Active noise reduction method and device for road noise, equipment and storage medium

Abstract

The invention discloses an active road noise reduction method, device and equipment and a storage medium, and relates to the technical field of automobile electronic control, and the method comprises the steps: obtaining road surface information; judging whether pavement abnormity exists according to the pavement information; when the pavement information is abnormal, predicting a vibration signal generated by the chassis based on the pavement information; the anti-phase control signal is generated according to the predicted vibration signal to counteract road noise in advance, safe driving of a driver is facilitated, the driving comfort of the vehicle is improved, and the quality of the whole vehicle is improved.

Description

Technical Field

[0001] This invention relates to the field of automotive electronic control technology, and in particular to a method, apparatus, device, and storage medium for active road noise reduction. Background Technology

[0002] The electrification of new energy vehicles has spurred the development of intelligent technology. Simultaneously, with the support of high-performance computing chips, Road Noise Cancellation (RNC) technology is being increasingly applied and promoted. RNC primarily uses the following methods to reduce noise: it collects vibration signals from the road surface using an accelerometer mounted on the vehicle chassis, and simultaneously collects real-time road noise signals using a microphone array inside the vehicle; it uses the vehicle's noise reduction chip to run a noise reduction algorithm, calculating sound wave data with the same amplitude but opposite phase to the road noise; and it emits inverse sound waves through the vehicle's speakers to cancel out the road noise waves, thereby reducing interior noise.

[0003] While RNC robustness gradually converges under stable road conditions, achieving optimal noise reduction performance, it often fails to guarantee robustness during sudden changes in road conditions, resulting in abnormal noises such as popping sounds. This is unacceptable to car owners and users. When popping sounds occur, the vibration signal from the chassis accelerometer conflicts with the feedback signal from the in-vehicle error microphone, often amplifying the popping sound and causing uncontrolled in-vehicle noise. Existing technologies either automatically shut down RNC immediately upon detecting a popping sound or prevent RNC from triggering when the chassis detects a transient single excitation, but these methods have inherent flaws and imperfections.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this invention is to provide a method, apparatus, device, and storage medium for active road noise reduction, aiming to solve the technical problem of how to improve the robustness of active road noise reduction and avoid popping noise caused by instantaneous changes in road surface.

[0006] To achieve the above objectives, the present invention provides an active road noise reduction method, which includes the following steps: Obtain road surface information; Determine whether there are any road surface anomalies based on the road surface information; When road surface anomalies are detected in the road surface information, the vibration signal generated by the chassis is predicted based on the road surface information. An inverse control signal is generated based on the predicted vibration signal to counteract road noise in advance.

[0007] In one embodiment, the step of determining whether there is a road surface anomaly based on the road surface information includes: The road surface information is compared with the preset road surface reference information to obtain the road surface deviation information; Determine whether the road surface deviation information exceeds a preset deviation threshold; When the road surface deviation information exceeds the preset deviation threshold, it is determined that there is a road surface anomaly.

[0008] In one embodiment, the step of predicting the vibration signal generated by the chassis based on the road surface information when road surface anomalies are present includes: Obtain the abnormal shape information and abnormal size information corresponding to the road surface abnormality; The chassis vibration response information is determined based on the abnormal shape information and the abnormal size information; A predicted vibration signal is generated based on the vibration response information.

[0009] In one embodiment, the step of generating an anti-phase control signal based on the predicted vibration signal to preemptively cancel road surface noise includes: The estimated arrival time of road noise is determined based on the spectral and amplitude characteristics of the predicted vibration signal. The total delay is determined based on the estimated arrival time. The predicted vibration signal is time-shifted and compensated based on the total time delay to obtain the compensated predicted signal. The compensated prediction signal is amplitude scaled and phase inverted to obtain an inverted control signal; The inverted control signal is sent to the speaker driver circuit so that the speaker emits an inverted sound wave in advance to cancel out the road noise when the road noise reaches the vehicle.

[0010] In one embodiment, the method further includes: Receive abnormal noise signals fed back from the in-vehicle error microphone; The abnormal noise signal is correlated with the road surface information to obtain the correlation calculation result; Based on the correlation calculation results, determine whether to perform suppression processing on the abnormal noise signal.

[0011] In one embodiment, the method further includes: When radar and imaging equipment are simultaneously deployed in front of the wheels, the first road surface information collected by the radar and the second road surface information collected by the imaging equipment are acquired respectively. The first road surface information and the second road surface information are time-synchronized to obtain synchronized first road surface information and second road surface information. The first and second road surface information after synchronization are weighted and fused to obtain the fused road surface information; The fused road surface information is used to determine road surface anomalies and predict vibration signals.

