Engine active noise reduction method and system and vehicle

Abstract

The invention provides an engine active noise reduction method and system and a vehicle, and the method comprises the steps: S1, determining the noise weight of each noise reduction region based on the personnel distribution in each noise reduction region, and weighting the noise collection value in the corresponding noise region based on the noise weight to form weighted noise; and S2, inputting the weighted noise into a control filter, generating a sound wave signal for reducing the noise in the noise reduction area by the control filter, and transmitting the sound wave signal to each noise reduction area. According to the change of people in the noise reduction area in the vehicle, the noise reduction effects of different noise reduction areas are adjusted in a self-adaptive mode, the noise reduction effect of the noise reduction area where people exist is mainly improved, and the noise reduction effect is more intelligent; the method is suitable for various types of vehicles including cars, SUVs, commercial vehicles and the like, and has high universality and market adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of active noise reduction, and provides an engine active noise reduction method, system and vehicle. Background Art

[0002] When exposed to the engine noise environment for a long time, the driver and passengers are prone to auditory fatigue. Reducing engine noise can relieve this fatigue, enable the driver and passengers to maintain a better mental state during long driving, and improve driving safety and comfort.

[0003] A quiet interior environment helps the driver and passengers to communicate, relax, and enhance the overall driving experience. With the development of the automotive industry, people's requirements for vehicle comfort are getting higher and higher, and reducing interior noise has become an important task to improve vehicle comfort.

[0004] Currently, engine active noise reduction technology has been widely applied, but most of the current noise reduction algorithms are processed based on the average value of the overall interior noise, and cannot perform relatively accurate noise reduction for the noise in different areas of the vehicle. Summary of the Invention

[0005] In view of this, the present application provides an engine active noise reduction method, aiming to improve the above problems.

[0006] Specifically, the following technical solutions are included:

[0007] On the one hand, an embodiment of the present application provides an engine active noise reduction method, which specifically includes the following steps:

[0008] S1. Determine the noise weight of each noise reduction area based on the personnel distribution in each noise reduction area, and weight the noise acquisition values in the corresponding noise area based on the noise weight to form weighted noise;

[0009] S2. Input the weighted noise into a control filter, and the control filter generates a sound wave signal for reducing the noise in the noise reduction area and propagates it to each noise reduction area.

[0010] In some embodiments of the present invention, if there are people in the noise reduction area, give a larger noise weight to the noise in the corresponding noise reduction area; if there are no people in the noise area, give a smaller noise weight to the noise in the corresponding noise area.

[0011] In some embodiments of the present invention, by collecting the noise time-domain signal in the corresponding noise area by at least one noise acquisition unit in the area, when there are people in the noise reduction area where the mth noise acquisition unit is located at the current time t, α m (t) = 1, when there are no people in the noise reduction area where the mth noise acquisition unit is located at the current time t, αm f(t) = b, where b < 0.5.

[0012] In some embodiments of the present invention, the method for determining the acoustic wave signal for reducing noise in the noise reduction area is as follows:

[0013] S21. Determine the engine noise frequency according to the current engine speed, and then generate a time-domain sine signal with the same frequency as the engine noise frequency, and use this time-domain sine signal as the reference signal x(t);

[0014] S22. Generate the control signals of each noise reduction unit according to the current reference signal vector and the weights of the control filters.

[0015] S23. Update the weights of each L-order control filter based on the noise time-domain signal collected by each noise acquisition unit at the current time t and the filtered reference signal X' km (t) at the current time t, and use the updated weights as the weights W k (t + 1) of each L-order control filter at the next time t + 1, and return to step S21.

[0016] In some embodiments of the present invention, the weight update formula of the k-th L-order control filter is as follows;

[0017]

[0018] Where W k (t) is the weight of the k-th L-order control filter at time t, K is the total number of noise reduction units, μ is the adjustment coefficient, X' km (t) = S km *X(t), S km is the acoustic transfer function from the k-th noise reduction unit to the m-th noise acquisition unit, * represents the convolution operation, e m (t) represents the noise time-domain signal collected by the m-th noise acquisition unit at the current time t, and α m (t) represents the noise weight collected by the m-th noise acquisition unit at the current time t. The noise reduction unit is used to output the acoustic wave signal for reducing noise in the noise reduction area to the corresponding noise reduction area.

