Active noise cancellation method and system for vehicle, and vehicle

Abstract

An active noise cancellation method for a vehicle, which is applied to a vehicle having an active noise cancellation system. The vehicle modulates to an ultrasonic frequency band a secondary signal obtained on the basis of an in-vehicle environment noise signal so as to generate a modulated signal, and generates an ultrasonic wave, so that the ultrasonic wave generates a self-demodulation signal that can restore the secondary signal and directionally propagates the self-demodulation signal towards a target noise cancellation region, so as to perform noise cancellation processing.

Description

Active noise reduction method, active noise reduction system and vehicle of vehicle

[0001] The present application claims priority to the Chinese application No. 202410844207.0, filed on June 26, 2024, entitled: Active noise reduction method, active noise reduction system and vehicle of vehicle, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] Embodiments of the present application relate to, but are not limited to, the noise control technical field, and more particularly, to an active noise reduction method, an active noise reduction system and a vehicle of vehicle. BACKGROUND

[0003] In the related art, the active noise reduction system of the vehicle mainly reduces noise by installing a secondary noise source at the headrest, and uses the secondary noise source to generate a noise reduction signal to destructively interfere with the noise signal. However, the active noise reduction system control algorithm is complex, and the partition noise reduction effect is not ideal, which can cause noise pollution to the non-target noise reduction area. TECHNICAL SOLUTION

[0004] One object of the present application is to provide a new technical solution for an active noise reduction method of a vehicle, which can at least solve one of the problems of complex noise reduction control algorithm, poor partition noise reduction effect, and easy noise pollution to the non-target noise reduction area in the prior art.

[0005] Another object of the present application is to provide an active noise reduction system of a vehicle.

[0006] Still another object of the present application is to provide a vehicle comprising the active noise reduction system of the vehicle described above.

[0007] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0008] According to a first aspect of the present application, an active noise reduction method of a vehicle is provided, comprising the following steps:

[0009] modulating the secondary signal to an ultrasonic frequency band to generate a modulated signal, the secondary signal being obtained based on an in-vehicle ambient noise signal; and

[0010] generating an ultrasonic wave according to the modulated signal, so that the ultrasonic wave generates a self-demodulation signal capable of restoring the secondary signal and is directionally propagated towards a target noise reduction area, to fuse with the noise of the target noise reduction area and perform noise reduction processing on the target noise reduction area.

[0011] Optionally, the active noise reduction method of the vehicle further comprises the following steps:

[0012] obtaining an in-vehicle ambient noise signal; and,

[0013] generating a secondary signal according to the collected in-vehicle ambient noise signal;

[0014] Optionally, the active noise reduction method of the vehicle further comprises the following steps:

[0015] collecting an operation parameter of the vehicle; and,

[0016] acquiring the in-vehicle ambient noise signal corresponding to the operation parameter according to the operation parameter.

[0017] Optionally, the active noise reduction method of the vehicle further comprises the following steps:

[0018] collecting a noise signal in a target noise reduction area; and,

[0019] adjusting the secondary signal according to the noise signal in the target noise reduction area.

[0020] Optionally, the active noise reduction method of the vehicle further comprises the following steps:

[0021] generating a theoretical signal according to the self-demodulation signal and a propagation path of the self-demodulation signal; and,

[0022] generating a reference signal according to the noise signal in the target noise reduction area and the theoretical signal;

[0023] adjusting the secondary signal according to the reference signal.

[0024] Optionally, the frequency of the self-demodulation signal is 20 Hz-20 kHz.

[0025] According to a second aspect of the present application, an active noise reduction system of a vehicle is provided, comprising: an acoustic gathering screen, the acoustic gathering screen comprising: a signal modulator, configured to modulate the secondary signal to an ultrasonic frequency to generate a modulated signal, the secondary signal being obtained based on an in-vehicle ambient noise signal; and an ultrasonic transducer, configured to generate corresponding ultrasonic waves according to the modulated signal, so that the ultrasonic waves generate a self-demodulation signal capable of restoring the secondary signal and propagate directionally towards a target noise reduction area, so as to fuse with noise of the target noise reduction area and perform noise reduction processing on the target noise reduction area.

[0026] Optionally, the center frequency of the resonance frequency of the ultrasonic transducer is 40 kHz-60 kHz.

[0027] Optionally, the active noise reduction system of the vehicle further comprises: an acquirer configured to acquire the in-vehicle ambient noise signal; and a first processor configured to generate a secondary signal according to the in-vehicle ambient noise signal.

[0028] Optionally, the active noise reduction system of the vehicle further comprises a first collector configured to collect an operation parameter of the vehicle, and the acquirer is configured to acquire the in-vehicle ambient noise signal according to the operation parameter.

[0029] Optionally, the first collector comprises an acceleration sensor and / or a noise microphone.

