CN114255727A - Active noise reduction method, vehicle-mounted active noise reduction system and automobile - Google Patents
Active noise reduction method, vehicle-mounted active noise reduction system and automobile Download PDFInfo
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- CN114255727A CN114255727A CN202110394864.6A CN202110394864A CN114255727A CN 114255727 A CN114255727 A CN 114255727A CN 202110394864 A CN202110394864 A CN 202110394864A CN 114255727 A CN114255727 A CN 114255727A
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
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- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/16—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/175—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound
- G10K11/178—Methods or devices for protecting against, or for damping, noise or other acoustic waves in general using interference effects; Masking sound by electro-acoustically regenerating the original acoustic waves in anti-phase
- G10K11/1785—Methods, e.g. algorithms; Devices
- G10K11/17853—Methods, e.g. algorithms; Devices of the filter
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
Abstract
The application provides an active noise reduction method, a vehicle-mounted active noise reduction system and an automobile, and relates to the technical field of noise reduction. The method comprises the following steps: acquiring a vehicle body vibration signal of an automobile; calculating to obtain a first noise reduction signal according to the vehicle body vibration signal and the first filter coefficient; and playing the first noise reduction signal through a loudspeaker array, wherein the loudspeaker array is arranged in a cabin of the automobile. According to the active noise reduction method, the vehicle-mounted active noise reduction system and the vehicle, noise reduction signals are generated according to vibration information of a vehicle body in an active noise reduction mode, noise reduction sound waves are emitted in a vehicle cabin to offset tire noise, therefore, adverse effects of the tire noise on a passenger are effectively reduced, and riding experience of the passenger is improved.
Description
Technical Field
The application relates to the technical field of noise reduction, in particular to an active noise reduction method, a vehicle-mounted active noise reduction system and an automobile.
Background
During the driving of the vehicle, the person sitting in the vehicle can feel very noticeable noise. Such noise is composed of various types of noise, such as tire noise (also called road noise), wind noise, and engine noise. The tire noise is composed of air noise at tire pattern gaps/tire bodies, pattern/tire body vibration noise, uneven road noise and the like, and is various in mechanism and complex in frequency component.
The presence of noise has a significant adverse effect on the ride experience of the occupant, and various solutions have been proposed in the prior art for reducing noise. In order to reduce the tire noise, most conventional automobile manufacturers adopt means such as increasing the rigidity of the automobile body, applying sound insulation materials, adding damping cushions and using high-performance silent tires, however, the means are high in implementation cost and have a limited effect of suppressing the tire noise.
Therefore, how to effectively suppress the tire noise to improve the riding experience of the passengers becomes a problem to be solved urgently in the field.
Disclosure of Invention
In order to solve the technical problem, embodiments of the present application provide an active noise reduction method, a vehicle-mounted active noise reduction system, and an automobile, which aim to eliminate a tire noise entering a cabin in an active noise reduction manner, thereby effectively reducing an influence of the tire noise on a passenger and improving a riding experience of the passenger.
A first aspect of the present application provides an active noise reduction method, including: acquiring a vehicle body vibration signal of an automobile; calculating to obtain a first noise reduction signal according to the vehicle body vibration signal and the first filter coefficient; and playing the first noise reduction signal through a loudspeaker array, wherein the loudspeaker array is arranged in a cabin of the automobile.
In an embodiment, before the calculating the first noise reduction signal according to the vehicle body vibration signal and the first filter coefficient, the method further includes: collecting a noise signal by at least one microphone, wherein the at least one microphone is arranged in a cabin of the automobile; from the noise signal, a first filter coefficient is determined.
In one embodiment, determining the first filter coefficient based on the noise signal comprises: adjusting an initial first filter coefficient according to the noise signal; a. determining an updated noise signal based on the vehicle body vibration signal and the adjusted first filter coefficient; b. when the updated noise signal does not meet the preset optimal condition, adjusting the adjusted first filter coefficient again; and (c) iteratively executing the steps a and b until the updated noise signal meets a preset optimal condition, and determining the currently adjusted first filter coefficient as the first filter coefficient.
In one embodiment, the at least one microphone includes a plurality of microphones each positioned adjacent to at least one seat within the cabin.
In one embodiment, acquiring a body vibration signal of an automobile comprises: the method comprises the steps of obtaining a vehicle body vibration signal through a plurality of vibration sensors, wherein the plurality of vibration sensors are respectively arranged on at least one hub of the vehicle, or on a suspension system of the vehicle, or on a frame near the at least one hub.
Further, in an embodiment, the method further comprises: acquiring frequency information of engine noise of an automobile; calculating to obtain a second noise reduction signal according to the frequency information of the engine noise and the coefficient of the second filter; playing the second noise reduction signal through the speaker array.
In one embodiment, before calculating the second noise reduction signal according to the frequency information of the engine noise and the second filter coefficient, the method further includes: collecting a noise signal by at least one microphone, wherein the at least one microphone is arranged in a cabin of the automobile; from the noise signal, a second filter coefficient is determined.
A second aspect of the present application provides a computer device comprising: a processor; a memory including computer instructions stored thereon, which, when executed by the processor, cause the processor to perform the active noise reduction method provided by any embodiment of the first aspect of the present application.