[0019] In some embodiments of the present invention, the calculation formula of the control signal y k (t) of the k-th noise reduction unit is as follows:

[0020] y k (t) = W k T (t)X(t), k = 1, 2,..., K...

[0021] Where W k (t) = [wk,1 (t), w k,2 (t),..., w k,L (t)] T , W k w(t) is the weight of the k-th L-order control filter at time t, K is the total number of noise reduction units, and X(t) = [x(t), x(t - 1),..., x(t - L + 1)] T is the reference signal vector at the current time.

[0022] On the other hand, an embodiment of the present application provides an engine active noise reduction system, which includes:

[0023] A noise collection unit arranged in each noise reduction area of the cockpit, and a noise reduction unit, a detection unit and a processing unit arranged in the cockpit. The noise collection unit, the detection unit are connected to the processing unit, and the processing unit is connected to the noise reduction unit; the noise collection unit is used to collect the noise in the noise reduction area and send it to the processing unit, the detection unit is used to detect the personnel distribution in the noise reduction area of the cockpit and send it to the processing unit, and the processing unit generates a sound wave signal for reducing the noise in the noise reduction area based on the above engine active noise reduction method, outputs it through the noise reduction unit, and propagates it to each noise area.

[0024] In some embodiments of the present invention, when there are s seats in the cockpit, it is divided into s noise reduction areas, each seat corresponds to a noise reduction area, and at least one noise collection unit is arranged in each noise reduction area, and at least one noise reduction unit is arranged in the cockpit.

[0025] In some embodiments of the present invention, the noise collection unit collects the noise time-domain signal in the corresponding noise reduction area through a microphone, and the microphone is arranged near the ceiling handle position or the seat headrest.

[0026] On the other hand, an embodiment of the present application provides that the above engine active noise reduction system is integrated on the vehicle.

[0027] The present invention adaptively adjusts the noise reduction effect of different noise reduction areas according to the change of personnel in the noise reduction area inside the vehicle, mainly improves the noise reduction effect of the noise reduction area where there are people, making the noise reduction effect more intelligent; it is applicable to various types of vehicles, including sedans, SUVs, commercial vehicles, etc., and has high versatility and market adaptability. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 This is a flowchart of the engine active noise reduction method provided by the embodiments of the present invention;

[0030] Figure 2 This is a schematic structural diagram of the engine active noise reduction system provided by the embodiments of the present invention;

[0031] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and more detailed descriptions will be given later. These drawings and text descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without making creative efforts shall fall within the protection scope of the present application.

[0033] Unless otherwise defined, all technical terms used in the embodiments of the present application have the same meaning as commonly understood by those of ordinary skill in the art.

[0034] Figure 1 This is a flowchart of the engine active noise reduction method provided by the embodiments of the present invention, and the method is as follows:

[0035] S1. Determine the noise weight of each noise reduction area based on the personnel distribution in each noise reduction area, and weight the noise acquisition values in the corresponding noise area based on the noise weight to form weighted noise;

[0036] S2. Input the weighted noise into a control filter, and the control filter generates a sound wave signal for reducing the noise in the noise reduction area and propagates it to each noise reduction area.

[0037] First, detect whether there are people in each noise reduction area. If there are people in the noise reduction area, give a larger noise weight to the noise in the corresponding noise reduction area. If there are no people in the noise area, give a smaller noise weight to the noise in the corresponding noise area. The noise weight of the noise in the noise reduction area is specifically as follows:

[0038] When there are people in the noise reduction area where the m-th noise acquisition unit is located at the current moment t, α m (t) = a, where a takes the value of 1. When there are no people in the noise reduction area where the m-th noise acquisition unit is located at the current moment t, α mη(t) = b, b < 0.5, and b is generally taken as 0.2. The weighted noise in the noise reduction area where there is no person is reduced through the noise weight, and the control filter performs active noise reduction based on the weighted noise.