[0012] In one embodiment, the method further includes: Obtain current vehicle speed information and historical road anomaly records; The pre-excitation intensity level is determined based on the current vehicle speed information and historical road surface anomaly records. Adjust the filter coefficients and speaker output gain of the active road noise reduction system according to the pre-excitation intensity level.

[0013] Furthermore, to achieve the above objectives, the present invention also proposes an active road noise reduction device, the device comprising: The road surface information receiving module is used to acquire road surface information; The road surface anomaly detection module is used to determine whether there is a road surface anomaly based on the road surface information; The prediction module is used to predict the vibration signal generated by the chassis based on the road surface information when there is a road surface anomaly. The noise reduction module is used to generate an inverse control signal based on the predicted vibration signal to cancel out road noise in advance.

[0014] In addition, to achieve the above objectives, the present invention also proposes an active road noise reduction device, the device comprising: a memory, a processor, and an active road noise reduction program stored in the memory and executable on the processor, the active road noise reduction program being configured to implement the steps of the active road noise reduction method as described above.

[0015] In addition, to achieve the above objectives, the present invention also proposes a storage medium storing a road noise active denoising program, wherein when the road noise active denoising program is executed by a processor, it implements the steps of the road noise active denoising method as described above.

[0016] In addition, to achieve the above objectives, this application also provides a computer program product, which includes a computer program that, when executed by a processor, implements the steps of the active road noise reduction method described above.

[0017] One or more technical solutions proposed in this application have at least the following technical effects: Attached Figure Description 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.

[0018] 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.

[0019] Figure 1 This is a flowchart illustrating an embodiment of the active road noise reduction method of this application. Figure 2 This is a schematic diagram of the imaging technology location provided in Embodiment 1 of the active road noise reduction method of this application; Figure 3 This is a flowchart illustrating Embodiment 2 of the active road noise reduction method of this application. Figure 4 This is a schematic diagram of the module structure of the active road noise reduction device according to an embodiment of this application; Figure 5 This is a schematic diagram of the device structure of the hardware operating environment involved in the active noise reduction method for road noise in the embodiments of this application.

[0020] 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

[0021] 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.

[0022] 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.

[0023] 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 an electronic device or active road noise reduction device capable of performing the above functions. The following description uses an active road noise reduction device as an example to illustrate this embodiment and the subsequent embodiments.

[0024] Based on this, the embodiments of this application provide an active road noise reduction method, referring to... Figure 1 , Figure 1 This is a flowchart illustrating the first embodiment of the active road noise reduction method of this application.

[0025] In this embodiment, the active road noise reduction method includes steps S10 to S40: Step S10: Obtain road surface information; This solution uses radar or imaging technology to monitor and obtain road condition information in real time in advance, and feeds it back to the vehicle chip to make preparations in advance, avoid popping noises, and improve the robustness of RNC.

[0026] Radar or imaging equipment is placed in front of the car wheels to monitor road conditions in real time. When the equipment detects road abnormalities, the chip can predict the vibration signals that the chassis accelerometer will collect by monitoring the road conditions fed back by the equipment, and perform RNC pre-excitation.

[0027] When the chip receives an abnormal noise signal from the in-vehicle error microphone in response to instantaneous road surface excitation, it calculates and determines whether to suppress the signal based on the data information fed back by the monitoring equipment, so as to prevent the speaker from emitting abnormal noise and producing popping sounds.

[0028] like Figure 2 As shown, Figure 2 This is a schematic diagram of the imaging technology location. The radar or imaging equipment placed in front of the wheel can monitor road information in real time. When there are sudden changes in the road surface such as stones or manhole covers, the detection equipment will promptly feed the collected information back to the on-board chip. After the chip calculates the result, it will prepare to react to the RNC system, avoid popping noise, and improve the robustness of RNC.

[0029] It should be noted that the purpose of this step is to obtain raw data on the road conditions in front of the vehicle through front-end sensing, so as to provide predictive input for the active noise cancellation system.

[0030] Road surface information refers to a digital description of road surface texture, obstacles, and abnormal features collected in real time by radar or imaging equipment; the acquisition methods include establishing a data transmission channel, receiving raw data, and parsing it into structured information.

[0031] Understandably, this step transforms the post-event response of traditional noise reduction systems into pre-event prediction, enabling early perception of road surface excitations, which is the primary prerequisite for improving noise reduction robustness.

