Active noise reduction method, storage medium, controller and vehicle

Abstract

This invention discloses an active noise cancellation method, storage medium, controller, and vehicle. The method, used in a vehicle, includes: monitoring the power supply voltage of the vehicle's main unit; correcting the original audio signal collected by the microphone based on the power supply voltage; generating a target cancellation signal based on the corrected audio signal; and controlling the vehicle's speakers to perform noise reduction processing on the vehicle cabin based on the target cancellation signal. This method uses active noise cancellation technology to solve the ear-piercing problem. During noise reduction processing, the original audio signal collected by the vehicle's microphone is corrected based on the power supply voltage of the vehicle's main unit. A target cancellation signal for noise reduction is generated based on the corrected audio signal, and the vehicle's speakers are controlled to perform noise reduction processing on the vehicle cabin based on the target cancellation signal, thereby improving the noise reduction effect.

Description

Technical Field

[0001] This invention relates to the field of noise control technology, and in particular to an active noise reduction method, storage medium, controller, and vehicle. Background Technology

[0002] When large and medium-sized SUVs and MPV-class hatchbacks drive on concrete roads or bumpy, damaged roads, low-frequency noise is generated in the passenger compartment, which can cause ear pressure for drivers and passengers, similar to the feeling during airplane takeoff and landing. In more severe cases, it can cause symptoms such as dizziness and nausea.

[0003] Manufacturers have adopted traditional technologies to address the pressure lug issue, such as reinforcing the body structure, reducing the stiffness of connecting rods and subframe bushings, and adding shock absorbers to the body and tailgate. However, these solutions have drawbacks, including increased costs, increased weight, and longer development cycles. Furthermore, some solutions may conflict with other aspects of vehicle performance. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one object of this invention is to propose an active noise cancellation method that uses active noise cancellation technology to solve the ear-piercing problem and improve the noise cancellation effect.

[0005] A second objective of this invention is to provide a computer-readable storage medium.

[0006] The third objective of this invention is to provide a controller.

[0007] The fourth objective of this invention is to provide a vehicle.

[0008] To achieve the above objectives, a first aspect of the present invention provides an active noise reduction method for a vehicle, the method comprising: monitoring the power supply voltage of the vehicle host, correcting the original audio signal collected by the vehicle microphone according to the power supply voltage; generating a target cancellation signal according to the corrected audio signal, and controlling the vehicle speaker to perform noise reduction processing on the vehicle cabin according to the target cancellation signal.

[0009] According to the active noise cancellation method of the present invention, active noise cancellation technology is used to solve the ear-pinch problem. During the noise cancellation process, the original audio signal collected by the vehicle microphone is corrected according to the voltage value of the power supply voltage of the vehicle host. A target cancellation signal for noise cancellation is generated according to the corrected audio signal, and the vehicle speaker is controlled to perform noise cancellation processing on the cabin according to the target cancellation signal, thereby improving the noise cancellation effect.

[0010] In addition, the active noise reduction method proposed in the above embodiments of the present invention may also have the following additional technical features: According to one embodiment of the present invention, the step of correcting the original audio signal acquired by the microphone based on the power supply voltage includes: determining a compensation coefficient based on the voltage value of the power supply voltage; and correcting the amplitude of the original audio signal based on the compensation coefficient.

[0011] According to one embodiment of the present invention, generating a target cancellation signal based on a corrected audio signal includes: performing echo cancellation processing on the corrected audio signal to obtain a reference signal; generating an initial cancellation signal based on the reference signal; and correcting the initial cancellation signal based on the reference signal and the corrected audio signal to obtain the target cancellation signal.

[0012] According to one embodiment of the present invention, generating an initial cancellation signal based on the reference signal includes: performing noise suppression processing on the reference signal using an algorithm combining fast Fourier transform and inverse filtering to obtain the initial cancellation signal.

