An active pipeline noise control device and control method

Abstract

The present invention relates to the technical field of pipeline noise elimination, and particularly relates to an active pipeline noise control device and a control method. The method collects the noise data of the suction pipe, and marks the negative pressure suction device vibration characteristic peak, air vibration characteristic peak and frequency characteristic peak in the spectrogram of the noise data; determines the intensity, phase and frequency of the negative pressure suction device vibration noise data and the air vibration noise data, and respectively uses the first speaker and the second speaker to emit reverse sound waves; extracts the noise data at a preset acquisition time interval, and compensates the noise data at the next adjacent acquisition moment of the acquisition moment with reverse sound waves according to the difference between the noise data at adjacent acquisition moments and the noise data from the moment when the first speaker and the second speaker emit reverse sound waves to the acquisition moment, so as to realize active pipeline noise control. The present invention can reduce the noise generated during the operation of the negative pressure suction device.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline noise elimination, and particularly relates to an active pipeline noise control device and a control method. Background Art

[0002] A negative pressure aspirator is a tool that creates a negative pressure state at the suction head to squeeze substances outside the suction head towards the suction head to complete the suction effect. The negative pressure aspirator is usually connected to a saliva suction tube for cleaning the patient's oral cavity. When the suction tube in the negative pressure aspirator is connected to a negative pressure pump and enters the saliva suction tube, air will flow through the pipeline, generating noise. Usually, sound-absorbing substances such as sound-absorbing plates or sound-absorbing cotton are added to the saliva suction tube to achieve the purpose of controlling and eliminating noise.

[0003] However, when the suction force provided by the negative pressure aspirator changes, the air flow in the pipeline will also change accordingly, that is, the generated noise will also change. The added sound-absorbing substances such as sound-absorbing plates or sound-absorbing cotton cannot provide a matching sound-absorbing ability for different levels of noise, so the sound-absorbing effect is not good. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an active pipeline noise control device and a control method, and the specific technical solutions adopted are as follows:

[0005] In a first aspect, an embodiment of the present invention provides an active pipeline noise control method, and the method includes the following steps:

[0006] Collect the noise data of the suction tube, obtain the spectrogram of the noise data, and mark the vibration characteristic peaks of the negative pressure aspirator, the air vibration characteristic peaks, and the frequency characteristic peaks in the spectrogram;

[0007] According to the differences between the frequency characteristic peaks and the vibration characteristic peaks of the negative pressure aspirator in the spectrogram, screen out the same type of frequency characteristic peaks of the vibration characteristic peaks of the negative pressure aspirator. According to all the same type of frequency characteristic peaks of the vibration characteristic peaks of the negative pressure aspirator, determine the vibration noise data of the negative pressure aspirator, as well as the corresponding intensity, phase, and frequency. Determine the intensity, phase, and frequency of the air vibration noise data. According to the intensity, phase, and frequency of the vibration noise data of the negative pressure aspirator and the air vibration noise data, use the first speaker and the second speaker to emit reverse sound waves respectively;

[0008] Starting from the moment when the first speaker and the second speaker emit reverse sound waves respectively, extract the noise data of a preset acquisition time interval. According to the differences between the noise data at adjacent acquisition moments and the noise data from the moment when the first speaker and the second speaker emit reverse sound waves to the acquisition moment, perform compensation of the reverse sound waves on the noise data at the next adjacent acquisition moment after the acquisition moment to achieve active pipeline noise control.

[0009] Furthermore, the specific methods for the negative pressure aspirator vibration characteristic peaks, air vibration characteristic peaks, and frequency characteristic peaks in the marked spectrogram are as follows:

[0010] Identify all the maximum points in the spectrogram of the noise data, and record the maximum point with the largest amplitude among all the maximum points as the negative pressure aspirator vibration characteristic peak;

[0011] Record the maximum point with the second largest amplitude among all the maximum points as the air vibration characteristic peak;

[0012] Record all the maximum points that are neither the negative pressure aspirator vibration characteristic peak nor the air vibration characteristic peak as the frequency characteristic peaks.