A third aspect of the present application provides a vehicle-mounted active noise reduction system, comprising: the vibration sensor is used for acquiring a vehicle body vibration signal of the automobile; a chip, configured to perform the active noise reduction method provided in any embodiment of the first aspect of the present application; the loudspeaker array is arranged in the cabin of the automobile and used for playing the noise reduction signal.
A fourth aspect of the present application provides an automobile comprising the vehicle-mounted active noise reduction system provided by the third aspect of the present application.
According to the active noise reduction method, the vehicle-mounted active noise reduction system and the vehicle, noise reduction signals are generated according to vibration information of a vehicle body in an active noise reduction mode, noise reduction sound waves are emitted in a vehicle cabin to offset tire noise, therefore, adverse effects of the tire noise on a passenger are effectively reduced, and riding experience of the passenger is improved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.
Drawings
In order to make the objects, technical solutions and advantages of the embodiments of the present application more apparent, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings. It is to be understood that the drawings form a part of the specification, illustrate the present application together with embodiments thereof, and are not to be construed as limiting the present application. Unless otherwise indicated, like reference numbers and designations in the drawings generally refer to like steps or components.
Fig. 1 is a schematic diagram illustrating an exemplary active noise reduction system according to an embodiment of the present application.
Fig. 2 is a schematic flow chart illustrating an active noise reduction method according to an embodiment of the present application.
Fig. 3 is a schematic flow chart of an active noise reduction method according to another embodiment of the present application.
Fig. 4 is a schematic flowchart illustrating a first filter coefficient determining process in the active noise reduction method according to the embodiment shown in fig. 3.
Fig. 5 is a schematic diagram illustrating an exemplary active noise reduction system according to another embodiment of the present application.
Fig. 6 is a schematic flowchart of an active noise reduction method according to another embodiment of the present application.
Fig. 7 is a schematic flowchart illustrating an active noise reduction method according to another embodiment of the present application.
Fig. 8 is a flowchart illustrating an exemplary active noise reduction method according to an embodiment of the present application.
Fig. 9 is a schematic view of a vehicle-mounted active noise reduction system according to an embodiment of the present application.
Fig. 10 is a schematic diagram of a computer device according to an embodiment of the present application.
Detailed Description
Exemplary System
Fig. 1 is a schematic diagram illustrating an exemplary active noise reduction system 100 according to an embodiment of the present application. Active noise reduction system 100 includes: a vibration sensor 110, a processor 120, a speaker array 130, and a microphone 140.
The vibration sensor 110 is used to collect a vibration signal of a body of the automobile. For example, the vibration sensor 110 may be an acceleration sensor mounted on a suspension system of each tire of the automobile or on both front and rear sides of a wheel well near a chassis of the automobile, and the like, and configured to detect vibration information of each tire and suspension to generate a vehicle body vibration signal.
The processor 120 is configured to obtain a vehicle body vibration signal, calculate a first noise reduction signal according to the vehicle body vibration signal and the first filter coefficient, and transmit the first noise reduction signal to the speaker array 130. In particular, the processor 120 may include an acquisition module 121 and a filter 122.
Specifically, the obtaining module 121 may be in communication connection with the vibration sensor 110, and is configured to obtain a vehicle body vibration signal from the vibration sensor 110 and transmit the vehicle body vibration signal to the filter 122; the filter 122 may calculate a first noise reduction signal from the vehicle body vibration signal and the first filter coefficient, and transmit the noise reduction signal to the speaker array 130.
The speaker array 130 is used for playing the noise reduction sound wave according to the received first noise reduction signal. Specifically, the speaker array 130 may include a plurality of speakers respectively disposed at respective positions in the vehicle compartment. For example, a plurality of speakers may be provided on the front and rear sides of the vehicle compartment, or may be provided near the headrest of each seat, or the like, so that noise reduction sound waves are well propagated in the vehicle compartment. It should be understood that, in the embodiment of the present application, the speaker array 130 may directly use the vehicle-mounted sound system, or may additionally provide speakers according to actual needs, which is not limited in the embodiment of the present application.
The microphone 140 is used to collect noise in the cabin and convert it to a noise signal that is transmitted to other parts of the system as needed.
Preferably, in another embodiment, the processor 120 may further include an adaptation module 123. The adaptive module 123 may be connected to the obtaining module 121 and the microphone 140, and configured to receive the vehicle body vibration signal from the obtaining module 121 and the noise signal from the microphone 140, and optimally adjust the first filter coefficient of the filter 122 according to the vehicle body vibration signal and the noise signal.
Wherein, after the active noise reduction mode is turned on, since the speaker array 130 is already playing the noise reduction sound wave, the noise signal obtained by the microphone 140 is the superposition of the original noise signal (i.e. the tire noise without noise reduction processing in the vehicle cabin) and the first noise reduction signal, i.e. the error between the two. After the adaptive module 123 receives the noise signal at this time, the first filter coefficient may be optimally adjusted by an adaptive algorithm according to the noise signal.
It should be understood that the paths shown by the dashed lines in fig. 1 represent the propagation paths of acoustic signals other than the circuit.
It should be understood that the above active noise reduction system is only an implementation manner of an exemplary system provided in the embodiments of the present application, and the above description is only used to make the technical solutions provided in the embodiments of the present application easier to understand, and is not to be considered as a limitation of the present application.
Exemplary method
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments that can be derived from the embodiments given herein by a person of ordinary skill in the art are intended to be within the scope of the present disclosure.