[0013] According to an embodiment of the present invention, the step of correcting the initial cancellation signal based on the reference signal and the corrected audio signal includes: using an adaptive filter to perform error correction on the reference signal and the corrected audio signal, and correcting the initial cancellation signal based on the error correction result, wherein the adaptive filter employs a least mean square or normalized least mean square algorithm.

[0014] According to one embodiment of the present invention, the method further includes: downsampling the original audio signal before correcting the original audio signal acquired by the microphone according to the power supply voltage; and upsampling the target cancellation signal to the frequency of the original audio signal before controlling the vehicle speaker to perform noise reduction according to the target cancellation signal.

[0015] According to one embodiment of the present invention, the method further includes: controlling the vehicle speaker to perform noise reduction processing on the vehicle cabin based on the target cancellation signal after upsampling and the vehicle multimedia sound effect.

[0016] To achieve the above objectives, a second aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the active noise reduction method as described above.

[0017] To achieve the above objectives, a third aspect of the present invention provides a controller, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the active noise reduction method as described above.

[0018] To achieve the above objectives, a fourth aspect of the present invention provides a vehicle including the controller described above.

[0019] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the acoustic cavity mode of the crew cabin at around 40Hz; Figure 2 This is a schematic diagram of the five-link suspension used in the vehicle; Figure 3 This is a flowchart of an active noise reduction method according to an embodiment of the present invention; Figure 4 This is a flowchart of correcting the original audio signal according to an embodiment of the present invention; Figure 5 This is a flowchart illustrating the determination of a target cancellation signal according to an embodiment of the present invention; Figure 6 This is a flowchart of an embodiment of the present invention without echo cancellation processing; Figure 7 This is a flowchart of an echo cancellation process according to an embodiment of the present invention; Figure 8 This is a data processing flowchart of a dual-closed-loop feedforward algorithm according to an embodiment of the present invention; Figure 9 This is a flowchart of an active noise reduction method according to a specific embodiment of the present invention; Figure 10 This is a structural block diagram of the controller according to an embodiment of the present invention; Figure 11 This is a schematic diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0022] It should be noted that when a vehicle is traveling at low speed on a rough or damaged road surface, a low-frequency pressure phenomenon of 20-50Hz is generated inside the vehicle.

[0023] Ear pressure (AP) refers to an acoustic phenomenon where the sound pressure level at the ears of passengers exceeds 85 decibels in the 20-50Hz frequency range. This is caused by the coupling of the rear suspension vibration modes with the passenger compartment cavity modes. See the diagram for the peak sound pressure level region in the rear passenger position under the cavity mode at around 40Hz. Figure 1 When the vehicle uses a five-link suspension (see...), Figure 2 The rear suspension features a flexible connection between its connecting rods and the subframe, which in turn is flexibly connected to the body. Combined with the tire mode, the entire rear suspension exhibits a rigid mode in the 30-40Hz range. Vibrations generated by the tires contacting the road surface are amplified by this rigid mode and transmitted to the body, causing a vibration peak around 40Hz. This body vibration peak, combined with the acoustic cavity mode, creates an indentation.

[0024] This invention employs Road Noise Cancellation (RNC) technology to address the ear-piercing problem. However, RNC requires an A2B (Automotive Audio Bus) vibration sensor and a high-efficiency digital signal processor (DSP), which increases the cost of noise reduction.

[0025] Mainstream automotive active noise cancellation (ANC) systems primarily revolve around three main technical approaches: noise source separation, spatial sound field control, and low-frequency resonance suppression. However, noise source separation technology uses multimodal sensors, such as vibration, air pressure, and thermal imaging sensors, to classify engine, wind, and road noise, and utilizes vehicle dynamic data for closed-loop control. This technology relies heavily on external sensors and high sampling rates to ensure classification accuracy, resulting in high hardware costs and computational demands. Low-frequency resonance suppression technology employs pole substitution, using piezoelectric actuators to modify the vehicle body's resonant frequency, suppressing low-frequency drumming sounds in the 20-100Hz range. This technology has strict requirements for actuator placement and system latency, and requires precise identification of vehicle body modes, making actual assembly difficult. Functional fusion technology acquires status information such as vehicle speed and engine RPM via the CAN bus, dynamically switching between engine and road noise according to a preset strategy. The logic switching for noise reduction in this technology relies on empirical thresholds, making it difficult to handle sensor sensitivity changes caused by sudden operating conditions such as voltage fluctuations.

