A headrest volume calibration method and system

Abstract

The present application belongs to the technical field of vehicle-mounted multimedia, and provides a vehicle-mounted headrest volume calibration method and system. The method plays test audio through a headrest loudspeaker and collects in real time with the aid of a vehicle-mounted microphone, realizes automatic perception of the acoustic characteristics of the headrest playing environment, and is fast and efficient in the calibration process. The recorded audio signal is disassembled into a background noise signal and a recorded audio signal, which are compared with a standard reference amplitude respectively, and the noise influence parameter and the sound pressure change influence parameter are calculated independently, which can accurately distinguish the two different factors of external environmental interference and headrest cover acoustic attenuation, and provide fine data basis for subsequent compensation. Based on the noise influence parameter and the sound pressure change influence parameter, dynamic switching compensation can adaptively cope with various complex scenes such as headrest surface interior cover mesh blockage, cover replacement or increase and decrease, change of in-vehicle sound insulation performance and external noise fluctuation, etc., to ensure that the headrest loudspeaker can output stable and appropriate volume under various working conditions.

Description

Technical Field

[0001] This invention belongs to the field of vehicle multimedia technology, specifically relating to a method and system for calibrating the volume of a vehicle headrest. Background Technology

[0002] Currently, headrest speakers are widely used as standard equipment in mid-to-high-end new energy vehicles, and this is gradually being extended to the front passenger seat and rear seats, aiming to improve immersive sound effects, driving comfort, and call privacy. However, because headrest speakers are very close to the ears, fluctuations and inconsistencies in their volume are easily perceived by users, significantly impacting the overall listening experience.

[0003] Due to limitations in installation structure and acoustic propagation characteristics, headrest speakers are more susceptible to external interference than other speakers in the vehicle during practical applications, thus exacerbating volume deviations and weakening the user experience. Specifically, most current models use the same volume curve calibration for both headrest and non-headrest modes. After a period of vehicle use, the surface mesh of the headrest speakers is prone to clogging due to dust or the addition of protective coverings, affecting acoustic output. Furthermore, since the tuning and calibration phase is mostly completed in an anechoic chamber or extremely quiet environment, it fails to cover complex background noise scenarios such as air conditioning and road noise encountered during daily driving. Because headrest speakers operate at relatively low sound pressure levels, they are more significantly affected by environmental noise, further amplifying the perceived differences in sound.

[0004] However, recalibrating the volume curve in headrest mode separately presents several practical challenges: First, calibrating each vehicle individually is not only a massive undertaking but also requires coordinated software changes, resulting in high implementation costs. Second, different users have significantly different driving environments and subjective preferences, making it difficult to achieve a unified adaptation. Third, with both headrest and non-headrest modes sharing the same basic curve, adjusting the headrest volume curve separately can easily have a ripple effect on the overall sound effect in non-headrest mode, causing new auditory imbalances. Summary of the Invention

[0005] The purpose of this invention is to disclose a method and system for calibrating the volume of a vehicle headrest, which solves the technical problem that existing headrest speakers, under the common volume curve calibration, suffer from volume deviations due to differences in mesh blockage, background noise, etc. in actual use, while recalibrating the headrest curve separately is difficult, making it hard to improve the user's listening experience.

[0006] To achieve the above objectives, this invention discloses a method for calibrating the volume of a vehicle headrest, comprising: Enter headrest mode and drive the headrest speaker to play the target test audio; Activate the vehicle microphone to record audio and obtain the recorded audio signal; Disassemble the recorded audio signal to obtain a background noise signal and at least two sets of recorded audio signals; The background noise signal and the recorded audio signal are compared and analyzed with the corresponding standard reference amplitude to calculate the corresponding noise impact parameters and sound pressure change impact parameters. Dynamic switching compensation is performed based on the noise impact parameters and the sound pressure change impact parameters. Compensation adjustment parameters are calculated, and headrest volume calibration is performed based on the compensation adjustment parameters.

