A noise reduction method, system, device and storage medium for vehicle audio compensation

Abstract

This application relates to the field of noise reduction technology, and more particularly to a noise reduction method, system, device, and storage medium for in-vehicle audio compensation. The noise reduction method for in-vehicle audio compensation includes: acquiring the audio file to be played and identifying the frequency characteristics of the audio file; acquiring engine speed characteristics; acquiring a frequency range where the frequency characteristics match the frequencies corresponding to the engine speed characteristics; and performing order energy compensation on the audio file within the frequency range. A controller acquires the frequency characteristics of the audio file and the engine speed characteristics, identifies similar components of the frequencies corresponding to the frequency characteristics of the audio file and the engine speed characteristics, calculates the control compensation time and compensation signal, and performs energy compensation on the audio file with similar components. During noise reduction, the music component is excluded, ensuring that noise reduction targets only the target sound source and not the music component, thereby avoiding the accidental elimination of music components during noise reduction, which would lead to a decline in the listening experience of the music.

Description

Technical Field

[0001] This application relates to the field of noise reduction technology, and in particular to a noise reduction method, system, device and storage medium for vehicle audio compensation. Background Technology

[0002] Active noise cancellation (ANC) systems are frequently used in vehicles to address engine noise issues. ANC is an adaptive system that emits a sound with the same amplitude but opposite phase as the target noise in real time, superimposing it at the desired noise reduction location to achieve sound cancellation.

[0003] Active noise reduction typically addresses the order peak noise components in engine noise. Its characteristics are: ① It is a single frequency in the frequency domain, exhibiting a narrow band with a prominent peak; ② Multiple peaks are in a multiple relationship. (See figure). Its formation frequency is determined by the number of ignitions per revolution of the engine crankshaft, meaning the frequency can be calculated from the engine speed. For example, at a 4-cylinder engine speed of 2100 revolutions per minute (rpm), the order noise frequencies are: 2nd order: 2100*2 / 60 = 70Hz, 4th order: 2100*4 / 60 = 140Hz, 6th order: 2100*6 / 60 = 210Hz.

[0004] The commonly used notch filter active noise cancellation is designed to eliminate these single-frequency peaks. The method is to acquire the engine speed signal, calculate the noise frequencies to be eliminated (70, 140 and 210 Hz when the engine speed is 2100 rpm, and also track and calculate in real time when the engine speed changes), use the frequency signal as a reference signal, input it into the adaptive filter for iteration, and control the adaptive filter to emit reverse sound waves to cancel the noise.

[0005] The characteristic of this method is that the target noise signal to be eliminated is identified only by frequency. In other words, not only engine order noise, but any sound with a matching or similar frequency that reaches the error microphone in the vehicle may be mistaken for the target noise and eliminated.

[0006] The most significant impact is when playing music through car audio media. Some common frequency components in the music are mistakenly eliminated. A 4-cylinder engine typically operates at speeds of 1200-5000 rpm, and its order frequencies can cover a range of 40Hz-500Hz. Within this range, single-frequency drum beats, harmonics of string instruments, and vocals can be affected. The mistaken elimination weakens their energy, leading to changes in subjective listening experience and affecting the sound quality. Summary of the Invention

[0007] The main purpose of this application is to provide a noise reduction method, system, device and storage medium for in-vehicle audio compensation, aiming to solve the technical problem that components in the music of the audio media are mistakenly eliminated, resulting in a deterioration in the music listening experience.

[0008] To achieve the above objectives, this application provides a noise reduction method for in-vehicle audio compensation, the method comprising:

[0009] Obtain the audio file to be played and identify the frequency characteristics of the audio file;

[0010] Obtain engine speed characteristics;

[0011] Obtain the frequency range that matches the frequency corresponding to the frequency feature and the engine speed feature, and perform order energy compensation on the audio file within the frequency range.

[0012] In one embodiment, the step of acquiring the audio file to be played and identifying the frequency characteristics of the audio file includes:

[0013] Obtain the audio file to be played, and obtain the music feature data of the audio file;

[0014] The frequency features of the audio file are obtained by performing a Fourier transform on the music feature data.

[0015] In one embodiment, obtaining the frequency range that matches the frequency characteristics corresponding to the engine speed characteristics, and performing order energy compensation on the audio file within the frequency range, includes:

[0016] Obtain the noise reduction order frequency corresponding to the engine speed;

[0017] Determine the frequency range that needs to be compensated in the frequency characteristics based on the noise reduction order frequency;

[0018] Order energy compensation is performed on audio files within the specified frequency range.

