Active noise reduction device, active noise reduction method and range hood

Abstract

The invention relates to an active noise reduction device, an active noise reduction method and a range hood, and the active noise reduction device comprises a sound signal collection device which is used for collecting a noise signal; the controller is electrically connected with the sound signal acquisition device, and the controller is configured to generate a noise reduction signal for counteracting the noise signal according to the noise signal acquired by the sound signal acquisition device; the sound signal transmitting device is electrically connected with the controller and is used for transmitting a noise reduction signal; the device is characterized in that the sound signal transmitting device comprises a plurality of plasma loudspeakers which are circumferentially arranged around the noise source, and the plasma loudspeakers are configured to be capable of generating electric arcs through high-voltage electricity so as to drive air to produce sound through the vibration of the electric arcs. The active noise reduction device can be suitable for a complex noise environment, is slightly influenced by the environment and is low in complexity; and the discharge parameters of the plasma loudspeaker can be obtained through a noise reduction method so as to meet the real-time requirement of a dynamic noise environment, and the method is suitable for active noise control, sound field regulation and control and other scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of noise reduction technology, and in particular to an active noise reduction device, an active noise reduction method and a range hood. BACKGROUND

[0002] The range hood is an important kitchen electrical equipment in the kitchen, and is crucial to keeping the air in the kitchen environment clean. The range hood usually produces noise when working, which seriously affects the user's experience when using the range hood. In order to reduce the adverse effects of range hood noise, passive noise reduction or active noise reduction is mainly used for noise reduction.

[0003] The most commonly used and simpler noise reduction method is passive noise reduction. For example, a range hood is disclosed in Chinese Utility Model No. ZL202123194779.X (Grant Announcement No. CN216744504U), wherein the first sound absorption assembly and the second assembly absorb the noise in the air inlet channel, thereby improving the noise reduction capability of the range hood. However, the current passive noise reduction method has noise reduction effect in a fixed noise reduction frequency band, and has no or limited noise reduction effect when exceeding the fixed noise reduction frequency band.

[0004] Therefore, the best way to reduce noise is active noise reduction. The active noise reduction method is to emit a sound wave with the same frequency and amplitude as the noise but opposite phase to interfere with the noise and achieve phase cancellation, thereby achieving the effect of noise reduction. However, due to the variable working conditions of the range hood when working, the noise generated by the motor of the range hood under different working conditions is not completely the same, so the active noise reduction method in the prior art is easily affected by the environment, has high complexity, and cannot meet the real-time requirements of dynamic noise environment. Therefore, further improvement is needed for the prior art. SUMMARY

[0005] The first technical problem to be solved by the present application is to provide an active noise reduction device suitable for complex noise environment.

[0006] The second technical problem to be solved by the present application is to provide an active noise reduction method applying the active noise reduction device, which can meet the real-time requirements of dynamic noise environment.

[0007] The third technical problem to be solved by the present application is to provide a range hood applying the active noise reduction method.

[0008] The technical solution adopted by the present application to solve the first technical problem is as follows: an active noise reduction device, comprising:

[0009] a sound signal acquisition device for acquiring noise signals;

[0010] A controller is electrically connected with the sound signal acquisition device, and is configured to generate a noise reduction signal for canceling the noise signal acquired by the sound signal acquisition device;

[0011] A sound signal emitting device is electrically connected with the controller, and is configured to emit the noise reduction signal.

[0012] Preferably, the sound signal emitting device comprises a plurality of plasma loudspeakers arranged circumferentially around the noise source, and the plasma loudspeakers are configured to generate an electric arc by high-voltage electricity, and then drive air to emit sound by vibration of the electric arc.

[0013] Preferably, the plasma loudspeaker comprises a shell, a negative electrode and a positive electrode arranged adjacent to the negative electrode are arranged in the shell, and the positive electrode and the negative electrode are electrically connected and connected with high-voltage electricity.

[0014] Further, a groove is arranged on the shell, the negative electrode is arranged at the bottom of the groove, and the two ends of the positive electrode are connected to the two opposite walls of the groove.

[0015] Preferably, the sound signal acquisition device adopts an acoustic sensor array.

[0016] The application solves the second technical problem by adopting the technical scheme of an active noise reduction method applied to the active noise reduction device, and the method comprises the following steps:

[0017] Step 1: collecting noise signals, discretizing the collected noise signals in a preset time window, and obtaining the power spectral density of the discretized noise signals;

[0018] Step 2: performing time-frequency domain multi-resolution analysis on the power spectral density of the discretized noise signals to construct a multi-dimensional noise feature vector F_noise.