[0013] Furthermore, the screening method for the same type of frequency characteristic peaks of the negative pressure aspirator vibration characteristic peak is as follows:

[0014] Record any one frequency characteristic peak as the target frequency characteristic peak; record the difference between the frequency of the target frequency characteristic peak and the frequency of the negative pressure aspirator vibration characteristic peak as the first difference between the target frequency characteristic peak and the negative pressure aspirator vibration characteristic peak; record the difference between the amplitude of the target frequency characteristic peak and the amplitude of the negative pressure aspirator vibration characteristic peak as the second difference between the target frequency characteristic peak and the negative pressure aspirator vibration characteristic peak; record the reciprocal of the absolute value of the product of the first difference and the second difference of the target frequency characteristic peak as the similarity between the target frequency characteristic peak and the negative pressure aspirator vibration characteristic peak;

[0015] According to the similarity between the negative pressure aspirator vibration characteristic peak and all the frequency characteristic peaks, screen the same type of frequency characteristic peaks of the negative pressure aspirator vibration characteristic peak.

[0016] Furthermore, the specific method for screening the same type of frequency characteristic peaks of the negative pressure aspirator vibration characteristic peak according to the similarity between the negative pressure aspirator vibration characteristic peak and all the frequency characteristic peaks is as follows:

[0017] Record the mean value of the similarity between the negative pressure aspirator vibration characteristic peak and all the frequency characteristic peaks as the classification threshold of the same type of the negative pressure aspirator vibration characteristic peak ;

[0018] Record the frequency characteristic peaks corresponding to the similarities greater than among the similarities corresponding to the negative pressure aspirator vibration characteristic peak as the same type of frequency characteristic peaks of the negative pressure aspirator vibration characteristic peak.

[0019] Furthermore, the determination methods for the intensity, phase, and frequency of the negative pressure aspirator vibration noise data are as follows:

[0020] Record the value of the negative pressure aspirator vibration noise data as the intensity of the negative pressure aspirator vibration noise data;

[0021] Perform time-frequency analysis on the vibration noise data of the negative pressure aspirator. According to the time-frequency analysis results, obtain the time-frequency diagram of the same type of frequency characteristic peaks of the vibration noise data of the negative pressure aspirator. According to the time-frequency diagram of the vibration noise data of the negative pressure aspirator, obtain the phase of the vibration noise data of the negative pressure aspirator.

[0022] Obtain the spectrogram of the vibration noise data of the negative pressure aspirator according to the vibration noise data of the negative pressure aspirator; obtain the frequency of the vibration noise data of the negative pressure aspirator according to the spectrogram of the vibration noise data of the negative pressure aspirator.

[0023] Further, the specific method of respectively using the first speaker and the second speaker to emit reverse sound waves according to the intensity, phase and frequency of the vibration noise data of the negative pressure aspirator and the air vibration noise data includes:

[0024] Record the sound wave with the same intensity and frequency as the vibration noise data of the negative pressure aspirator but with the opposite phase as the reverse sound wave emitted by the first speaker.

[0025] Record the sound wave with the same intensity and frequency as the air vibration noise data but with the opposite phase as the reverse sound wave emitted by the second speaker.

[0026] Further, the specific method of compensating the reverse sound wave for the noise data at the next adjacent acquisition moment according to the difference between the noise data at adjacent acquisition moments and the noise data from the moment when the first speaker and the second speaker emit the reverse sound wave to the acquisition moment to achieve active pipeline noise control includes:

[0027] Record any acquisition moment starting from the second acquisition moment as the target acquisition moment, record the absolute value of the difference between the noise data at the target acquisition moment and the noise data at the previous adjacent acquisition moment of the target acquisition moment as the absolute noise difference at the target acquisition moment; record the ratio of the absolute noise difference at the target acquisition moment to the noise data at the previous adjacent acquisition moment of the target acquisition moment as the sound wave cancellation degree at the target acquisition moment.

[0028] When the sound wave cancellation degree at the target acquisition moment is greater than or equal to the first constant value, compensate the reverse sound wave for the noise data at the next adjacent acquisition moment according to the noise data from the moment when the first speaker and the second speaker emit the reverse sound wave to the target acquisition moment.

[0029] Further, the specific content of compensating the reverse sound wave for the noise data at the next adjacent acquisition moment according to the noise data from the moment when the first speaker and the second speaker emit the reverse sound wave to the target acquisition moment includes:

[0030] Record the noise data at the target acquisition moment as the initial compensation value at the target acquisition moment.

