CN113724681B - A method and system for active noise reduction - Google Patents

Abstract

The application relates to an active silencing method and system, and relates to the technical field of automobile silencing, wherein the method comprises the following steps: a plurality of noise audio signals to be silenced are obtained in advance, and a gear and an engine rotating speed interval corresponding to each noise audio signal are used as a noise interval to be silenced; after the vehicle is electrified, the gear and the engine rotating speed of the vehicle are obtained, and when the gear and the engine rotating speed are in any interval to be silenced, the loudspeaker is controlled to send out the audio with the opposite phase of the noise audio signal corresponding to the interval to be silenced. The system comprises: the acquisition module is used for acquiring the gear and the engine speed of the vehicle after the vehicle is electrified; the silencing controller pre-stores all intervals to be silenced, and is used for sending a control instruction to the loudspeaker when the gear and the engine speed are in any interval to be silenced; the loudspeaker is used for sending out audio frequency to cancel noise based on the control instruction. The active silencing method and the active silencing system can realize real-time noise cancellation and provide good driving experience for users.

Description

A method and system for active noise reduction

technical field

The present application relates to the technical field of automobile noise reduction, in particular to an active noise reduction method and system.

Background technique

At present, there are various forms of vehicle mufflers, including resistive, resistive, and impedance hybrid mufflers. Among them, the impedance hybrid muffler is often used. The impedance hybrid muffler includes a shell and the inner components of the muffler. The shell of the muffler includes a cylinder and front and rear end covers or upper and lower shells. Acoustic material, inserts, and quarter-wavelength tubes.

In related technologies, with the fierce competition in the automobile market, major OEMs have increasingly strict targets for NVH (Noise, Vibration, Harshness, noise, vibration and harshness).

However, for new energy vehicles such as PHEV (Plug in Hybrid Electric Vehicle), HEV (Hybrid Electric Vehicle, hybrid electric vehicle), REV (Range Electric Vehicle, extended-range electric vehicle), due to its layout Compactness leads to limited space for the muffler to be arranged, and the noise reduction volume often cannot meet the noise of the NVH target part frequency, which brings a bad experience to the user and makes the market competitiveness of the vehicle after it is launched is not strong, affecting the sales cycle. At the same time, it damages the reputation of the brand among users.

Contents of the invention

In view of the defects existing in the prior art, the purpose of this application is to provide an active noise reduction method and system to solve the problem that the compact layout of the new energy vehicles in the related art results in limited space for the arrangement of the silencer, resulting in the failure of the noise reduction volume to meet the NVH target. The problem.

The first aspect of the present application provides an active noise reduction method, which includes:

Acquiring multiple noise audio signals to be silenced in advance, and using the gear position and engine speed interval corresponding to each noise audio signal as an interval to be silenced;

After the vehicle is powered on, the gear position and engine speed of the vehicle are obtained. When the above gear position and engine speed are in any interval to be silenced, the speaker device is controlled to send out an audio with the opposite phase to the noise audio signal corresponding to the interval to be silenced, and to perform noise reduction. offset.

In some embodiments, after acquiring a plurality of noise audio signals to be silenced, the method further includes:

The audio in the opposite phase to the noise audio signal is acquired and stored in the speaker device.

In some embodiments, the above-mentioned speaker device includes a recorder and a speaker connected to the recorder, and the recorder stores audio with an opposite phase to the noise audio signal.

In some embodiments, the pre-acquisition of multiple noise audio signals to be silenced includes:

Start the engine in different working conditions in turn, and record the process noise;

The audio signal in the process noise that cannot be eliminated by the muffler in the car is extracted as the noise audio signal to be silenced, and the gear position and engine speed range corresponding to each noise audio signal are obtained.

In some embodiments, among the above-mentioned process noises, the audio signals that cannot be eliminated by the muffler in the vehicle are: audio signals of noises whose noise sound pressure level is greater than the noise sound pressure level threshold.

In some embodiments, when recording the process noise above, it also includes:

Record the emission location of the noise audio signal, and determine the primary and secondary relationship between the emission locations;

The emitting position includes at least one of the front wall, the front muffler, and the rear muffler, and a loudspeaker device is respectively provided adjacent to the front wall, the front muffler, and the rear muffler.

