hear external sounds while driving, creating safety hazards. For example, if a neighboring vehicle sounds its horn in a dangerous situation, and the driver is enjoying music while driving, they may not be able to accurately and promptly recognize the horn, thus failing to take timely emergency measures and creating a safety risk. Summary of the Invention

[0003] The main objective of this invention is to provide a method, apparatus, device, and computer-readable storage medium for external sound alerts. The aim is to propose an external sound alert scheme that, without affecting the vehicle's NVH performance, ensures that the driver can accurately identify external sounds so that timely countermeasures can be taken to eliminate safety hazards.

[0004] To achieve the above objectives, the present invention provides a method for external sound alerts, which is applied to a vehicle. The vehicle has at least two microphones arranged around its perimeter and at least two speakers installed inside the vehicle. The external sound alert method includes:

[0005] Acquire the ambient sound signals collected by each of the microphones;

[0006] Extract the target sound signal from each of the ambient sound signals, and locate the sound source direction of the target sound signal based on at least two of the microphones;

[0007] Obtain the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source, and control each of the speakers to play the target sound signal according to its corresponding playback parameter values.

[0008] Optionally, the step of obtaining the playback parameter values ​​for simulating the direction of the sound source corresponding to each of the speakers includes:

[0009] Obtain a pre-set parameter mapping table, wherein the parameter mapping table contains the mapping relationship between the playback parameter values ​​and the direction of each speaker;

[0010] By searching the parameter mapping table according to the direction of the sound source, the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source are obtained.

[0011] Optionally, at least four speakers are installed in the vehicle, and the direction of the sound source is represented by the target azimuth angle in the vehicle coordinate system, which is a horizontal coordinate system established with the driver's seat position as the origin; the step of obtaining the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source includes:

[0012] The two azimuth angles closest to the target azimuth angle are determined from each preset azimuth angle and used as reference azimuth angles. The number of preset azimuth angles is greater than the number of loudspeakers. For each preset azimuth angle, the playback parameter values ​​of each loudspeaker are preset to simulate the sound source from the preset azimuth angle.

[0013] The weights corresponding to the two reference azimuths are determined according to the angle difference between the target azimuth and the two reference azimuths, wherein the reference azimuth with a smaller angle difference from the target azimuth has a larger weight.

[0014] For each loudspeaker, the playback parameter values ​​of the loudspeakers corresponding to the two reference azimuth angles are weighted and averaged according to the weights corresponding to the two reference azimuth angles to obtain the playback parameter values ​​of the loudspeakers used to simulate the direction of the sound source.

[0015] Optionally, the step of extracting the target sound signal from each of the ambient sound signals includes:

[0016] Calculate the signal-to-noise ratio (SNR) of each ambient sound signal and select the ambient sound signal with the highest SNR as the signal to be processed.

[0017] The signal to be processed is subjected to noise reduction processing to obtain the noise-reduced signal;

[0018] Extract the target sound signal from the noise-reduced signal.

[0019] Optionally, the step of extracting the target sound signal from the denoised signal includes:

[0020] The noise-reduced signal is filtered using a preset adaptive filter corresponding to the target sound type to obtain a filtered signal, and the filtered signal is used as the target sound signal; wherein, the adaptive filter adaptively adjusts the filter parameters based on the error between the preset model signal corresponding to the target sound type and the filtered signal to minimize the error.

[0021] Optionally, the microphone is an omnidirectional microphone, and a soft vibration-damping material is provided between the microphone and the vehicle body; at least three sets of microphones are provided around the outer perimeter of the vehicle body, each set of microphones includes two microphones, and the distance between the two microphones is greater than half the width of the rear of the vehicle; at least one set of microphones is located on the right rear side of the vehicle, at least one set of microphones is located on the left rear side of the vehicle, and at least one set of microphones is located on the rear side of the vehicle; the microphone located on the left rear side of the vehicle and the microphone located on the right rear side of the vehicle are symmetrically arranged based on the central axis of the vehicle parallel to its length direction.

[0022] Optionally, the step of locating the sound source direction of the target sound signal based on at least two of the microphones includes:

[0023] Calculate the signal-to-noise ratio of each ambient sound signal, and select the two sets of microphones corresponding to the ambient sound signals with the highest signal-to-noise ratio as two sets of sound source localization microphones;

[0024] The target sound signal is located by locating the sound source using the two sets of sound source locating microphones, and the sound source direction of the target sound signal is obtained based on the location results obtained by the two sets of sound source locating microphones.

[0025] Optionally, before the step of acquiring the ambient sound signals collected by each of the microphones, the method further includes:

[0026] After detecting that the vehicle has started, it checks whether the vehicle is in a closed state;

[0027] If the vehicle is in a closed state, then the step of acquiring the ambient sound signals collected by each of the microphones is performed.

[0028] To achieve the above objectives, the present invention also provides an external sound alert device, wherein the external sound alert device is deployed in a vehicle, at least two microphones are arranged around the perimeter of the vehicle body, and at least two speakers are arranged inside the vehicle. The external sound alert device includes:

[0029] The acquisition module is used to acquire the ambient sound signals collected by each of the microphones;

[0030] An extraction module is used to extract a target sound signal from each of the ambient sound signals and locate the sound source direction of the target sound signal based on at least two of the microphones;

[0031] The control module is used to acquire the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source, and to control each of the speakers to play the target sound signal according to its corresponding playback parameter values.

[0032] To achieve the above objectives, the present invention also provides an external vehicle sound alert device, which includes: a memory, a processor, and an external vehicle sound alert program stored in the memory and executable on the processor. When the external vehicle sound alert program is executed by the processor, it implements the steps of the external vehicle sound alert method described above.

[0033] In addition, to achieve the above objectives, the present invention also proposes a computer-readable storage medium storing an external sound prompting program, which, when executed by a processor, implements the steps of the external sound prompting method described above.