[0032] It should be understood that radar can detect objects and identify their size and shape through reflected radio waves. When a vehicle is driving on a smooth road, the road surface detected by the radar is also smooth and uniform. When abnormal conditions such as manhole covers, speed bumps, stones, seams, and potholes suddenly appear on the smooth road surface, the radar can identify the shape, size, and other characteristics of the abnormal road surface in advance and feed them back to the onboard chip for preprocessing, thereby improving the robustness of RNC and reducing abnormal phenomena such as popping sounds.

[0033] Step S20: Determine whether there is a road surface anomaly based on the road surface information; It should be noted that the purpose of this step is to identify abnormal areas that differ significantly from standard smooth road surfaces from the acquired road surface information, and to use these areas as criteria for triggering predictive noise reduction.

[0034] The judgment process involves comparing the deviation value with the preset road surface reference information, calculating the deviation value, and verifying whether the deviation exceeds the preset threshold; if it exceeds the threshold, it is marked as a road surface anomaly.

[0035] Understandably, this judgment mechanism enables the automatic identification of typical interference sources such as speed bumps, manhole covers, and potholes, avoiding excessive response of the system to minor undulations on normal road surfaces and ensuring the accuracy of noise reduction intervention.

[0036] In one feasible implementation, step S20 includes steps A11 to A13: Step A11: Compare the road surface information with the preset road surface reference information to obtain the road surface deviation information; It should be noted that the purpose of this step is to quantify the degree of difference between the current road surface and the ideal smooth road surface.

[0037] The road reference information is a feature template representing a smooth road surface that is pre-stored in the system. The comparison process calculates the difference between the two through a feature matching algorithm and outputs the road deviation information.

[0038] Understandably, this comparison provides a numerical basis for subsequent threshold judgments, and its algorithm needs to have real-time performance and anti-interference capabilities to ensure that it can still accurately identify abrupt change areas when the vehicle speed changes.

[0039] Step A12: Determine whether the road surface deviation information exceeds the preset deviation threshold; It should be noted that the purpose of this step is to set a sensitivity threshold for triggering noise reduction, filtering out minor road surface irregularities that do not need to be processed.

[0040] The deviation threshold is an empirical parameter set based on the noise reduction system's tolerance and user experience requirements. The judgment process is a simple numerical comparison.

[0041] Understandably, threshold settings need to balance the risks of missed detections and false triggers. Too high a threshold may result in no response to obvious anomalies, while too low a threshold may cause the system to be frequently triggered by tiny cracks, increasing the computational burden.

[0042] Step A13: When the road deviation information exceeds the preset deviation threshold, it is determined that there is a road abnormality.

[0043] It should be noted that the purpose of this step is to generate a Boolean-type anomaly flag, which formally activates the subsequent vibration prediction process.

[0044] Once a road surface anomaly is identified, a status flag is set or a trigger event is sent, causing the system to switch from monitoring mode to prediction and noise reduction mode.

[0045] Understandably, this state transition needs to have a latching mechanism to prevent repeated triggering within the same abnormal region, and it also needs to record the coordinates of the time when the abnormality occurs to provide a benchmark for subsequent timing calculations.

[0046] Step S30: When there is road surface anomaly in the road surface information, predict the vibration signal generated by the chassis based on the road surface information; It should be noted that the purpose of this step is to convert the abnormal road surface features at the geometric level into vibration signal descriptions at the dynamic level, thus achieving a leap from "seeing" to "feeling".

[0047] The prediction process is based on the physical model of the vehicle chassis, combined with the abnormal shape, size and vehicle speed, to calculate the time-domain and frequency-domain characteristics of the vibration that the accelerometer will collect.

[0048] Understandably, this prediction is the core of early cancellation, and its accuracy directly determines the noise reduction effect. Nonlinear factors such as suspension transfer function and tire stiffness need to be considered.

[0049] In one feasible implementation, step S30 includes steps A21 to A23: Step A21: Obtain the abnormal shape and size information corresponding to the road surface abnormality; It should be noted that the purpose of this step is to extract the physical parameters that affect vibration from the original road surface information.

[0050] Abnormal shape information refers to geometric categories such as the circle of a manhole cover and the arc of a speed bump, while abnormal size information refers to the height, width, and length dimensions; the method of acquisition is to perform edge detection and size estimation on radar point clouds or images.

[0051] Understandably, these parameters are input variables for the vibration response model, and different shapes and sizes will result in drastically different vibration spectrum characteristics.

[0052] Step A22: Determine the chassis vibration response information based on the abnormal shape and size information; It should be noted that the purpose of this step is to apply a vehicle dynamics model to convert the abnormal geometric impact of the road surface into the acceleration response of the chassis.