[0031] Obtain the noise cancellation spectrogram of the noise data from the moment when the first speaker and the second speaker emit reverse sound waves to the target acquisition moment. Denote the sum of the amplitudes of all the same type of frequency characteristic peaks in the noise cancellation spectrogram whose frequency values are the same as those of the air vibration characteristic peaks as the amplitude sum at the target acquisition moment; Denote the sum of the amplitudes corresponding to all frequencies in the noise cancellation spectrogram as the total amplitude sum at the target acquisition moment; Denote the ratio of the amplitude sum at the target acquisition moment to the total amplitude sum as the compensation weight at the target acquisition moment;

[0032] Denote the product of the initial compensation value at the target acquisition moment and the compensation weight as the sound wave compensation value at the target acquisition moment;

[0033] Denote the difference between the noise data at the target acquisition moment and the previous adjacent acquisition moment of the target acquisition moment as the noise difference at the target acquisition moment; Denote the difference between the values of the reverse sound wave emitted by the second speaker at the target acquisition moment and the previous adjacent acquisition moment of the target acquisition moment as the reverse sound wave difference at the target acquisition moment; Denote the product of the noise difference at the target acquisition moment and the reverse sound wave difference as the compensation direction value at the target acquisition moment;

[0034] Adjust the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment according to the value of the compensation direction value at the target acquisition moment.

[0035] Furthermore, the specific method included in adjusting the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment according to the value of the compensation direction value at the target acquisition moment is as follows:

[0036] When the compensation direction value at the target acquisition moment is negative, use the sum of the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment and the sound wave compensation value at the target acquisition moment as the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment;

[0037] When the compensation direction value at the target acquisition moment is positive, use the difference between the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment and the sound wave compensation value at the target acquisition moment as the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment;

[0038] When the value of the compensation direction value at the target acquisition moment is 0, do not adjust the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment.

[0039] In a second aspect, another embodiment of the present invention provides an active pipeline noise control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned active pipeline noise control method are implemented.

[0040] The embodiments of the present invention have at least the following beneficial effects:

[0041] First, according to the characteristics that the noise data mainly includes strong noise generated by air flow and noise generated by the vibration of the negative pressure aspirator, the present application identifies the air vibration characteristic peak and the vibration characteristic peak of the negative pressure aspirator. Since the vibration amplitudes of the noise generated by the vibration of the negative pressure aspirator and the noise generated by air flow are not constant, the frequency characteristic peaks include the frequency characteristic peaks corresponding to the noise generated by the vibration of the negative pressure aspirator and the noise generated by air flow. According to the difference between the frequency characteristic peaks and the vibration characteristic peaks of the negative pressure aspirator in the spectrogram, the present application determines the noise generated by the vibration of the negative pressure aspirator, that is, the vibration noise data of the negative pressure aspirator, and determines the intensity of the noise generated by air flow, that is, the air vibration noise data, in the same way, and respectively uses the first speaker and the second speaker to emit reverse sound waves to cancel the noise generated by air flow and the noise generated by the vibration of the negative pressure aspirator; considering that the noise will attenuate during propagation and the noise intensity will change at any time, when using the first speaker and the second speaker to emit reverse sound waves for cancellation respectively, there may be a phenomenon of incomplete cancellation, or there may be a phenomenon of generating new noise due to excessive cancellation. Therefore, the present application further compensates the reverse sound waves for the noise data at the next adjacent acquisition moment after the acquisition moment according to the cancellation result, realizes active pipeline noise control, solves the problem that the negative pressure aspirator cannot provide a matching sound absorption ability for different degrees of noise during operation, resulting in poor sound absorption effect, and improves the sound absorption effect of active pipeline noise control. Description of the Drawings

[0042] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0043] Figure 1 It is a flowchart of the steps of an active pipeline noise control method provided by an embodiment of the present invention;

[0044] Figure 2 It is a schematic diagram of the pipeline noise control effect provided by an embodiment of the present invention. Detailed Embodiments

[0045] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following specifically describes, in conjunction with the accompanying drawings and preferred embodiments, a kind of active pipeline noise control device and control method proposed according to the present invention, including its specific implementation manners, structures, features and effects. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs.

[0047] The following specifically describes, in conjunction with the accompanying drawings, the specific solutions of a kind of active pipeline noise control device and control method provided by the present invention.