[0026] Common technical bottlenecks in noise source separation, spatial sound field control, and low-frequency resonance suppression include: unstable front-end signals, with fluctuations in the onboard host voltage due to function switching, directly affecting microphone sensitivity and weakening the coherence between the reference signal and the noise signal; computational and cost pressures, with high sampling rates and multi-sensor layouts leading to limited DSP resources, making it difficult to achieve efficient noise reduction without increasing costs; and low latency tolerance of the noise reduction system, with low-frequency broadband feedforward being sensitive to system latency. Commonly used road noise active noise cancellation (RNC) systems often require latency of less than 3ms, while actual onboard networks often reach 5-6ms, resulting in a decrease in noise reduction depth.

[0027] To address the aforementioned problems, embodiments of the present invention provide an active noise cancellation method, a storage medium, a controller, and a vehicle. The active noise cancellation method, storage medium, controller, and vehicle of the present invention will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0028] The active noise reduction method in this invention is used in vehicles to solve the problem that low-frequency noise is generated in the passenger compartment when the vehicle is driving on cement roads or bumpy and damaged roads, causing the driver and passengers to feel ear pressure.

[0029] Figure 3 This is a flowchart of an active noise reduction method according to an embodiment of the present invention. Figure 3 As shown, active noise reduction methods may include: S101 monitors the power supply voltage of the vehicle-mounted host and corrects the raw audio signal collected by the vehicle-mounted microphone based on the power supply voltage.

[0030] It's important to note that the common industry issue of unstable front-end signals in automotive active noise cancellation technology stems from the fact that the sensitivity of the automotive microphone is affected by the voltage of the vehicle's head unit. The voltage of the head unit fluctuates with the use of the vehicle's infotainment system, which in turn causes fluctuations in microphone sensitivity, reducing the noise cancellation effect. It's also worth noting that the head unit and the microphone share the same power supply voltage.

[0031] This invention addresses the common industry problem of unstable front-end signals in automotive active noise cancellation technology by correcting the raw audio signal captured by the microphone. Specifically, it monitors the power supply voltage of the vehicle's main unit in real time and corrects the raw audio signal captured by the vehicle's microphone based on the voltage value of the main unit's power supply.

[0032] In practice, a host voltage detection module for real-time monitoring of the power supply voltage of the vehicle host is set in the active noise cancellation control framework, and a microphone sensitivity compensation module is set in the active noise cancellation control framework. The microphone sensitivity compensation module is used to correct the original audio signal collected by the microphone according to the power supply voltage of the vehicle host.

[0033] S102 generates a target cancellation signal based on the corrected audio signal, and controls the vehicle speakers to perform noise reduction processing on the cabin based on the target cancellation signal.

[0034] Specifically, a target cancellation signal for suppressing bass noise is generated based on the corrected audio signal, and the target cancellation signal is sent to the vehicle speaker. The vehicle speaker converts the target cancellation signal into sound waves and radiates them into the vehicle cabin to achieve active noise reduction. This invention employs active noise cancellation technology to address the ear-pressure problem. The active noise cancellation method in this invention shares existing in-vehicle microphones (voice-activated, Bluetooth) and speakers, incurring no additional cost. To improve noise cancellation effectiveness, the original audio signal collected by the in-vehicle microphone is corrected based on the voltage value of the in-vehicle host's power supply. A target cancellation signal for noise cancellation is generated based on the corrected audio signal, and the in-vehicle speakers are used to control noise reduction in the passenger cabin based on the target cancellation signal. This invention solves the problem of low-frequency noise causing ear pressure in the passenger compartment when the vehicle is traveling on concrete roads or bumpy / damaged roads.