In some embodiments, when the above-mentioned gear position and engine speed are not in the range to be silenced, the above-mentioned speaker device is controlled not to work.

The second aspect of the present application provides an active noise reduction system based on the above method, which includes:

An acquisition module, which is used to acquire the gear position and engine speed of the vehicle after the vehicle is powered on, and send them to the muffler controller;

The above-mentioned silencer controller pre-stores all waiting intervals for silence, which is used to send a control command to the speaker device when the above-mentioned gear position and engine speed are in any interval to be silenced;

The loudspeaker device is used for noise cancellation based on the above-mentioned control instruction, emitting an audio with an opposite phase to that of the noise audio signal corresponding to the interval to be silenced.

In some embodiments, the above-mentioned system further includes a recording module, and the above-mentioned recording module is used to obtain audio with a phase opposite to that of the noise audio signal, and record it into the above-mentioned speaker device.

In some embodiments, the above-mentioned noise reduction controller includes:

A storage sub-module, the above-mentioned storage sub-module is used to store all intervals to be silenced;

Judging sub-module, the above-mentioned judging sub-module is used to judge whether the received gear position and engine speed are in any interval to be silenced;

A control sub-module, the control sub-module is used to issue a control command to the speaker device when the judgment sub-module judges yes.

The beneficial effects brought by the technical solution provided by the application include:

The embodiment of the present application provides an active silencing method and system, by pre-acquiring a plurality of noise audio signals to be silencing, and respectively using the gear position and engine speed interval corresponding to each noise audio signal as a silencing interval; After power on, obtain the gear position and engine speed of the vehicle, and judge whether the gear position and engine speed are in a certain interval to be silenced. The acoustic device emits audio with the opposite phase to the noise audio signal corresponding to the interval to be silenced to perform noise cancellation; in this application, based on the principle of mutual cancellation of sound waves, the audio with the opposite phase to the noise audio signal corresponding to the interval to be silenced is selected for real-time noise cancellation. Avoid the problem of not being able to meet the NVH development goals due to insufficient noise reduction volume in the car, and at the same time bring a good driving experience to users.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is the flow chart of active noise reduction method in the embodiment of the present application;

Fig. 2 is a schematic diagram of the layout of the active noise reduction system in the embodiment of the present application.

Reference signs:

1. Acquisition module; 2. Silencer controller; 3. First recorder; 4. First speaker; 5. Second recorder; 6. Second speaker; 7. Third recorder; 8. Third speaker.

Detailed ways

In order to make the purpose, technical solution and advantages of the present application clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

The embodiment of the present application provides an active noise reduction method, which can solve the problem in the related art that the compact layout of the new energy vehicle leads to the limited space for the arrangement of the silencer, so that the noise reduction volume cannot meet the NVH target.

As shown in Figure 1, the active noise reduction method of the embodiment of the present application specifically includes the following steps:

S10. Pre-acquire a plurality of noise audio signals to be silenced, and use the gear position and engine speed interval corresponding to each noise audio signal as an interval to be silenced.

S20. After the vehicle is powered on, the gear position and the engine speed of the vehicle are obtained. When the above gear position and the engine speed are in any interval to be silenced, the speaker device is controlled to emit an audio with an opposite phase to the noise audio signal corresponding to the interval to be silenced. Perform noise cancellation.

The active noise reduction method of the embodiment of the present application obtains a plurality of noise audio signals to be silenced in advance, and respectively uses the gear position and the engine speed interval corresponding to each noise audio signal as an interval to be silenced; after the vehicle is powered on, the acquisition The gear position and engine speed of the vehicle, and judge whether the gear position and engine speed are in a certain interval to be silenced. When it is judged that the gear position and engine speed are in any interval to be silenced, the speaker device can be controlled to emit a The audio frequency corresponding to the opposite phase of the noise audio signal in the interval to be silenced is used for noise cancellation; the active noise cancellation method of this embodiment is based on the principle of mutual cancellation of sound waves, and the audio frequency corresponding to the opposite phase of the noise audio signal in the interval to be silenced is selected for real-time noise cancellation. The NVH development goal cannot be met due to insufficient noise reduction volume in the car, and it can also bring a good driving experience to users.