[0007] This basic solution plays test audio through headrest speakers and collects it in real time using an in-vehicle microphone, enabling automatic perception of the acoustic characteristics of the headrest playback environment and a fast and efficient calibration process. The recorded audio signal is decomposed into background noise and recorded audio signals, which are then compared separately with standard reference amplitudes. Noise impact parameters and sound pressure level change impact parameters are calculated independently, accurately distinguishing between external environmental interference and acoustic attenuation from the headrest covering. This provides a refined data foundation for subsequent compensation. Dynamic switching compensation based on noise and sound pressure level change impact parameters adapts to various complex scenarios, such as blocked mesh in the headrest surface interior covering, replacement or addition of coverings, changes in in-vehicle sound insulation performance, and external noise fluctuations. This ensures that the headrest speakers output stable and appropriate volume under various conditions. Thus, after intelligent calibration, the volume in headrest mode is more closely aligned with the user's actual listening habits, improving audio playback comfort and satisfaction during driving and enhancing the intelligence level of the in-vehicle entertainment system.

[0008] As an optional implementation, entering headrest mode and driving the headrest speaker to play the target test audio includes: Create target test audio, segmented by flag bits, and composed of target test audio based on silence signal, standard media music signal, standard navigation tone signal, standard voice signal, and standard telephone tone signal; Enter headrest mode, configure the target volume for the target test audio, and drive the headrest speaker to play the target test audio.

[0009] This solution segments audio based on flags and generates target test audio signals according to mute signals, standard media music signals, standard navigation audio signals, standard voice signals, and standard telephone audio signals. Through flag segmentation and structured standardized signal combinations, it accurately locates the playback performance of various sound effects. The headrest mode, combined with the target volume configuration, simulates real-world usage scenarios such as "playing media, navigation, voice, and telephone calls," effectively improving the accuracy and scenario adaptability of in-vehicle headrest volume calibration. Furthermore, it only involves intelligent calibration of the volume curve in headrest mode, without affecting the sound experience of various audio sources in non-headrest modes.

[0010] As an optional implementation, the recorded audio signal is disassembled to obtain a background noise signal and at least two sets of recorded audio signals, specifically: The recorded audio signal is acquired, and the recorded audio signal is split based on the pre-embedded flag bit to obtain the background noise signal corresponding to the silence signal, and at least two sets of recorded audio signals; the recorded audio signal includes the recording signal corresponding to the audio content of the standard media music signal, standard navigation tone signal, standard voice signal, and standard telephone tone signal.

[0011] This solution utilizes pre-embedded flags to achieve precise segmentation of recorded audio, effectively separating background noise from various standardized audio source signals.

[0012] As an optional implementation, the background noise signal and the recorded audio signal are compared and analyzed with the corresponding standard reference amplitude to calculate the corresponding noise impact parameters and sound pressure change impact parameters, including: The background noise signal and the recorded audio signal are processed by Fast Fourier Transform to convert them into corresponding amplitude-frequency data, which are then further converted into voltage amplitude values ​​as audio output amplitude values. Obtain the standard audio file corresponding to the target test audio, perform fast Fourier transform processing on it, convert it into the corresponding amplitude frequency data, and further convert it into voltage amplitude as the standard output amplitude; Obtain the audio output amplitude and standard output amplitude corresponding to the background noise signal, compare and analyze the volume change and map it to the perceptual domain, and output the noise influence parameter; The audio output amplitude and standard output amplitude corresponding to the recorded audio signal are obtained, the volume changes are compared and analyzed and mapped to the perceptual domain, and the parameters affecting the sound pressure change are output.

[0013] As an optional implementation, the volume change mapping formula is as follows:

[0014] In the formula, Indicates the audio output amplitude. This indicates the standard output amplitude.

[0015] This solution eliminates differences in signal format and dimensions by performing Fast Fourier Transform on background noise signals, recorded audio signals, and standard audio files, converting them all into voltage amplitude values. Noise impact parameters and sound pressure level change impact parameters are calculated independently for both background noise and recorded audio signals, enabling the assessment of the interference level of ambient background noise and the measurement of the headrest speaker's response deviation to the target signal. Furthermore, by mapping volume changes in the physical domain to the perceptual domain, the calculation results are transformed from simple voltage differences into acoustic indicators that better reflect human hearing characteristics. It aligns with the user's subjective experience.