[0034] In this embodiment of the invention, by setting at least two microphones around the vehicle body, the external environmental sound signals are collected and the sound source is located, obtaining the target sound signal and the direction of the target sound signal outside the vehicle. Then, the target sound signal is played back by at least two speakers installed inside the vehicle. Furthermore, by obtaining the playback parameter values ​​corresponding to each speaker for simulating the direction of the sound source, each speaker is controlled to play the target sound signal according to its corresponding playback parameter values. This allows the occupants of the vehicle to hear the external sounds clearly and intuitively perceive the direction of the external sounds without affecting the vehicle's NVH performance. This facilitates the occupants of the vehicle to identify external sounds and take timely countermeasures to eliminate safety hazards when encountering danger. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating the first embodiment of the vehicle exterior sound prompting method of the present invention;

[0036] Figure 2 This is an example diagram of a preset azimuth angle according to an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram illustrating the arrangement of in-vehicle speakers according to an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of a loudspeaker control scheme according to an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram illustrating the principle of extracting whistle sound signals based on an adaptive filter according to an embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of the installation structure of an external microphone according to an embodiment of the present invention;

[0041] Figure 7 This is a schematic diagram illustrating the placement of an external microphone in an embodiment of the present invention.

[0042] Figure 8This is a schematic diagram of an external sound prompting process according to an embodiment of the present invention;

[0043] Figure 9 This is a schematic diagram of the functional modules of a preferred embodiment of the vehicle exterior sound prompting device of the present invention.

[0044] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0045] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0046] Reference Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the vehicle exterior sound prompting method of the present invention.

[0047] This invention provides an embodiment of an external sound prompting method. It should be noted that although the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order. This invention's external sound prompting method is applied to a vehicle, which can be a vehicle with a closed driver's cab; the specific vehicle model is not limited in this embodiment. In this embodiment, the external sound prompting method includes steps S10 to S30:

[0048] Step S10: Acquire the ambient sound signals collected by each of the microphones.

[0049] In this embodiment, at least two microphones are installed around the perimeter of the vehicle body, and at least two speakers are installed inside the vehicle to implement the external sound prompting scheme proposed in this embodiment of the invention. It should be noted that the vehicle may also be equipped with microphones and speakers for other functions, such as microphones and speakers for voice calls and music playback. Where there is no functional conflict, the microphones and speakers implementing the external sound prompting scheme in this embodiment can also be used to implement other functions, thereby saving and reducing the complexity of the vehicle hardware system. Furthermore, for ease of description, the microphones and speakers mentioned in each embodiment refer to the microphones and speakers implementing the external sound prompting scheme of this embodiment of the invention.

[0050] The microphones are positioned around the exterior of the vehicle body, but their specific locations are not limited in this embodiment. The speakers are positioned inside the vehicle, but their specific locations are also not limited in this embodiment.

[0051] In this embodiment, microphones positioned around the perimeter of the vehicle body can be used to collect external sound signals (hereinafter referred to as ambient sound signals). At least two ambient sound signals can be acquired using at least two microphones.

[0052] In a specific implementation, the vehicle may start collecting ambient sound signals via the microphone immediately after starting; or it may activate the external sound alert function after receiving a user-triggered command, and then start collecting ambient sound signals via the microphone; or it may activate the external sound alert function after detecting a pre-set automatic trigger condition, and then start collecting ambient sound signals via the microphone. For example, the automatic trigger condition may be detecting that the vehicle is in a closed state or in music playback state after starting the vehicle, where the closed state may refer to the state where both windows and doors are closed.

[0053] Step S20: Extract the target sound signal from each of the ambient sound signals, and locate the sound source direction of the target sound signal based on at least two of the microphones.

[0054] The target sound signal is extracted from various ambient sound signals. In one feasible embodiment, one or more specific sound types can be preset, and the target sound signal can be the sound signal of that one or more specific sound types extracted from the various ambient sound signals; for example, the sound signal of a siren can be extracted from the various ambient sound signals as the target sound signal, the sound signal of a warning tone can be extracted from the various ambient sound signals as the target sound signal, and the sound signal of a human voice can be extracted from the various ambient sound signals as the target sound signal. The method of extracting the target sound signal is not limited in this embodiment. For example, a filter set for a certain sound type can be used to filter the ambient sound signal, thereby extracting the sound signal of that sound type as the target sound signal.

[0055] For a given sound type, there can be one or more target sound signals of that sound type extracted. For example, multiple ambient sound signals may contain sound signals of that sound type. A target sound signal can be extracted from each of the multiple ambient sound signals, or the extracted multiple sound signals can be merged into a single target sound signal, or only one target sound signal can be extracted from a single ambient sound signal. This embodiment does not impose any specific limitations. Each sound type corresponds to at least one target sound signal. Therefore, for n sound types, at least n target sound signals must be extracted. The following explanation uses a single target sound signal as an example.

[0056] For a target sound signal, the direction of its sound source can be located using at least two microphones. The sound source direction is the direction of the sound source relative to the vehicle. This embodiment does not limit the specific implementation of sound source localization using microphones. For example, in one feasible embodiment, a microphone array formed by two microphones can be used for sound source localization. The sound wave emitted by the sound source travels to the microphone array, forming an angle with the line connecting the two microphones. If the angle is perpendicular (90°), the sound waves reach both microphones simultaneously. If they are not perpendicular, there is a delay between the microphones. The superposition of the two microphone signals will produce different results due to the different incident angles of the sound waves. Therefore, the incident angle of the sound waves can be calculated based on the superposition of the signals, thus obtaining the sound source direction. In one feasible embodiment, the sound source direction can be represented by an angle in the vehicle coordinate system. The vehicle coordinate system can be pre-set as needed and jointly calibrated with the microphone positions. After locating the direction of the target sound signal's sound source relative to the microphone array using at least two microphones, the sound source direction located by the microphone array can be converted into an angle in the vehicle coordinate system using the correspondence between the microphone array's position and the vehicle coordinate system. In one feasible implementation, the vehicle coordinate system can be based on the driver's location in the vehicle as the origin, so that the located sound source direction can represent the direction of the target sound signal source relative to the driver, thereby enabling the sound signal source direction relative to the driver to be realistically simulated when the sound source direction is simulated through a loudspeaker.