[0053] Vibration response information includes amplitude, frequency, and damping characteristics. The determination process requires querying or calculating the suspension transfer function in real time.

[0054] Understandably, the model needs to be calibrated in advance to ensure that the error between the predicted value and the actual collected value is within an acceptable range; otherwise, it will lead to mismatch of the inverted signal, failure of noise reduction, or even aggravation of noise.

[0055] Step A23: Generate the predicted vibration signal based on the vibration response information.

[0056] It should be noted that the purpose of this step is to convert the abstract response parameters into a specific digital signal sequence, which can be directly used for subsequent inversion calculations.

[0057] The generated vibration signal is a discrete time series, and the sampling rate must be consistent with the noise reduction system, usually several kilohertz.

[0058] It is understandable that the signal is ahead of the actual acquired signal in terms of timing, and the lead is equal to the prediction time window. The accuracy of the signal determines the accuracy of the phase cancellation.

[0059] Step S40: Generate an anti-phase control signal based on the predicted vibration signal to cancel out road noise in advance.

[0060] It should be noted that the purpose of this step is to convert the predicted vibration signal into a drive signal that the speaker can execute, thereby achieving sound wave cancellation.

[0061] The generation process includes operations such as timing compensation, amplitude adjustment, and phase reversal to ensure that the antiphase sound wave meets the real noise synchronously and cancels each other out.

[0062] It is understandable that the core effect of this invention is to cancel out in advance. The difficulty lies in controlling the timing accuracy, which requires compensating for the processing delay of the entire chain from prediction to sound production.

[0063] In one feasible implementation, step S40 includes steps A31 to A35: Step A31: Determine the estimated arrival time of road noise based on the spectral and amplitude characteristics of the predicted vibration signal; It should be noted that the purpose of this step is to calculate the time it takes for a road impact to travel from the tires to the occupant's ears.

[0064] The spectral characteristics reflect the frequency components of the noise, the amplitude characteristics reflect the energy level, and the estimated arrival time provides a benchmark for subsequent time delay compensation.

[0065] Understandably, this moment needs to take into account both the mechanical delay of vibration propagation in the chassis and the air delay of sound waves propagation inside the vehicle, and the arrival times of different frequency components may vary slightly.

[0066] Step A32: Determine the total delay based on the estimated arrival time; It should be noted that the purpose of this step is to quantify the total time cost required for the system from prediction to sound output.

[0067] The total delay includes signal processing delay, digital-to-analog conversion delay, power amplifier response delay, and acoustic propagation delay, which is obtained by summing the calibration values ​​of each component.

[0068] Understandably, this time delay directly determines how far in advance the signal needs to be generated. If the calculation is inaccurate, it will cause the antiphase sound wave and the noise waveform to be misaligned, and the cancellation effect will drop sharply.

[0069] Step A33: Perform time-shift compensation on the predicted vibration signal based on the total time delay to obtain the compensated predicted signal; It should be noted that the purpose of this step is to correct the time base of the predicted signal so that it is aligned with the real noise in time.

[0070] Time shift compensation uses digital signal processing algorithms to shift the entire signal sequence forward, with the shift amount equal to the total time delay.

[0071] Understandably, this compensation ensures that after the inverted signal is emitted, it passes through various delays and meets the listening position exactly at the moment the noise arrives, thus achieving synchronous cancellation.

[0072] Step A34: Scaling and reversing the phase of the compensated prediction signal to obtain an inverted control signal; It should be noted that the purpose of this step is to generate a canceled signal that is equal in amplitude and opposite in phase to the noise.

[0073] Amplitude scaling matches the energy of the antiphase sound wave with the noise, while phase reversal reverses its polarity. The combination of these two methods achieves destructive interference of the sound waves.

[0074] Understandably, the amplitude scaling factor needs to take into account factors such as speaker efficiency and in-vehicle acoustic gain. The phase reversal is usually 180 degrees, but the high precision of the zero crossing moment requires extremely high system clock synchronization.

[0075] Step A35: Send the inverted control signal to the speaker driver circuit so that the speaker can emit inverted sound waves in advance to cancel out the road noise when the road noise reaches the vehicle.

[0076] It should be noted that the purpose of this step is to perform the final sound wave output action and complete the noise reduction closed loop.

[0077] The transmission process transmits the inverting control signal to the power amplifier through the digital audio interface, driving the speaker diaphragm to vibrate and produce sound.

[0078] It is understandable that the frequency response linearity and transient response speed of the speaker directly affect the cancellation accuracy, so a wide-bandwidth, low-distortion car audio unit should be selected, and its frequency response curve should be compensated in the algorithm.