[0030] Optionally, the first processor is configured to process the in-vehicle ambient noise signal and generate the secondary signal which is opposite in phase and identical in amplitude to the in-vehicle ambient noise signal.

[0031] Optionally, the first processor comprises a filter.

[0032] Optionally, the active noise reduction system of the vehicle further comprises a second collector configured to collect a noise signal in a target noise reduction area, and the first processor is configured to adjust the secondary signal according to the noise signal in the target noise reduction area.

[0033] Optionally, the second collector comprises an error microphone.

[0034] Optionally, the active noise reduction system of the vehicle further comprises a second processor configured to generate a theoretical signal according to the self-demodulation signal and a propagation path of the self-demodulation signal, and a third processor configured to generate a reference signal according to the noise signal in the target noise reduction area and the theoretical signal, and the first processor is configured to adjust the secondary signal according to the reference signal.

[0035] Optionally, the third processor is configured to subtract the noise signal in the target noise reduction area from the theoretical signal to generate the reference signal.

[0036] Optionally, the second collector is arranged at a headrest of a seat in the vehicle.

[0037] Optionally, the self-demodulation signal has a frequency of 20 Hz to 20 kHz.

[0038] Optionally, the sound collecting screen is arranged on an instrument panel of the vehicle and faces the driver.

[0039] Optionally, the active noise reduction system comprises a plurality of sound collecting screens, and the plurality of sound collecting screens are arranged to face a plurality of seats in the vehicle.

[0040] According to a third aspect of the present application, a vehicle is provided, comprising the active noise reduction system of the vehicle according to any one of the above embodiments.

[0041] According to the active noise reduction method of the vehicle, the secondary signal is modulated to an ultrasonic frequency, and an ultrasonic wave is output through an ultrasonic transducer, so that the ultrasonic wave self-demodulates to generate a self-demodulation signal capable of restoring the secondary signal. The high directivity characteristic, high frequency attenuation effect and frequency superposition effect of the ultrasonic wave enable the self-demodulation signal to have high directivity and be transmitted to a long distance, and the self-demodulation signal can have high directivity even if it is a low-frequency sound, so as to be fused with noise in a target noise reduction area to achieve noise reduction. Therefore, the active noise reduction method of the vehicle can reduce secondary noise pollution to a non-target noise reduction area while performing partition noise reduction, and has the advantages of simple algorithm.

[0042] In addition, the sound gathering screen can replace the original instrument screen and / or entertainment screen in the vehicle, avoid adding a secondary sound source, reduce the production cost of the active noise reduction system, effectively control the noise level in the vehicle, improve the comfort of the sound environment in the vehicle, and reduce the addition of hardware in the vehicle. Compared with the traditional headrest speaker, the comfort of the seat is improved, and the condition of whether the whole vehicle audio system is turned on is not limited.

[0043] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0044] The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments of the present application and, together with the description, serve to explain the principles of the application.

[0045] FIG. 1 is a control flow diagram of an active noise reduction system of a vehicle according to an embodiment of the present application;

[0046] FIG. 2 is a control flow diagram of a sound gathering screen in an active noise reduction system of a vehicle according to an embodiment of the present application;

[0047] FIG. 3 is a parametric array principle diagram of a sound gathering screen in an active noise reduction system of a vehicle according to an embodiment of the present application;

[0048] FIG. 4 is a basic acoustic principle diagram of a sound gathering screen in an active noise reduction system of a vehicle according to an embodiment of the present application;

[0049] FIG. 5 is a schematic diagram of the installation of an active noise reduction system of a vehicle on a vehicle according to an embodiment of the present application;

[0050] FIG. 6 is a flowchart of an active noise reduction method of a vehicle according to a first embodiment of the present application;

[0051] FIG. 7 is a flowchart of an active noise reduction method of a vehicle according to a second embodiment of the present application;

[0052] Fig. 8 is a flow chart of an active noise reduction method for a vehicle according to a third embodiment of the present application;

[0053] Fig. 9 is a flow chart of an active noise reduction method for a vehicle according to a fourth embodiment of the present application.

[0054] Fig. 1 is a diagram of a vehicle according to an embodiment of the present application;

[0055] Embodiments of the present application

[0056] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It can be noted that the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments are not limiting to the scope of the present application unless specifically stated otherwise.

[0057] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the scope of the application or its application or uses.

[0058] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail herein, but can be considered as part of the specification, where appropriate.

[0059] In all of the examples shown and discussed herein, any specific values can be interpreted as merely illustrative and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0060] It can be noted that like numerals and letters refer to like items throughout the drawings, and as such, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0061] The active noise reduction method for a vehicle according to embodiments of the present application will now be described in detail below with reference to the accompanying drawings.

[0062] The active noise reduction method for a vehicle according to embodiments of the present application will now be described in detail below with reference to the accompanying drawings.