[0016] As an optional implementation, dynamic switching compensation is performed based on the noise impact parameters and the sound pressure change impact parameters, and compensation adjustment parameters are calculated, including: The impact of environmental noise on the fluctuation of listening experience is analyzed based on the aforementioned noise impact parameters. Dynamic switching compensation is performed based on the fluctuation impact. If the fluctuation impact is greater than a preset threshold, the noise impact parameter and the sound pressure change impact parameter are combined for joint analysis to calculate the compensation adjustment parameter; otherwise, the compensation adjustment parameter is calculated based on the sound pressure change impact parameter.

[0017] This solution first analyzes the fluctuation of environmental noise on the listening experience based on noise impact parameters. When the impact is small, it directly calculates compensation and adjustment parameters based on the sound pressure change impact parameters to quickly respond to sound pressure changes. When the ambient background noise exceeds the standard, it then links the noise impact parameters and the sound pressure change impact parameters to calculate compensation and adjustment parameters. Through graded compensation and adjustment, it avoids invalid calculations, saves computing power, and can accurately guarantee the listening experience in complex noise environments.

[0018] As an optional implementation, a joint analysis is performed on the noise impact parameters and the sound pressure change impact parameters to calculate compensation adjustment parameters, including: Obtain the audio output amplitude corresponding to the recorded audio signal and the background noise signal; The audio output amplitude is normalized and then mapped to the perceptual domain to obtain the corresponding target influence parameters; Obtain the target influence parameters corresponding to the background noise signal and the recorded audio signal, compare and analyze the relative interference of environmental noise, and calculate the joint adjustment coefficient; Based on the joint adjustment coefficient, at least one set of compensation adjustment parameters is obtained by combining the noise impact parameters and the sound pressure change impact parameters through joint analysis.

[0019] This solution normalizes the audio output amplitude and maps it to the "perceptual domain," eliminating the discrepancy between purely physical measurements and human hearing, making the compensation more aligned with subjective experience. Simultaneously, it acquires the corresponding background noise signal, calculates the joint adjustment coefficients based on the target influence parameters of the recorded audio signal, and compares and analyzes the relative interference of environmental noise. By synergistically coupling environmental noise with signal sound pressure, it achieves targeted dynamic compensation in complex dynamic noise, effectively avoiding auditory distortion caused by overcompensation or undercompensation.

[0020] As an optional implementation, headrest volume calibration is performed according to the compensation adjustment parameters, including: Obtain the compensation adjustment parameters corresponding to the recorded audio signal and the current volume curve. Based on the current volume curve, superimpose the compensation adjustment parameters to form a new volume curve, thus completing the headrest volume calibration.

[0021] The present invention also provides a vehicle headrest volume calibration system for implementing the vehicle headrest volume calibration method described above, including a vehicle infotainment system, a power amplifier module, and at least one set of headrest speakers and a vehicle microphone; the vehicle infotainment system is connected to the power amplifier module and the vehicle microphone, and the power amplifier module is connected to the headrest speakers.

[0022] As an optional implementation, the vehicle infotainment system includes a main controller, an audio processing module, an audio playback module, an audio storage module, and an audio recording module. The main controller is connected to the power amplifier module, the audio processing module, and the audio playback module. The audio storage module is connected to the audio processing module, the audio playback module, and the audio recording module. The audio playback module is connected to the power amplifier module, and the audio recording module is connected to the vehicle microphone.

[0023] This basic solution constructs a volume calibration system using the vehicle's basic infotainment system, amplifier module, and at least one set of headrest speakers and in-vehicle microphones. It can intelligently calibrate the headrest mode volume without additional hardware or software changes or the presence of a sound engineer. It solves the sound differences caused by environmental factors, aging, or scene changes at a low cost. It calculates and adjusts parameters independently for different audio playback scenarios in different scenarios, effectively improving the user's sound experience in headrest mode for audio-visual, navigation, voice, and telephone use scenarios, without affecting the original sound quality in non-headrest mode. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating the process of a vehicle headrest volume calibration method provided in an embodiment of the present invention; Figure 2 This is a system framework diagram of a vehicle headrest volume calibration system provided in an embodiment of the present invention. Detailed Implementation

[0026] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation.