[0035] In one embodiment of the present invention, such as Figure 4 As shown, correcting the raw audio signal captured by the microphone based on the power supply voltage can include: S201, determine the compensation coefficient based on the supply voltage value.

[0036] Specifically, the compensation coefficient is calculated based on the voltage value output by the host voltage detection module using a preset function, or the compensation coefficient is determined based on the voltage value output by the host voltage detection module by looking up a table.

[0037] It should be noted that the embodiments of the present invention do not limit the specific method of determining the compensation coefficient based on the voltage value of the supply voltage, and other methods can also be used to determine the compensation coefficient based on the voltage value of the supply voltage.

[0038] S202, corrects the amplitude of the original audio signal according to the compensation coefficient.

[0039] Specifically, the original audio signal collected by the vehicle microphone is multiplied by the compensation coefficient to correct the amplitude of the original audio signal, thereby keeping the microphone sensitivity stable. This solves the problem that the sensitivity of the vehicle microphone is affected by the voltage fluctuation of the host unit, which leads to changes in the sensitivity of the vehicle microphone and reduces the active noise cancellation effect, thus ensuring the noise cancellation effect under different conditions.

[0040] In one embodiment of the present invention, such as Figure 5 As shown, generating a target cancellation signal based on the corrected audio signal may include: S301 performs echo cancellation processing on the corrected audio signal to obtain a reference signal.

[0041] When a vehicle travels on concrete or bumpy / damaged roads, the raw audio signal captured by the vehicle's microphone includes not only low-frequency noise signals generated in the passenger compartment due to these conditions, but also noise cancellation signals emitted by the vehicle's speakers. Directly performing noise cancellation based on the corrected audio signal would cause the gain of the active noise cancellation system to exceed 1, resulting in active noise cancellation divergence. (See [link to documentation]). Figure 6 . Figure 6 The noise cancellation is performed directly based on the corrected audio signal, obtained from the microphone. Include and ,in, The audio signal output by the car speakers. This is the reference signal, also known as the low-frequency noise signal.

[0042] This invention performs echo cancellation processing on the corrected audio signal, retaining only the low-frequency noise signal generated in the passenger compartment when the vehicle travels on concrete roads or bumpy / damaged roads. The signal obtained after echo cancellation processing is denoted as the reference signal. See Figure 7 . Figure 7 After echo cancellation processing, the centrally corrected audio signal obtained from the microphone... It contains only low-frequency noise signals, which is closer to the reference signal. .

[0043] Reference signal in the embodiments of the present invention This is also because low-frequency noise signals are generated in the passenger compartment when the vehicle is driving on concrete roads or bumpy, damaged roads. .

[0044] In practice, an echo cancellation module can be set up in the active noise reduction control framework to perform echo cancellation processing on the corrected audio signal.

[0045] In one specific embodiment, the echo cancellation module estimates the echo path transfer function H5 and uses adaptive filtering to pre-cancel the echo (the noise cancellation signal emitted by the vehicle speaker) in order to suppress the secondary echo of the speaker sound waves inside the vehicle cabin.

[0046] S302, an initial cancellation signal is generated based on the reference signal, and the initial cancellation signal is corrected based on the reference signal and the corrected audio signal to obtain the target cancellation signal.

[0047] In this embodiment of the invention, a dual-closed-loop feedforward algorithm is used to generate a target cancellation signal based on the corrected audio signal.

[0048] Specifically, the dual closed loop in this embodiment of the invention includes a feedforward closed loop and a feedback closed loop. For example... Figure 8 As shown, the feedforward closed loop is based on the reference signal Generate an initial cancellation signal. The feedback closed loop is based on the reference signal. and the corrected audio signal The initial cancellation signal is corrected to obtain the noise cancellation signal output by the dual-loop feedforward algorithm, which is used to control the output of the vehicle-mounted microphone. .