[0057] Since sounds outside the vehicle come from different directions, in this embodiment, sound source localization can be achieved by setting at least two microphones to form a microphone array. In some feasible implementations, more than two microphones can be set to achieve more accurate sound source localization.

[0058] Step S30: Obtain the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source, and control each speaker to play the target sound signal according to its corresponding playback parameter values.

[0059] The playback parameters used by the loudspeakers to simulate the direction of a sound source may include gain, time delay, etc., and are not limited in this embodiment. By using at least two loudspeakers to form a loudspeaker array and controlling the playback parameter values ​​of each loudspeaker, stereo sound can be achieved to simulate the direction of a sound source. In some feasible embodiments, more than two loudspeakers can be set to achieve a more accurate reproduction of the direction of the sound source.

[0060] After obtaining the sound source direction of the target sound signal, the playback parameter values ​​corresponding to each speaker for simulating that sound source direction can be obtained, such as delay and gain values. In this embodiment, there are no restrictions on the method of obtaining the playback parameter values ​​of each speaker. For example, they can be calculated using a pre-set conversion formula between the sound source direction and the playback parameter values; the conversion formula for each speaker can be pre-calculated by testing multiple sets of data in a test environment (each set of data includes a set of playback parameter values ​​for the speaker and a simulated sound source direction), based on the multiple sets of test data.

[0061] After obtaining the playback parameter values ​​of each speaker, each speaker can be controlled to play the target sound signal according to its corresponding playback parameter values. In some feasible implementations, if other audio signals, such as music or navigation audio, are also playing inside the vehicle while the target sound signal is being played through the speakers, the playback of other audio signals can be stopped or the volume of the other audio signals can be reduced so that the driver can hear the replayed external sounds more clearly.

[0062] In one feasible embodiment, step S30, which involves obtaining playback parameter values ​​for simulating the direction of the sound source corresponding to each of the speakers, includes steps S301 to S302:

[0063] Step S301: Obtain a pre-set parameter mapping table, wherein the parameter mapping table contains the mapping relationship between the playback parameter values ​​and the direction of each speaker.

[0064] A parameter mapping table can be pre-set in the vehicle. This table contains the mapping relationship (or correspondence) between the playback parameter values ​​of each speaker and their direction. Direction can refer to an angle in the vehicle coordinate system. The parameter mapping table includes the playback parameter values ​​for each speaker at various angles. These playback parameter values ​​can be obtained by pre-tuning the speaker playback parameters in a test environment. That is, the desired angle can be set, and by adjusting the playback parameter values ​​of each speaker, the direction of the sound source simulated by the played sound signal is the direction of the sound source corresponding to that angle. The correspondence between the angle and the playback parameter value is recorded. After adjusting multiple angles (e.g., 0 degrees, 15 degrees, 30 degrees, 45 degrees... 345 degrees, 360 degrees), multiple sets of correspondences can be obtained, which can then be used as the parameter mapping table in the vehicle.

[0065] Step S302: Search the parameter mapping table according to the sound source direction to obtain the playback parameter values ​​corresponding to each of the speakers for simulating the sound source direction.

[0066] After obtaining the direction of the target sound signal, the parameter mapping table can be consulted to obtain the playback parameter values ​​corresponding to each speaker and the direction of the sound source, that is, the playback parameter values ​​for each speaker to simulate the direction of the sound source.

[0067] In one feasible embodiment, step S301, which involves obtaining playback parameter values ​​for simulating the direction of the sound source corresponding to each of the speakers, includes steps S303 to S305:

[0068] Step S303: Determine the two azimuth angles closest to the target azimuth angle from each preset azimuth angle as reference azimuth angles. The number of preset azimuth angles is greater than the number of loudspeakers. For each preset azimuth angle, preset playback parameter values ​​for each loudspeaker are set to simulate the sound source from the preset azimuth angle.

[0069] At least four speakers can be installed inside the vehicle. The placement of each speaker within the vehicle is not limited in this embodiment; for example, the speakers can be positioned around the driver's seat. The direction of the target sound signal source can be represented by the target azimuth angle in the vehicle coordinate system, which is a horizontal coordinate system with the driver's seat position as the origin.

[0070] To more accurately simulate the direction of external sounds inside the vehicle, this embodiment pre-sets multiple preset azimuth angles. For each preset azimuth angle, each speaker is pre-set with playback parameter values ​​to simulate the sound source from that preset azimuth angle. These playback parameter values ​​can be obtained by pre-adjusting the speaker playback parameters in a test environment. That is, the desired angle can be set, and then the playback parameter values ​​of each speaker can be adjusted so that the direction of the sound source simulated by the played sound signal is the direction of the sound source corresponding to that angle. The number of preset azimuth angles is greater than the number of speakers installed in the vehicle, thereby simulating the direction of sound sources beyond the number of speakers and improving the accuracy of the simulated direction of external sounds. In a specific embodiment, the azimuth angle range in the vehicle coordinate system can be equally divided to obtain multiple preset azimuth angles, that is, the angle difference between any two adjacent preset azimuth angles is equal. For example, when there are four speakers in the vehicle, the following settings can be configured: Figure 2 The five preset azimuth angles shown are L, R, RR, RL, and B.