[0019] In one embodiment, performing order energy compensation on audio files within the frequency range includes:

[0020] The transfer function of the corresponding audio signal emitted by each speaker to the human ear was measured separately.

[0021] The compensation signal for the frequency range that needs to be compensated is calculated using the transfer function.

[0022] The frequency range is subjected to order energy compensation using the compensation signal.

[0023] In one embodiment, performing order energy compensation on the frequency range using the compensation signal includes:

[0024] The compensation signal is input to the adaptive filter, and the first sound wave is output at the output end of the adaptive filter by iteratively controlling the weight coefficients of the adaptive filter.

[0025] The frequency range is compensated for by order energy using the first sound wave.

[0026] In one embodiment, after the step of performing order energy compensation on the frequency range using the first sound wave, the method further includes:

[0027] The engine's current speed is converted into frequency data and input to the adaptive filter. The weight coefficients of the adaptive filter are controlled to iteratively output a second reverse sound wave at the output of the adaptive filter.

[0028] The noise remaining after cancellation is obtained by canceling out the sound transmitted to the human ear, the first sound wave, and the second reverse sound wave.

[0029] The remaining noise after cancellation is input into an adaptive filter, and an adaptive algorithm is used to iterate until the remaining noise after cancellation is minimized. The remaining noise after cancellation is then input into the adaptive filter, and the adaptive algorithm of the adaptive filter is used to iterate until the remaining noise after cancellation is minimized.

[0030] Furthermore, to achieve the above objectives, this application also provides a noise reduction system for in-vehicle audio compensation, the noise reduction system for in-vehicle audio compensation comprising:

[0031] Noise reduction system, music playback system, and audio compensation module;

[0032] The noise reduction system uses the frequency signal of the engine speed as a reference signal and inputs it into the adaptive filter for iteration. It controls the adaptive filter to emit reverse sound waves to cancel noise, and at the same time, it introduces a compensation signal into the noise reduction algorithm of the adaptive filter to cancel the music components that are mistakenly eliminated during noise reduction.

[0033] The music player is used to play music and output music track files;

[0034] The audio compensation module is used to calculate a compensation signal based on audio media data and engine signal data, and to control the noise reduction module to perform output compensation.

[0035] In one embodiment, the noise reduction system includes: a control module, an engine module, and a vehicle audio system;

[0036] The vehicle audio system includes multiple speakers and microphones for playing music or sound;

[0037] The engine module is used to acquire engine speed characteristics and transmit them to the control module;

[0038] The control module is used to input the frequency signal of the engine speed as a reference signal into the adaptive filter for iteration, control the adaptive filter to emit reverse sound waves to cancel noise, and introduce the compensation signal into the noise reduction algorithm of the adaptive filter to cancel the music components that were mistakenly eliminated during noise reduction.

[0039] In addition, to achieve the above objectives, this application also provides a noise reduction device for in-vehicle audio compensation, the device comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the noise reduction method for in-vehicle audio compensation as described above.

[0040] In addition, to achieve the above objectives, this application also provides a storage medium, which is a computer-readable storage medium, storing a program that implements a noise reduction method for vehicle audio compensation. The program that implements the noise reduction method for vehicle audio compensation is executed by a processor to implement the steps of the noise reduction method for vehicle audio compensation as described above.

[0041] This application relates to the field of noise reduction technology, and more particularly to a noise reduction method, system, device, and storage medium for in-vehicle audio compensation. The noise reduction method for in-vehicle audio compensation includes: acquiring the audio file to be played and identifying the frequency characteristics of the audio file; acquiring engine speed characteristics; acquiring a frequency range where the frequency characteristics match the frequencies corresponding to the engine speed characteristics; and performing order energy compensation on the audio file within the frequency range. A controller acquires the frequency characteristics of the audio file and the engine speed characteristics, identifies similar components of the frequencies corresponding to the frequency characteristics of the audio file and the engine speed characteristics, calculates the control compensation time and compensation signal, and performs energy compensation on the audio file with similar components. During noise reduction, the music component is excluded, ensuring that noise reduction targets only the target sound source and not the music component, thereby avoiding the accidental elimination of music components during noise reduction, which would lead to a decline in the listening experience of the music. Attached Figure Description

[0042] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0043] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a flowchart illustrating an embodiment of the noise reduction method for in-vehicle audio compensation provided in this application.