[0049] Implementably, an active noise cancellation processing module is set up in the active noise cancellation control framework. The active noise cancellation processing module adopts a dual closed-loop feedforward algorithm based on the corrected audio signal. Generate a target cancellation signal.

[0050] It should be noted that the corrected audio signal This is the residual noise signal, which is the original audio signal captured by the microphone that has been corrected by the compensation coefficient but has not undergone echo cancellation processing. In one embodiment of the present invention, generating an initial cancellation signal based on a reference signal may include: An algorithm combining fast Fourier transform and inverse filtering is used to suppress noise in the reference signal to obtain the initial canceled signal.

[0051] Specifically, the feedforward closed loop employs an algorithm combining Fast Fourier Transform (FFT) and inverse filtering to process the reference signal. Noise suppression processing is performed to generate an initial cancellation signal.

[0052] In one embodiment of the present invention, correcting the initial cancellation signal based on the reference signal and the corrected audio signal may include: An adaptive filter is used to correct the error of the reference signal and the corrected audio signal, and the initial cancellation signal is corrected according to the error correction result. The adaptive filter uses the least mean square or normalized least mean square algorithm.

[0053] Specifically, the feedback closed loop uses a least mean square (LMS) or normalized least mean square (NLMS) adaptive filter to filter the reference signal. and the corrected audio signal Error correction is performed, and the initial cancellation signal is modified based on the error correction results.

[0054] See Figure 8 In this embodiment of the invention, the audio signal collected by the vehicle-mounted microphone contains low-frequency noise signals generated in the passenger compartment when the vehicle is driving on a cement road or a bumpy or damaged road surface. (The low-frequency noise signal after coefficient compensation) enters the active noise reduction module through two paths. a) as a low-frequency noise signal Target cancellation signal generated by vehicle speakers ( The residual noise signal is obtained by superposition. Residual noise signal (a) Entering the LMS adaptive filter to form the first path; (b) as a reference signal The signal enters the LMS adaptive filter via a secondary path, forming a second path. The output of the LMS adaptive filter is connected to the adaptive module in the feedforward closed loop, and the target cancellation signal is output from the adaptive module in the feedforward closed loop. The signal is sent to the speaker to control the vehicle speaker to generate the corresponding sound wave signal.

[0055] In one embodiment of the present invention, the active noise reduction method may further include: The original audio signal is downsampled before being corrected based on the power supply voltage. Before controlling the vehicle speakers to perform noise reduction based on the target cancellation signal, the target cancellation signal is upsampled to the frequency of the original audio signal.

[0056] To address the issue of limited computing power in vehicle-mounted DSPs, this embodiment of the invention downsamples the original audio signal before correcting it based on the power supply voltage, and upsamples the target cancellation signal to the frequency of the original audio signal before controlling the vehicle-mounted speaker to perform noise reduction based on the target cancellation signal.

[0057] In practice, a downsampling module can be set up in the active noise cancellation control framework to reduce the sampling rate of the original audio signal collected by the vehicle microphone from 48kHz to 1kHz–3kHz, so as to reduce the computational load of the active noise cancellation algorithm.

[0058] In practice, an upsampling module can be set up in the active noise cancellation control framework to upsample the target cancellation signal generated after processing by the dual closed-loop feedforward algorithm to 48kHz (the frequency of the original audio signal) and then send it to the vehicle speaker.

[0059] This invention relates to noise reduction in the 20-100Hz frequency range, which has relatively relaxed requirements on system latency. For example, the latency of a commonly used active road noise cancellation (RNC) system is less than 3 milliseconds, while for noise reduction in the 20-100Hz frequency range, the system latency can be relaxed to 5-6 milliseconds. Due to the relaxed system latency, the sampling rate after downsampling can also be reduced from the usual 3K (the current sampling rate of RNC) to 1K, and the direct result of reducing the sampling rate is a 50% saving of computing power. It should be noted that, given the limited computing power of existing onboard DSPs, this 50% saving of computing power is a decisive factor in whether this algorithm can be implemented without increasing costs.