[0079] Furthermore, this plan also includes: Receive abnormal noise signals fed back from the in-vehicle error microphone; The abnormal noise signal is correlated with the road surface information to obtain the correlation calculation result; Determine whether to perform suppression processing on abnormal noise signals based on the correlation calculation results.

[0080] It should be noted that the purpose of this section is to construct a feedback correction mechanism to handle prediction errors or residual noise that is not completely canceled.

[0081] The correlation calculation determines whether the abnormal noise captured by the microphone is caused by the current road surface anomaly through time delay matching. If so, it is identified as residual noise and suppressed; otherwise, it is identified as other interference sources and is not processed.

[0082] Understandably, this mechanism gives the system dual insurance capabilities, enabling proactive prevention before anomalies occur and remediation after anomalies occur, significantly improving robustness. This fully aligns with the core idea in the briefing document: "When road conditions change abruptly, the pre-captured road condition information is input into the onboard chip for calculation, preprocessing, and reduction of popping noises."

[0083] Furthermore, this plan also includes: With radar and imaging equipment simultaneously deployed in front of the wheels, the first road surface information collected by the radar and the second road surface information collected by the imaging equipment are acquired respectively. The first road surface information and the second road surface information are synchronized in time to obtain synchronized first road surface information and second road surface information; The first and second road surface information after synchronization are weighted and fused to obtain the fused road surface information; The fused road surface information is used to identify road surface anomalies and predict vibration signals.

[0084] It should be noted that the purpose of this section is to improve the reliability and prediction accuracy of road anomaly detection through heterogeneous sensor fusion.

[0085] Radar performs stably in rain and fog but has low shape resolution, while imaging equipment provides rich detail in good lighting but is greatly affected by weather conditions. Weighted fusion can combine the advantages of both. Time synchronization processing ensures that both types of data describe the same spatiotemporal location, and weighted fusion dynamically allocates weights based on confidence levels.

[0086] Understandably, this multi-sensor fusion solution embodies systematic innovative thinking, transforming potentially redundant or conflicting heterogeneous data sources into complementary information, greatly enhancing the system's adaptability under complex weather and lighting conditions, and is a key extension for improving the overall vehicle intelligence level.

[0087] Furthermore, this plan also includes: Obtain current vehicle speed information and historical road anomaly records; The pre-excitation intensity level is determined based on current vehicle speed information and historical road surface anomaly records. Adjust the filter coefficients and speaker output gain of the active road noise reduction system according to the pre-excitation intensity level.

[0088] It should be noted that the purpose of this section is to achieve adaptive hierarchical noise reduction, which dynamically adjusts the system response intensity according to the degree of danger and the probability of occurrence.

[0089] The faster the vehicle speed, the more severe the impact of an anomaly of the same size, requiring a higher pre-excitation intensity; areas with dense historical anomaly records indicate poor road maintenance, and the alert level should be raised in advance. Adjusting the filter coefficient can change the noise reduction frequency band, and adjusting the speaker gain can change the cancellation strength.

[0090] Understandably, this adaptive mechanism enables the system to evolve from a "one-size-fits-all" extensive control to a "case-specific" precise control. It avoids overcompensation when there are abnormalities at low speeds and ensures effective noise reduction when there are large impacts at high speeds, achieving an optimal balance between energy consumption, lifespan, and performance. This is an important manifestation of intelligent improvement.

[0091] This embodiment provides an active road noise reduction method. Using radar or imaging technology, it monitors road surface information in real time. When road conditions change abruptly, the pre-captured road condition information is input into the onboard chip for preprocessing, reducing popping noises, improving RNC robustness, and decreasing customer complaints. This is more conducive to safer driving, improves vehicle ride comfort, and enhances overall vehicle quality.

[0092] 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 3 Step S40 includes steps S401 to S405: Step S401: Determine the estimated arrival time of road noise based on the spectral and amplitude characteristics of the predicted vibration signal; It should be noted that the purpose of this step is to accurately predict the specific time when road impacts are transmitted from the tires to the occupant's ears.

[0093] The spectral characteristics reflect the frequency component distribution of noise, while the amplitude characteristics reflect the energy intensity. Together, they determine the sound wave propagation speed and perception delay. The determination process requires calculations based on the chassis mechanical transfer function and the acoustic path length inside the vehicle.

[0094] Understandably, this moment is the benchmark for all subsequent timing compensations. The accuracy of the prediction directly affects whether the antiphase sound wave and the real noise can meet synchronously. The error needs to be controlled within 5 milliseconds to ensure effective cancellation.