[0045] Figure 2 This is a flowchart illustrating Embodiment 2 of the noise reduction method for in-vehicle audio compensation provided in this application;

[0046] Figure 3 This is a flowchart illustrating Embodiment 3 of the noise reduction method for vehicle audio compensation provided in this application;

[0047] Figure 4 This is a diagram of the noise reduction algorithm in the noise reduction method for vehicle audio compensation in this application;

[0048] Figure 5 A schematic diagram of the structure of an embodiment of the noise reduction system for vehicle audio compensation provided in this application;

[0049] Figure 6 This is a schematic diagram of the noise reduction device structure for in-vehicle audio compensation, which is part of the hardware operating environment involved in the noise reduction method for in-vehicle audio compensation in this embodiment of the application.

[0050] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0051] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0052] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0053] Some frequency components in music that are the same as the engine's order noise may be mistakenly eliminated. A 4-cylinder engine typically operates at speeds of 1200-5000 rpm, and its order frequency can cover a range of 40Hz-500Hz. Within this range of music components, single-frequency drum beats, harmonics of certain frequencies of string instruments and vocals may be affected. The mistaken elimination weakens their energy, causing changes in subjective listening experience and affecting the sound quality.

[0054] The traditional approach involves verifying the reduction of variation through real-vehicle testing and then applying EQ compensation to the frequency range to increase the amplitude within that range. However, this method is not precise enough in terms of frequency accuracy, as it only addresses a single frequency while actually processing the entire frequency band. Furthermore, the compensation amplitude cannot be quantified using a fixed value; factors such as the convergence of the active noise cancellation system, the noise level under different engine operating conditions, the noise level at different seating positions, and the noise level of musical components all have an impact.

[0055] The main solution of this application embodiment is: to acquire the audio file to be played and identify the frequency characteristics of the audio file; to acquire the engine speed characteristics; to acquire the frequency range that matches the frequency of the frequency characteristics and the frequency corresponding to the engine speed characteristics, and to perform order energy compensation on the audio file within the frequency range. The controller acquires the frequency characteristics of the audio file and the engine speed characteristics, identifies the similar components of the frequencies corresponding to the frequency characteristics of the audio file and the engine speed characteristics, calculates the control compensation time and compensation signal to perform energy compensation on the audio file with similar components, and excludes the music component during noise reduction, so that noise reduction is only for the target sound source and not for the music component, thereby avoiding the accidental elimination of music components during noise reduction, which would lead to a decrease in the listening experience of the music.

[0056] It is understandable that this application uses noise reduction frequency point compensation rather than EQ band compensation, which is more accurate; secondly, the compensation method used in this application is to directly introduce the compensation noise into the noise reduction algorithm for cancellation, rather than reducing noise first and then compensating for the EQ response; finally, whether to compensate is dynamically controlled in real time based on the characteristics of the music, rather than simply switching modes by judging whether noise reduction is on or off. In order to improve the accuracy of the compensation frequency and amplitude, this application constantly corrects for false elimination based on the real-time operating noise of the engine and the real-time components of the music, while also avoiding over-compensation.

[0057] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or a noise reduction device for in-vehicle audio compensation capable of the above functions. The following description uses a noise reduction controller as an example to illustrate this embodiment and the subsequent embodiments.

[0058] Based on this, this application provides a noise reduction method for in-vehicle audio compensation, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the noise reduction method for in-vehicle audio compensation in this application.

[0059] In this embodiment, the noise reduction method for in-vehicle audio compensation includes steps S10 to S30.

[0060] Step S10: Obtain the audio file to be played and identify the frequency characteristics of the audio file.

[0061] It should be noted that the controller connects to the music playback system to obtain the audio files to be played.

[0062] Step S20: Obtain engine speed characteristics.

[0063] It should be noted that the actual engine speed in a vehicle depends on many factors, and the engine speed varies under different operating conditions. For example, in the REV model, the engine is only used for charging and usually maintains a constant speed. If the REV model's engine is involved in power output, the speed will be related to the vehicle's speed, gear position, and other parameters.

[0064] It's understandable. For example, during constant-speed charging, the engine speed is a fixed value. For a certain model, the engine speed during charging may be 1800rpm, 2100rpm, 260rpm, and 3500rpm.

[0065] Optionally, for dynamic speed conditions, short-term predictions can be made based on user driving habits and road conditions. The prediction method can be a variety of deep learning prediction model algorithms.

[0066] Step S30: Obtain the frequency range that matches the frequency corresponding to the frequency feature and the engine speed feature, and perform order energy compensation on the audio file within the frequency range.

[0067] It should be noted that, based on different audio files, frequency features are pre-identified, and possible frequency components within these features are extracted to form key features such as frequency, time, and amplitude, which are used for compensation judgment. Simultaneously, the frequency corresponding to the current (or predicted) engine speed is compared to determine whether compensation should be activated. Specific similar features are not fixed and are determined in real-time based on different audio sources and noise reduction conditions. Once the frequencies of the audio files to be eliminated during noise reduction are identified, a compensation signal is calculated and directly incorporated into the noise reduction algorithm for cancellation.