[0028] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0029] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0030] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0031] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0032] Example 1 Please see Figure 1 As shown in the figure, this application provides a method for calibrating the volume of a vehicle headrest, including: S1. Enter headrest mode and drive the headrest speaker to play the target test audio, including: Create target test audio, segmented by flag bits, and composed of target test audio based on silence signal, standard media music signal, standard navigation tone signal, standard voice signal, and standard telephone tone signal; Enter headrest mode, configure the target volume for the target test audio, and drive the headrest speaker to play the target test audio.

[0033] Specifically, the audio file for the target test consists of 5 signals: a mute signal, a standard media music signal, a standard navigation tone signal, a standard voice signal, and a standard telephone tone signal. The playback duration of each signal is fixed, and each signal is distinguished by a flag.

[0034] Audio playback is performed according to the target volume preset by the vehicle's infotainment system. Since the sound pressure level of the headrest speakers is relatively low, the preset target volume needs to be above 80% of the maximum volume.

[0035] In headrest mode, different audio sources such as media, navigation, voice, and telephone are all emitted through the headrest speaker, while other speakers do not emit sound. Each audio source has a corresponding volume bar, which corresponds to a pre-calibrated volume curve. At this time, the volume adjustment of the headrest speaker uses the system's default volume curve.

[0036] This solution segments audio based on flags and generates target test audio signals according to mute signals, standard media music signals, standard navigation audio signals, standard voice signals, and standard telephone audio signals. Through flag segmentation and structured standardized signal combinations, it accurately locates the playback performance of various sound effects. The headrest mode, combined with the target volume configuration, simulates real-world usage scenarios such as "playing media, navigation, voice, and telephone calls," effectively improving the accuracy and scenario adaptability of in-vehicle headrest volume calibration. Furthermore, it only involves intelligent calibration of the volume curve in headrest mode, without affecting the sound experience of various audio sources in non-headrest modes.

[0037] S2. Start the vehicle microphone to record audio and obtain the recorded audio signal; Specifically, while playing the audio, the vehicle microphone is simultaneously activated (i.e., steps S1 and S2 are executed simultaneously). Since there are usually multiple microphones in a car, the microphone closest to the headrest speaker is usually selected to reduce measurement errors. The recorded audio is saved in the vehicle's storage area.

[0038] S3. Disassemble the recorded audio signal to obtain a background noise signal and at least two sets of recorded audio signals, specifically: The recorded audio signal is acquired, and the recorded audio signal is split based on the pre-embedded flag bit to obtain the background noise signal corresponding to the silence signal, and at least two sets of recorded audio signals; the recorded audio signal includes the recording signal corresponding to the audio content of the standard media music signal, standard navigation tone signal, standard voice signal, and standard telephone tone signal.

[0039] For example, the audio file containing the recorded audio signal and the original stored standard reference audio file are analyzed to calculate the difference. Before the calculation, the recorded audio signal is first split into five audio signals according to the flag bits: a mute signal, a media music signal, a navigation sound signal, a voice signal, and a telephone sound signal. This is because the first mute signal recorded in the actual vehicle is actually a background noise signal, and the other four signals are composite signals of the corresponding sound source and background noise. Similarly, the standard reference audio stored in the vehicle's infotainment system is also divided into five audio segments.

[0040] This solution utilizes pre-embedded flags to achieve precise segmentation of recorded audio, effectively separating background noise from various standardized audio source signals.