[0048] Please refer to Figure 1 , which shows a flow chart of the steps of a kind of active pipeline noise control method provided by an embodiment of the present invention. The method includes the following steps:

[0049] Step S001, collect the noise data of the suction tube, obtain the spectrogram of the noise data, and mark the vibration characteristic peaks, air vibration characteristic peaks and frequency characteristic peaks of the negative pressure suction device in the spectrogram.

[0050] Fix an acoustic sensor at the position of the suction tube wall at the connection of the negative pressure suction device and the suction tube, and set speakers at 20 cm and 40 cm away from the acoustic sensor respectively. The speakers at 20 cm and 40 cm away from the acoustic sensor are respectively denoted as the first speaker and the second speaker.

[0051] Start collecting the noise data of the suction tube using the acoustic sensor when the negative pressure suction device starts to work.

[0052] Specifically, the acoustic sensor can use a piezoelectric acoustic wave sensor; the noise data is acoustic waves.

[0053] It can be understood that, comparatively speaking, the propagation speed of low-frequency noise is slower, and a longer time is required as the noise elimination time interval for eliminating noise, while the propagation speed of high-frequency noise is faster, and a shorter time is required as the noise elimination time interval for eliminating noise. The first speaker is closer to the acoustic sensor. Therefore, the first speaker is used to emit a reverse acoustic wave with the opposite phase, the same intensity, frequency and opposite direction as the noise signal to eliminate the higher-frequency noise; the second speaker is farther away from the acoustic sensor. Therefore, the second speaker is used to emit a reverse acoustic wave with the opposite phase, the same intensity, frequency and opposite direction as the noise signal to eliminate the lower-frequency noise.

[0054] When the negative pressure aspirator is working, air flows through the saliva suction tube, generating noise. When the suction force provided by the negative pressure aspirator changes, the air flow in the tube will change accordingly, and the noise will also change accordingly. The operation of the negative pressure aspirator will also cause the negative pressure aspirator to vibrate, and the stronger the vibration of the negative pressure aspirator, the greater the noise generated by the negative pressure aspirator. The environment will also provide part of the noise source. Therefore, the noise data of the suction tube collected by the acoustic sensor is the superposition of three kinds of noises: the noise generated by air flow, the noise generated by the vibration of the negative pressure aspirator, and the environmental noise. In order to control the noise generated by the air flow in the saliva suction tube, it is necessary to first extract the noise of this type from the collected noise data.

[0055] Use Fourier transform to process the noise data to obtain the spectrogram of the noise data.

[0056] The abscissa of the spectrogram is the frequency, and the unit of frequency is Hertz, which represents the number of vibrations of the noise data; the ordinate of the spectrogram is the amplitude, and the amplitude represents the intensity and importance of each frequency component in the noise data.

[0057] Since the noise data mainly includes the noise generated by air flow and the noise generated by the vibration of the negative pressure aspirator, and the intensity of the noise data corresponding to these two kinds of noises is significantly larger, therefore, the amplitude of the frequency components corresponding to these two kinds of noises in the spectrogram should be the largest.

[0058] Identify all the maximum points in the spectrogram of the noise data. Denote the maximum point with the largest amplitude among all the maximum points as the vibration characteristic peak of the negative pressure aspirator, denote the maximum point with the second largest amplitude among all the maximum points as the air vibration characteristic peak, and denote all the maximum points that are neither the vibration characteristic peak of the negative pressure aspirator nor the air vibration characteristic peak as the frequency characteristic peak.

[0059] It can be understood that the vibration characteristic peak of the negative pressure aspirator corresponds to the noise generated by the vibration of the negative pressure aspirator, and the air vibration characteristic peak corresponds to the noise generated by air flow.

[0060] So far, the vibration characteristic peak of the negative pressure aspirator, the air vibration characteristic peak and the frequency characteristic peak in the spectrogram of the noise data are obtained.

[0061] Step S002, according to the difference between the frequency characteristic peak and the vibration characteristic peak of the negative pressure aspirator in the spectrogram, screen the frequency characteristic peaks of the same type as the vibration characteristic peak of the negative pressure aspirator. According to all the frequency characteristic peaks of the same type as the vibration characteristic peak of the negative pressure aspirator, determine the vibration noise data of the negative pressure aspirator, as well as the corresponding intensity, phase and frequency, determine the intensity, phase and frequency of the air vibration noise data. According to the intensity, phase and frequency of the vibration noise data of the negative pressure aspirator and the air vibration noise data, use the first speaker and the second speaker to emit reverse sound waves respectively.