[0071] The number of preset azimuth angles that can be simulated is limited, and it is impossible to exhaust all angles. In this case, in order to simulate the direction of the sound source outside the preset azimuth angle, this embodiment can calculate the playback parameter value used to simulate the direction of the sound source corresponding to the target azimuth angle based on the playback parameter values ​​set by the two reference azimuth angles with the smallest angular difference from the target azimuth angle. This further improves the accuracy of the simulated direction of the sound outside the vehicle. It should be noted that the two reference azimuth angles sandwich the target azimuth angle; that is, one reference azimuth angle is larger than the target azimuth angle, and the other reference azimuth angle is smaller than the target azimuth angle.

[0072] Step S304: Determine the weights of the two reference azimuths according to the angle difference between the target azimuth and the two reference azimuths, wherein the reference azimuth with a smaller angle difference from the target azimuth has a larger weight.

[0073] In a specific implementation, the sum of the weights corresponding to the two reference azimuth angles can be set to 1. There are many ways to determine the weights corresponding to the two reference azimuth angles, and this implementation does not impose any restrictions; it is only necessary to ensure that the smaller the angular difference between the reference azimuth angle and the target azimuth angle, the larger the weight corresponding to that reference azimuth angle. In one feasible implementation, the proportion of the angular difference between one reference azimuth angle and the target azimuth angle to the sum of the angular differences between the two reference azimuth angles and the target azimuth angle can be calculated as the weight corresponding to the other reference azimuth angle.

[0074] Step S305: For each speaker, the playback parameter values ​​of the speaker corresponding to the two reference azimuth angles are weighted and averaged according to the weights corresponding to the two reference azimuth angles to obtain the playback parameter values ​​of the speaker used to simulate the direction of the sound source.

[0075] For example, four speakers are set up as SPKR1, SPKR2, SPKR3, and SPKR4, with two reference azimuth angles d1 and d2. Reference azimuth angle d1 corresponds to preset playback parameter values ​​for each speaker: SPKR1-d1, SPKR2-d1, SPKR3-d1, SPKR4-d1. Reference azimuth angle d2 corresponds to preset playback parameter values ​​for each speaker: SPKR1-d2, SPKR2-d2, SPKR4-d1. For 3-d2 and SPKR4-d2, the weights corresponding to d1 and d2 are φ1 and φ2 respectively. Then, the playback parameter value of the speaker SPKR1 used to simulate the sound source direction of the target sound signal is (SPKR1-d1*φ1+SPKR1-d2*φ2), the playback parameter value of the speaker SPKR2 used to simulate the sound source direction of the target sound signal is (SPKR2-d1*φ1+SPKR2-d2*φ2), and so on for SPKR3 and SPKR4.

[0076] In one feasible implementation, such as Figure 3 As shown, the vehicle interior is equipped with 6 speakers. Figure 4 As shown, the extracted target sound signal can be processed internally by the DSP (Digital Signal Processor) and distributed to different channels (speakers). Based on the directional information output by the sound source localization algorithm, the DSP gives different gains and delays to the six channels, and then plays it through the six speakers in the car. The speakers cooperate with each other to simulate the sound field at the location of the actual target sound signal source.

[0077] In this embodiment, by setting at least two microphones around the vehicle body, the external environmental sound signals are collected and the sound source is located, obtaining the target sound signal and the direction of the target sound signal. Then, the target sound signal is played back by at least two speakers installed inside the vehicle. Furthermore, by obtaining the playback parameter values ​​corresponding to each speaker for simulating the direction of the sound source, each speaker is controlled to play the target sound signal according to its corresponding playback parameter values. This allows the occupants to hear the external sounds clearly and intuitively perceive the direction of the external sounds without affecting the vehicle's NVH performance. This facilitates the occupants in identifying external sounds and taking timely countermeasures to eliminate safety hazards when encountering danger.

[0078] Based on the first embodiment described above, a second embodiment of the vehicle exterior sound prompting method of the present invention is proposed. In this embodiment, the step of extracting the target sound signal from each of the environmental sound signals in step S20 includes S201 to S203:

[0079] Step S201: Calculate the signal-to-noise ratio (SNR) of each ambient sound signal and select the ambient sound signal with the highest SNR as the signal to be processed.

[0080] In this embodiment, after acquiring the ambient sound signals collected by each microphone, the signal-to-noise ratio (SNR) of each ambient sound signal can be calculated separately. Because the microphones are positioned differently, the direction of the sound source outside the vehicle changes, so some microphones will collect stronger and clearer sound signals, while others may collect weaker signals. By calculating the SNR of each ambient sound signal, the ambient sound signal with the highest SNR is selected as the signal to be processed, in order to extract a clearer target sound signal, thereby allowing occupants to hear the outside sounds more clearly during playback inside the vehicle.

[0081] Step S202: Perform noise reduction processing on the signal to be processed to obtain the noise-reduced signal.

[0082] After determining the signal to be processed, noise reduction processing can be performed on the signal. The noise-reduced signal will be referred to as the "noise-reduced signal" for distinction. There are many noise reduction methods, and this embodiment does not impose any limitations. For example, spectral subtraction can be used to reduce the noise of the signal to be processed. During vehicle operation, the microphone picks up a lot of noise besides the target sound signal, such as engine noise, tire noise, wind noise, and ambient noise. Noise reduction can further reduce the noise in the ambient sound signal, making it easier to extract a clear target sound signal. This allows passengers to hear the outside sounds more clearly when the sound is played back inside the vehicle.

[0083] Step S203: Extract the target sound signal from the noise-reduced signal.

[0084] After obtaining the denoised signal, the target sound signal is extracted from it. The method for extracting the target sound signal is not limited in this embodiment. For example, a filter designed for a specific sound type can be used to filter the denoised signal, thereby extracting the sound signal of that sound type as the target sound signal.