On the basis of the above-mentioned embodiment, in this embodiment, in the above-mentioned step S10, after obtaining a plurality of noise audio signals to be silenced, the following steps are further included:

Audio in phase opposite to the noise audio signal is acquired and stored in the speaker device.

In this embodiment, after acquiring a plurality of noise audio signals to be silenced, an audio wave with a phase opposite to that of the noise audio signals to be silenced can be recorded and stored in the speaker device, so that in the subsequent actual driving process, by recording The audio waves are acoustically canceled out with the noise.

Further, the speaker device includes a recorder and a speaker, the recorder is connected to the speaker, and the recorder stores audio in phase opposite to the noise audio signal.

In this embodiment, the recorder uses a hard magnetic material as a carrier, and uses the remanent magnetic property of the magnetic material to record the sound signal in the carrier. Specifically, when the loudspeaker device needs to emit audio with an opposite phase to the noise audio signal corresponding to the interval to be silenced, the tape recorder amplifies the generated audio current and sends it to the speaker, and the speaker restores the audio current to audio for playback, so as to be consistent with The current noise is cancelled.

On the basis of the above embodiments, in this embodiment, the pre-acquisition of multiple noise audio signals to be silenced in the above step S10 specifically includes the following steps:

First, start the engine under different working conditions in sequence, and record the process noise.

Among them, the different working conditions include vehicle idling and AC ON (air condition ON, automotive air control system on) working condition, idling and AC OFF (air condition OFF, automotive air control system off) working condition, acceleration working condition, etc.

In this embodiment, the process noise is recorded through the microphone during early tuning, specifically, the engine is started when the vehicle is idling and the ACON working condition, and the first process noise is recorded through the microphone; the engine is started when the vehicle is idling and the AC OFF working condition , and record the second process noise through the microphone; start the engine under acceleration conditions, and record the third process noise through the microphone. Optionally, the above acceleration condition is a full throttle acceleration condition.

Then, the audio signal that cannot be eliminated by the muffler in the process noise is extracted as the noise audio signal to be silenced, and the gear position and engine speed range corresponding to each noise audio signal are obtained as the corresponding noise audio signal. Waiting for silence interval.

In this embodiment, among the first process noise, the second process noise, and the third process noise, the audio signals that cannot be eliminated by the muffler inside the vehicle are sequentially extracted as the noise audio signals to be silenced.

In this embodiment, among the above-mentioned process noises, the audio signals that cannot be eliminated by the muffler in the vehicle are: audio signals of noises whose noise sound pressure level is greater than the noise sound pressure level threshold.

That is, the audio signal in the noise in the above extraction process that cannot be eliminated by the muffler in the car, specifically includes the following steps:

Among the process noises, the audio signals of the noise whose noise sound pressure level is greater than the noise sound pressure level threshold are taken as the audio signals that cannot be eliminated by the muffler in the vehicle.

Therefore, before extracting the audio signal in the process noise that cannot be eliminated by the muffler in the car, it is necessary to set a noise sound pressure level threshold in advance. In this embodiment, the noise sound pressure level threshold can be set according to actual conditions or NVH development goals. That is, in the process noise, if the noise sound pressure level of a certain noise is greater than the noise sound pressure level threshold, the audio signal of the noise is a noise audio signal to be silenced, which needs to be actively eliminated by the speaker device.

On the basis of the above embodiment, in this embodiment, when the above gear position and the engine speed are not in the interval to be silenced, the above speaker device is controlled not to work. That is, when the above-mentioned gear position and engine speed are not in the range to be silenced, it means that there is currently no noise or the noise can be eliminated by the muffler in the car, and there is no need to eliminate noise through the speaker device.

On the basis of the above-mentioned embodiment, in this embodiment, the above-mentioned recording process noise also includes the following steps:

Record the emission location of the noise audio signal, and determine the primary and secondary relationship between the emission locations.

Wherein, the emitting position includes at least one of the front wall, the front muffler, and the rear muffler, and a loudspeaker device is respectively provided adjacent to the front wall, the front muffler, and the rear muffler.

In this embodiment, the above-mentioned speaker device includes a first speaker device, a second speaker device and a third speaker device.