[0039] In the embodiment of the present invention, the acoustic wave signal used to reduce the noise in the noise reduction area is essentially a time-domain signal with a phase opposite to that of the noise time-domain signal, and its determination method is as follows:

[0040] S21. Determine the engine noise frequency according to the current engine speed, and then generate a time-domain sine signal with the same frequency as the engine noise frequency, and use this time-domain sine signal as the reference signal x(t);

[0041] S22. Generate the control signals of each noise reduction unit according to the current reference signal vector and the control filter. The control signal y k (t) of the kth noise reduction unit is calculated as follows:

[0042] y k (t) = W k T (t)X(t), k = 1, 2,..., K;

[0043] where W k (t) = [w k,1 (t), w k,2 (t),..., w k,L (t)] T , W k (t) is the weight of the kth L-order control filter at time t, K is the total number of noise reduction units, one noise reduction unit corresponds to one L-order control filter, and X(t) = [x(t), x(t - 1),..., x(t - L + 1)] T is the reference signal vector at the current time.

[0044] S23. Update the weights of each L-order control filter based on the noise time-domain signal collected by each noise acquisition unit at the current time t and the filtered reference signal X' km (t) at the current time t, and use the updated weights as the weights W k (t + 1) of each L-order control filter at the next time t + 1, and return to step S21.

[0045] In the embodiment of the present invention, the weight update formula of the kth L-order control filter is as follows;

[0046]

[0047] where W k(t) is the weight of the k-th L-order control filter at the current time t, μ is the adjustment coefficient, X' km (t) = S km *X(t), S km is the acoustic transfer function from the k-th noise reduction unit to the m-th noise acquisition unit, * represents the convolution operation, e m (t) represents the noise time-domain signal collected by the m-th noise acquisition unit at the current time t, α m (t) represents the noise weight of the m-th noise acquisition unit collected at the current time t.

[0048] Figure 2 This is a schematic structural diagram of the engine active noise reduction system provided by the embodiments of the present invention. For the sake of convenience of description, only the parts related to the embodiments of the present invention are shown. The system includes:

[0049] Noise acquisition units arranged in each noise reduction area of the cockpit, as well as noise reduction units, detection units and processing units arranged in the cockpit. The noise acquisition units, detection units are connected to the processing unit, and the processing unit is connected to the noise reduction unit; the noise acquisition units are used to collect the noise in the noise reduction area and send it to the processing unit, and the detection unit is used to detect the personnel distribution in the noise reduction area of the cockpit and send it to the processing unit;

[0050] Based on the personnel distribution in the noise reduction area, determine the noise weights of the noise acquisition units in each noise reduction area, weight the noise time-domain signals collected by the corresponding noise acquisition units based on the noise weights to generate weighted noise time-domain signals, input the weighted noise time-domain signals into the corresponding control filters, and the control filters generate anti-sound wave signals for reducing the noise in the noise reduction area and output them through the noise reduction units, so as to actively reduce the noise around the vehicle occupants. The main noise source in the cockpit is the engine noise generated during engine operation.

[0051] In the embodiments of the present invention, the cockpit is divided into two noise reduction areas, namely the area where the front row seats are located and the area where the rear row seats are located. In order to achieve more accurate active noise reduction, when there are s seats in the cockpit, it is divided into s noise reduction areas, and each seat corresponds to a noise reduction area. The noise time-domain signals collected by the noise acquisition units in the noise reduction area can reflect the noise level in the corresponding noise reduction area. In order to more accurately reflect the noise felt by the drivers and passengers, two noise acquisition units are arranged in the noise area where each seat is located, and the two noise acquisition units are arranged on the left and right sides of the seat headrest to collect the noise of the driver and passengers' left and right ears.

[0052] In the embodiment of the present invention, the noise acquisition unit collects the noise time-domain signal in the noise reduction area through a microphone, and the microphone is generally arranged near the ceiling handle position or on the seat headrest to comprehensively pick up the noise signal. The corresponding noise reduction unit outputs a sound wave signal for canceling the noise in the noise reduction area through a speaker to achieve noise reduction in the noise reduction area.