[0085] In one feasible implementation, step S203 includes:

[0086] Step S2031: The noise-reduced signal is filtered using a preset adaptive filter corresponding to the target sound type to obtain a filtered signal, and the filtered signal is used as the target sound signal; wherein, the adaptive filter adaptively adjusts the filter parameters based on the error between the preset model signal corresponding to the target sound type and the filtered signal to minimize the error.

[0087] In this embodiment, an adaptive filter can be used to extract the target sound signal, thereby improving the accuracy of the extracted target sound signal. Specifically, for the sound type to be extracted (hereinafter referred to as the target sound type for distinction), an adaptive filter corresponding to the target sound type can be set in the vehicle. The noise-reduced signal is filtered using a preset adaptive filter corresponding to the target sound type. The filtered signal is referred to as the "filtered signal" for distinction. The filtered signal is the target sound signal corresponding to the target sound type. The filter parameters of the adaptive filter are adjusted based on an adaptive algorithm during the extraction of the target sound signal. That is, the filter parameters can be adaptively adjusted based on the error between the preset model signal and the filter signal corresponding to the target sound type. The goal of the adjustment is to minimize this error. The model signal corresponding to the target sound type can be a pre-acquired sound signal of the target sound type, such as a pre-acquired horn, warning sound, or human voice. For example, in one feasible embodiment, such as... Figure 5 As shown, the target sound type is a whistle. For the original signal (ambient sound signal or sound signal to be processed) with noise and whistle sound, a parameter-adjustable digital filter can be used to filter the signal to obtain the filtered signal. Based on the filtered signal and the whistle sound model signal, the error signal can be calculated. Based on the error signal, an adaptive algorithm is used to adjust the filter parameters of the parameter-adjustable digital filter.

[0088] Based on the first and / or second embodiments described above, a third embodiment of the vehicle exterior sound prompting method of the present invention is proposed. In this embodiment, at least three sets of microphones can be arranged around the perimeter of the vehicle body. Each set of microphones includes two microphones, and the distance between the two microphones is greater than half the width of the rear of the vehicle. At least one set of microphones is located on the right rear side of the vehicle, at least one set of microphones is located on the left rear side of the vehicle, and at least one set of microphones is located on the rear side of the vehicle. Two microphones are used as a group for sound source localization. By setting the distance between them to be greater than half the width of the rear of the vehicle, the two microphones can perform sound source localization more accurately. The width of the rear of the vehicle can refer to the distance between two planes parallel to the longitudinal symmetry plane of the vehicle and respectively close to the fixed protruding parts on both sides of the vehicle. By setting multiple sets of microphones, environmental sound signals from all directions can be collected and located more accurately. For example, the microphone group on the left side of the vehicle is more conducive to collecting and locating environmental sound signals transmitted from the left, the microphone group on the right side of the vehicle is more conducive to collecting and locating environmental sound signals transmitted from the right, and the microphone group on the rear side of the vehicle is more conducive to collecting and locating environmental sound signals transmitted from the rear. In one feasible embodiment, the microphone can be an omnidirectional microphone, such as an omnidirectional MEMS microphone, to further improve the accuracy of sound source direction localization. In one feasible embodiment, such as Figure 6As shown, a soft vibration-damping material can be placed between the microphone and the vehicle body to reduce noise caused by vehicle vibrations transmitted to the microphone, thereby improving the signal-to-noise ratio of the acquired target sound signal. In one feasible embodiment, the microphones located on the left rear side and the right rear side of the vehicle can be symmetrically arranged based on the vehicle's central axis parallel to its length direction, making the microphone positioning algorithms on both sides highly reusable, thus reducing the implementation complexity of the microphone positioning algorithm. In another feasible embodiment, the distance between the microphone closer to the rear edge of the vehicle in the group of microphones located on the left rear side and the rear edge of the vehicle can be set to be equal to the distance between the microphone closer to the left edge of the vehicle in the group of microphones located on the rear side and the left edge of the vehicle, making the microphone positioning algorithms on both sides and the rear side highly reusable, thus reducing the implementation complexity of the microphone positioning algorithm.

[0089] In one feasible implementation, three sets of microphones can be set up, such as Figure 7 As shown, each microphone group consists of two microphones: ① and ② form one group, located on the left rear side of the vehicle; ③ and ④ form another group, located on the right rear side of the vehicle; and ⑤ and ⑥ form a third group, located on the rear side of the vehicle, i.e., the rear end. This allows for the precise acquisition and localization of ambient sound signals from all directions with a relatively small number of microphones.

[0090] In one feasible implementation, the microphone can be an omnidirectional high signal-to-noise ratio microphone, such as a microphone with an SNR (signal-to-noise ratio) ≥ 65dB, to improve the signal-to-noise ratio of the acquired ambient sound signal.

[0091] In one feasible implementation, step S20, which involves locating the sound source direction of the target sound signal based on at least two of the microphones, includes steps S204 to S205:

[0092] Step S204: Calculate the signal-to-noise ratio of each ambient sound signal, and select the two sets of microphones corresponding to the ambient sound signal with the highest signal-to-noise ratio as two sets of sound source localization microphones.

[0093] When multiple microphones are installed around the vehicle's exterior, the signal-to-noise ratio (SNR) of the ambient sound signal collected by each microphone can be calculated when locating the target sound signal. For a group of microphones, the higher SNR of the ambient sound signal collected by the two microphones represents the SNR of the ambient sound signal collected by that group of microphones. The SNRs of the ambient sound signals collected by each group of microphones are compared, and the two groups of microphones with the highest SNR are selected. For distinction, these two groups of microphones are called sound source localization microphones.

[0094] It should be noted that, in the specific implementation, the sound source positioning microphone can be reselected based on the latest collected ambient sound signal at regular intervals (the length of time can be set according to the real-time requirements of sound source direction positioning; the higher the real-time requirements, the shorter the interval). That is, the selection of which two sets of microphones to perform sound source positioning is real-time and not static, thus enabling accurate sound source direction positioning in real time.