[0041] S4. Compare and analyze the background noise signal and the recorded audio signal with the corresponding standard reference amplitude, and calculate the corresponding noise impact parameters and sound pressure change impact parameters, including: S41. Perform Fast Fourier Transform on the background noise signal and the recorded audio signal to convert them into corresponding amplitude-frequency data, and further convert them into voltage amplitude as audio output amplitude. Specifically: First, the amplitude-frequency data corresponding to the background noise signal and the recorded audio signal are sampled to obtain several sets of sampled signals corresponding to the volume and then the average value is calculated to obtain the signal average value as the digital sample value. The voltage amplitude is converted based on the digital sampled values. The formula for calculating the voltage amplitude is as follows:

[0042] Where D represents the digital sampled value, n represents the bit depth (e.g., 16-bit, 24-bit), and Vref represents the reference voltage value (obtained based on the properties of the hardware sampling device).

[0043] Thus, five audio output amplitudes are obtained. This corresponds to the first segment of background noise signal. ; Corresponding to the second segment of media music signal, ; Corresponds to the third navigation tone signal, ; Corresponding to the 4th segment of the speech signal, ; Corresponds to the 5th segment of the telephone tone signal, .

[0044] S42. Obtain the standard audio file corresponding to the target test audio, perform fast Fourier transform processing on it, convert it into the corresponding amplitude-frequency data, and further convert it into voltage amplitude as the standard output amplitude. Accordingly, five standard output amplitudes are obtained. This corresponds to the first segment of background noise signal. ; Corresponding to the second segment of media music signal, ; Corresponds to the third navigation tone signal, ; Corresponding to the 4th segment of the speech signal, ; Corresponds to the 5th segment of the telephone tone signal, .

[0045] S43. Obtain the audio output amplitude and standard output amplitude corresponding to the background noise signal, compare and analyze the volume change and map it to the perceptual domain, and output the noise influence parameter; S44. Obtain the audio output amplitude and standard output amplitude corresponding to the recorded audio signal, compare and analyze the volume change and map it to the perception domain, and output the sound pressure change influence parameter.

[0046] In this embodiment, the increase and decrease of sound exhibit a logarithmic relationship, typically expressed in dB. Therefore, when calculating audio gain or attenuation, the... The formula for mapping volume changes is as follows:

[0047] In the formula, Indicates the audio output amplitude. This indicates the standard output amplitude.

[0048] By successively substituting the five sets of audio output amplitude and standard output amplitude, the noise impact parameters are obtained. The parameters affected by changes in sound pressure levels for media playback, navigation, voice, and telephone calls. , , , .

[0049] This solution eliminates differences in signal format and dimensions by performing Fast Fourier Transform on background noise signals, recorded audio signals, and standard audio files, converting them all into voltage amplitude values. Noise impact parameters and sound pressure level change impact parameters are calculated independently for both background noise and recorded audio signals, enabling the assessment of the interference level of ambient background noise and the measurement of the headrest speaker's response deviation to the target signal. Furthermore, by mapping volume changes in the physical domain to the perceptual domain, the calculation results are transformed from simple voltage differences into acoustic indicators that better reflect human hearing characteristics. It aligns with the user's subjective experience.

[0050] S5. Perform dynamic switching compensation based on the noise impact parameters and the sound pressure change impact parameters, and calculate the compensation adjustment parameters, including: The impact of environmental noise on the fluctuation of listening experience is analyzed based on the aforementioned noise impact parameters. Dynamic switching compensation is performed based on the fluctuation impact. If the fluctuation impact is greater than a preset threshold, the noise impact parameter and the sound pressure change impact parameter are combined for joint analysis to calculate the compensation adjustment parameter; otherwise, the compensation adjustment parameter is calculated based on the sound pressure change impact parameter.

[0051] In this embodiment, the noise impact parameters and the sound pressure change impact parameters are jointly analyzed to calculate the compensation adjustment parameters, including: a. Obtain the audio output amplitude corresponding to the recorded audio signal and the background noise signal; b. Normalize the amplitude of the audio output and then map it to the perceptual domain to obtain the corresponding target influence parameters; c. Obtain the target influence parameters corresponding to the background noise signal and the recorded audio signal, compare and analyze the relative interference of environmental noise, and calculate the joint adjustment coefficient; The following are the joint adjustment coefficients for the corresponding media music signal, navigation tone signal, voice signal, and telephone tone signal: , , , The calculation formula is as follows:

[0052]

[0053]

[0054]

[0055] d. Based on the joint adjustment coefficient, a joint analysis is performed on the noise influence parameters and the sound pressure change influence parameters to obtain at least one set of compensation adjustment parameters.