[0063] The secondary signal is modulated to an ultrasonic frequency band to generate a modulated signal, and the secondary signal is obtained based on the in-vehicle ambient noise signal;

[0064] The ultrasonic wave is generated according to the modulated signal, so that the ultrasonic wave generates a self-demodulation signal 13 of the secondary signal and is directionally propagated toward the target noise reduction area to be fused with the noise of the target noise reduction area and to perform a noise reduction process on the target noise reduction area.

[0065] Thus, according to the active noise reduction method of the vehicle of the embodiment of the present application, the secondary signal is modulated to an ultrasonic frequency, and then the ultrasonic wave is output through the ultrasonic transducer 11, so that the ultrasonic wave self-demodulates to generate a self-demodulation signal 13 capable of restoring the secondary signal. The high directivity characteristic, high frequency attenuation effect, and frequency superposition effect of the ultrasonic wave enable the self-demodulation signal 13 to have high directivity and be propagated to a long distance. Even if the self-demodulation signal 13 is a low-frequency sound, it can also have high directivity, so as to be fused with the noise in the target noise reduction area to achieve noise reduction. Therefore, the active noise reduction method of the vehicle of the embodiment of the present application can reduce the secondary noise pollution to the non-target noise reduction area while performing the partition noise reduction, and has the advantages of simple algorithm.

[0066] For example, the driver position can retain part of the road noise, so that the driver can master the road conditions in real time. Other passengers can enjoy a quieter ride. That is, the sound field in the vehicle can be partitioned and reduced, and different degrees of noise reduction effect can be achieved for different positions.

[0067] In some specific embodiments, the step of modulating the obtained modulated signal through the power amplifier and then outputting the modulated signal to the ultrasonic transducer 11 can be further included.

[0068] In some optional embodiments, the steps of modulating the secondary signal to the ultrasonic frequency to generate a modulated signal and generating an ultrasonic wave according to the modulated signal can be performed in the sound gathering screen 1.

[0069] As shown in FIG. 7, according to one embodiment of the present application, the active noise reduction method of the vehicle further includes the following steps:

[0070] Obtaining an in-vehicle environmental noise signal;

[0071] Generating a secondary signal according to the collected in-vehicle environmental noise signal.

[0072] Specifically, the secondary signal can be opposite in phase and the same in amplitude to the in-vehicle environmental noise signal, so that the self-demodulation signal 13 restored by self-demodulation is opposite in phase and the same in amplitude to the in-vehicle environmental noise signal. Therefore, the self-demodulation signal 13 can be coherent and destructive with the in-vehicle environmental noise signal, so as to achieve the purpose of noise reduction.

[0073] In some specific embodiments of the present application, the active noise reduction method of the vehicle further includes the following steps:

[0074] Collecting a running parameter of the vehicle;

[0075] Obtaining an in-vehicle environmental noise signal corresponding to the running parameter according to the running parameter.

[0076] Specifically, the operating parameters of the vehicle can include, but are not limited to, the rotating speed of the engine of the vehicle, the rotating speed of the motor, and the acceleration of the vehicle. Among them, the rotating speed of the engine, the rotating speed of the motor, and the acceleration of the vehicle have a corresponding relationship with the environmental noise signal in the vehicle.

[0077] In addition, the acquisition of the operating parameters of the vehicle can be realized by reading the data information transmitted by the CAN bus of the vehicle.

[0078] According to some other embodiments of the present application, as shown in FIG. 8, the active noise reduction method of the vehicle further includes the following steps:

[0079] Collecting the noise signal in the target noise reduction area;

[0080] Adjusting the secondary signal according to the noise signal in the target noise reduction area.

[0081] That is, the secondary signal can be generated according to the collected environmental noise signal in the vehicle and the noise signal in the target noise reduction area. For example, the filter adjusts its parameters according to the noise signal in the target noise reduction area, and then the environmental noise signal in the vehicle is input into the adjusted filter as feedback to generate the secondary signal, thereby forming feedback control, which is conducive to improving the effect of noise control.

[0082] In some specific embodiments of the present application, as shown in FIG. 9, the active noise reduction method of the vehicle further includes the following steps:

[0083] Generating a theoretical signal according to the self-demodulation signal 13 and the propagation path of the self-demodulation signal 13;

[0084] Generating a reference signal according to the noise signal in the target noise reduction area and the theoretical signal;

[0085] Adjusting the secondary signal according to the reference signal.

[0086] Specifically, as shown in FIG. 1, the self-demodulation signal propagates along the secondary path, that is, the self-demodulation signal propagates towards the target noise reduction area, and the self-demodulation signal is the restoration of the secondary signal, so it can be understood that the secondary signal in the target noise reduction area cancels the original noise signal in the target noise reduction area.