[0095] Step S206: Based on the two sets of sound source localization microphones, the target sound signal is localized, and the sound source direction of the target sound signal is obtained based on the localization results obtained by the two sets of sound source localization microphones.

[0096] After identifying two sets of sound source localization microphones, the target sound signal can be located based on these two sets of microphones. The localization results obtained by the two sets of microphones can be an angular range. In a specific implementation, the sound source direction of the target sound signal can be determined from the overlapping portion of the two angular ranges. For example, the middle angle of the overlapping range can be taken as the sound source direction of the target sound signal.

[0097] In this embodiment, by setting up multiple sets of microphones, each set including two microphones, and selecting the two sets of microphones with the highest signal-to-noise ratio, the sound source direction of the target sound signal is located by the two sets of microphones respectively, and then the location results of the two sets of microphones are combined to obtain the final location of the sound source direction, which improves the accuracy of sound source direction location. Thus, when the target sound signal is played back in the vehicle, the direction of the target sound signal can be simulated more accurately, allowing the people in the vehicle to judge the situation outside the vehicle more accurately.

[0098] In one feasible implementation, it can be done according to... Figure 8 The process shown is for providing external sound cues. Microphones installed on the outside of the vehicle collect ambient sound signals; these signals are then noise-reduced and filtered to extract the target sound signal; the sound source is located using the microphone's beamforming principle to determine the direction of the target sound signal; finally, the target sound signal is played back through the various speakers inside the vehicle, and the direction of the target sound signal is simulated by obtaining playback parameter values ​​that match each speaker.

[0099] Furthermore, this invention also proposes an external sound alert device, which is deployed in a vehicle. At least two microphones are arranged around the perimeter of the vehicle body, and at least two speakers are installed inside the vehicle. (Refer to...) Figure 9 The external sound warning device includes:

[0100] Acquisition module 10 is used to acquire ambient sound signals collected by each of the microphones;

[0101] Extraction module 20 is used to extract target sound signals from each of the ambient sound signals and locate the sound source direction of the target sound signal based on at least two of the microphones;

[0102] The control module 30 is used to acquire the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source, and control each of the speakers to play the target sound signal according to its corresponding playback parameter values.

[0103] In one feasible embodiment, the control module 30 is further configured to:

[0104] Obtain a pre-set parameter mapping table, wherein the parameter mapping table contains the mapping relationship between the playback parameter values ​​and the direction of each speaker;

[0105] By searching the parameter mapping table according to the direction of the sound source, the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source are obtained.

[0106] At least four speakers are installed inside the vehicle. The direction of the sound source is represented by a target azimuth angle in a vehicle coordinate system, which is a horizontal coordinate system with the driver's seat position as the origin. The step of obtaining the playback parameter values ​​for simulating the direction of the sound source for each speaker includes:

[0107] The two azimuth angles closest to the target azimuth angle are determined from each preset azimuth angle and used as reference azimuth angles. The number of preset azimuth angles is greater than the number of loudspeakers. For each preset azimuth angle, the playback parameter values ​​of each loudspeaker are preset to simulate the sound source from the preset azimuth angle.

[0108] The weights corresponding to the two reference azimuths are determined according to the angle difference between the target azimuth and the two reference azimuths, wherein the reference azimuth with a smaller angle difference from the target azimuth has a larger weight.

[0109] For each loudspeaker, the playback parameter values ​​of the loudspeakers corresponding to the two reference azimuth angles are weighted and averaged according to the weights corresponding to the two reference azimuth angles to obtain the playback parameter values ​​of the loudspeakers used to simulate the direction of the sound source.

[0110] In one feasible embodiment, the extraction module 20 is further configured to:

[0111] Calculate the signal-to-noise ratio (SNR) of each ambient sound signal and select the ambient sound signal with the highest SNR as the signal to be processed.

[0112] The signal to be processed is subjected to noise reduction processing to obtain the noise-reduced signal;

[0113] Extract the target sound signal from the noise-reduced signal.

[0114] In one feasible embodiment, the extraction module 20 is further configured to:

[0115] The noise-reduced signal is filtered using a preset adaptive filter corresponding to the target sound type to obtain a filtered signal, and the filtered signal is used as the target sound signal; wherein, the adaptive filter adaptively adjusts the filter parameters based on the error between the preset model signal corresponding to the target sound type and the filtered signal to minimize the error.

[0116] In one feasible embodiment, the microphone is an omnidirectional microphone, and a soft vibration-damping material is provided between the microphone and the vehicle body; at least three sets of the microphones are provided around the outer perimeter of the vehicle body, each set of the microphones includes two microphones, and the distance between the two microphones is greater than half the width of the rear of the vehicle; at least one set of microphones is located on the right rear side of the vehicle, at least one set of microphones is located on the left rear side of the vehicle, and at least one set of microphones is located on the rear side of the vehicle; the microphone located on the left rear side of the vehicle and the microphone located on the right rear side of the vehicle are symmetrically arranged based on the central axis of the vehicle parallel to its length direction.

[0117] In one feasible embodiment, the extraction module 20 is further configured to:

[0118] Calculate the signal-to-noise ratio of each ambient sound signal, and select the two sets of microphones corresponding to the ambient sound signals with the highest signal-to-noise ratio as two sets of sound source localization microphones;

[0119] The target sound signal is located by locating the sound source using the two sets of sound source locating microphones, and the sound source direction of the target sound signal is obtained based on the location results obtained by the two sets of sound source locating microphones.

[0120] In one feasible embodiment, the external sound prompting device further includes:

[0121] The detection module is used to detect whether the vehicle is in a closed state after the vehicle is detected to be started.

[0122] The acquisition module 10 is further configured to: if the vehicle is in a closed state, perform the operation of acquiring the ambient sound signals collected by each of the microphones.