The above-mentioned first speaker device is arranged near the front wall, and the above-mentioned first speaker device stores audio in opposite phase to the noise audio signal emitted from the front wall.

The above-mentioned second speaker device is arranged near the front muffler, and the above-mentioned second speaker device stores audio in phase opposite to the noise audio signal emitted from the front muffler.

The above-mentioned third speaker device is arranged near the rear muffler, and the above-mentioned third speaker device stores audio in opposite phase to the noise audio signal emitted from the rear muffler.

In this embodiment, the above step S10 specifically includes the following steps:

S11. Start the engine in different working conditions in turn, and record the process noise through the microphone;

S12. Extract the audio signal in the process noise that cannot be eliminated by the muffler through sound processing, and use it as the noise audio signal to be silenced, and simultaneously record the gear position and engine speed interval corresponding to the noise audio signal, as the interval to be silenced;

S13. Store the primary and secondary relationship between the interval to be silenced corresponding to each noise audio signal and the position where the noise audio signal is emitted in the noise cancellation controller.

S14. Record the audio with the phase opposite to the noise audio signal and store it in the above-mentioned speaker device.

In this embodiment, the gear position and the engine speed interval corresponding to each noise audio signal are calibrated in the early stage as the interval to be silenced corresponding to each noise audio signal, and then the information on the interval to be silenced is stored, so that the later vehicle After the power is turned on, the gear position and engine speed of the vehicle can be obtained according to the CAN bus for real-time judgment. Whether the current gear position and engine speed are in the interval to be silenced corresponding to the audio signal that cannot be eliminated by the muffler in the car; When the engine speed is in any interval to be silenced, the loudspeaker device is controlled to emit an audio frequency with an opposite phase to the noise audio signal corresponding to the interval to be silenced to cancel the noise. If the current gear and the engine speed are not in any interval to be silenced, the loudspeaker device is controlled to stop sounding.

An embodiment of the present application also provides an active noise cancellation system based on the above method, and the active noise cancellation system includes: an acquisition module, a noise cancellation controller, and a loudspeaker device.

The acquisition module above is used to acquire the gear position and engine speed of the vehicle after the vehicle is powered on, and send them to the noise reduction controller.

The above-mentioned muffler controller pre-stores all the intervals to be muffled, and the above-mentioned muffler controller is used to send a control command to the speaker device when the above-mentioned gear position and engine speed are in any interval to be muffled.

The loudspeaker device is used for noise cancellation based on the above-mentioned control instruction, emitting an audio with an opposite phase to that of the noise audio signal corresponding to the interval to be silenced.

Optionally, the above-mentioned speaker device includes a first speaker device, a second speaker device and a third speaker device, the first speaker device is arranged at the front wall, and the second speaker device is arranged at the front muffler, The third speaker device is arranged at the rear muffler.

Wherein, the first speaker device includes a first recorder and a first speaker; the first speaker device includes a second recorder and a second speaker; the third speaker device includes a third recorder and a third speaker.

The active muffler system of this embodiment, when the vehicle is powered on, obtains the gear position and engine speed of the vehicle through the acquisition module, and sends them to the muffler controller. Whether the rotation speed is in any interval to be silenced; if the gear position and engine speed are in a certain interval to be silenced, the noise reduction controller will issue a control command to control the speaker device to emit an audio with the opposite phase to the noise audio signal corresponding to the interval to be silenced. offset; if the gear position and engine speed are not in any interval to be silenced, the noise reduction controller controls the speaker device to not work; the active noise reduction system is in a limited layout space, and some frequencies still cannot meet the NVH target after tuning Under certain circumstances, through active selective noise reduction, real-time noise cancellation can be realized, and a good driving experience can be brought to users, thereby avoiding problems affecting the launch of the vehicle, or customer complaints and poor sales caused by the launch of the vehicle.

In this embodiment, when the noise reduction controller judges that the gear position and the engine speed are not in the range to be silenced, if the speaker device is in the sounding state at this time, the noise reduction controller is also used to control the speaker device not to work.

In this embodiment, after the vehicle is powered on, the active noise cancellation method for noise cancellation specifically includes the following steps:

S21. The above-mentioned muffler controller obtains the gear position and the engine speed sent by the above-mentioned acquisition module through the CAN bus;

S22. The muffler controller judges whether the gear position and the engine speed are in a certain interval to be muffled; if so, turn to S23, otherwise, turn to S25.