[0060] The active noise reduction method in this embodiment of the invention can reduce the computing power requirement by about 50% by reducing the sampling rate when the on-board DSP resources are scarce, thereby achieving the above-mentioned dual closed-loop feedforward algorithm noise reduction function without increasing hardware costs.

[0061] In one embodiment of the present invention, the active noise reduction method may further include: Based on the target cancellation signal after the upgrade and the in-vehicle multimedia sound effects, the in-vehicle speakers are controlled to reduce noise in the cabin.

[0062] Specifically, when the in-vehicle multimedia system plays relevant sound effects such as music, calls, and system prompts through the in-vehicle speakers, the target cancellation signal after upsampling is mixed with the in-vehicle multimedia sound effects. The mixed signal is then used to control the in-vehicle speakers to play corresponding sound waves and radiate them into the vehicle's cabin.

[0063] In this embodiment of the invention, the active noise cancellation control framework uses a unified digital bus for time-synchronized transmission between modules, so that the compensation coefficient, feedforward command, feedback correction command and echo cancellation parameters are updated within the same frame, reducing cross-module latency and improving system response speed.

[0064] The active noise cancellation method in this embodiment of the invention detects the host power supply voltage and calculates the compensation coefficient of the original audio signal collected by the vehicle microphone. The original audio signal collected by the vehicle microphone is multiplied by the compensation coefficient to obtain a stabilized signal (corrected audio signal). Echo cancellation processing is performed on the corrected audio signal to obtain a reference signal. In the dual-loop feedforward algorithm, the feedforward closed loop generates an initial cancellation command based on the reference signal. In the dual-loop feedforward algorithm, the feedback closed loop adaptively corrects the initial cancellation signal based on the reference signal and the corrected audio signal to obtain a target cancellation signal. The target cancellation signal is then sent to the vehicle speaker to achieve active noise cancellation. In this embodiment of the invention, all signals involved in the active noise cancellation processing are executed synchronously within a unified digital bus clock domain, ensuring that the overall system latency does not exceed 6ms to meet the real-time requirements of the 20Hz–100Hz low-frequency noise reduction range.

[0065] The following is a specific embodiment of the active noise cancellation method for vehicles according to the present invention. (See attached image.) Figure 9 : Vehicle status information such as vehicle speed and engine speed is acquired via the CAN bus. When the vehicle is determined to be traveling at low speed on a concrete road or a bumpy / damaged road surface based on the vehicle status signals, the raw audio signal collected by the onboard microphone is acquired. A downsampling module is used to downsample the raw audio signal, reducing its frequency from 48kHz to 1kHz-3kHz. The downsampled raw audio signal is then transmitted from the host DSP to the power amplifier DSP via a transmission line.

[0066] The active noise reduction module receives the downsampled original audio signal, corrects the downsampled original audio signal (coefficient compensation), and uses a dual closed-loop feedforward algorithm to generate a target cancellation signal based on the corrected audio signal.

[0067] The output target cancellation signal from the dual closed-loop feedforward algorithm is processed by the upsampling module, which upsamples the target cancellation signal to the 48K input mixing module. After mixing with the multimedia signal, the signal is emitted as sound waves through the speaker.

[0068] It should be noted that the important factors affecting the noise reduction amount are the coherence between the reference signal x(n) and the low-frequency noise signal d(n) and the system delay between the acquisition time of the reference signal x(n) and the time when the control sound wave emitted by the vehicle speaker is emitted.

[0069] In this embodiment of the invention, the dual-closed-loop feedforward algorithm is based on broadband feedforward theory. Specifically, in broadband feedforward theory, the maximum noise reduction value of the dual-closed-loop feedforward algorithm is determined by the reference signal. and low-frequency noise signals The coherence between them determines:

[0070] in, This is the theoretical noise reduction amount. For reference sensor signal and in-car noise signals The coherence between them , Cross-power spectrum, and This is the self-power spectrum. For example: in When the value is 0.9, the theoretical noise reduction is =10 decibels; in When the value is 0.7, the theoretical noise reduction is =5.4 decibels.