[0068] It is understood that the method for determining the frequency range may include characteristic duration, characteristic frequency variation range, peak energy threshold, etc.

[0069] In this embodiment, the frequency characteristics of the audio file and the similar frequency components corresponding to the engine speed characteristics are identified. During noise reduction, the frequency characteristics of the audio file are excluded, ensuring that noise reduction targets only the target sound source and not the musical components. This avoids accidentally eliminating musical components during noise reduction, which could degrade the listening experience. Furthermore, this application considers the different characteristics of different music tracks, dynamically matching and identifying the frequency characteristics of the audio file based on the current engine speed characteristics, rather than using fixed sound frequency band compensation, thus enhancing the accuracy of the compensated sound frequency.

[0070] Based on the first embodiment of this application, in the second embodiment of this application, the content that is the same as or similar to that in the first embodiment described above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 2 , Figure 2 This is a flowchart illustrating a second embodiment of the noise reduction method for in-vehicle audio compensation according to this application. In the steps described, the noise reduction method for in-vehicle audio compensation includes:

[0071] Step S201: Obtain the audio file to be played and obtain the music feature data of the audio file.

[0072] It's important to note that acquiring the audio file to be played involves obtaining music characteristic data such as sampling rate, bit depth, number of channels, and time-domain data. Sampling rate: used to calculate the number of data points corresponding to time; for example, a sampling rate of 48kHz means that 1 second of the audio corresponds to the 48,000th data point. Bit depth: used to determine the amplitude range of the audio and calculate the sound energy. Number of channels: determines whether the sound source is mono, stereo, or multi-channel; different channel data characteristics need to be identified.

[0073] Step S202: Perform a Fourier transform on the music feature data to obtain the frequency features of the audio file.

[0074] It should be noted that by performing a Fourier transform on the time-domain data to obtain the frequency domain characteristics, and by analyzing the time-frequency characteristics of the music to identify prominent peaks in the 40-500Hz range, the following music characteristic data was obtained:

[0075] The number of sampling points N1 at the time of occurrence, the number of sampling points N2 at the time of disappearance, the frequency f1 at the time of occurrence, the frequency f2 at the time of disappearance, and the peak energy Ga at the time of occurrence.

[0076] Step S203: Obtain the noise reduction order frequency corresponding to the engine speed.

[0077] It should be noted that during constant engine speed charging, the charging operating speeds are 1800 rpm, 2100 rpm, 2600 rpm, and 3500 rpm, which correspond to the 2nd, 4th, and 6th order frequencies fno2, fno4, and fno6, respectively. The noise reduction order frequency corresponding to the engine speed is x(n).

[0078] Step S204: Determine the frequency range that needs to be compensated in the frequency characteristics based on the noise reduction order frequency.

[0079] It should be noted that the noise reduction order frequency x(n) corresponding to the engine speed is compared with the frequency characteristics of the audio file to determine if they match. The matching frequency range is the frequency range that needs to be compensated. The methods for determining the matching frequency range between the frequency characteristics and the frequency x(n) corresponding to the engine speed characteristics include the following:

[0080] Whether the feature duration Δt = t2 - t1 exceeds the judgment threshold t*; whether the feature frequency variation range Δf = f2 - f1 exceeds the judgment threshold f*; whether the peak energy Ga exceeds the judgment threshold Ga*; and the weight judgment based on the above features, etc.

[0081] It is understandable that when the duration Δt is too small or Δf changes too quickly, much less than the ANC system response time, or when the peak energy is significantly less than the engine noise energy, such peak characteristics can be disregarded and left unprocessed. Instead, the characteristic frequencies within the threshold range are identified as the frequency ranges that need to be compensated (the t* and f* thresholds are set according to the convergence performance speed of the active noise reduction adaptive system, and the Ga* threshold is set according to the noise reduction target value of the adaptive system).

[0082] Finally, for the first track played, k features to be compensated were identified, corresponding to parameters N1(k), N2(k), f1(k), f2(k), and Ga(k).

[0083] In this embodiment, the music feature data of the audio file is acquired, including the number of sampling points N1 at the time of appearance, the number of sampling points N2 at the time of disappearance, the frequency f1 at the time of appearance, the frequency f2 at the time of disappearance, and the peak energy Ga at the time of appearance. The noise reduction order frequency x(n) corresponding to the engine speed is acquired. The presence of x(n) in the music feature data of the audio file is determined by combining the characteristic duration of x(n), the characteristic frequency variation range of x(n) at its appearance and disappearance, and the peak energy at the time of appearance of x(n). A matching frequency range is the frequency range that needs compensation. If there is no matching frequency range for x(n) in the audio file, the noise reduction system does not interfere with the audio, and no compensation is needed. The frequency features and x(n) are constantly corrected, and the frequency range for determining the matching frequency features and x(n) also changes in real time, improving the accuracy of the compensated frequency and amplitude.