[0087] In the vehicle, the path between the sound gathering screen and the target noise reduction area is known, which can be estimated according to the known secondary path and the self-demodulation signal to obtain a theoretical signal after the secondary signal and the original noise signal in the target noise reduction area are superimposed.

[0088] Then, the reference signal can be obtained by subtracting the collected noise signal in the target noise reduction area from the theoretical signal, and then the reference signal is used as feedback to adjust the secondary signal, so that the feedback control is more efficient and stable.

[0089] According to one embodiment of the present application, the frequency of the self-demodulation signal is 20Hz-20kHz, so that the self-demodulation signal 13 is in the audible frequency range of 20Hz-20kHz, thereby utilizing the high directivity characteristics, high frequency attenuation effect, and frequency superposition effect of ultrasonic waves to generate audible sound with extremely high directivity that can propagate to a long distance, so that the low-frequency sound also has high directivity, which is beneficial to achieve zoned noise reduction and stimulation noise pollution in non-target noise reduction areas.

[0090] As shown in FIGS. 1 and 2, the present application also provides an active noise reduction system of a vehicle, which comprises a sound gathering screen 1.

[0091] Specifically, the sound gathering screen 1 comprises a signal modulator and an ultrasonic transducer 11. The signal modulator is configured to modulate the secondary signal to an ultrasonic frequency to generate a modulated signal. The ultrasonic transducer 11 is configured to generate corresponding ultrasonic waves according to the modulated signal, so that the ultrasonic waves generate a self-demodulation signal 13 capable of restoring the secondary signal and are directionally propagated toward the target noise reduction area to be fused with the noise of the target noise reduction area and to perform noise reduction on the target noise reduction area.

[0092] The active noise reduction system of the present application can be at least partially applicable to the above-mentioned active noise reduction method.

[0093] Specifically, the sound gathering screen 1 is a kind of directional sound emitting device, and simultaneously has the functions of a display and a loudspeaker. The sound gathering screen 1 is different from a conventional loudspeaker, and can not only realize directional propagation of sound, but also does not affect the optical properties of the display, so that the display gradually expands to the directions of voice, human-computer interaction, and intelligent control in addition to the conventional display, touch, and other functions, thereby bringing a completely immersive “sound and picture integration” experience to the user.

[0094] The sound gathering screen 1 comprises a signal modulator and an ultrasonic transducer 11. The modulator can modulate the secondary signal to an ultrasonic frequency to generate a modulated signal.

[0095] The modulated signal is then input to the ultrasonic transducer 11. The ultrasonic transducer 11 can convert an electrical signal into an acoustic signal, so that the ultrasonic transducer 11 can output ultrasonic waves according to the input modulated signal, and the ultrasonic waves can be propagated through the air for self-demodulation. The nonlinear effect of the ultrasonic waves in the medium enables the self-demodulation signal 13 formed by the self-demodulation of the ultrasonic waves to restore the above-mentioned secondary signal. Optionally, the ultrasonic transducer 11 can be an ultrasonic transducer array.

[0096] For example, the secondary signal is 1kHZ, which is modulated to an ultrasonic frequency of 40k and then output by the ultrasonic transducer, so that the self-demodulation signal 13 is 1kHZ obtained by the nonlinear demodulation of the 39k ultrasonic waves and the 40k ultrasonic waves, thereby restoring the secondary signal.

[0097] Specifically, the audible sound generated by the sound focusing screen 1 system is achieved by driving the transparent directional sound generating transducer on the upper layer of the screen to vibrate slightly. As shown in FIG. 4, when there are two sound waves of different frequencies in the space, the propagation of each sound wave is in a medium disturbed by the other sound wave, so scattering occurs due to the unevenness of the medium. This phenomenon of scattering of a sound wave in an uneven medium disturbed by another sound wave is commonly referred to as "scattered sound". Because the medium is disturbed by another sound wave, it can be qualitatively understood that there is a frequency component modulated by another sound wave in the scattered sound, i.e. there are difference frequency and sum frequency components of the two sound waves, which can be simply represented as:

[0098] In the above formula, P1 and P2 are the amplitudes of the two primary frequency ultrasonic waves, ω1 and ω2 are the frequencies of the two primary frequency ultrasonic waves, S represents the strength of the nonlinear effect, and t is time.

[0099] As shown in FIG. 3, because the two primary frequency ultrasonic waves continuously generate scattered sound during propagation, the forward scattered part (the part in the same direction as the propagation direction of the primary frequency ultrasonic wave) is in phase with the scattered sound generated at an earlier time and is gradually strengthened by superposition. This process can be regarded as a volume array composed of an infinite number of virtual sources generating a secondary sound field, commonly referred to as a parametric array.