S23. The muffler controller sends a control command to the speaker device;

S24. Based on the above-mentioned control instruction, the speaker device emits an audio with a phase opposite to that of the noise audio signal corresponding to the interval to be silenced for noise cancellation, and turns to S21.

S25. Determine whether the speaker device is in a sounding state, if yes, turn to S26; otherwise, turn to S21.

S26. Turn off the speaker device, and turn to S21.

Optionally, the acquisition module includes a gear position sensor and a rotation speed sensor.

The above-mentioned gear position sensor is used to obtain the gear position of the vehicle, and after acquiring the gear position of the vehicle, send the gear position to the muffler controller through the CAN bus.

The above-mentioned speed sensor is used to obtain the engine speed, and after obtaining the engine speed, send the engine speed to the muffler controller through the CAN bus.

On the basis of the above embodiments, in this embodiment, the above-mentioned active noise reduction system further includes a recording module, and the above-mentioned recording module is used to acquire audio with a phase opposite to that of the noise audio signal, and record it into the above-mentioned speaker device.

Further, the above-mentioned noise reduction controller includes a storage submodule, a judging submodule and a control submodule.

The above-mentioned storage sub-module is used for storing all intervals to be silenced. Wherein, a section to be silenced is a gear position and an engine speed section corresponding to a noise audio signal.

The judging sub-module is used to obtain the current gear position and engine speed of the vehicle from the CAN bus signal, and determine whether the received gear position and engine speed are in any interval to be silenced stored in the storage sub-module. The above judgment sub-module is also used to send the judgment result to the control sub-module.

When the judging sub-module judges yes, that is, the received gear position and engine speed are in a certain interval to be silenced stored in the storage sub-module, the control sub-module is used to send a control command to the speaker device. The above-mentioned control sub-module is also used for controlling the speaker device not to make a sound when the above-mentioned judging sub-module judges No.

Preferably, the active noise reduction system of this embodiment further includes a calibration module, which is used to start the engine in different working conditions in sequence, and record the process noise through the microphone; the calibration module is also used to extract the process noise that cannot pass through the muffler The eliminated audio signal is used as the noise audio signal to be silenced, and the gear position and engine speed range corresponding to each noise audio signal are obtained.

In this embodiment, among the process noises, the audio signals that cannot be eliminated by the muffler in the vehicle are: audio signals of noises whose noise sound pressure level is greater than the noise sound pressure level threshold.

Optionally, the above-mentioned calibration module also includes recording the emission position of the noise audio signal, and determining the primary and secondary relationship between the emission positions; the above-mentioned emission position includes at least one of the cowl, the front muffler, and the rear muffler.

Preferably, a speaker device is respectively provided adjacent to the above-mentioned front wall, adjacent to the front muffler and adjacent to the rear muffler.

In this embodiment, the above-mentioned noise reduction controller also pre-stores the sending position of each noise audio signal and the primary and secondary relationship between the sending positions.

Preferably, the noise cancellation controller is further configured to control the loudspeaker devices at each emitting position based on the primary and secondary relationship between the emitting positions of the noise audio signal.

As shown in Figure 2, the active noise cancellation system of the embodiment of the present application includes an acquisition module 1, a noise cancellation controller 2, a first recorder 3, a first speaker 4, a second recorder 5, a second speaker 6, a third recorder 7, and Third speaker 8 . The first recorder 3 and the first speaker 4 are disposed adjacent to the cowl, the second recorder 5 and the second speaker 6 are disposed adjacent to the front muffler, and the third recorder 7 and third speaker 8 are disposed adjacent to the rear muffler.

In this embodiment, when the noise reduction controller judges that the current gear position and the engine speed are in a certain range to be silenced, the noise reduction controller may base on the primary and secondary relationship between the noise audio signal A corresponding to the noise reduction range and its emitting position, for each The loudspeaker device at the emitting position is controlled accordingly.