[0053] In the embodiment of the present invention, the detection unit collects the images in the cockpit through a camera, determines the personnel distribution in each noise reduction area in real time based on the collected images, and sends it to the processing unit. The processing unit first determines the noise weight of the noise acquisition unit in each noise reduction area. If there are people in the noise reduction area, the noise weight of the noise acquisition unit in the corresponding noise reduction area is increased. If there are no people in the noise area, the noise weight of the noise acquisition unit in the corresponding noise area is reduced. When setting a noise reduction area for each seat, the detection unit detects whether there are people on the corresponding seat (noise reduction area) through a weight sensor at the seat.

[0054] In the embodiment of the present invention, the calculation formula of the noise weight of the noise acquisition unit is specifically as follows:

[0055]

[0056] where α m (t) is the noise weight of the m-th noise acquisition unit at the current moment t. When there are people in the noise reduction area where the m-th noise acquisition unit is located at the current moment t, α m (t) = a = 1. When there are no people in the noise reduction area where the m-th noise acquisition unit is located at the current moment t, α m (t) = b, b < 0.5. The input noise of the noise reduction area without people is reduced through the noise weight.

[0057] In the embodiment of the present invention, the sound wave signal for reducing the noise in the noise reduction area is also a time-domain signal, and its determination method is specifically as follows:

[0058] (1) Determine the engine noise frequency according to the current engine speed, and then generate a time-domain sine signal with the same frequency as the engine noise frequency, and use this time-domain sine signal as the reference signal x(t);

[0059] (2) Generate the control signals of each noise reduction unit according to the current reference signal vector and the control filter. The calculation formula of the control signal y k (t) of the k-th noise reduction unit is specifically as follows:

[0060] y k (t) = W k T (t)X(t), k = 1, 2,..., K;

[0061] Among them, W k (t) = [w k,1 (t), w k,2 (t),..., w k,L (t)] T , W k (t) is the weight of the k-th L-order control filter at time t, K is the total number of noise reduction units, and one noise reduction unit corresponds to one L-order control filter. X(t) = [x(t), x(t - 1),..., x(t - L + 1)] T is the reference signal vector at the current time.

[0062] (3) Based on the noise time-domain signals collected by each noise acquisition unit at the current time t and the filtered reference signal X' km (t) at the current time t, update the weights of each L-order control filter, and use the updated weights as the weights W k (t + 1) of each L-order control filter at the next time t + 1, and return to step (1).

[0063] In the embodiment of the present invention, the weight update formula of the k-th L-order control filter is specifically as follows;

[0064]

[0065] Among them, W k (t) is the weight of the k-th L-order control filter at the current time t, μ is the adjustment coefficient, X' km (t) = S km * X(t), S km is the acoustic transfer function from the k-th noise reduction unit to the m-th noise acquisition unit, * represents the convolution operation, e m (t) represents the noise time-domain signal collected by the m-th noise acquisition unit at the current time t, and α m (t) represents the noise weight collected by the m-th noise acquisition unit at the current time t.

[0066] The engine active noise reduction system provided by the present invention has the following beneficial technical effects: According to the changes in the personnel in the noise reduction area inside the vehicle, adaptively adjust the noise reduction effects of different noise reduction areas, mainly improve the noise reduction effects of the noise reduction areas where there are personnel, making the noise reduction effects more intelligent; applicable to various types of vehicles, including sedans, SUVs, commercial vehicles, etc., with high versatility and market adaptability.

[0067] The embodiment of the present invention also provides a vehicle, on which an engine active noise reduction system is integrated. After the vehicle is started, the engine noise near the positions of the passengers and drivers in the cockpit is reduced by the above-mentioned engine active noise reduction system.

[0068] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the present application disclosed herein. The present application is intended to cover any variations, uses, or adaptations of the present application, which follow the general principles of the present application and include well-known knowledge or conventional technical means in the technical field not disclosed in the present application. The specification and examples are only regarded as exemplary.

[0069] It should be understood that the present application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present application is only limited by the appended claims.

Claims

1. An active noise reduction method for an engine, characterized in that, The method specifically comprises the following steps: S1. Determine the noise weight of each noise reduction area based on the distribution of people in each noise reduction area, and weight the noise collection value in the corresponding noise area based on the noise weight to form weighted noise; S2. Input the weighted noise into the control filter, and the control filter generates a sound wave signal for reducing the noise in the noise reduction area and propagates it to each noise reduction area.