[0100] For ease of explanation, the frequencies of the two ultrasonic waves of different frequencies can be defined as f1 and f2. According to the principle of air nonlinear action, the two ultrasonic waves of different frequencies can form two sound waves with frequencies f1+f2 and f1-f2 after superposition, where f1-f2 is the self-demodulation signal 13.

[0101] The higher the frequency of a sound wave, the faster it decays in air and is absorbed by air until it disappears. Therefore, as time goes on, only a small amount of low-frequency sound energy propagates to a long distance. That is, the sound wave signals of frequencies f1, f2, and f1+f2 are absorbed by air, and only the self-demodulation signal 13 of frequency f1-f2 is not absorbed or is absorbed in a small amount, i.e. only the self-demodulation signal 13 of frequency f1-f2 is left.

[0102] Therefore, the self-demodulation signal 13 generated after the superposition of ultrasonic waves can restore the above-mentioned secondary signal, and because of the high directivity of ultrasonic waves, the self-demodulation signal 13 can be made to propagate towards the target noise reduction area and fuse with noise in the target noise reduction area, achieving active noise reduction in the vehicle.

[0103] Thus, the active noise reduction system of the vehicle according to the embodiments of the present application utilizes the sound gathering effect of the sound gathering screen 1, modulates the secondary signal to an ultrasonic frequency by using the signal modulator, and outputs the ultrasonic wave through the ultrasonic transducer 11, so that the ultrasonic wave self-demodulates to generate a self-demodulation signal 13 capable of restoring the secondary signal. The self-demodulation signal 13 has high directivity and can propagate to a long distance due to the high directivity, high frequency attenuation effect, and frequency superposition effect of the ultrasonic wave. Even if the self-demodulation signal 13 is a low-frequency sound, it can also have high directivity, so as to be combined with the noise in the target noise reduction area to achieve noise reduction. Therefore, the active noise reduction system of the vehicle according to the embodiments of the present application can reduce the secondary noise pollution to the non-target noise reduction area while performing partition noise reduction, and has the advantages of simple algorithm.

[0104] In addition, the sound gathering screen 1 can replace the original instrument screen and / or entertainment screen in the vehicle, avoid adding a secondary sound source, reduce the production cost of the active noise reduction system, effectively control the noise level in the vehicle, improve the comfort of the sound environment in the vehicle, and reduce the addition of hardware in the vehicle. Compared with the traditional headrest 3 loudspeaker, the comfort of the seat is improved, and the condition of whether the audio system of the whole vehicle is turned on is not limited.

[0105] For example, the driver position can retain part of the road noise, so that the driver can master the road conditions in real time. Other passengers can enjoy a quieter ride. That is, the sound field in the vehicle can be partitioned and noise reduced, and different degrees of noise reduction effect can be achieved for different positions.

[0106] In some specific embodiments of the present application, the active noise reduction system of the vehicle further includes an obtainer and a first processor. The obtainer is configured to obtain an in-vehicle ambient noise signal. The first processor is configured to generate a secondary signal based on the in-vehicle ambient noise signal.

[0107] Specifically, the obtainer can obtain an in-vehicle ambient noise signal, and the frequency of the in-vehicle ambient noise signal has a corresponding relationship with the road noise in the vehicle. The obtaining method includes but is not limited to directly collecting the in-vehicle ambient noise signal, and obtaining the in-vehicle ambient noise signal corresponding to the running parameter of the vehicle according to the running parameter of the vehicle.

[0108] The first processor can receive the in-vehicle ambient noise signal from the obtainer, and generate a corresponding secondary signal based on the in-vehicle ambient noise signal. That is, the first processor can send the secondary signal to the sound gathering screen 1 as a secondary noise source.

[0109] In some specific embodiments, the sound gathering screen 1 can further include a power amplifier. The modulated signal obtained by modulation is amplified by the power amplifier and then output to the ultrasonic transducer 11.

[0110] According to some other embodiments of the present application, the center frequency of the resonance frequency of the ultrasonic transducer 11 is 40-60 kHz, which can make the ultrasonic transducer 11 have a high energy conversion efficiency in the process of converting electrical energy into mechanical energy, thereby reducing energy consumption and cost.

[0111] In some specific embodiments of the present application, the active noise reduction system of the vehicle further comprises a first collector for collecting the operating parameters of the vehicle. The acquirer acquires the corresponding in-vehicle ambient noise signal according to the operating parameters.

[0112] Specifically, the first collector can be electrically connected to the acquirer, and the operating parameters of the vehicle collected by the first collector can be sent to the acquirer, and the acquirer acquires the corresponding in-vehicle ambient noise signal according to the operating parameters.

[0113] The operating parameters of the vehicle can include but are not limited to the speed of the engine of the vehicle, the speed of the motor, and the acceleration of the vehicle. Among them, the speed of the engine, the speed of the motor, and the acceleration of the vehicle have a corresponding relationship with the in-vehicle ambient noise signal.