[0095] Step S402: Determine the total delay based on the estimated arrival time; It should be noted that the purpose of this step is to quantify the total time required for the system to go from generating the inverted signal to the speaker actually producing sound.

[0096] The total delay includes signal processing delay, digital-to-analog conversion delay, power amplifier response delay, and acoustic propagation delay, which is obtained by summing the calibration values ​​of each component.

[0097] Understandably, this delay directly determines how far in advance the signal needs to be generated. If the calculation is inaccurate, it will cause the anti-phase sound wave and the noise waveform to be misaligned, and the cancellation effect will drop sharply. Usually, the total delay needs to be controlled within 80% of the estimated arrival time to retain a safety margin.

[0098] Step S403: Perform time shift compensation on the predicted vibration signal based on the total time delay to obtain the compensated predicted signal; It should be noted that the purpose of this step is to correct the time base of the predicted signal so that it is aligned with the real noise in time.

[0099] Time shift compensation uses digital signal processing algorithms to shift the entire signal sequence forward, with the shift amount equal to the total time delay.

[0100] Understandably, this compensation ensures that after the inverted signal is emitted, it meets the listening position exactly at the moment the noise arrives, after the delay of each stage, thus achieving synchronous cancellation. This is the key means to realize "early cancellation" from concept to implementation.

[0101] Step S404: The compensated prediction signal is scaled and phase-reversed to obtain an inverted control signal; It should be noted that the purpose of this step is to generate a canceled signal that is equal in amplitude and opposite in phase to the noise.

[0102] Amplitude scaling matches the energy of the antiphase sound wave with the noise. The scaling factor needs to take into account factors such as speaker efficiency and in-vehicle acoustic gain. Phase reversal reverses the polarity of the sound waves, usually by 180 degrees, to achieve destructive interference of the sound waves.

[0103] Understandably, the amplitude and phase accuracy directly determine the cancellation depth. High-precision zero-crossing timing places extremely high demands on system clock synchronization. An amplitude error exceeding 10% or a phase error exceeding 15 degrees will significantly reduce the noise reduction effect.

[0104] Step S405: Send the inverted control signal to the speaker driver circuit so that the speaker can emit inverted sound waves in advance to cancel out the road noise when the road noise reaches the vehicle.

[0105] It should be noted that the purpose of this step is to perform the final sound wave output action and complete the noise reduction closed loop.

[0106] The transmission process transmits the inverting control signal to the power amplifier through the digital audio interface, driving the speaker diaphragm to vibrate and produce sound.

[0107] Understandably, the frequency response linearity and transient response speed of a loudspeaker directly affect the cancellation accuracy. Therefore, it is necessary to select a wide-bandwidth, low-distortion car audio unit and compensate its frequency response curve in the algorithm to ensure that the antiphase sound wave and the noise waveform are accurately mirrored in the time and frequency domains.

[0108] This embodiment provides an active road noise reduction method. It accurately predicts the arrival time of road noise by analyzing the predicted vibration signal spectrum and amplitude characteristics. Time-shift compensation is then performed based on the total system delay to ensure the anti-phase control signal is precisely aligned with the actual noise in timing. By scaling the amplitude and reversing the phase of the compensated signal, the anti-phase sound wave emitted by the speaker is highly matched to the road noise in energy and polarity, achieving destructive interference. The control signal is sent to the drive circuit, ensuring the speaker emits sound synchronously at the moment of noise arrival, effectively solving the cancellation failure problem caused by processing delays in traditional noise reduction systems. This precise timing control mechanism significantly reduces the probability of popping noises caused by sudden changes in road surface conditions, significantly improving the robustness and noise reduction depth of the active road noise reduction system. Ultimately, it creates a quieter and more comfortable in-vehicle acoustic environment, enhancing driving quality and safety.

[0109] It should be noted that the above examples are only for understanding this application and do not constitute a limitation on the active road noise reduction method of this application. Any simple modifications based on this technical concept are within the protection scope of this application.

[0110] This application also provides an active road noise reduction device; please refer to... Figure 4 The active road noise reduction device includes: Road surface information receiving module 10 is used to acquire road surface information; The road surface anomaly detection module 20 is used to determine whether there is a road surface anomaly based on road surface information. Prediction module 30 is used to predict the vibration signal generated by the chassis based on the road surface information when there is road surface anomaly. The noise reduction module 40 is used to generate an inverse control signal based on the predicted vibration signal to cancel out road noise in advance.