[0019] Step 3: constructing an anti-phase acoustic feature vector F_anti-noise with a cancellation interference characteristic;

[0020] Step 4: establishing a coupling model of the plasma loudspeaker discharge parameters and the multi-dimensional noise feature vector, and jointly solving the sound field distribution by the finite element method through the thermoacoustic wave equation and the plasma heat source quantization formula, obtaining a training set, recording the sound wave signals formed by each plasma loudspeaker discharge parameter, and each training sample input signal in the training set is the sound wave signal, and the output signal is the plasma loudspeaker discharge parameter corresponding to the sound wave signal.

[0021] Step 5, constructing a neural network, training the neural network with the training set, obtaining the trained neural network, and finally inputting the inverse acoustic feature vector into the trained neural network to obtain the plasma loudspeaker discharge parameter.

[0022] The step 1 is to obtain the power spectrum density of the discretized noise signal based on the Hanning window fast Fourier transform.

[0023] The step 2 is to obtain the multi-dimensional noise feature vector Wherein f1 is the peak frequency, A1 is the 1 / 3 octave amplitude, is the phase difference matrix;

[0024] The step 3 is to obtain the inverse acoustic feature vector

[0025] The step 4 is to obtain the plasma loudspeaker discharge parameter, which is the plasma loudspeaker voltage, the plasma loudspeaker current and the pulse width.

[0026] Preferably, the neural network in step 5 is a DNN network.

[0027] The technical solution adopted by the application to solve the third technical problem is: a range hood characterized by applying the above-mentioned active noise reduction method.

[0028] Compared with the prior art, the application has the advantages that by setting the plasma loudspeaker, using plasma as ionized gas, the density and temperature of the plasma can be adjusted by the electric field to change the local sound speed and thus interfere with the sound wave propagation path; and there is a tunable overlapping area between the plasma oscillation frequency and the sound wave frequency band, which can realize wide-band sound wave interference. Therefore, the active noise reduction device can adapt to complex noise environments, has small environmental impact and low complexity; and the discharge parameters of the plasma loudspeaker can be obtained by the noise reduction method to meet the real-time requirements of dynamic noise environments, and the device is suitable for active noise control, sound field regulation and other scenes. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a structural schematic diagram of the plasma loudspeaker in the embodiment of the application;

[0030] Figure 2 is a flowchart of the active noise reduction method in the embodiment of the application. DETAILED DESCRIPTION

[0031] The application will be further described in detail below with reference to the embodiments of the drawings.

[0032] The embodiment provides an active noise reduction device applicable to an extractor hood. The active noise reduction device comprises a sound signal acquisition device, a controller and a sound signal emitting device. The sound signal acquisition device is used for acquiring a noise signal, the controller is electrically connected with the sound signal acquisition device, and the controller is configured to generate a noise reduction signal for canceling the noise signal according to the noise signal acquired by the sound signal acquisition device; and the sound signal emitting device is electrically connected with the controller and is used for emitting the noise reduction signal. The sound signal acquisition device in the embodiment adopts an acoustic sensor array.

[0033] The sound signal emitting device comprises a plurality of plasma loudspeakers arranged circumferentially around a noise source. The plasma loudspeakers are configured to generate an electric arc through high-voltage electricity, and then drive air to sound by vibration of the electric arc. The plasma loudspeaker comprises a shell 1, wherein a negative electrode 11 and a positive electrode 12 adjacent to the negative electrode 11 are arranged in the shell 1. The positive electrode 12 and the negative electrode 11 are electrically connected and connected with high-voltage electricity. As shown in the figure, the shell 1 is provided with a groove 10 in the embodiment, the negative electrode 11 is arranged at the bottom of the groove 10, and the two ends of the positive electrode 12 are connected to the two opposite walls of the groove 10. Figure 1

[0034] The embodiment further provides an active noise reduction method applied to the active noise reduction device, as shown in the figure, the active noise reduction method comprises the following steps: Figure 2

[0035] Step 1, collecting a noise signal, discretizing the collected noise signal in a preset time window, and obtaining a power spectral density of the discretized noise signal;

[0036] In the embodiment, the power spectral density of the discretized noise signal is obtained based on a fast Fourier transform of a Hanning window;

[0037] Step 2, performing time-frequency domain multi-resolution analysis on the power spectral density of the discretized noise signal to construct a multi-dimensional noise feature vector Wherein f1 is a peak frequency, A1 is a 1 / 3 octave amplitude, is a phase difference matrix;

[0038] Step 3, constructing an anti-phase acoustic feature vector F_anti-noise with a cancellation interference characteristic;

[0039] The anti-phase acoustic feature vector F_anti-noise in the embodiment is

[0040] ​​Step 4, a coupling model of the plasma loudspeaker discharge parameter and the multi-dimensional noise feature vector is established, and a thermoacoustic wave equation and a plasma heat source quantification formula are combined to solve the sound field distribution by a finite element method to obtain a training set, record the sound wave signals formed by each plasma loudspeaker discharge parameter, and input the sound wave signals as each training sample in the training set, and output the plasma loudspeaker discharge parameters corresponding to the sound wave signals;