[0114] In addition, the acquisition of the operating parameters of the vehicle can be realized by reading the data information transmitted by the CAN bus of the vehicle.

[0115] According to some optional embodiments of the present application, the first collector comprises an acceleration sensor and / or a noise microphone. The acceleration sensor can be used to collect the acceleration information of the vehicle, and the acceleration information of the vehicle has a corresponding relationship with the frequency of the in-vehicle ambient noise signal. Therefore, the in-vehicle ambient noise signal can be obtained according to the acceleration information of the vehicle.

[0116] The acceleration sensor is part of the electronic control system of the vehicle, and the in-vehicle ambient noise signal is acquired by using the acceleration sensor of the vehicle itself, without the need to add additional hardware devices, which is conducive to reducing the production cost of the active noise reduction system of the vehicle.

[0117] In addition, the noise microphone can directly collect the noise in the vehicle environment as the in-vehicle ambient noise signal.

[0118] In some specific embodiments of the present application, the first processor is configured to process the in-vehicle ambient noise signal and generate a secondary signal having the same amplitude and opposite phase as the in-vehicle ambient noise signal. The self-demodulation signal 13 restored by the self-demodulation can have the same amplitude and opposite phase as the in-vehicle ambient noise signal, so that the self-demodulation signal 13 can be coherent with the in-vehicle ambient noise signal and can be cancelled, thereby achieving the purpose of noise reduction.

[0119] According to some other embodiments of the present application, the first processor comprises a filter, which adjusts its parameters according to the noise signal in the target noise reduction area, and then inputs the in-vehicle ambient noise signal as a reference signal into the parameter-adjusted filter to generate a secondary signal, thereby realizing feedback adjustment, adapting to the noise changes in the target noise reduction area, and improving the noise reduction effect.

[0120] In addition, a desired signal can be input to the first processor as a noise reduction target during noise reduction. For example, if complete noise elimination is desired, the desired signal can be set to 0.

[0121] Optionally, the first processor can be an adaptive filter.

[0122] In some specific embodiments of the present application, the active noise reduction system of the vehicle further comprises a second collector for collecting the noise signal in the target noise reduction area. The first processor adjusts the secondary signal according to the noise signal in the target noise reduction area.

[0123] Specifically, the second collector can be arranged in the target noise reduction area to be reduced, for collecting the noise signal in the target noise reduction area and sending the collection result to the first processor, which can adjust the secondary signal according to the noise signal in the target noise reduction area.

[0124] That is, the second collector can serve as a feedback structure to feed back the noise signal in the target noise reduction area to the first processor during noise reduction.

[0125] Since the noise in the target noise reduction area is unstable and fluctuates at any time, an error signal will be generated after the self-demodulation signal 13 cancels the original noise in the target noise reduction area. This error signal is the sound actually heard by the human ear. The second collector can collect this error signal as the noise signal in the target noise reduction area, and then the first processor adjusts the secondary signal according to the feedback noise signal in the target noise reduction area to cope with the fluctuating noise in the target noise reduction area. In addition, the feedback structure is conducive to more effectively controlling the noise level in the target noise reduction area and enhancing the noise reduction effect.

[0126] According to some optional embodiments of the present application, the second collector comprises an error microphone, which can collect the noise in the target noise reduction area and convert it into an electrical signal. The microphone has good directivity, which helps to pick up the required sound source and reduce the interference of background noise.

[0127] According to some other embodiments of the present application, the active noise reduction system of the vehicle further comprises a second processor and a third processor. The second processor is configured to generate a theoretical signal according to the self-demodulation signal 13 and a propagation path of the self-demodulation signal 13. The third processor is configured to generate a reference signal according to a noise signal in the target noise reduction area and the theoretical signal, and the first processor adjusts the secondary signal according to the reference signal.

[0128] As shown in FIG. 1, the self-demodulation signal output by the sound focusing screen propagates along the secondary path, i.e., the self-demodulation signal propagates towards the target noise reduction area, and the self-demodulation signal is the restoration of the secondary signal, so it can be understood that the secondary signal is incoherent with the original noise signal in the target noise reduction area at the target noise reduction area.

[0129] In the vehicle, the path between the sound focusing screen and the target noise reduction area is known, and the second processor can estimate the theoretical signal of the superposition of the secondary signal and the original noise signal in the target noise reduction area according to the known secondary path and the self-demodulation signal. The second processor can include but is not limited to a filter.

[0130] Then the theoretical signal and the noise signal in the target noise reduction area collected by the error microphone are input into the third processor to obtain the reference signal, and the reference signal is fed back to the first processor, and the first processor adjusts the secondary signal according to the reference signal, so that the feedback control is more efficient and stable.