[0071] Under voltage fluctuation conditions, the reference signal With low-frequency noise signals The decreased coherence prevents the theoretical maximum noise reduction from being achieved, especially in low-frequency (20-90Hz) broadband feedforward scenarios. In this embodiment of the invention, due to the reference signal... and low-frequency noise signals The data is collected simultaneously by the same microphone and undergoes compensation coefficient correction and echo cancellation processing. The coherence between the samples is very high, approaching the maximum value of 1, thus theoretically achieving a noise reduction of over 20 dB. The impact of system delay on noise reduction increases with the noise reduction frequency. The dual-loop feedforward algorithm operates in a wide frequency range of 20-90 Hz, with peak noise reduction exceeding 8 dB within this band.

[0072] The active noise reduction method of this invention shares the vehicle microphone and vehicle speaker, eliminating the need for additional hardware. It can achieve active noise reduction in a wide frequency range of 20-90Hz with a sampling rate of 1kHz, and the latency can be relaxed to 5-6ms. The noise reduction is improved by 8-10dB, the computing power is halved, and no additional hardware cost is required.

[0073] This invention employs active noise cancellation technology to solve the ear-pinch problem, completely eliminating it without increasing cost or weight. For example, when a vehicle is traveling on rough or damaged roads at speeds below 30 km / h, the noise cancellation method described in this invention can achieve a low-frequency (20Hz–50Hz) ear-pinch noise reduction effect of 8dB–10dB, without requiring additional hardware costs or weight increases.

[0074] This invention addresses the common industry problem of unstable front-end signals by sharing a vehicle-mounted microphone and a vehicle-mounted speaker. It calculates a compensation coefficient based on the voltage value of the vehicle-mounted host's power supply and performs amplitude correction on the original audio signal collected by the microphone. This ensures that the reference signal obtained after echo cancellation based on the corrected audio signal remains consistent under voltage fluctuations. Furthermore, a dual-loop feedforward algorithm is used to generate a target cancellation signal based on the reference signal and the corrected audio signal.

[0075] The active noise reduction method in this invention embodiment can improve the effect of dual closed-loop feedforward noise reduction and significantly save computing power requirements without increasing any hardware costs. It solves the problems of related active noise reduction processing methods, such as not considering the drift of microphone sensitivity with host voltage fluctuations, insufficient robustness to power supply noise, and reliance on additional multiple sensors and high sampling rates.

[0076] When presenting evidence of infringement, the methods of presentation may include: 1. Obtaining competitor vehicle models; 2. Artificially altering the power supply voltage of the main unit; 3. Monitoring the response of the active noise cancellation system. If the noise cancellation command remains stable after voltage fluctuations and the noise cancellation depth does not decrease, it indicates that the system has implemented a similar voltage compensation function and may have adopted our technical solution. If the noise cancellation performance fluctuates significantly or fails, it can be inferred that this compensation module has not been implemented; 4. Recording experimental data, such as voltage change curves, microphone sensitivity changes, noise cancellation SPL changes, etc., and compiling the comparison results into a technical report as objective evidence of infringement.

[0077] This invention provides a computer-readable storage medium.

[0078] In this embodiment, a computer program is stored on a computer-readable storage medium, and when the computer program is executed by a processor, it implements the active noise reduction method as described above.

[0079] This invention provides a controller.

[0080] In this embodiment, the controller may include a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, it implements the active noise reduction method described above.

[0081] Figure 10 This is a structural block diagram of the controller according to an embodiment of the present invention.

[0082] like Figure 10 As shown, the controller 500 includes a processor 501 and a memory 503. The processor 501 and the memory 503 are connected, for example, via a bus 502. Optionally, the controller 500 may also include a transceiver 504. It should be noted that in practical applications, the transceiver 504 is not limited to one, and the structure of the controller 500 does not constitute a limitation on the embodiments of the present invention.