[0041] According to the relationship between the plasma loudspeaker discharge parameter and the multi-dimensional noise feature vector, a coupling model is established; the method for establishing the coupling model is prior art, and will not be described here;

[0042] The thermoacoustic wave equation in this embodiment is:

[0043] wherein, is a sound pressure Laplace term, w is an angular frequency, c is a sound speed, p is a sound pressure, j is an imaginary unit, p is a medium density, Q0 is a heat source intensity, c p is a constant-pressure specific heat capacity, and T0 is an ambient temperature;

[0044] The plasma heat source quantification formula in this embodiment is: Q0=α.V.I.τ.(t p .A gas )

[0045] wherein, a is the efficiency of the plasma, V, I and t are the voltage, current and pulse width of the plasma respectively, t p is a pulse period, and A gas is a gas acting area;

[0046] The calculation method for solving the sound field distribution by the finite element method in this embodiment is prior art, and will not be described here;

[0047] In this embodiment, the plasma loudspeaker discharge parameter is the voltage of the plasma loudspeaker, the current of the plasma loudspeaker and the pulse width;

[0048] Step 5, a neural network is constructed, and the training set is trained on the neural network to obtain the trained neural network, and finally the inverse acoustic feature vector is input into the trained neural network to obtain the plasma loudspeaker discharge parameter;

[0049] The neural network in this embodiment is a DNN network.

[0050] In this embodiment, a range hood is also provided, and the active noise reduction method described above is applied to the range hood.

[0051] The above merely describes the preferred embodiments of the present application, and it should be pointed out that, for those skilled in the art, several improvements and refinements can be made without departing from the technical principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. An active noise reduction device, comprising: A sound signal collecting device, used for collecting noise signals; A controller electrically connected to the sound signal collecting device, wherein the controller is configured to: generate a noise reduction signal to cancel the noise signal according to the noise signal collected by the sound signal collecting device; A sound signal transmitting device, electrically connected to the controller, for transmitting a noise reduction signal; It is characterized in that the sound signal emitting device includes a plurality of plasma speakers arranged circumferentially around the noise source, and the plasma speakers are configured to generate an arc through high voltage electricity, and then use the vibration of the arc to drive the air to produce sound.

2. The active noise reduction device according to claim 1, characterized in that: The plasma speaker includes a shell. A negative electrode and a positive electrode adjacent to the negative electrode are provided in the shell. The positive electrode and the negative electrode are electrically connected and connected to high voltage.

3. The active noise reduction device according to claim 2, characterized in that: The shell is provided with a groove, the negative electrode is arranged at the bottom of the groove, and the two ends of the positive electrode are connected to two opposite wall surfaces of the groove.

4. The active noise reduction device according to any one of claims 1 to 3, characterized in that: The sound signal collecting device adopts an acoustic sensor array.

5. An active noise reduction method using the active noise reduction device according to any one of claims 1 to 4, characterized in that The steps include: Step 1: Collect a noise signal, discretize the collected noise signal within a preset time window, and obtain the power spectrum density of the discretized noise signal; Step 2: Perform time-frequency domain multi-resolution analysis on the power spectrum density of the discretized noise signal to construct a multi-dimensional noise feature vector F_noise; Step 3: Construct an anti-phase acoustic eigenvector F_anti-noise with destructive interference characteristics; Step 4: Establish a coupling model between the plasma speaker discharge parameters and the multidimensional noise characteristic vector. Combined with the thermoacoustic wave equation and the plasma heat source quantification formula, the sound field distribution is solved by the finite element method to obtain a training set. The acoustic wave signal generated by each plasma speaker discharge parameter is recorded. The input signal of each training sample in the training set is the acoustic wave signal, and the output signal is the plasma speaker discharge parameter corresponding to the acoustic wave signal. Step 5: Construct a neural network and train the neural network with the training set to obtain a trained neural network. Finally, input the inverse acoustic feature vector into the trained neural network to obtain the plasma speaker discharge parameters.

6. The active noise reduction method according to claim 5, characterized in that: In step 1, the power spectral density of the discretized noise signal is obtained by fast Fourier transform based on the Hanning window.

7. The active noise reduction method according to claim 5, wherein: In step 2, the multidimensional noise feature vector F_noise1=[f1, A1, φ1], where f1 is the peak frequency, A1 is the 1 / 3 octave amplitude, and φ1 is the phase difference matrix; The anti-phase acoustic eigenvector F_anti-noise in step 3 is [f1, A1, φ1+π].

8. The active noise reduction method according to claim 5, wherein: The plasma speaker discharge parameters in step 4 are the plasma speaker voltage, the plasma speaker current and the pulse width.

9. The active noise reduction method according to claim 5, characterized in that: The neural network in step 5 is a DNN network.

10. A range hood, characterized in that: The active noise reduction method according to any one of claims 5 to 9 is applied.

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