[0084] Based on the first and / or second embodiments of this application, in the third embodiment of this application, the content that is the same as or similar to that in embodiments one and two above can be referred to the above description, and will not be repeated hereafter. Based on this, please refer to... Figure 3 and Figure 4 , Figure 3 This is a flowchart illustrating Embodiment 3 of the noise reduction method for in-vehicle audio compensation provided in this application. Figure 4 This refers to a noise reduction algorithm used in noise reduction methods for in-vehicle audio compensation.

[0085] Step S301: Calculate the compensation signal for the frequency range that needs to be compensated using the transfer function.

[0086] The procedure before step S301 also includes:

[0087] Step S300: Measure the transfer function of the corresponding audio emitted by each speaker to the human ear.

[0088] It should be noted that the audio source file undergoes a series of changes before reaching the human ear through the audio system. These changes include alterations to the tuning algorithm, hardware circuit delays and amplification, and the physical process of sound transmission from the speaker to the ear. These processes result in changes to the time phase and amplitude of the sound at different frequencies, all of which affect the original audio quality. Therefore, it is necessary to measure the transfer function H of this part. m Considering the influence of amplitude and phase, the audio characteristic parameters are compensated, and the compensated sound parameters are N1ˋ(k), N2ˋ(k), and Gaˋ(k).

[0089] Understandably, since multiple speakers throughout the vehicle emit sound frequencies close to those of the active noise cancellation, such as the woofers and subwoofers in the four doors, the transfer function of each speaker's corresponding audio frequency to the human ear is measured. m1 (z), H m1 (z), ..., H m1 (z), based on the transmission function of each transmission path, calculate the compensated sound parameters N1ˋ1(k), N2ˋ1(k), Gaˋ1(k), ..., N1ˋn(k), N2ˋn(k), Gaˋn(k) for each path respectively.

[0090] Step S302: Input the compensation signal to the adaptive filter, and output the first sound wave at the output end of the adaptive filter by controlling the weight coefficients of the adaptive filter iteratively.

[0091] It should be noted that in traditional noise reduction algorithms, taking the LMS algorithm as an example, the noise d(n) emitted by the engine source is the target sound for noise reduction when it reaches the human ear. At the same time, the current engine speed is converted into frequency as x(n) and input to the adaptive filter. The control weight coefficients w11(n) and w2(n) iteratively generate the reverse sound wave y(n), which cancels out d(n). The remaining noise after cancellation is e(n), which is also input to the adaptive algorithm as residual noise, i.e., e(n) = d(n) - y(n). Through adaptation, e(n) is iterated to the minimum, thus achieving the purpose of noise reduction. The influence of musical interference dˋ(n) was not considered during the process. In reality, e(n) = d(n) + dˋ(n) - y(n). The adaptively generated y(n) cancels out d(n) + dˋ(n). Traditional noise reduction also eliminates musical interference dˋ(n). Musical interference is the frequency range in the frequency characteristics of the audio file that matches x(n). Traditional noise reduction algorithms eliminate the frequencies in the music that are the same as x(n), which affects the sound quality of the music.

[0092] Understandably, after determining and obtaining the frequency range that matches the frequency x(n) corresponding to the frequency feature and the engine speed feature, the compensation signal yˋˋ(n) of the frequency range is calculated through the transfer function. The compensation signal yˋˋ(n) is input to the adaptive filter, and the compensation signal yˋˋ(n) is introduced into the calculation of e(n). By controlling the weight coefficients of the adaptive filter, the first sound wave is output at the output of the adaptive filter.

[0093] Step S303: Perform order energy compensation on the frequency range using the first sound wave.

[0094] It should be noted that by superimposing the first sound wave onto the noise d(n) transmitted to the human ear from the engine sound source, the musical interference sound dˋ(n), and the iteratively generated reverse sound wave y(n), the following can be achieved:

[0095] e(n) = d(n) + dˋ(n) - y(n) - yˋˋ(n), which eliminates the influence of dˋ(n), meaning that active noise cancellation will not additionally reduce the frequency components in the music.

[0096] Step S331: Convert the current engine speed into frequency data and input it to the adaptive filter. By controlling the weight coefficients of the adaptive filter, iteratively output the second reverse sound wave at the output end of the adaptive filter.