[0062] Since the vibration amplitudes of the noise generated by the vibration of the negative pressure aspirator and the noise generated by the air flow are not constant, there is not only one maximum point corresponding to the noise generated by the vibration of the negative pressure aspirator and the noise generated by the air flow. That is to say, the frequency characteristic peaks include the frequency characteristic peaks corresponding to the noise generated by the vibration of the negative pressure aspirator and the noise generated by the air flow.

[0063] According to the differences between the frequency characteristic peaks and the vibration characteristic peaks of the negative pressure aspirator in the spectrogram, the same type of frequency characteristic peaks of the vibration characteristic peaks of the negative pressure aspirator are screened.

[0064] Denote any one frequency characteristic peak as the target frequency characteristic peak, denote the difference between the frequency of the target frequency characteristic peak and the frequency of the vibration characteristic peak of the negative pressure aspirator as the first difference between the target frequency characteristic peak and the vibration characteristic peak of the negative pressure aspirator, and denote the difference between the amplitude of the target frequency characteristic peak and the amplitude of the vibration characteristic peak of the negative pressure aspirator as the second difference between the target frequency characteristic peak and the vibration characteristic peak of the negative pressure aspirator; Denote the reciprocal of the absolute value of the product of the first difference and the second difference of the target frequency characteristic peak as the similarity between the target frequency characteristic peak and the vibration characteristic peak of the negative pressure aspirator.

[0065] It can be understood that, it should be noted that, for the convenience of calculation, all the frequencies involved in the operation in this embodiment have undergone data preprocessing, thereby eliminating the influence of the dimension. In this embodiment, the Z-Score standard normalization method is used to process the data for dimension elimination. In the actual application process, the implementer can use other methods such as the existing technology of the maximum-minimum normalization method for dimension elimination, which is not limited here. According to the same method, the similarity between any one frequency characteristic peak and the vibration characteristic peak of the negative pressure aspirator can be obtained. That is to say, there is a corresponding similarity between each frequency characteristic peak and the vibration characteristic peak of the negative pressure aspirator.

[0066] Denote the mean value of the similarities between the vibration characteristic peak of the negative pressure aspirator and all the frequency characteristic peaks as the threshold for classifying the same type of the vibration characteristic peak of the negative pressure aspirator . Denote the frequency characteristic peaks corresponding to the similarities greater than among the similarities corresponding to the vibration characteristic peak of the negative pressure aspirator as the same type of frequency characteristic peaks of the vibration characteristic peak of the negative pressure aspirator.

[0067] It can be understood that the same type of frequency characteristic peaks of the vibration characteristic peak of the negative pressure aspirator are the frequency characteristic peaks generated by the change of the vibration amplitude of the noise generated by the vibration of the negative pressure aspirator.

[0068] Determine the vibration noise data of the negative pressure aspirator, as well as the corresponding intensity, phase and frequency, according to all the same type of frequency characteristic peaks of the vibration characteristic peak of the negative pressure aspirator.

[0069] Perform inverse Fourier transform on all frequency characteristic peaks of the same type of the vibration characteristic peaks of the negative pressure aspirator to obtain the vibration noise data of the negative pressure aspirator. The value of the vibration noise data of the negative pressure aspirator, that is, the intensity of the vibration noise data of the negative pressure aspirator.

[0070] It can be understood that the vibration noise data of the negative pressure aspirator is the noise data generated by the vibration of the negative pressure aspirator.

[0071] Perform time-frequency analysis on the vibration noise data of the negative pressure aspirator using short-time Fourier transform, perform Fourier transform on the time-frequency analysis result, obtain the time-frequency diagram of the frequency characteristic peaks of the same type of the vibration noise data of the negative pressure aspirator, and obtain the phase of the vibration noise data of the negative pressure aspirator according to the time-frequency diagram of the vibration noise data of the negative pressure aspirator.