Fig. 2 is a schematic flow chart illustrating an active noise reduction method according to an embodiment of the present application. The method may be performed, for example, by processor 120 in exemplary active noise reduction system 100. As shown in fig. 2, the method includes:
s210: and acquiring a vehicle body vibration signal of the automobile.
In one embodiment, the vehicle may be provided with a vibration sensor for acquiring a vehicle body vibration signal, for example, an acceleration sensor may be provided at a position near a vehicle chassis on the front and rear sides of a wheel house or a suspension system of a tire, so as to acquire an acceleration signal as a vehicle body vibration signal.
Preferably, in an embodiment, a plurality of vibration sensors may be provided on the vehicle for acquiring a vehicle body vibration signal corresponding to at least one tire. Wherein, a plurality of vibration sensors can be respectively arranged at the position which is near at least one tire and is easy to collect vibration signals. For example, it may be provided on at least one wheel hub of the vehicle, or on the suspension system of the vehicle, or on the frame in the vicinity of at least one wheel hub.
Here, one vibration sensor may be provided near each tire, a plurality of vibration sensors may be provided near each tire, and a specific arrangement manner may be determined according to actual requirements, which is not limited in the embodiments of the present application.
S220: and calculating to obtain a first noise reduction signal according to the vehicle body vibration signal and the first filter coefficient.
After the processor 120 receives the vehicle body vibration signal, the filter therein may be calculated based on the vehicle body vibration signal and the first filter coefficient to obtain a first noise reduction signal for canceling the tire noise (entering the vehicle cabin).
It should be understood that the tire noise transmitted into the vehicle cabin includes a plurality of component noises, but at the root of this, the tire noise is highly correlated with the vehicle body vibration. Therefore, by setting an appropriate filter coefficient after the vehicle body vibration signal is grasped, the tire noise can be "tracked" in the sound field, and a noise reduction signal corresponding to the tire noise can be generated.
S230: the first noise reduction signal is played through the speaker array.
Wherein the loudspeaker array is arranged in a cabin of the automobile.
After the speaker array receives the first noise reduction signal, the noise reduction sound wave can be played based on the first noise reduction signal. The noise reduction sound waves are transmitted in the vehicle cabin and reach spatial points near the seats, and the noise reduction sound waves and the tire noise are mutually offset so as to weaken the tire noise at the spatial points.
Specifically, the speaker array may include a plurality of speakers respectively provided at respective positions in the vehicle compartment. For example, a plurality of speakers may be provided on the front and rear sides of the vehicle compartment, or may be provided near the headrest of each seat, or the like, so that noise reduction sound waves are well propagated in the vehicle compartment. It should be understood that the speaker array may be a sound system of the vehicle itself, or may be a speaker additionally provided according to actual needs, which is not limited by the embodiment of the present application.
According to the active noise reduction method, the noise reduction signal is generated according to the vibration information of the vehicle body in an active noise reduction mode, and the noise reduction sound wave is sent out in the vehicle cabin to offset the tire noise, so that the adverse effect of the tire noise on a passenger is effectively reduced, and the riding experience of the passenger is improved.
Fig. 3 is a schematic flow chart of an active noise reduction method according to another embodiment of the present application. The method may be performed, for example, by processor 120 in exemplary active noise reduction system 100.
It will be appreciated that after the active noise reduction mode is enabled, the first noise reduction signal played by the speaker array is determined by the filter in the processor based on the body vibration signal and the initial first filter coefficients. At this time, since the initial first filter coefficient is not debugged online, an error between the first noise reduction signal and the original noise signal (i.e., the tire noise in the vehicle cabin that is not subjected to noise reduction processing) may be large.
In view of this, in order to further improve the active noise reduction effect for the fetal noise, in this embodiment, after receiving the noise signal, the processor 120 may perform an optimal adjustment on the initial first filter coefficient according to the noise signal to determine an (optimal) first filter coefficient.
As shown in fig. 3, in this embodiment, the active noise reduction method shown in fig. 2 may further include:
s310: noise signals are collected by at least one microphone.
The microphone is arranged in a cabin of the automobile and used for collecting noise in the cabin and converting the collected noise into a noise signal. For example, at least one microphone may be provided in the cabin near above the seat so that the noise picked up is closer to the noise actually heard by the occupant.
Preferably, the at least one microphone may comprise an array of microphones distributed about a plurality of seats in the vehicle cabin. For example, a microphone can be respectively arranged at positions, close to ears of a passenger, of a headrest of each seat or a hand grip above the seat in an inclined manner, so that multiple passengers in the cabin can be considered simultaneously, active noise reduction is achieved more pertinently, and riding experience is improved.
In this embodiment, since the speaker array has already started playing the first noise reduction signal, the noise signal collected by the microphone is the superposition of the original noise signal and the first noise reduction signal, i.e. the error between the two.
S320: from the noise signal, a first filter coefficient is determined.
After the noise signal is acquired by the at least one microphone, the noise signal may be passed through circuitry to the processor 120. After receiving the noise signal, the processor 120 may perform an optimal adjustment on the initial first filter coefficient according to the noise signal, so as to obtain an optimal filter coefficient as the first filter coefficient.
In an embodiment, as shown in fig. 4, S320 may specifically include the following steps:
s321: the initial first filter coefficients are adjusted based on the noise signal.
S322: and determining an updated noise signal based on the vehicle body vibration signal and the adjusted first filter coefficient.