[0097] It should be noted that in this embodiment, the noise emitted by the engine source is transmitted to the human ear as d(n), which is the target sound for noise reduction. At the same time, the current engine speed is converted into frequency as x(n) and input to the adaptive filter. The control weight coefficients w11(n) and w2(n) iteratively generate the reverse sound wave y(n).

[0098] Step S332: The sound transmitted to the human ear, the first sound wave, and the second reverse sound wave are canceled to obtain the noise remaining after cancellation.

[0099] It should be noted that the compensation signal yˋˋ(n) is introduced into the adaptive filter to achieve...

[0100] e(n)=d(n)+dˋ(n)-y(n)-yˋˋ(n)

[0101] The sound transmitted to the human ear includes the noise d(n) from the engine sound source and the music interference dˋ(n). The remaining noise after cancellation is e(n), which is also input into the adaptive algorithm as residual noise.

[0102] Step S333: Input the remaining noise after cancellation into the adaptive filter, and use the adaptive algorithm to iterate the remaining noise after cancellation to the minimum. Input the remaining noise after cancellation into the adaptive filter, and use the adaptive algorithm of the adaptive filter to iterate the remaining noise after cancellation to the minimum.

[0103] It is understood that the method of this application can automatically control whether active noise reduction is needed at any time based on the frequency characteristics of the music, and perform noise reduction and interference elimination control based on the signal in the music, so as to achieve the purpose of never eliminating the components in the music at any time.

[0104] In this embodiment, when the frequency x(n) corresponding to the generator speed matches the frequency characteristics of the audio file, the frequency characteristics of the audio file are compensated. A compensation signal is calculated through a transfer function and introduced into an adaptive filter. The weight coefficients of the adaptive filter are iteratively controlled to output a first sound wave at the output of the adaptive filter. The first sound wave performs order energy compensation on the frequency range of the audio file. The frequency signal of the engine speed generates a second reverse wave in the adaptive filter. The noise d(n) emitted by the engine sound source, the music interference dˋ(n), the first sound wave, and the second reverse wave are canceled out at the human ear. The remaining noise after cancellation is iterated to a minimum.

[0105] Reference Figure 5 , Figure 5 This is a schematic diagram of the first embodiment of the noise reduction system for in-vehicle audio compensation proposed in this invention. Based on Figure 5 The present invention presents a first embodiment of a noise reduction system for in-vehicle audio compensation.

[0106] The noise reduction system for in-vehicle audio compensation includes: a noise reduction system 10, a music playback system 20, and an audio compensation module 30; the noise reduction system 10 is used to use the frequency signal of the engine speed as a reference signal, input it to the adaptive filter for iteration, control the adaptive filter to emit reverse sound waves to cancel noise, and simultaneously introduce the compensation signal into the noise reduction algorithm of the adaptive filter to cancel the music components that are mistakenly eliminated during noise reduction; the music player 20 is used to play music and output music track files; the audio compensation module 30 is used to calculate the compensation signal based on audio media data and engine signal data, and control the noise reduction module to perform output compensation.

[0107] It should be noted that the noise reduction system is a traditional noise reduction system, including a control module, an error microphone, a speaker, and an engine module. The music playback system is used to acquire audio files, and the audio compensation module 30 is used to calculate a compensation signal based on the frequency characteristics of the audio file and the engine speed signal, and control the noise reduction system to perform compensation. The audio compensation module 30 determines whether the frequencies corresponding to the frequency characteristics and the engine speed characteristics match, obtains the matching frequency range, calculates the compensation signal for the frequency range through a transfer function, and performs order energy compensation on the frequency range of the audio file.

[0108] Understandably, the noise emitted by the engine source, d(n), is the target sound for noise reduction when it reaches the human ear. The noise reduction system 10 converts the current engine speed into frequency as x(n) and inputs it to the adaptive filter. The control weight coefficients w11(n) and w2(n) iteratively generate the reverse sound wave y(n). The noise reduction system receives the compensation signal yˋˋ(n) sent by the audio compensation module 30. The noise emitted by the engine source, d(n), music interference sound dˋ(n), the first sound wave, and the second reverse wave are canceled out. The remaining noise after cancellation is iteratively reduced to a minimum, so that active noise reduction does not additionally reduce the frequency components in the music.

[0109] The noise reduction system includes a control module, an engine module, and a vehicle audio system. The vehicle audio system includes multiple speakers and microphones for playing music or sound. The engine module is used to acquire engine speed characteristics and transmit them to the control module. The control module uses the frequency signal of the engine speed as a reference signal and inputs it to the adaptive filter for iteration. It controls the adaptive filter to emit reverse sound waves to cancel noise and introduces the compensation signal into the noise reduction algorithm of the adaptive filter to cancel the music components that are mistakenly eliminated during noise reduction.