[0083] Processor 501 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this invention. Processor 501 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0084] Bus 502 may include a pathway for transmitting information between the aforementioned components. Bus 502 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. Bus 502 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 10 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0085] The memory 503 stores a computer program corresponding to the active noise reduction method of the above embodiments of the present invention. This computer program is controlled and executed by the processor 501. The processor 501 executes the computer program stored in the memory 503 to implement the content shown in the foregoing method embodiments.

[0086] The controller 500 includes, but is not limited to, mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), and in-vehicle terminals (such as in-vehicle navigation terminals), as well as fixed terminals such as digital TVs and desktop computers. Figure 10 The controller 500 shown is merely an example and should not be construed as limiting the functionality and scope of use of embodiments of the present invention.

[0087] In this embodiment of the invention, the computer storage medium and controller employ the above-mentioned active noise reduction method to solve the problem that low-frequency noise is generated in the passenger compartment when the vehicle is driving on cement roads or bumpy and damaged roads, causing the driver and passengers to feel ear pressure.

[0088] This invention provides a vehicle.

[0089] Figure 11 This is a schematic diagram of a vehicle according to an embodiment of the present invention. Figure 11 As shown, vehicle 1000 includes controller 500 as described above.

[0090] The vehicle in this embodiment of the invention, based on the aforementioned controller, solves the problem that low-frequency noise is generated in the passenger compartment when the vehicle is driving on cement roads or bumpy, damaged roads, causing the driver and passengers to feel ear pressure.

[0091] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0092] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0093] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0095] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0096] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0097] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0098] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An active noise reduction method, characterized in that, For use in a vehicle, the method includes: Monitor the power supply voltage of the vehicle-mounted host and correct the raw audio signal collected by the vehicle-mounted microphone according to the power supply voltage; A target cancellation signal is generated based on the corrected audio signal, and the vehicle speakers are controlled to perform noise reduction processing on the vehicle cabin based on the target cancellation signal.

2. The active noise reduction method according to claim 1, characterized in that, The step of correcting the original audio signal acquired by the microphone based on the power supply voltage includes: The compensation coefficient is determined based on the voltage value of the supply voltage; The amplitude of the original audio signal is corrected according to the compensation coefficient.

3. The active noise reduction method according to claim 1, characterized in that, The step of generating the target cancellation signal based on the corrected audio signal includes: The corrected audio signal is subjected to echo cancellation processing to obtain a reference signal; An initial cancellation signal is generated based on the reference signal, and the initial cancellation signal is corrected based on the reference signal and the corrected audio signal to obtain the target cancellation signal.

4. The active noise reduction method according to claim 3, characterized in that, The step of generating an initial cancellation signal based on the reference signal includes: The reference signal is subjected to noise suppression processing using an algorithm combining fast Fourier transform and inverse filtering to obtain the initial cancellation signal.

5. The active noise reduction method according to claim 3, characterized in that, The step of correcting the initial cancellation signal based on the reference signal and the corrected audio signal includes: An adaptive filter is used to correct the error of the reference signal and the corrected audio signal, and the initial cancellation signal is corrected according to the error correction result. The adaptive filter uses the least mean square or normalized least mean square algorithm.

6. The active noise reduction method according to claim 1, characterized in that, The method further includes: The original audio signal is downsampled before being corrected according to the power supply voltage. Before controlling the vehicle speaker to perform noise reduction based on the target cancellation signal, the target cancellation signal is upsampled to the frequency of the original audio signal.

7. The active noise reduction method according to claim 6, characterized in that, The method further includes: Based on the target cancellation signal after the upgrade and the vehicle multimedia sound effects, the vehicle speakers are controlled to perform noise reduction processing on the vehicle cabin.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the active noise reduction method as described in any one of claims 1-7.

9. A controller, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the computer program is executed by the processor, it implements the active noise reduction method as described in any one of claims 1-7.

10. A vehicle, characterized in that, Includes the controller as described in claim 9.

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