S323: and judging whether the currently updated noise signal meets preset optimal conditions, if so, executing S325, and if not, executing S324.
S324: the adjusted first filter coefficient is adjusted again, and S322 is performed again.
Before the updated noise signal satisfies the preset optimal condition, steps S322 and S324 may be iteratively performed until the updated noise signal satisfies the preset optimal condition.
S325: the currently adjusted first filter coefficient is determined to be the (optimal) first filter coefficient.
Specifically, when it is determined that the noise signal does not reach the preset optimal condition, the initial first filter coefficient may be adjusted, and the updated first noise reduction signal may be determined by using the adjusted first filter coefficient. After the updated first noise reduction signal is played by the loudspeaker array, the updated noise signal can be collected by the microphone. When the updated noise signal is judged to still not reach the preset optimal condition, the first filter coefficient can be adjusted again to obtain the noise signal updated again. And repeating the steps until the noise signal meets the preset optimal condition, stopping adjustment, and determining the current first filter coefficient (namely the first filter coefficient after the last adjustment) as the final first filter coefficient.
In one embodiment, for example, the energy of the noise signal reaching the minimum value may be set as the optimal condition, that is, whether the noise signal satisfies the preset optimal condition is determined by determining whether the energy of the noise signal reaches the minimum value.
Here, the process of repeatedly adjusting the first filter coefficient and updating the noise signal may be implemented by using an adaptive algorithm, such as an LMS (Least Mean Square) algorithm, and the first filter coefficient is updated each time until the noise signal is optimized. It should be understood that the embodiments of the present application do not limit the algorithm actually used.
In another embodiment of the present application, the optimal first filter coefficient corresponding to different road conditions may also be determined in advance. In the actual driving process of the vehicle, the processor 120 may determine the current vibration condition of the vehicle body in real time, determine the corresponding road condition, and directly switch the first filter coefficient to a predetermined first filter coefficient corresponding to the current road condition.
It is understood that the vehicle body vibration signal may fluctuate due to the actual running of the automobile, and the seated position, movement, etc. of the occupant may change the change of the acoustic path in the cabin. Therefore, preferably, in another embodiment, a predetermined first filter coefficient may be called according to a road condition, and when a vehicle body vibration signal fluctuates or an acoustic path in a vehicle cabin changes, the first filter coefficient may be further debugged through the foregoing adaptive process, so as to further improve a noise reduction effect.
According to the active noise reduction method, residual noise signals after noise reduction are collected in real time in the driving process of the vehicle, and the first filter coefficient is optimized and updated according to the noise signals, so that the active noise reduction effect for tire noise is greatly improved, and the riding experience is further improved.
As described above, engine noise is a very significant noise in addition to tire noise during the running of an automobile. The engine noise may cause physiological discomfort of a passenger due to the inclusion of significant narrow-band (fundamental and harmonic) components, and is difficult to be physically isolated or absorbed due to its low-frequency noise, high diffraction capability, and reduced energy attenuation.
In view of this, the embodiment of the present application further provides a technical solution capable of actively reducing noise of tire noise and engine noise at the same time, and aims to further reduce noise pollution in the cabin and improve riding experience of a rider.
Fig. 5 is a schematic diagram illustrating an exemplary active noise reduction system 500 according to another embodiment of the present application. As shown in FIG. 5, active noise reduction system 500 differs from active noise reduction system 100 shown in FIG. 1 in that: processor 520 is configured to calculate not only a first noise reduction signal corresponding to the tire noise, but also a second noise reduction signal corresponding to the engine noise.
In particular, the processor 520 may include an acquisition module 521, a signal generator 522, and a filter 523.
The acquisition module 521 may be used to acquire frequency information of engine noise in addition to the vehicle body vibration signal. For example, the obtaining module 521 may directly obtain the rotation speed information of the engine from an electronic control system of the automobile and extract the frequency information of the engine noise from the rotation speed information; alternatively, the obtaining module 521 may also be connected to the microphone 140 to obtain a noise signal, and extract the fundamental frequency noise and the harmonic frequency noise from the noise signal to determine the frequency information of the engine noise.
The signal generator 522 may generate a reference signal corresponding to engine noise from the frequency information from the acquisition module 521 and transmit the reference signal to the filter 523.
The filter 523 may calculate a second noise reduction signal according to the reference signal and the second filter coefficient, and transmit the second noise reduction signal and the first noise reduction signal to the speaker array 130 together, so that the noise reduction sound waves played by the speaker array 130 can simultaneously cancel the tire noise and the engine noise.
Preferably, in another embodiment, processor 520 may also include an adaptation module 524. The adaptation module 524 may be connected between the obtaining module 521 and the microphone 140, and may also be connected between the signal generator 522 and the microphone 140, and configured to receive the vehicle body vibration signal from the obtaining module 521, the reference signal from the signal generator 522, and the noise signal from the microphone 140, and perform optimal adjustment on the second filter coefficient of the filter 523 according to the reference signal and the noise signal while performing optimal adjustment on the first filter coefficient of the filter 523 according to the vehicle body vibration signal and the noise signal.
It should be noted that, in the active noise reduction system shown in fig. 5, the obtaining module 521 only needs to transmit the frequency information of the engine noise to the signal generator 522, and the vehicle body vibration signal from the vibration sensor 110 can be directly input to the filter 523 and/or the adaptive module 524 via the obtaining module 521 without passing through the signal generator 522.