[0056] Specifically: There are four volume curves corresponding to the four sound sources, each with an independent adjustment parameter, denoted as T in this embodiment. The main influencing factor for the gain or attenuation difference in background noise is environmental noise, and the difference can vary considerably. Therefore, the noise-affecting parameters... Perform an absolute value determination and set a preset threshold α. For example, the preset threshold α is set to 3dB based on actual usage.

[0057] The compensation adjustment parameters for the volume curves of the four signals—media music signal, navigation tone signal, voice signal, and telephone tone signal—are respectively used... , , , express.

[0058] (1) When |LdB1|> preset threshold α:

[0059]

[0060]

[0061]

[0062] (2) When |LdB1|≤ preset threshold α:

[0063]

[0064]

[0065]

[0066] This solution normalizes the audio output amplitude and maps it to the "perceptual domain," eliminating the discrepancy between purely physical measurements and human hearing, making the compensation more aligned with subjective experience. Simultaneously, it acquires the corresponding background noise signal, calculates the joint adjustment coefficients based on the target influence parameters of the recorded audio signal, and compares and analyzes the relative interference of environmental noise. By synergistically coupling environmental noise with signal sound pressure, it achieves targeted dynamic compensation in complex dynamic noise, effectively avoiding auditory distortion caused by overcompensation or undercompensation.

[0067] This solution first analyzes the fluctuation of environmental noise on the listening experience based on noise impact parameters. When the impact is small, it directly calculates compensation and adjustment parameters based on the sound pressure change impact parameters to quickly respond to sound pressure changes. When the ambient background noise exceeds the standard, it then links the noise impact parameters and the sound pressure change impact parameters to calculate compensation and adjustment parameters. Through graded compensation and adjustment, it avoids invalid calculations, saves computing power, and can accurately guarantee the listening experience in complex noise environments.

[0068] S6. Perform headrest volume calibration according to the compensation adjustment parameters, including: Obtain the compensation adjustment parameters corresponding to the recorded audio signal and the current volume curve. Based on the current volume curve, superimpose the compensation adjustment parameters to form a new volume curve, thus completing the headrest volume calibration.

[0069] Specifically, at this time , , , These four compensation adjustment parameters are applied to each level of the media music signal volume curve, navigation sound signal volume curve, voice signal volume curve, and telephone sound signal volume curve to form a new volume curve. In headrest mode, the system executes the adjusted new volume curve. When exiting headrest mode and entering non-headrest mode, the system reverts to the original volume curve. This effectively improves the audio experience in headrest mode, mitigating the degradation caused by changes in the headrest speaker's sound output due to external environmental changes, aging of the headrest speaker module and surface covering, and changes in usage scenarios. It significantly enhances the user's sound experience in headrest mode for audio-visual, navigation, voice, and telephone use.

[0070] Meanwhile, to meet the diverse needs of users, the vehicle's infotainment system has a restore setting, which helps users easily restore the default settings.

[0071] This invention, through headrest speakers playing test audio and using an in-vehicle microphone to collect data in real time, achieves automatic perception of the acoustic characteristics of the headrest playback environment, making the calibration process quick and efficient. The recorded audio signal is decomposed into background noise and recorded audio signals, which are then compared with standard reference amplitudes. Noise impact parameters and sound pressure level change impact parameters are calculated independently, accurately distinguishing between external environmental interference and acoustic attenuation from the headrest covering, providing a refined data foundation for subsequent compensation. Dynamic switching compensation based on noise and sound pressure level change impact parameters adaptively addresses various complex scenarios such as blocked mesh in the headrest surface covering, replacement or addition of coverings, changes in in-vehicle sound insulation performance, and external noise fluctuations, ensuring the headrest speakers output stable and appropriate volume under various conditions. Thus, after intelligent calibration, the sound level in headrest mode better matches the user's actual listening habits, improving audio playback comfort and satisfaction during driving and enhancing the intelligence level of the in-vehicle entertainment system.