[0123] The extended content of the specific implementation of the vehicle exterior sound prompting device of the present invention is basically the same as the various embodiments of the above-described vehicle exterior sound prompting method, and will not be repeated here.

[0124] This invention also provides an external sound alert device, which is deployed in a vehicle. At least two microphones are installed around the perimeter of the vehicle body, and at least two speakers are installed inside the vehicle. The external sound alert device includes a memory, a processor, and an external sound alert program stored in the memory and executable on the processor. When executed by the processor, the external sound alert program performs the following operations:

[0125] Acquire the ambient sound signals collected by each of the microphones;

[0126] Extract the target sound signal from each of the ambient sound signals, and locate the sound source direction of the target sound signal based on at least two of the microphones;

[0127] Obtain the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source, and control each of the speakers to play the target sound signal according to its corresponding playback parameter values.

[0128] In one feasible implementation, the operation of obtaining the playback parameter values ​​for simulating the direction of the sound source corresponding to each of the speakers includes:

[0129] Obtain a pre-set parameter mapping table, wherein the parameter mapping table contains the mapping relationship between the playback parameter values ​​and the direction of each speaker;

[0130] By searching the parameter mapping table according to the direction of the sound source, the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source are obtained.

[0131] In one feasible embodiment, at least four speakers are installed inside the vehicle, and the direction of the sound source is represented by a target azimuth angle in a vehicle coordinate system, wherein the vehicle coordinate system is a horizontal coordinate system established with the driver's seat position as the origin; the operation of obtaining the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source includes:

[0132] The two azimuth angles closest to the target azimuth angle are determined from each preset azimuth angle and used as reference azimuth angles. The number of preset azimuth angles is greater than the number of loudspeakers. For each preset azimuth angle, the playback parameter values ​​of each loudspeaker are preset to simulate the sound source from the preset azimuth angle.

[0133] The weights corresponding to the two reference azimuths are determined according to the angle difference between the target azimuth and the two reference azimuths, wherein the reference azimuth with a smaller angle difference from the target azimuth has a larger weight.

[0134] For each loudspeaker, the playback parameter values ​​of the loudspeakers corresponding to the two reference azimuth angles are weighted and averaged according to the weights corresponding to the two reference azimuth angles to obtain the playback parameter values ​​of the loudspeakers used to simulate the direction of the sound source.

[0135] In one feasible implementation, the operation of extracting the target sound signal from each of the ambient sound signals includes:

[0136] Calculate the signal-to-noise ratio (SNR) of each ambient sound signal and select the ambient sound signal with the highest SNR as the signal to be processed.

[0137] The signal to be processed is subjected to noise reduction processing to obtain the noise-reduced signal;

[0138] Extract the target sound signal from the noise-reduced signal.

[0139] In one feasible implementation, the operation of extracting the target sound signal from the noise-reduced signal includes:

[0140] The noise-reduced signal is filtered using a preset adaptive filter corresponding to the target sound type to obtain a filtered signal, and the filtered signal is used as the target sound signal; wherein, the adaptive filter adaptively adjusts the filter parameters based on the error between the preset model signal corresponding to the target sound type and the filtered signal to minimize the error.

[0141] In one feasible embodiment, the microphone is an omnidirectional microphone, and a soft vibration-damping material is provided between the microphone and the vehicle body; at least three sets of the microphones are provided around the outer perimeter of the vehicle body, each set of the microphones includes two microphones, and the distance between the two microphones is greater than half the width of the rear of the vehicle; at least one set of microphones is located on the right rear side of the vehicle, at least one set of microphones is located on the left rear side of the vehicle, and at least one set of microphones is located on the rear side of the vehicle; the microphone located on the left rear side of the vehicle and the microphone located on the right rear side of the vehicle are symmetrically arranged based on the central axis of the vehicle parallel to its length direction.

[0142] In one feasible implementation, the operation of locating the sound source direction of the target sound signal based on at least two of the microphones includes:

[0143] Calculate the signal-to-noise ratio of each ambient sound signal, and select the two sets of microphones corresponding to the ambient sound signals with the highest signal-to-noise ratio as two sets of sound source localization microphones;

[0144] The target sound signal is located by locating the sound source using the two sets of sound source locating microphones, and the sound source direction of the target sound signal is obtained based on the location results obtained by the two sets of sound source locating microphones.

[0145] In one feasible implementation, prior to the operation of acquiring the ambient sound signals collected by each of the microphones, the external sound prompting program, when executed by the processor, further performs the following operations:

[0146] After detecting that the vehicle has started, it checks whether the vehicle is in a closed state;

[0147] If the vehicle is in a closed state, then the step of acquiring the ambient sound signals collected by each of the microphones is performed.

[0148] The various embodiments of the vehicle exterior sound prompting device and computer-readable storage medium of the present invention can be referred to the various embodiments of the vehicle exterior sound prompting method of the present invention, and will not be repeated here.

[0149] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0150] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0151] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0152] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for providing external vehicle sound prompts, characterized in that, The external sound prompting method is applied to a vehicle, wherein at least two microphones are installed around the perimeter of the vehicle body, and at least two speakers are installed inside the vehicle. The external sound prompting method includes: Acquire the ambient sound signals collected by each of the microphones; Extract the target sound signal from each of the ambient sound signals, and locate the sound source direction of the target sound signal based on at least two of the microphones; Obtain the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source, and control each of the speakers to play the target sound signal according to its corresponding playback parameter values; When the target sound signal is played, if other audio signals are played simultaneously inside the vehicle, the playback of the other audio signals is stopped or the volume of the other audio signals is reduced. The vehicle is equipped with at least four speakers, and the direction of the sound source is represented by a target azimuth angle in a vehicle coordinate system, which is a horizontal coordinate system with the driver's seat position as the origin. The step of obtaining the playback parameter values ​​for simulating the direction of the sound source for each speaker includes: The two azimuth angles closest to the target azimuth angle are determined from each preset azimuth angle and used as reference azimuth angles. The number of preset azimuth angles is greater than the number of loudspeakers. For each preset azimuth angle, the playback parameter values ​​of each loudspeaker are preset to simulate the sound source from the preset azimuth angle. The weights corresponding to the two reference azimuths are determined according to the angle difference between the target azimuth and the two reference azimuths, wherein the reference azimuth with a smaller angle difference from the target azimuth has a larger weight. For each loudspeaker, the playback parameter values ​​of the loudspeakers corresponding to the two reference azimuth angles are weighted and averaged according to the weights corresponding to the two reference azimuth angles to obtain the playback parameter values ​​of the loudspeakers used to simulate the direction of the sound source.