Fig. 6 is a schematic flowchart of an active noise reduction method according to another embodiment of the present application. The method may be performed, for example, by processor 520 in exemplary active noise reduction system 500. As shown in fig. 6, the method further includes, on the basis of the method shown in fig. 2:
s610: frequency information of engine noise of an automobile is acquired.
As described above, the engine noise is related to the rotational speed of the engine, and is mainly composed of fundamental frequency noise and harmonic frequency noise. That is, the frequencies of fundamental frequency noise and harmonic frequency noise in the engine noise (for example, rpm/60Hz (fundamental frequency), 2rpm/60Hz, 4rpm/60 Hz..) can be determined as long as the rotational speed information of the engine is grasped.
Therefore, in one embodiment, the frequency information of the engine noise may be obtained by acquiring engine speed information of the automobile and based on the engine speed information.
Specifically, the engine speed information may be directly obtained by a vehicle electronic control system (for example, a data bus in a CAN bus or a CAN FD bus of the vehicle), or may be collected by a speed sensor provided in the engine.
In addition, because the engine noise mainly consists of fundamental frequency noise and harmonic frequency noise, and the fundamental frequency noise and the harmonic frequency noise are narrow-band signals, the engine noise is obviously different from other noises and is easy to extract.
Therefore, in another embodiment, the frequency information of the engine noise can also be determined by collecting the noise in the vehicle cabin and extracting the fundamental frequency signal and the harmonic frequency signal from the noise.
S620: and calculating to obtain a second noise reduction signal according to the frequency information of the engine noise and the second filter coefficient.
After the filter receives the frequency information of the engine noise, calculation can be carried out on the basis of the frequency information and the second filter coefficient, and a second noise reduction signal with the phase opposite to that of the engine noise is obtained.
Specifically, the process of calculating the second noise reduction signal based on the frequency information and the second filter coefficient may include: generating a reference signal according to the frequency information; and calculating to obtain a second noise reduction signal according to the reference signal and the second filter coefficient.
After obtaining the frequency information of the engine noise, processor 520 may generate a reference signal having the same frequency distribution as the engine noise based on the frequency information, so that the filter further calculates a second noise reduction signal having the same amplitude and opposite phase to the engine noise based on the reference signal.
In an embodiment, the reference signal may include at least one pair of sine reference signal and cosine reference signal having the same frequency, wherein the frequency of each pair of sine reference signal and cosine reference signal is equal to the fundamental frequency or any harmonic frequency in the frequency information.
It can be understood that the distribution of the fundamental frequency signal or the harmonic frequency signal in the frequency domain can be regarded as the frequency domain distribution of a sinusoidal signal, and the sinusoidal signal can be completely restored by obtaining the amplitude and the phase of the corresponding fundamental frequency signal or the corresponding harmonic frequency signal. Based on this, the applicant found that it is possible to set a sine signal and a cosine signal having the same frequency as the fundamental frequency signal or the harmonic frequency signal as reference signals (i.e., a sine reference signal and a cosine reference signal) corresponding to the fundamental frequency signal or the harmonic frequency signal, and to calculate a linear combination of the sine reference signal and the cosine reference signal (i.e., a sine signal having the same frequency domain distribution as the fundamental frequency signal or the harmonic frequency signal) by setting coefficients for the sine reference signal and the cosine reference signal, respectively, and to adjust the coefficients corresponding to the sine reference signal and the cosine reference signal (i.e., to adjust the amplitude and the phase of the linear combination signal) to restore the fundamental frequency signal or the harmonic frequency signal.
Based on this, when the noise reduction signal is calculated for a fundamental frequency signal or any harmonic frequency signal in the engine noise, a sine reference signal and a cosine reference signal may be set for the fundamental frequency signal or the harmonic frequency signal, and coefficients corresponding to the sine reference signal and the cosine reference signal are implemented as filter coefficients, so that the calculated linear combination of the two has the same amplitude and opposite phase as the fundamental frequency signal or the harmonic frequency signal. That is, based on a sine reference signal and a cosine reference signal, and corresponding filter coefficients, a noise reduction signal corresponding to a fundamental frequency signal or a harmonic frequency signal can be calculated.
Thus, in this embodiment, the second filter coefficients may include at least one pair of sine and cosine coefficients. That is, a pair of sine coefficient and cosine coefficient may be set for each fundamental frequency signal or harmonic frequency signal. Each pair of sine coefficient and cosine coefficient respectively corresponds to each pair of sine reference signal and cosine reference signal, and is used for calculating the linear combination of each pair of sine reference signal and cosine reference signal, so as to obtain a noise reduction signal (i.e. a second noise reduction signal after superposition) corresponding to each fundamental frequency signal or harmonic frequency signal.
It should be understood that, according to the actual energy spectrum of the engine noise and the requirement of noise reduction, it may be selected to reduce the noise of only the fundamental frequency signal in the engine noise, or to reduce the noise of only one/multiple harmonic frequency signals, or to simultaneously reduce the noise of multiple signals in the fundamental frequency signal and the harmonic frequency signal. When the noise of a plurality of signals in the engine noise is reduced, the noise reduction signals of all the signals are obtained through calculation by the method and then are superposed.
S630: playing the second noise reduction signal through the speaker array.