If the noise audio signal A is only sent by the front wall and the front muffler, and the front wall accounts for the main sound source (higher decibel value), and the front muffler accounts for the secondary sound source (lower decibel value), then the noise reduction controller controls the first A tape recorder 3 and the first loudspeaker 4 send out the main muffled audio with the opposite phase and higher decibels with the noise audio signal A, and control the second tape recorder 5 and the second loudspeaker 6 to send out the opposite phase with the noise audio signal A and the decibel is higher Low secondary anechoic audio for noise cancellation, while third recorder 7 and third speaker 8 are not working.

If this noise audio signal A is only sent by the front muffler and the rear muffler, and the rear muffler accounts for the main sound source, and the front muffler accounts for the secondary sound source, then the muffler controller controls the third tape recorder 7 and the third loudspeaker 8 to send out the same sound as This noise audio signal A is the main noise-cancelling audio of the opposite phase, and controls the second recorder 5 and the second loudspeaker 6 to send out the secondary noise-cancelling audio of the opposite phase with the noise audio signal A, and controls the first sound recorder 3 and the first loudspeaker simultaneously 4 does not work.

If the noise audio signal A is only sent by the front wall and the rear silencer, and the front wall accounts for the main sound source, and the rear silencer accounts for the secondary sound source, then the noise reduction controller controls the first recorder 3 and the first loudspeaker 4 to send out the same noise. audio signal A of the opposite phase of the main noise cancellation, and control the third recorder 7 and the third loudspeaker 8 to send out the secondary noise audio signal A of the opposite phase of the noise audio, while controlling the second recorder 5 and the second loudspeaker 6 not to Work.

If this noise audio signal A is only sent by the cowl place, then the noise reduction controller only controls the first tape recorder 3 and the first loudspeaker 4 to send the noise elimination audio with the opposite phase of this noise audio signal A, and controls the second tape recorder 5, the first speaker 4 The second speaker 6, the third recorder 7, and the third speaker 8 do not work.

If this noise audio signal A is only sent by the rear muffler, then the noise reduction controller only controls the third tape recorder 7 and the third loudspeaker 8 to send the noise audio signal A in opposite phase to the noise audio signal A, and controls the first tape recorder 3, The first loudspeaker 4, the second tape recorder 5 and the second loudspeaker 6 do not work.

If the noise audio signal A is sent by the front wall, the front silencer and the rear silencer, and the front wall accounts for the main sound source, and the front silencer and the rear silencer all account for the secondary sound source, then the noise reduction controller controls the first recorder 3 and The first loudspeaker 4 sends the main muffled audio with the opposite phase of the noise audio signal A, and controls the second recorder 5, the second speaker 6, the third recorder 7 and the third speaker 8 to send the noise audio signal A with the opposite phase Secondary muffler audio for noise cancellation.

The active noise reduction system of the embodiment of the present application is applicable to the above-mentioned active noise reduction methods. When the noise reduction controller judges that the gear position and the engine speed are in a certain interval to be silenced, the noise reduction controller sends a control command to the speaker device, so that the speaker device The audio with the phase opposite to that of the noise audio signal corresponding to the interval to be silenced is emitted for noise cancellation, so as to play the role of noise cancellation.

Optionally, the embodiment of the present application also provides an electronic device for active noise reduction, the electronic device includes a processor and a memory, and the processor executes the code in the memory to implement the following active noise reduction method:

Acquiring multiple noise audio signals to be silenced in advance, and using the gear position and engine speed interval corresponding to each noise audio signal as an interval to be silenced;

After the vehicle is powered on, the gear position and engine speed of the vehicle are obtained. When the above gear position and engine speed are in any interval to be silenced, the speaker device is controlled to send out an audio with the opposite phase to the noise audio signal corresponding to the interval to be silenced, and to perform noise reduction. offset.

Optionally, the above-mentioned processor executes the code in the above-mentioned memory to implement the following active noise reduction method:

After acquiring a plurality of noise audio signals to be silenced, acquire audio with an opposite phase to the noise audio signal and store it in the speaker device.

Optionally, the above-mentioned processor executes the code in the above-mentioned memory to implement the following active noise reduction method:

Start the engine in different working conditions in turn, and record the process noise;

The audio signal in the process noise that cannot be eliminated by the muffler in the car is extracted as the noise audio signal to be silenced, and the gear position and engine speed range corresponding to each noise audio signal are obtained.