2. The vehicle exterior sound prompting method as described in claim 1, characterized in that, The step of obtaining the playback parameter values ​​for simulating the direction of the sound source corresponding to each of the speakers includes: Obtain a pre-set parameter mapping table, wherein the parameter mapping table contains the mapping relationship between the playback parameter values ​​and the direction of each speaker; By searching the parameter mapping table according to the direction of the sound source, the playback parameter values ​​corresponding to each of the speakers for simulating the direction of the sound source are obtained.

3. The vehicle exterior sound prompting method as described in claim 1, characterized in that, The step of extracting the target sound signal from each of the environmental sound signals includes: Calculate the signal-to-noise ratio (SNR) of each ambient sound signal and select the ambient sound signal with the highest SNR as the signal to be processed. The signal to be processed is subjected to noise reduction processing to obtain the noise-reduced signal; Extract the target sound signal from the noise-reduced signal.

4. The vehicle exterior sound prompting method as described in claim 3, characterized in that, The step of extracting the target sound signal from the noise-reduced signal includes: The noise-reduced signal is filtered using a preset adaptive filter corresponding to the target sound type to obtain a filtered signal, and the filtered signal is used as the target sound signal; wherein, the adaptive filter adaptively adjusts the filter parameters based on the error between the preset model signal corresponding to the target sound type and the filtered signal to minimize the error.

5. The method for external sound prompts as described in claim 1, characterized in that, The microphone is an omnidirectional microphone, and a soft vibration-damping material is provided between the microphone and the vehicle body; at least three sets of the microphones are provided around the outer perimeter of the vehicle body, each set of the microphones includes two microphones, and the distance between the two microphones is greater than half the width of the rear of the vehicle; at least one set of microphones is located on the right rear side of the vehicle, at least one set of microphones is located on the left rear side of the vehicle, and at least one set of microphones is located on the rear side of the vehicle; the microphone located on the left rear side of the vehicle and the microphone located on the right rear side of the vehicle are symmetrically arranged based on the central axis of the vehicle parallel to its length direction.

6. The vehicle exterior sound prompting method as described in claim 5, characterized in that, The step of locating the sound source direction of the target sound signal based on at least two of the microphones includes: Calculate the signal-to-noise ratio of each ambient sound signal, and select the two sets of microphones corresponding to the ambient sound signals with the highest signal-to-noise ratio as two sets of sound source localization microphones; The target sound signal is located by locating the sound source using the two sets of sound source locating microphones, and the sound source direction of the target sound signal is obtained based on the location results obtained by the two sets of sound source locating microphones.

7. The vehicle exterior sound prompting method as described in any one of claims 1 to 6, characterized in that, Before the step of acquiring the ambient sound signals collected by each of the microphones, the method further includes: After detecting that the vehicle has started, it checks whether the vehicle is in a closed state; If the vehicle is in a closed state, then the step of acquiring the ambient sound signals collected by each of the microphones is performed.

8. An external vehicle sound warning device, characterized in that, The external sound alert device is deployed in the vehicle, with at least two microphones installed around the perimeter of the vehicle body and at least two speakers installed inside the vehicle. The external sound alert device includes: The acquisition module is used to acquire the ambient sound signals collected by each of the microphones; An extraction module is used to extract a target sound signal from each of the ambient sound signals and locate the sound source direction of the target sound signal based on at least two of the microphones; The control module is used to acquire playback parameter values ​​corresponding to each of the speakers for simulating the sound source direction, and to control each speaker to play the target sound signal according to its corresponding playback parameter values. When playing the target sound signal, if other audio signals are simultaneously played inside the vehicle, the playback of the other audio signals is stopped or the volume of the other audio signals is reduced. At least four speakers are installed inside the vehicle. The sound source direction is represented by a target azimuth angle in the vehicle coordinate system, which is a horizontal coordinate system established with the driver's seat position as the origin. Specifically, the control module is used to determine the two azimuth angles closest to the target azimuth angle from a set of preset azimuth angles, as parameters. The system considers azimuth angles, wherein the number of preset azimuth angles is greater than the number of loudspeakers. For each preset azimuth angle, playback parameter values ​​for each loudspeaker are preset to simulate a sound source from that preset azimuth angle. Weights are determined for the two reference azimuth angles based on the angular difference between the target azimuth angle and the two reference azimuth angles, with the reference azimuth angle having a smaller angular difference from the target azimuth angle having a larger weight. For each loudspeaker, the preset playback parameter values ​​for the loudspeakers corresponding to the two reference azimuth angles are weighted and averaged according to their respective weights to obtain the playback parameter values ​​for the loudspeakers used to simulate the direction of the sound source.

9. An external vehicle sound alert device, characterized in that, The vehicle exterior sound alert device includes: a memory, a processor, and a vehicle exterior sound alert program stored in the memory and executable on the processor. When the vehicle exterior sound alert program is executed by the processor, it implements the steps of the vehicle exterior sound alert method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores an external sound prompting program, which, when executed by a processor, implements the steps of the external sound prompting method as described in any one of claims 1 to 7.

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