Similarly to the first noise reduction signal, the speaker array may play the noise reduction sound wave based on the second noise reduction signal after receiving the noise reduction signal. The noise reduction sound waves are transmitted in the vehicle cabin and reach spatial points near the seats, and the noise reduction sound waves and the engine noise are offset with each other, so that the engine noise at the spatial points is weakened.
According to the active noise reduction method, through an active noise reduction mode, a first noise reduction signal aiming at the tire noise and a second noise reduction signal aiming at the engine noise can be respectively calculated according to different information, two noise reduction signals are played in the vehicle cabin at the same time, the tire noise and the engine noise in the vehicle cabin are eliminated at the same time, the noise born by a passenger when the vehicle runs can be greatly reduced, and the riding environment is effectively improved.
Fig. 7 is a schematic flowchart illustrating an active noise reduction method according to another embodiment of the present application. The method may be performed, for example, by processor 520 in exemplary active noise reduction system 500.
Similarly to the first noise reduction signal, after the active noise reduction mode is enabled, a second noise reduction signal played by the speaker array is determined by a filter in the processor based on frequency information of the engine noise and the initial second filter coefficients. At this time, since the initial second filter coefficient is not debugged online, an error between the second noise reduction signal and the original noise signal (i.e., the engine noise in the vehicle cabin that is not subjected to the noise reduction processing) may be large.
In view of this, in order to further improve the active noise reduction effect for the engine noise, in this embodiment, after receiving the noise signal, the processor 520 may perform an optimal adjustment on the initial second filter coefficient according to the noise signal to determine an optimal second filter coefficient. As shown in fig. 7, in this embodiment, the active noise reduction method shown in fig. 6 may further include:
s710: noise signals are collected by at least one microphone.
The microphone is arranged in a cabin of the automobile and used for collecting noise in the cabin and converting the collected noise into a noise signal.
It should be appreciated that at least one microphone disposed within the vehicle cabin may be used to implement both S310 in the embodiment shown in fig. 3 and S710 in this embodiment, and may also be used to collect a noise signal before the active noise reduction mode is turned on so that the processor 520 determines frequency information of the engine noise from the noise signal. In the process of implementing the technical solution, a person skilled in the art may set and assign functions to the microphones according to specific requirements, which is not limited in the embodiments of the present application.
In this embodiment, since the speaker array has already started playing the noise reduction signal, the noise signal collected by the microphone is the superposition of the original noise signal and the second noise reduction signal, i.e. the error between the two.
It should be noted that, the steps mentioned in this embodiment are performed together with the active noise reduction step of the tire noise (simultaneously or alternatively, the specific sequence is not limited). Since the engine noise signal and the second noise reduction signal are both narrow-band signals and are easily distinguished from the tire noise signal and the first noise reduction signal of wide band, for brevity of description, the description of the tire noise signal and the first noise reduction signal is omitted in this embodiment, and only the narrow-band part of the noise signal is focused.
S720: from the noise signal, a second filter coefficient is determined.
After the noise signal is acquired by the at least one microphone, the noise signal may be passed through circuitry to the processor 520. After receiving the noise signal, the processor 520 may perform an optimal adjustment on the initial second filter coefficient according to the noise signal, so as to obtain an optimal filter coefficient as the second filter coefficient.
In an embodiment, S720 may specifically include the following steps:
adjusting the initial second filter coefficient according to the noise signal;
a. determining an updated noise signal based on the frequency information of the engine noise and the adjusted second filter coefficient;
b. when the updated noise signal does not meet the preset optimal condition, adjusting the adjusted second filter coefficient again;
and (c) iteratively executing the steps a and b until the updated noise signal meets a preset optimal condition, and determining the currently adjusted second filter coefficient as the (optimal) second filter coefficient.
The specific principle and execution manner of the above steps are similar to the determination process of the first filter coefficient, and are not described herein again.
In another embodiment of the present application, the second filter coefficients corresponding to different rotational speeds of the engine, respectively, may also be predetermined. During the actual running process of the automobile, the processor can confirm the current engine speed (or directly confirm the frequency information of the engine noise) in real time and directly switch the second filter coefficient into a predetermined second filter coefficient corresponding to the current engine speed.
It is understood that the rotation speed of the engine may fluctuate when the automobile is actually running, and the landing, movement, and the like of the occupant may change the change of the acoustic path in the cabin. Therefore, in another embodiment, a predetermined second filter coefficient may be called according to the engine speed, and the second filter coefficient may be further adjusted through the foregoing adaptive process when the engine speed or the acoustic path in the vehicle cabin changes, so as to further improve the noise reduction effect for the engine noise.
According to the active noise reduction method, the residual noise signals after noise reduction are collected in real time in the driving process of the vehicle, and the coefficient of the second filter is optimized and updated according to the noise signals, so that the active noise reduction effect aiming at the engine noise is greatly improved, and the riding experience is further improved.
FIG. 8 is a flowchart illustrating an exemplary active noise reduction method provided by an embodiment of the present application and executable by processor 520 of active noise reduction system 500 of FIG. 5 for simultaneously actively reducing both the tire noise entering the cabin and the fundamental noise of the engine noise.
As shown in fig. 8, the method may include the steps of:
s811: and acquiring a vehicle body vibration signal of the automobile.
S812: and calculating to obtain an initial first noise reduction signal according to the vehicle body vibration signal and the initial first filter coefficient.
S821: and acquiring the engine speed information of the automobile.