[0110] It should be noted that the audio compensation module 30 considers the entire vehicle audio system, including the transmission from multiple speaker channels to the listener's ear. It takes into account the impact of different transfer functions along the entire path due to differences in tuning algorithms, hardware, and transmission paths. It calculates the control compensation timing and compensation energy separately, and inputs these into the noise reduction system to ensure the accuracy of the final compensation for error noise at the listener's ear. For example, it considers the influence of the door speaker tuning hardware parameters (the emitted low-frequency components start from 60Hz, and no compensation is needed before 60Hz), the sound passing through the vehicle's interior to the listener's ear (compensation for delay phase and energy attenuation), and the subwoofer tuning in the trunk (starting from 40Hz), passing through the vehicle's interior to the listener's ear (compensation for delay phase, energy attenuation, etc.). It considers and compensates for the influence of all speaker paths emitting similar frequencies (from the sound source to the tuning to the transmission process).

[0111] Understandably, noise reduction systems for in-vehicle audio compensation, based on traditional active engine noise reduction systems, add automatic control methods to eliminate interference from similar features (in the music component) other than engine noise, achieving noise reduction only for engine noise, avoiding the additional elimination of other components (such as music causing component loss and degraded listening experience), without adding other hardware, only upgrading the software algorithm level.

[0112] In this embodiment, the music player outputs an audio file, the engine module outputs the engine speed, the audio compensation module is used to measure and output the transfer function of each speaker, the audio compensation module is used to calculate the compensation signal based on the audio file, engine speed and transfer function, the control module inputs the compensation signal and engine speed to the adaptive filter, and the control module controls the adaptive filter to eliminate noise.

[0113] This application provides a noise reduction device for vehicle audio compensation. The noise reduction device for vehicle audio compensation includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the noise reduction method for vehicle audio compensation in the above embodiment 1.

[0114] The following is for reference. Figure 6 This document illustrates a structural schematic diagram of a noise reduction device suitable for implementing the embodiments of this application for in-vehicle audio compensation. The noise reduction device for in-vehicle audio compensation in the embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), in-vehicle terminals (e.g., in-vehicle navigation terminals), and fixed terminals such as digital TVs and desktop computers. Figure 6 The noise reduction device for in-vehicle audio compensation shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments of this application.

[0115] like Figure 6As shown, the noise reduction device for in-vehicle audio compensation may include a processing unit 1001 (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 1002 or a program loaded from storage device 1003 into random access memory (RAM) 1004. The RAM 1004 also stores various programs and data required for the operation of the noise reduction device for in-vehicle audio compensation. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems can be connected to I / O interface 1006: input devices 1007 including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices 1008 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices 1003 including, for example, magnetic tapes, hard disks, etc.; and communication devices 1009. Communication device 1009 allows the noise reduction device for in-vehicle audio compensation to exchange data wirelessly or via wired communication with other devices. Although the figure shows a noise reduction device for in-vehicle audio compensation with various systems, it should be understood that it is not required to implement or possess all the systems shown. More or fewer systems may be implemented alternatively.

[0116] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device, or installed from storage device 1003, or installed from ROM 1002. When the computer program is executed by processing device 1001, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0117] The noise reduction device for in-vehicle audio compensation provided in this application employs the noise reduction method for in-vehicle audio compensation described in the above embodiments, which can solve the technical problem of components in audio media being mistakenly eliminated, resulting in a deterioration in the listening experience. Compared with the prior art, the beneficial effects of the noise reduction device for in-vehicle audio compensation provided in this application are the same as those of the noise reduction method for in-vehicle audio compensation provided in the above embodiments, and other technical features of this noise reduction device for in-vehicle audio compensation are the same as those disclosed in the method of the previous embodiment, and will not be repeated here.

[0118] It should be understood that the various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0119] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0120] This application provides a computer-readable storage medium having computer-readable program instructions (i.e., a computer program) stored thereon, the computer-readable program instructions being used to execute the noise reduction method for vehicle audio compensation in the above embodiments.

[0121] The computer-readable storage medium provided in this application may be, for example, a USB flash drive, but is not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, system, or device. The program code contained on the computer-readable storage medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (Radio Frequency), etc., or any suitable combination thereof.

[0122] The aforementioned computer-readable storage medium may be included in a noise reduction device for vehicle audio compensation; or it may exist independently and not assembled into a noise reduction device for vehicle audio compensation.

[0123] Computer program code for performing the operations of this application can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0124] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0125] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.