[0072] Example 2 This invention also provides a vehicle headrest volume calibration system for implementing the vehicle headrest volume calibration method described in Embodiment 1 above. (See also...) Figure 2 The system includes a vehicle infotainment system 1, an amplifier module 2, and at least one set of headrest speakers 3 and a vehicle microphone 4; the vehicle infotainment system 1 is connected to the amplifier module 2 and the vehicle microphone 4, and the amplifier module 3 is connected to the headrest speakers 4.

[0073] This includes at least one set of headrest speakers installed in the driver's left headrest, driver's right headrest, passenger's headrest, and rear headrest.

[0074] In this embodiment, the vehicle infotainment system 1 includes a main controller 11, an audio processing module 12, an audio playback module 13, an audio storage module 14, and an audio recording module 15. The main controller 11 is connected to the power amplifier module 3, the audio processing module 12, and the audio playback module 13. The audio storage module 14 is connected to the audio processing module 12, the audio playback module 13, and the audio recording module 15. The audio playback module 15 is connected to the power amplifier module 3, and the audio recording module 15 is connected to the vehicle microphone 4.

[0075] The main controller transmits control signals to the power amplifier module via a CAN bus, while the audio playback module and the power amplifier module transmit audio signals via an A2B line.

[0076] After entering volume calibration mode, the vehicle's infotainment system plays a pre-stored target test audio, with a fixed playback duration for each signal in the target test audio. Simultaneously, control signals (including start signals and volume control signals) are sent to the power amplifier module via the CAN bus, and the audio stream is transmitted to the power amplifier module for amplification via the A2B line. Then, the headrest speakers play sound; the vehicle's microphone records background noise and sound from the headrest speakers, obtaining a recorded audio signal; the audio file containing the recorded audio signal is stored in the audio storage module; and the vehicle's audio processing module analyzes and compares the audio file containing the recorded audio signal with the original stored standard reference audio file.

[0077] This invention constructs a volume calibration system using a vehicle-mounted infotainment system, an amplifier module, at least one set of headrest speakers, and an in-vehicle microphone. It can intelligently calibrate the headrest mode volume without additional hardware or software changes or the presence of a sound engineer. This low-cost solution addresses sound differences caused by environmental factors, aging, or scene changes. It calculates and independently adjusts parameters for different audio playback scenarios, effectively improving the user's sound experience in headrest mode for audio-visual, navigation, voice, and telephone use scenarios, without affecting the original sound quality in non-headrest modes.

[0078] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A method for calibrating the volume of a vehicle headrest, characterized in that, include: Enter headrest mode and drive the headrest speaker to play the target test audio; Activate the vehicle microphone to record audio and obtain the recorded audio signal; Disassemble the recorded audio signal to obtain a background noise signal and at least two sets of recorded audio signals; The background noise signal and the recorded audio signal are compared and analyzed with the corresponding standard reference amplitude to calculate the corresponding noise impact parameters and sound pressure change impact parameters. Dynamic switching compensation is performed based on the noise impact parameters and the sound pressure change impact parameters. Compensation adjustment parameters are calculated, and headrest volume calibration is performed based on the compensation adjustment parameters.

2. The method for calibrating the volume of a vehicle headrest as described in claim 1, characterized in that... Entering headrest mode, the headrest speaker is driven to play the target test audio, including: Create target test audio, segmented by flag bits, and composed of target test audio based on silence signal, standard media music signal, standard navigation tone signal, standard voice signal, and standard telephone tone signal; Enter headrest mode, configure the target volume for the target test audio, and drive the headrest speaker to play the target test audio.

3. The method for calibrating the volume of a vehicle headrest as described in claim 2, characterized in that, Disassembling the recorded audio signal yields a background noise signal and at least two sets of recorded audio signals, specifically: The recorded audio signal is acquired, and the recorded audio signal is split based on the pre-embedded flag bit to obtain the background noise signal corresponding to the silence signal, and at least two sets of recorded audio signals; the recorded audio signal includes the recording signal corresponding to the audio content of the standard media music signal, standard navigation tone signal, standard voice signal, and standard telephone tone signal.