[0111] The active road noise reduction device provided in this application, employing the active road noise reduction method described in the above embodiments, can solve the technical problem of how to improve the robustness of active road noise reduction and avoid popping noises caused by instantaneous changes in road surface. Compared with the prior art, the beneficial effects of the active road noise reduction device provided in this application are the same as those of the active road noise reduction method provided in the above embodiments, and other technical features in the active road noise reduction device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0112] In one embodiment, the road surface information receiving module 10 is further configured to compare the road surface information with preset road surface reference information to obtain road surface deviation information; Determine whether the road surface deviation information exceeds the preset deviation threshold; When the road surface deviation information exceeds the preset deviation threshold, it is determined that there is a road surface anomaly.

[0113] In one embodiment, the road surface anomaly judgment module 20 is further configured to obtain anomaly shape information and anomaly size information corresponding to the road surface anomaly; The chassis vibration response information is determined based on the abnormal shape and size information; The predicted vibration signal is generated based on the vibration response information.

[0114] In one embodiment, the prediction module 30 is further configured to determine the estimated arrival time of the road noise based on the spectral characteristics and amplitude characteristics of the predicted vibration signal. The total delay is determined based on the estimated arrival time. The predicted vibration signal is compensated for by time shift based on the total time delay to obtain the compensated predicted signal. The compensated prediction signal is scaled and phase-reversed to obtain an inverted control signal. An inverted control signal is sent to the speaker driver circuit so that the speaker emits an inverted sound wave in advance to cancel out the road noise when it arrives inside the vehicle.

[0115] In one embodiment, the noise reduction module 40 is further configured to receive abnormal noise signals fed back from the in-vehicle error microphone; The abnormal noise signal is correlated with the road surface information to obtain the correlation calculation result; Determine whether to perform suppression processing on abnormal noise signals based on the correlation calculation results.

[0116] In one embodiment, the noise reduction module 40 is also used to acquire first road surface information collected by the radar and second road surface information collected by the imaging device when radar and imaging device are arranged in front of the wheel at the same time. The first road surface information and the second road surface information are synchronized in time to obtain synchronized first road surface information and second road surface information; The first and second road surface information after synchronization are weighted and fused to obtain the fused road surface information; The fused road surface information is used to identify road surface anomalies and predict vibration signals.

[0117] In one embodiment, the noise reduction module 40 is further configured to acquire current vehicle speed information and historical road surface anomaly record information; The pre-excitation intensity level is determined based on current vehicle speed information and historical road surface anomaly records. Adjust the filter coefficients and speaker output gain of the active road noise reduction system according to the pre-excitation intensity level.

[0118] This application provides an active road noise reduction device, which 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 active road noise reduction method in the above embodiment 1.

[0119] The following is for reference. Figure 5 The diagram illustrates a structural schematic suitable for implementing the active road noise reduction device of the embodiments of this application. The active road noise reduction device in the embodiments of this application may include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast 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 5 The road noise active noise reduction device shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0120] like Figure 5As shown, the active noise cancellation device 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 ROM (Read Only Memory) 1002 or a program loaded from storage device 1003 into RAM (Random Access Memory) 1004. RAM 1004 also stores various programs and data required for the operation of the active noise cancellation device. The processing unit 1001, ROM 1002, and RAM 1004 are interconnected via bus 1005. 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, touch screens, 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 active road noise reduction device to communicate wirelessly or wiredly with other devices to exchange data. Although the figures show active road noise reduction devices with various systems, it should be understood that implementation or possession of all the systems shown is not required. More or fewer systems may be implemented alternatively.

[0121] 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.

[0122] The active road noise reduction device provided in this application, employing the active road noise reduction method described in the above embodiments, can solve the technical problem of how to improve the robustness of active road noise reduction and avoid popping noises caused by instantaneous changes in road surface. Compared with the prior art, the beneficial effects of the active road noise reduction device provided in this application are the same as those of the active road noise reduction method provided in the above embodiments, and other technical features of this active road noise reduction device are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0123] 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.

[0124] 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.

[0125] 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 active road noise reduction method in the above embodiments.

[0126] 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, RAM (Random Access Memory), ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory or Flash Memory), optical fibers, CD-ROM (CD-Read Only Memory), 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.

[0127] The aforementioned computer-readable storage medium may be included in the active road noise reduction device; or it may exist independently and not assembled into the active road noise reduction device.

[0128] The aforementioned computer-readable storage medium carries one or more programs. When the aforementioned one or more programs are executed by the road noise active noise reduction device, the road noise active noise reduction device: acquires road surface information; determines whether there is a road surface anomaly based on the road surface information; when there is a road surface anomaly in the road surface information, predicts the vibration signal generated by the chassis based on the road surface information; and generates an inverse control signal based on the predicted vibration signal to cancel the road surface noise in advance.