S822: and obtaining the frequency information of the fundamental frequency noise in the engine noise based on the engine rotating speed information.
S823: and calculating to obtain an initial second noise reduction signal according to the frequency information of the fundamental frequency noise and the initial second filter coefficient.
S801: the initial first noise reduction signal and the initial second noise reduction signal are played through the speaker array.
S802: noise signals are collected by a microphone array.
S803: the initial first filter coefficients and the initial second filter coefficients are adjusted according to the noise signal.
S804: and determining an updated noise signal based on the vehicle body vibration signal, the adjusted first filter coefficient, the frequency signal of the fundamental frequency noise and the adjusted second filter coefficient.
S805: and judging whether the current updated noise signal meets preset optimal conditions, if so, executing S807, and if not, executing S806.
S806: the adjusted first filter coefficient and second filter coefficient are adjusted again, and S804 is executed again.
S807: and determining the first filter coefficient after current adjustment as a first filter coefficient, and determining the second filter coefficient after current adjustment as a second filter coefficient.
S808: a first noise reduction signal and a second noise reduction signal are calculated based on the first filter coefficient and the second filter coefficient.
S809: the first noise reduction signal and the second noise reduction signal are played through the speaker array.
It should be understood that S811 to S812 and S821 to S823 may be performed simultaneously or alternately, as long as active noise reduction of tire noise and engine noise can be achieved, and the specific execution sequence and relationship of these steps are not limited in the embodiments of the present application.
In addition, in the method shown in the present embodiment, only the method for reducing the noise of the fundamental frequency in the engine noise is shown, and the method for reducing the noise of the harmonic frequency (the center frequency is 2 ω), the method for reducing the noise of the fundamental frequency in the engine noise is shown0、4ω0、6ω0...) and may be implemented simultaneously therewith, and will not be described in detail herein.
Exemplary devices
An embodiment of the present application further provides an active noise reduction device, which may include: the acquisition module is used for acquiring a vehicle body vibration signal of the automobile; the calculation module is used for calculating to obtain a first noise reduction signal according to the vehicle body vibration signal and the first filter coefficient; and the sending module is used for sending the first noise reduction signal to the loudspeaker array so as to enable the loudspeaker array to play the first noise reduction signal. Wherein the loudspeaker array may be provided in a cabin of the vehicle.
In one embodiment, the obtaining module may obtain the vehicle body vibration signal through a plurality of vibration sensors. The vibration sensors are respectively arranged on at least one hub of the automobile, or on a suspension system of the automobile, or on the frame near the at least one hub.
Preferably, in another embodiment, the calculation module may be further configured to receive a noise signal collected by at least one microphone, and determine the first filter coefficient according to the noise signal. Wherein at least one microphone is arranged in the cabin of the automobile.
In an embodiment, the at least one microphone may include a plurality of microphones each located near at least one seat within the cabin.
Specifically, in an embodiment, the process of determining the first filter coefficient according to the noise signal by the calculation module may be implemented based on an adaptive algorithm, and the process may include: adjusting an initial first filter coefficient according to the noise signal; a. determining an updated noise signal based on the vehicle body vibration signal and the adjusted first filter coefficient; b. when the updated noise signal does not meet the preset optimal condition, adjusting the adjusted first filter coefficient again; and (c) iteratively executing the steps a and b until the updated noise signal meets a preset optimal condition, and determining the currently adjusted first filter coefficient as the first filter coefficient.
In one embodiment, the obtaining module may be further configured to obtain frequency information of engine noise of the vehicle; the calculation module can be further used for calculating to obtain a second noise reduction signal according to the frequency information of the engine noise and the second filter coefficient; the sending module may be further configured to send the second noise reduction signal to the speaker array, so that the speaker array plays the second noise reduction signal.
Preferably, in another embodiment, the calculation module may be further configured to determine a second noise reduction signal from the noise signal from the microphone.
Specifically, in an embodiment, the process of determining the second filter coefficient according to the noise signal by the calculation module may also be implemented based on an adaptive algorithm, and the process may include: adjusting the initial second filter coefficient according to the noise signal; a. determining an updated noise signal based on the frequency information of the engine noise and the adjusted second filter coefficient; b. when the updated noise signal does not meet the preset optimal condition, adjusting the adjusted second filter coefficient again; and (c) iteratively executing the steps a and b until the updated noise signal meets a preset optimal condition, and determining the currently adjusted second filter coefficient as the optimal second filter coefficient.
The active noise reduction device provided by the application generates noise reduction signals according to vibration information of a vehicle body in an active noise reduction mode, and sends noise reduction sound waves in a vehicle cabin to offset tire noise, so that adverse effects of the tire noise on a passenger are effectively reduced, and passenger riding experience is improved.
It should be understood that the principles, functions, and technical effects of the components in the active noise reduction apparatus provided in the foregoing embodiments may refer to corresponding contents in the exemplary method, and are not described in detail herein.
Fig. 9 is a schematic diagram illustrating a vehicle active noise reduction system 900 according to an embodiment of the present disclosure. As shown in fig. 9, the vehicle active noise reduction system 900 includes a vibration sensor 910, a chip 920, and a speaker array 930.
The vibration sensor 910 may be configured to collect a body vibration signal of the vehicle; chip 920 may be used to perform an active noise reduction method as provided in any of the above embodiments; the speaker array 930 may be disposed in a cabin of an automobile for playing noise reduction signals.