Optionally, the above-mentioned processor executes the code in the above-mentioned memory to implement the following active noise reduction method:

In the extraction process noise, the audio signal of the noise whose noise sound pressure level is greater than the noise sound pressure level threshold is regarded as the audio signal that cannot be eliminated by the muffler in the car

Optionally, the above-mentioned processor executes the code in the above-mentioned memory to implement the following active noise reduction method:

When the above-mentioned gear position and the engine speed are not in the interval to be silenced, the above-mentioned loudspeaker device is controlled not to work.

Preferably, the above-mentioned processor executes the code in the above-mentioned memory to also implement other steps in the above-mentioned active noise reduction method.

In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower" and so on is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description. It is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed, or operate in a particular orientation, and thus should not be construed as limiting the application. Unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be interpreted in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, It can also be an electrical connection; it can be a direct connection, or an indirect connection through an intermediary, or an internal communication between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

It should be noted that in this application, relative terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply There is no such actual relationship or order between these entities or operations. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The above descriptions are only specific implementation manners of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the present application will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims (8)

1. An active noise reduction method, characterized in that it comprises steps: Acquiring multiple noise audio signals to be silenced in advance, and using the gear position and engine speed interval corresponding to each noise audio signal as an interval to be silenced; After the vehicle is powered on, the gear position and the engine speed of the vehicle are obtained. When the gear position and the engine speed are in any interval to be silenced, the speaker device is controlled to send out an audio with an opposite phase to the noise audio signal corresponding to the interval to be silenced, and the noise cancellation; The pre-acquisition of multiple noise audio signals to be silenced specifically includes: Start the engine in different working conditions in turn, and record the process noise; Extract the audio signal in the process noise that cannot be eliminated by the muffler in the car as the noise audio signal to be silenced, and obtain the gear position and engine speed range corresponding to each noise audio signal; When recording process noise, it also includes: Record the emission location of the noise audio signal, and determine the primary and secondary relationship between the emission locations; The emitting position includes at least one of the front wall, the front muffler, and the rear muffler, and a loudspeaker device is respectively provided adjacent to the front wall, the front muffler, and the rear muffler; When controlling the loudspeaker device to emit an audio with an opposite phase to the noise audio signal corresponding to the noise-absorbing interval, it also includes: Based on the primary and secondary relationship between the emitting positions of the noise audio signal, corresponding control is performed on the loudspeaker devices at each emitting position. 2. The active noise reduction method according to claim 1, wherein, after obtaining a plurality of noise audio signals to be silenced, further comprising: The audio in the opposite phase to the noise audio signal is acquired and stored in the speaker device. 3. The active noise canceling method according to claim 1, wherein the loudspeaker device comprises a recorder and a speaker connected to the recorder, and the recorder stores audio in phase opposite to the noise audio signal. 4. The active noise reduction method according to claim 1, wherein the audio signal of the process noise that cannot be eliminated by the muffler in the vehicle is: an audio signal of noise whose sound pressure level is greater than the noise sound pressure level threshold. 5. The active noise reduction method according to claim 1, characterized in that: when the gear position and the engine speed are not in the range to be silenced, the speaker device is controlled not to work. 6. An active noise reduction system based on the method of claim 1, characterized in that it comprises: An acquisition module, which is used to acquire the gear position and engine speed of the vehicle after the vehicle is powered on, and send them to the muffler controller; The muffler controller pre-stores all to-be-silenced intervals, which are used to send control commands to the speaker device when the gear position and engine speed are in any of the to-be-silenced intervals; The loudspeaker device is used for, based on the control instruction, emitting an audio with an opposite phase to that of the noise audio signal corresponding to the interval to be silenced for noise cancellation. 7. The active noise reduction system according to claim 6, further comprising a recording module, the recording module is used to obtain audio with a phase opposite to that of the noise audio signal, and record it into the speaker device. 8. The active noise reduction system according to claim 6, wherein the noise reduction controller comprises: A storage submodule, the storage submodule is used to store all the intervals to be silenced; A judging submodule, the judging submodule is used to judge whether the received gear position and engine speed are in any interval to be silenced; A control submodule, the control submodule is used to send a control instruction to the speaker device when the judgment submodule judges yes.

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