[0131] According to one embodiment of the present application, the third processor subtracts the noise signal in the target noise reduction area from the theoretical signal to generate the reference signal, and the feedback control is more reliable and efficient.

[0132] According to some other embodiments of the present application, the second collector is arranged at the headrest 3 of the seat in the vehicle. In the vehicle, the target noise reduction area mainly refers to the area near the ear of the occupant, and the area is closest to the headrest 3 of the seat in the vehicle, so arranging the second collector at the headrest 3 can pick up the sound of the target noise reduction area to the maximum extent, improve the correctness of the feedback, and thus enhance the noise reduction effect.

[0133] According to one embodiment of the present application, the frequency of the self-demodulation signal 13 is 20Hz-20kHz, so that the self-demodulation signal 13 is in the audible frequency range of 20Hz-20kHz, thereby utilizing the high directivity characteristics, high frequency attenuation effect and frequency superposition effect of ultrasonic waves to generate audible sound with extremely high directivity that can propagate to a long distance, so that low-frequency sound also has high directivity, which is conducive to realizing partition noise reduction and stimulating noise pollution in non-target noise reduction areas.

[0134] In some specific embodiments of the present application, the sound focusing screen 1 is arranged on the instrument table of the vehicle and is arranged towards the driver. For example, the sound focusing screen 1 can replace the instrument screen.

[0135] Since the sound gathering screen 1 is arranged towards the driver, the pointing range of the sound gathering screen 1 can include the entire passenger cabin. By controlling the sound gathering screen 1, the directivity of sound gathering can be controlled, so that different areas where different positions in the vehicle are located are respectively subjected to noise reduction, while realizing partitioned noise reduction and reducing secondary noise pollution to non-target noise reduction areas.

[0136] According to some optional embodiments of the present application, as shown in FIG. 5, the active noise reduction system includes a plurality of sound gathering screens 1, and the plurality of sound gathering screens 1 are arranged towards a plurality of seats 2 in the vehicle. In this way, each sound gathering screen 1 can facilitate partitioned noise reduction for the areas where different seats 2 are located, thereby enhancing the control effect of partitioned noise reduction.

[0137] Arranging the plurality of sound gathering screens 1 towards the plurality of seats 2 in the vehicle can include, but is not limited to, the following cases.

[0138] It should be noted that the number of sound gathering screens 1 and the number of seats 2 can be equal or not equal. A single sound gathering screen 1 can be arranged towards a plurality of seats 2 and perform partitioned noise reduction for the areas where the plurality of seats 2 are located. A plurality of sound gathering screens 1 can be arranged towards the same seat 2 and perform noise reduction for the area where the seat 2 is located. For example, as shown in FIG. 5, the seat 2 of the main driver and the seat 2 of the co-driver in the front row of the vehicle can be respectively provided with a sound gathering screen 1.

[0139] The embodiments of the present application also provide a vehicle including the active noise reduction system of the vehicle according to any of the above embodiments. Since the active noise reduction system of the vehicle according to the embodiments of the present application has the above technical effects, the vehicle according to the embodiments of the present application also has corresponding technical effects, that is, by utilizing the sound gathering effect of the sound gathering screen 1, using the signal modulator to modulate the secondary signal to an ultrasonic frequency, and then outputting ultrasonic waves through the ultrasonic transducer 11, so that the ultrasonic waves self-demodulate to generate a self-demodulation signal 13 capable of restoring the secondary signal, and by utilizing the high directivity, high frequency attenuation effect and frequency superposition effect of the ultrasonic waves, the self-demodulation signal 13 can have high directivity and can propagate to a long distance, and the self-demodulation signal 13 can have very high directivity even if it is a low-frequency sound, so as to be able to fuse with the noise in the target noise reduction area to achieve noise reduction. Therefore, the active noise reduction system of the vehicle according to the embodiments of the present application can reduce secondary noise pollution to non-target noise reduction areas while performing partitioned noise reduction, and also has the advantage of simple algorithm.

[0140] In addition, the sound gathering screen 1 can replace the original instrument screen and / or entertainment screen in the vehicle, avoid adding a secondary sound source, reduce the production cost of the active noise reduction system, effectively control the noise level in the vehicle, improve the comfort of the sound environment in the vehicle, and reduce the addition of hardware in the vehicle. Compared with the traditional headrest 3 speaker, the comfort of the seat is improved, and it is not limited by whether the audio system of the entire vehicle is turned on or not.

[0141] While certain embodiments of the application have been described in detail as examples, those skilled in the art who study the preceeding descriptions will understand that they are merely examples and are not intended to limit the scope of the present application. Those skilled in the art can understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An active noise reduction method for a vehicle, wherein, Includes the following steps: The secondary signal is modulated onto the ultrasonic frequency band to generate a modulated signal, wherein the secondary signal is obtained based on the in-vehicle environmental noise signal; and, Ultrasonic waves are generated based on the modulated signal, such that the generated ultrasonic waves can reconstruct the secondary signal and propagate directionally toward the target noise reduction area, so as to fuse with the noise in the target noise reduction area and perform noise reduction processing on the target noise reduction area.