[0072] Specifically, it can be understood that since the abscissa of the time-frequency diagram is time and the ordinate is frequency, and in the time-frequency analysis result, each frequency characteristic peak of the same type corresponds to a complex value, and the angle of the complex value is the phase. Therefore, according to the time-frequency analysis result and the time-frequency diagram, the phase of each vibration noise data of the negative pressure aspirator can be determined.

[0073] Process the vibration noise data of the negative pressure aspirator using Fourier transform to obtain the spectrogram of the vibration noise data of the negative pressure aspirator. Obtain the frequency of the vibration noise data of the negative pressure aspirator according to the spectrogram of the vibration noise data of the negative pressure aspirator.

[0074] According to the method of obtaining the frequency characteristic peaks of the same type of the vibration characteristic peaks of the negative pressure aspirator, obtain the frequency characteristic peaks of the same type of the air vibration characteristic peaks, determine the air vibration noise data, and determine the intensity, phase and frequency of the air vibration noise data. The specific method is as follows:

[0075] Screen the frequency characteristic peaks of the same type of the air vibration characteristic peaks according to the difference between the frequency characteristic peaks and the air vibration characteristic peaks in the spectrogram.

[0076] Denote any one frequency characteristic peak as the target frequency characteristic peak, denote the difference between the frequency of the target frequency characteristic peak and the air vibration characteristic peak as the first difference between the target frequency characteristic peak and the air vibration characteristic peak, and denote the difference between the amplitude of the target frequency characteristic peak and the air vibration characteristic peak as the second difference between the target frequency characteristic peak and the air vibration characteristic peak; denote the reciprocal of the absolute value of the product of the first difference and the second difference of the target frequency characteristic peak as the similarity between the target frequency characteristic peak and the air vibration characteristic peak.

[0077] The similarity between any one frequency characteristic peak and the air vibration characteristic peak can be obtained according to the same method. That is to say, there is a corresponding similarity between each frequency characteristic peak and the air vibration characteristic peak.

[0078] The average similarity between the air vibration characteristic peaks and all frequency characteristic peaks is denoted as the threshold for classifying the air vibration characteristic peaks of the same type. The frequency characteristic peaks corresponding to the similarities greater than among the similarities corresponding to the air vibration characteristic peaks are denoted as the frequency characteristic peaks of the same type of the air vibration characteristic peaks.

[0079] It can be understood that the frequency characteristic peaks of the same type of the air vibration characteristic peaks are the frequency characteristic peaks generated by the change in the vibration amplitude of the noise generated by air flow.

[0080] Based on all the frequency characteristic peaks of the same type of the air vibration characteristic peaks, the air vibration noise data is determined, and the intensity, phase, and frequency of the air vibration noise data are determined.

[0081] Perform an inverse Fourier transform on all the frequency characteristic peaks of the same type of the air vibration characteristic peaks to obtain the air vibration noise data. The value of the air vibration noise data is the intensity of the air vibration noise data.

[0082] It can be understood that the air vibration noise data is the noise data generated by the vibration of the negative pressure aspirator.

[0083] Perform time-frequency analysis on the air vibration noise data using the short-time Fourier transform, and perform a Fourier transform on the time-frequency analysis result to obtain the time-frequency diagram of the frequency characteristic peaks of the same type of the air vibration noise data. Based on the time-frequency diagram of the air vibration noise data, the phase of the air vibration noise data is obtained.

[0084] Perform a Fourier transform on the air vibration noise data to obtain the frequency spectrum diagram of the air vibration noise data. Based on the frequency spectrum diagram of the air vibration noise data, the frequency of the air vibration noise data is obtained.

[0085] Use the first speaker to emit a reverse sound wave. The reverse sound wave emitted by the first speaker is a sound wave with the same intensity and frequency as the vibration noise data of the negative pressure aspirator, but with the opposite phase. Use the second speaker to emit a reverse sound wave. The reverse sound wave emitted by the second speaker is a sound wave with the same intensity and frequency as the air vibration noise data, but with the opposite phase.

[0086] It can be understood that two sound waves with the same intensity and frequency but opposite phases can cancel each other out. Since the frequency of the noise generated by the vibration of the negative pressure aspirator is significantly higher than the frequency of the noise generated by air flow, and the first speaker is closer to the acoustic sensor than the second speaker, the reverse sound wave emitted by the first speaker is used to cancel the vibration noise data of the negative pressure aspirator, and the reverse sound wave emitted by the second speaker is used to cancel the air vibration noise data.