4. The method for calibrating the volume of a vehicle headrest as described in claim 1, characterized in that, The background noise signal and the recorded audio signal are compared and analyzed with the corresponding standard reference amplitude to calculate the corresponding noise impact parameters and sound pressure change impact parameters, including: The background noise signal and the recorded audio signal are processed by Fast Fourier Transform to convert them into corresponding amplitude-frequency data, which are then further converted into voltage amplitude values ​​as audio output amplitude values. Obtain the standard audio file corresponding to the target test audio, perform fast Fourier transform processing on it, convert it into the corresponding amplitude frequency data, and further convert it into voltage amplitude as the standard output amplitude; Obtain the audio output amplitude and standard output amplitude corresponding to the background noise signal, compare and analyze the volume change and map it to the perceptual domain, and output the noise influence parameter; The audio output amplitude and standard output amplitude corresponding to the recorded audio signal are obtained, the volume changes are compared and analyzed and mapped to the perceptual domain, and the parameters affecting the sound pressure change are output.

5. The method for calibrating the volume of a vehicle headrest as described in claim 4, characterized in that, The formula for mapping volume changes is as follows: In the formula, Indicates the audio output amplitude. This indicates the standard output amplitude.

6. The method for calibrating the volume of a vehicle headrest as described in claim 4, characterized in that, Dynamic switching compensation is performed based on the noise impact parameters and the sound pressure change impact parameters, and compensation adjustment parameters are calculated, including: The impact of environmental noise on the fluctuation of listening experience is analyzed based on the aforementioned noise impact parameters. Dynamic switching compensation is performed based on the fluctuation impact. If the fluctuation impact is greater than a preset threshold, the noise impact parameter and the sound pressure change impact parameter are combined for joint analysis to calculate the compensation adjustment parameter; otherwise, the compensation adjustment parameter is calculated based on the sound pressure change impact parameter.

7. The method for calibrating the volume of a vehicle headrest as described in claim 6, characterized in that, A joint analysis is performed on the noise impact parameters and the sound pressure change impact parameters to calculate compensation and adjustment parameters, including: Obtain the audio output amplitude corresponding to the recorded audio signal and the background noise signal; The audio output amplitude is normalized and then mapped to the perceptual domain to obtain the corresponding target influence parameters; Obtain the target influence parameters corresponding to the background noise signal and the recorded audio signal, compare and analyze the relative interference of environmental noise, and calculate the joint adjustment coefficient; Based on the joint adjustment coefficient, at least one set of compensation adjustment parameters is obtained by combining the noise impact parameters and the sound pressure change impact parameters through joint analysis.

8. The method for calibrating the volume of a vehicle headrest as described in claim 1, characterized in that, Perform headrest volume calibration according to the aforementioned compensation adjustment parameters, including: Obtain the compensation adjustment parameters corresponding to the recorded audio signal and the current volume curve. Based on the current volume curve, superimpose the compensation adjustment parameters to form a new volume curve, thus completing the headrest volume calibration.

9. A vehicle headrest volume calibration system, used to implement the vehicle headrest volume calibration method as described in any one of claims 1 to 8, characterized in that: It includes a vehicle infotainment system, an amplifier module, and at least one set of headrest speakers and a vehicle microphone; the vehicle infotainment system is connected to the amplifier module and the vehicle microphone, and the amplifier module is connected to the headrest speakers.

10. The vehicle headrest volume calibration system as described in claim 9, characterized in that: The vehicle infotainment system includes a main controller, an audio processing module, an audio playback module, an audio storage module, and an audio recording module. The main controller is connected to the power amplifier module, the audio processing module, and the audio playback module. The audio storage module is connected to the audio processing module, the audio playback module, and the audio recording module. The audio playback module is connected to the power amplifier module, and the audio recording module is connected to the vehicle microphone.

Images