2. The active noise reduction method for vehicles according to claim 1, wherein, It also includes the following steps: Acquire the in-vehicle ambient noise signal; and, The secondary signal is generated based on the collected in-vehicle environmental noise signal.

3. The active noise reduction method for a vehicle according to any one of claims 1-2, wherein, It also includes the following steps: Collect vehicle operating parameters; and, The in-vehicle environmental noise signal corresponding to the operating parameters is obtained based on the operating parameters.

4. The active noise reduction method for a vehicle according to any one of claims 1-3, wherein, It also includes the following steps: Collect noise signals within the target noise reduction area; and, The secondary signal is adjusted based on the noise signal within the target noise reduction area.

5. The active noise reduction method for a vehicle according to any one of claims 1-4, wherein, It also includes the following steps: A theoretical signal is generated based on the self-demodulated signal and the propagation path of the self-demodulated signal; A reference signal is generated based on the noise signal within the target noise reduction region and the theoretical signal; and, The secondary signal is adjusted according to the reference signal.

6. The active noise reduction method for a vehicle according to any one of claims 1-5, wherein, The frequency of the self-demodulated signal is 20Hz to 20kHz.

7. An active noise cancellation system for a vehicle, wherein, include: The sound-focusing screen includes: A signal modulator is used to modulate a secondary signal to an ultrasonic frequency to generate a modulated signal, the secondary signal being obtained based on an in-vehicle ambient noise signal; and, An ultrasonic transducer is used to generate corresponding ultrasonic waves based on the modulated signal, so that the generated ultrasonic waves can reconstruct the secondary signal and propagate directionally toward the target noise reduction area, so as to fuse with the noise in the target noise reduction area and perform noise reduction processing on the target noise reduction area.

8. The active noise cancellation system for a vehicle according to claim 7, wherein, The center frequency of the resonant frequency of the ultrasonic transducer is 40kHz to 60kHz.

9. The active noise cancellation system for a vehicle according to claim 7 or 8, wherein, Also includes: Acquisition unit, used to acquire in-vehicle ambient noise signals; and, A first processor is configured to generate the secondary signal based on the in-vehicle ambient noise signal.

10. The active noise cancellation system for a vehicle according to claim 9, wherein, Also includes: The first data acquisition device is used to collect the vehicle's operating parameters, and the acquisition device obtains the corresponding in-vehicle environmental noise signal based on the operating parameters.

11. The active noise cancellation system for a vehicle according to claim 10, wherein, The first data acquisition unit includes an accelerometer and / or a noise microphone.

12. The active noise cancellation system for a vehicle according to claim 11, wherein, The first processor is used to process the in-vehicle ambient noise signal and generate a secondary signal that is opposite in phase and has the same amplitude as the in-vehicle ambient noise signal.

13. The active noise cancellation system for a vehicle according to any one of claims 9-12, wherein, The first processor includes a filter.

14. The active noise cancellation system for a vehicle according to any one of claims 9-13, wherein, Also includes: The second collector is used to collect noise signals within the target noise reduction area, and the first processor adjusts the secondary signal based on the noise signals within the target noise reduction area.

15. The active noise cancellation system for a vehicle according to claim 14, wherein, The second data acquisition device includes an error microphone.

16. The active noise cancellation system for a vehicle according to claim 14 or 15, wherein, Also includes: A second processor is configured to generate a theoretical signal based on the self-demodulated signal and the propagation path of the self-demodulated signal; and, A third processor is configured to generate a reference signal based on the noise signal within the target noise reduction area and the theoretical signal, and the first processor adjusts the secondary signal based on the reference signal.

17. The active noise cancellation system for a vehicle according to claim 16, wherein, The third processor subtracts the noise signal and the theoretical signal within the target noise reduction area to generate the reference signal.

18. The active noise cancellation system for a vehicle according to any one of claims 14-17, wherein, The second data collector is located in the headrest of the vehicle seat.

19. The active noise cancellation system for a vehicle according to any one of claims 7-18, wherein, The frequency of the self-demodulated signal is 20Hz to 20kHz.

20. The active noise cancellation system for a vehicle according to any one of claims 7-19, wherein, The sound-absorbing screen is mounted on the vehicle's dashboard and faces the driver.

21. The active noise cancellation system for a vehicle according to any one of claims 7-20, wherein, The active noise cancellation system includes multiple sound-focusing screens, which are positioned facing multiple seats inside the vehicle.

22. A vehicle, wherein, include: The active noise reduction system for a vehicle according to any one of claims 7-21.

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