2. The engine active noise reduction method according to claim 1, characterized in that If there are people in the noise reduction area, a larger noise weight is given to the noise in the corresponding noise reduction area. If there are no people in the noise area, a smaller noise weight is given to the noise in the corresponding noise area.

3. The engine active noise reduction method according to claim 2, characterized in that, By collecting the noise time-domain signal in the corresponding noise area by at least one noise collection unit within the area, when there is a person in the noise reduction area where the m-th noise collection unit is located at the current moment t, α m (t) = 1, when there is no person in the noise reduction area where the m-th noise collection unit is located at the current moment t, α m (t) = b, b < 0.

5.

4. The engine active noise reduction method according to claim 1, characterized in that, The method for determining the acoustic wave signal for reducing noise in the noise reduction area is as follows: S21, determining the engine noise frequency according to the current engine speed, and then generating a time domain sinusoidal signal with the same frequency as the engine noise, and using the time domain sinusoidal signal as a reference signal x(t); S22, generating control signals for each noise reduction unit according to the current reference signal vector and the weight of the control filter; S23. Update the weights of each L - order control filter based on the noise time - domain signal collected by each noise acquisition unit at the current moment t and the filtering reference signal X'(t) at the current moment t, and use the updated weights as the weights W(t + 1) of each L - order control filter at the next moment t + 1, then return to step S21. km (t) Update the weights of each L - order control filter, and use the updated weights as the weights W(t + 1) of each L - order control filter at the next moment t + 1. k (t + 1), and return to step S21.

5. The engine active noise reduction method according to claim 4, wherein, The weight update formula of the kth L-order control filter is as follows; Among them, W k (t) is the weight of the k-th L-order control filter at time t, K is the total number of noise reduction units, μ is the adjustment coefficient, X' km (t) = S km *X(t), S km is the acoustic transfer function from the k-th noise reduction unit to the m-th noise acquisition unit, * represents the convolution operation, e m (t) represents the noise time-domain signal collected by the m-th noise acquisition unit at the current time t, α m (t) represents the noise weight collected by the m-th noise acquisition unit at the current time t. The noise reduction unit is used to output the acoustic wave signal that reduces the noise in the noise reduction area to the corresponding noise reduction area.

6. The engine active noise reduction method according to claim 4, characterized in that, The control signal y of the k-th noise reduction unit k (t) The calculation formula is as follows: y k y(t) = W k T y(t)X(t), k = 1, 2,..., K where, W k (t) = [w k,1 (t), w k,2 (t),..., w k,L (t)] T , W k (t) is the weight of the k-th L-order control filter at time t, K is the total number of noise reduction units, and X(t) = [x(t), x(t - 1),..., x(t - L + 1)] T is the reference signal vector at the current time.

7. An active engine noise reduction system, characterized in that, The system comprises: A noise collection unit is arranged in each noise reduction area of the cockpit, and a noise reduction unit, a detection unit and a processing unit are arranged in the cockpit. The noise collection unit, the detection unit and the processing unit are connected, and the processing unit is connected to the noise reduction unit; the noise collection unit is used to collect noise in the noise reduction area and send it to the processing unit; the detection unit is used to detect the distribution of people in the noise reduction area in the cockpit and send it to the processing unit; the processing unit generates a sound wave signal for reducing the noise in the noise reduction area based on the engine active noise reduction method according to any one of claims 1 to 6, and outputs it through the corresponding noise reduction unit, and propagates it to each noise area.

8. The engine active noise reduction system according to claim 7, characterized in that, When there are s seats in the cockpit, it will be divided into s noise reduction areas, each seat corresponds to a noise reduction area, at least one noise collection unit is set in each noise reduction area, and at least one noise reduction unit is set in the cockpit.

9. The engine active noise reduction system according to claim 8, wherein, The noise collection unit collects the noise time domain signal in the noise reduction area through a microphone, and the microphone is arranged near the ceiling handle or the seat headrest.

10. A vehicle, characterized in that, The vehicle is integrated with the engine active noise reduction system described in any one of claims 7 to 9.

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