The vehicle-mounted active noise reduction system provided by the application generates a noise reduction signal according to vibration information of a vehicle body in an active noise reduction mode, and sends noise reduction sound waves in a vehicle cabin to offset tire noise, so that adverse effects of the tire noise on a passenger are effectively reduced, and riding experience of the passenger is improved.
Exemplary device
An embodiment of the present application further provides an automobile, which includes the aforementioned vehicle-mounted active noise reduction system 900. During the driving period of the automobile, the vehicle-mounted active noise reduction system can actively reduce the noise of the tire noise entering the automobile cabin, improve the riding environment of a passenger and improve riding experience.
Fig. 10 is a schematic diagram of a computer device according to an embodiment of the present application. As shown in fig. 10, the computer apparatus includes: a processor 1010; memory 1020, memory 1020 including computer instructions stored thereon, which when executed by processor 1010, cause processor 1010 to perform an active noise reduction method as provided by any of the embodiments described above.
Exemplary computer readable storage Medium
Other embodiments of the present application further provide a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the active noise reduction method according to any of the above embodiments. It is understood that the computer storage medium can be any tangible medium, such as: floppy disks, CD-ROMs, DVDs, hard drives, network media, or the like.
The block diagrams of apparatuses, devices, systems referred to in this application are only given as illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. Those skilled in the art will appreciate that the devices, apparatus, systems, etc. may be connected, arranged, or configured in any manner. Words such as "comprising," "including," "having," and the like are open-ended words to "including, but not limited to," and may be used interchangeably therewith unless the context clearly dictates otherwise. The word "such as" is used herein to mean, and is used interchangeably with, the phrase "such as but not limited to".
It should also be noted that in the devices, apparatuses, and methods of the present application, the modules or steps may be decomposed and/or recombined. These decompositions and/or recombinations are to be considered as equivalents of the present application.
The previous description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the application. Thus, the present application is not intended to be limited to the above aspects but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
The above description is intended to be illustrative and descriptive of the present technology. Furthermore, the description is not intended to limit embodiments of the application to the form disclosed above. While a number of exemplary aspects and embodiments have been discussed above, other variations, modifications, changes, additions, and sub-combinations will readily occur to those skilled in the art based upon the foregoing.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modifications, equivalents and the like that are within the spirit and principle of the present application should be included in the scope of the present application.
Claims (10)
1. An active noise reduction method, comprising:
acquiring a vehicle body vibration signal of an automobile;
calculating to obtain a first noise reduction signal according to the vehicle body vibration signal and a first filter coefficient;
and playing the first noise reduction signal through a loudspeaker array, wherein the loudspeaker array is arranged in the cabin of the automobile.
2. The active noise reduction method of claim 1, further comprising, before calculating a first noise reduction signal based on the vehicle body vibration signal and the first filter coefficient:
collecting a noise signal by at least one microphone, wherein the at least one microphone is disposed in a cabin of the automobile;
determining the first filter coefficient based on the noise signal.
3. The active noise reduction method of claim 2, wherein determining the first filter coefficient from the noise signal comprises:
adjusting an initial first filter coefficient according to the noise signal;
a. determining an updated noise signal based on the vehicle body vibration signal and the adjusted first filter coefficient;
b. when the updated noise signal does not meet the preset optimal condition, adjusting the adjusted first filter coefficient again;
and a, iteratively executing the steps a and b until the updated noise signal meets the preset optimal condition, and determining the currently adjusted first filter coefficient as the first filter coefficient.
4. The active noise reduction method of claim 2,
the at least one microphone includes a plurality of microphones each positioned adjacent to at least one seat within the cabin.
5. The active noise reduction method of claim 1, wherein obtaining a body vibration signal of the automobile comprises:
the vehicle body vibration signals are obtained through a plurality of vibration sensors,
the vibration sensors are respectively arranged on at least one hub of the automobile, or on a suspension system of the automobile, or on a frame near the at least one hub.
6. The active noise reduction method according to any of claims 1-5, further comprising:
acquiring frequency information of engine noise of the automobile;
calculating to obtain a second noise reduction signal according to the frequency information of the engine noise and a second filter coefficient;
playing the second noise reduction signal through the speaker array.
7. The active noise reduction method of claim 6, further comprising, before calculating a second noise reduction signal based on the frequency information of the engine noise and the second filter coefficient:
collecting a noise signal by at least one microphone, wherein the at least one microphone is disposed in a cabin of the automobile;
determining the second filter coefficient based on the noise signal.
8. A computer device, comprising:
a processor;
a memory including computer instructions stored thereon that, when executed by the processor, cause the processor to perform the active noise reduction method of any of claims 1-7.
9. An on-vehicle active noise reduction system, comprising:
the vibration sensor is used for acquiring a vehicle body vibration signal of the automobile;
a chip for performing the active noise reduction method of any one of claims 1-7;
and the loudspeaker array is arranged in the cabin of the automobile and used for playing the noise reduction signal.
10. An automobile comprising the on-board active noise reduction system of claim 9.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116246607A (en) * | 2023-05-09 | 2023-06-09 | 宁波胜维德赫华翔汽车镜有限公司 | Automobile cockpit noise control system and method and automobile |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116246607A (en) * | 2023-05-09 | 2023-06-09 | 宁波胜维德赫华翔汽车镜有限公司 | Automobile cockpit noise control system and method and automobile |
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