[0126] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described noise reduction method for in-vehicle audio compensation. This solves the technical problem of components in audio media being mistakenly eliminated, resulting in a deterioration in the listening experience. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as those of the noise reduction method for in-vehicle audio compensation provided in the above embodiments, and will not be repeated here.

[0127] The above description is only a part of the embodiments of this application and does not limit the patent scope of this application. All equivalent structural transformations made under the technical concept of this application and using the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this application.

Claims

1. A noise reduction method for in-vehicle audio compensation, characterized in that, The noise reduction method for in-vehicle audio compensation includes: Obtain the audio file to be played and identify the frequency characteristics of the audio file; Obtain engine speed characteristics; Obtain the frequency range that matches the frequency corresponding to the frequency feature and the engine speed feature, and perform order energy compensation on the audio file within the frequency range; The steps of obtaining the audio file to be played and identifying the frequency characteristics of the audio file include: Obtain the audio file to be played, and obtain the music feature data of the audio file; The frequency features of the audio file are obtained by performing a Fourier transform on the music feature data; The step of obtaining the frequency range that matches the frequency characteristics corresponding to the engine speed characteristics, and performing order energy compensation on the audio files within the frequency range, includes: Obtain the noise reduction order frequency corresponding to the engine speed; Determine the frequency range that needs to be compensated in the frequency characteristics based on the noise reduction order frequency; Order energy compensation is performed on audio files within the specified frequency range; The order energy compensation for audio files within the frequency range includes: The transfer function of the corresponding audio signal emitted by each speaker to the human ear was measured separately. The compensation signal for the frequency range that needs to be compensated is calculated using the transfer function. The frequency range is subjected to order energy compensation using the compensation signal. The step of performing order energy compensation on the frequency range using the compensation signal includes: The compensation signal is input to the adaptive filter, and the first sound wave is output at the output end of the adaptive filter by controlling the weight coefficients of the adaptive filter to avoid eliminating music with the same frequency as the engine speed during noise reduction, thus reducing the music sound quality. The frequency range is compensated for by order energy using the first sound wave.

2. The noise reduction method for in-vehicle sound compensation according to claim 1, wherein, After the step of performing order energy compensation on the frequency range using the first sound wave, the method further includes: The engine's current speed is converted into frequency data and input to the adaptive filter. The weight coefficients of the adaptive filter are controlled to iteratively output a second reverse sound wave at the output of the adaptive filter. The noise remaining after cancellation is obtained by canceling out the sound transmitted to the human ear, the first sound wave, and the second reverse sound wave. The remaining noise after cancellation is input into an adaptive filter, and an adaptive algorithm is used to iterate until the remaining noise after cancellation is minimized. The remaining noise after cancellation is then input into the adaptive filter, and the adaptive algorithm of the adaptive filter is used to iterate until the remaining noise after cancellation is minimized.

3. A noise reduction system for in-vehicle audio compensation, the system comprising: The noise reduction method for vehicle audio compensation as described in claim 1 is applied to the noise reduction system for vehicle audio compensation, wherein the noise reduction system for vehicle audio compensation includes: a noise reduction system, a music playback system, and an audio compensation module; The noise reduction system uses the frequency signal of the engine speed as a reference signal and inputs it into the adaptive filter for iteration. It controls the adaptive filter to emit reverse sound waves to cancel noise, and at the same time, it introduces a compensation signal into the noise reduction algorithm of the adaptive filter to cancel the music components that are mistakenly eliminated during noise reduction. The music playback system is used to play music and output music track files; The audio compensation module is used to calculate a compensation signal based on audio media data and engine signal data, and to control the noise reduction module to perform output compensation.

4. The noise cancelling system for in-vehicle audio compensation of claim 3, wherein, The noise reduction system for in-vehicle audio compensation also includes: a control module, an engine module, and a full vehicle audio system; The vehicle audio system includes multiple speakers and microphones for playing music or sound; The engine module is used to acquire engine speed characteristics and transmit them to the control module; The control module is used to input the frequency signal of the engine speed as a reference signal into the adaptive filter for iteration, control the adaptive filter to emit reverse sound waves to cancel noise, and introduce the compensation signal into the noise reduction algorithm of the adaptive filter to cancel the music components that were mistakenly eliminated during noise reduction.

5. A noise reduction device for in-vehicle audio compensation, characterized in that, The device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the noise reduction method for in-vehicle audio compensation as claimed in any one of claims 1 to 2.

6. A storage medium, characterized in that, The storage medium is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, it implements the steps of the noise reduction method for vehicle audio compensation as described in any one of claims 1 to 2.

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