[0129] 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++, as well as 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 LAN (Local Area Network) or WAN (Wide Area Network)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0130] 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.

[0131] 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.

[0132] 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 active road noise reduction method. This solves the technical problem of how to improve the robustness of active road noise reduction and avoid popping noises caused by sudden changes in road surface conditions. 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 active road noise reduction method provided in the above embodiments, and will not be repeated here.

[0133] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the active road noise reduction method described above.

[0134] The computer program product provided in this application can solve the technical problem of how to improve the robustness of active road noise reduction and avoid popping noise caused by instantaneous changes in road surface. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the active road noise reduction method provided in the above embodiments, and will not be repeated here.

[0135] 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 road noise active noise reduction method, characterized by, The method comprises: acquiring road surface information; determining whether there is a road surface anomaly according to the road surface information; when the road surface information has a road surface anomaly, predicting a vibration signal generated by a chassis based on the road surface information; generating an anti-phase control signal according to the predicted vibration signal to offset road surface noise in advance.

2. The method of claim 1, wherein, The step of determining whether there is a road surface anomaly according to the road surface information comprises: comparing the road surface information with preset road surface reference information to obtain road surface deviation information; determining whether the road surface deviation information exceeds a preset deviation threshold; when the road surface deviation information exceeds the preset deviation threshold, determining that the road surface information has a road surface anomaly.

3. The method of claim 1, wherein, The step of predicting a vibration signal generated by a chassis based on the road surface information when the road surface information has a road surface anomaly comprises: obtaining abnormal shape information and abnormal size information corresponding to the road surface anomaly; determining vibration response information of the chassis according to the abnormal shape information and the abnormal size information; generating a predicted vibration signal according to the vibration response information.

4. The method of claim 1, wherein, The step of generating an anti-phase control signal according to the predicted vibration signal to offset road surface noise in advance comprises: determining an estimated arrival time of road surface noise according to spectral characteristics and amplitude characteristics of the predicted vibration signal; determining a total time delay according to the estimated arrival time; compensating the predicted vibration signal by time translation based on the total time delay to obtain a compensated predicted signal; performing amplitude scaling and phase inversion on the compensated predicted signal to obtain an anti-phase control signal; sending the anti-phase control signal to a loudspeaker driving circuit to make the loudspeaker emit anti-phase sound waves to offset road surface noise in advance when the road surface noise arrives in the vehicle.

5. The method of claim 1, wherein, The method further comprises: receiving an abnormal noise signal fed back from an error microphone in the vehicle; associating and calculating the abnormal noise signal with road surface information to obtain an association calculation result; determining whether to perform suppression processing on the abnormal noise signal according to the association calculation result.

6. The method of claim 1, wherein, The method further comprises: when a radar and an imaging device are arranged simultaneously in front of a wheel, acquiring first road surface information collected by the radar and second road surface information collected by the imaging device; performing time synchronization processing on the first road surface information and the second road surface information to obtain synchronized first road surface information and second road surface information; performing weighted fusion according to the synchronized first road surface information and the second road surface information to obtain fused road surface information; using the fused road surface information for the determination of the road surface anomaly and the prediction of the vibration signal.

7. The method of claim 1, wherein, The method further comprises: acquiring current vehicle speed information and historical road surface anomaly record information; determining a pre-excitation intensity level according to the current vehicle speed information and the historical road surface anomaly record information; adjusting filter coefficients and loudspeaker output gain of a road noise active noise reduction system according to the pre-excitation intensity level.

8. A road noise active noise reduction device, characterized by, The device comprises: a road surface information receiving module for acquiring road surface information; a road surface anomaly determination module for determining whether there is a road surface anomaly according to the road surface information; a prediction module configured to predict a vibration signal generated by the chassis based on the road surface information when the road surface information indicates a road surface anomaly; a noise reduction module configured to generate an anti-phase control signal based on the predicted vibration signal to pre-emptively cancel the road surface noise.

9. A road noise active noise reduction device, characterized by, The device comprises a memory, a processor, and a road noise active reduction program stored on the memory and executable on the processor, the road noise active reduction program being configured to implement the steps of the road noise active reduction method according to any one of claims 1 to 7.

10. A storage medium, characterized by The storage medium has stored thereon a road noise active reduction program, the road noise active reduction program being executable by the processor to implement the steps of the road noise active reduction method according to any one of claims 1 to 7.

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