[0087] So far, the first loudspeaker is used to emit a reverse sound wave to cancel the vibration noise data of the negative pressure aspirator, and the second loudspeaker is used to emit a reverse sound wave to cancel the air vibration noise data.

[0088] Step S003: Starting from the moment when the first loudspeaker and the second loudspeaker respectively emit reverse sound waves, extract the noise data within a preset acquisition time interval. According to the difference between the noise data at adjacent acquisition moments, and the noise data from the moment when the first loudspeaker and the second loudspeaker emit reverse sound waves to the acquisition moment, compensate the noise data at the next adjacent acquisition moment after the acquisition moment with a reverse sound wave, so as to achieve active pipeline noise control.

[0089] Since noise will attenuate during propagation and the noise intensity changes at any time, when using the first loudspeaker and the second loudspeaker to emit reverse sound waves for cancellation respectively, there may be a phenomenon of incomplete cancellation, or a phenomenon of generating new noise due to excessive cancellation. Therefore, it is necessary to further improve the sound insulation effect of active pipeline noise control according to the cancellation result.

[0090] At the same time, it can be understood that starting from the moment when the first loudspeaker and the second loudspeaker respectively emit reverse sound waves, the noise data of the suction tube collected is the superposition of two reverse sound waves, the noise generated by air flow, the noise generated by the vibration of the negative pressure aspirator, and the ambient noise. When the noise data of the suction tube collected is equal to 0, the reverse sound wave completely cancels the noise; when the noise data of the suction tube collected is not equal to 0, it is necessary to further improve the sound insulation effect of active pipeline noise control according to the cancellation result.

[0091] Starting from the moment when the first loudspeaker and the second loudspeaker respectively emit reverse sound waves, extract the noise data at an acquisition time interval of 0.1 second. Starting from the second acquisition moment, compare the noise data at each acquisition moment with the noise data at the previous adjacent acquisition moment respectively. Specifically: Denote any acquisition moment starting from the second acquisition moment as the target acquisition moment, denote the absolute value of the difference between the noise data at the target acquisition moment and the noise data at the previous adjacent acquisition moment of the target acquisition moment as the absolute noise difference at the target acquisition moment, and denote the ratio of the absolute noise difference at the target acquisition moment to the noise data at the previous adjacent acquisition moment of the target acquisition moment as the sound wave cancellation degree at the target acquisition moment.

[0092] When the sound wave cancellation degree at the target acquisition moment is greater than or equal to the first constant value, compensate the noise data at the next adjacent acquisition moment after the target acquisition moment with a reverse sound wave according to the noise data from the moment when the first loudspeaker and the second loudspeaker emit reverse sound waves to the target acquisition moment.

[0093] Among them, the first constant value is a preset constant value, and in this embodiment, the value of the first constant value is 2.

[0094] The noise data at the target acquisition time is denoted as the initial compensation value at the target acquisition time. The noise data from the time when the first speaker and the second speaker emit reverse sound waves to the target acquisition time is processed using Fourier transform to obtain the noise cancellation spectrogram of the noise data from the time when the first speaker and the second speaker emit reverse sound waves to the target acquisition time. The sum of all amplitudes with the same type of frequency peaks as the air vibration characteristic peaks in the noise cancellation spectrogram is denoted as the amplitude sum at the target acquisition time; the sum of the amplitudes corresponding to all frequencies in the noise cancellation spectrogram is denoted as the total amplitude sum at the target acquisition time; the ratio of the amplitude sum at the target acquisition time to the total amplitude sum is denoted as the compensation weight at the target acquisition time. The product of the initial compensation value at the target acquisition time and the compensation weight is denoted as the acoustic wave compensation value at the target acquisition time.

[0095] The difference between the noise data at the target acquisition time and the noise data at the previous adjacent acquisition time of the target acquisition time is denoted as the noise difference at the target acquisition time, and the difference between the values of the reverse sound wave emitted by the second speaker at the target acquisition time and the previous adjacent acquisition time of the target acquisition time is denoted as the reverse sound wave difference at the target acquisition time; the product of the noise difference at the target acquisition time and the reverse sound wave difference is denoted as the compensation direction value at the target acquisition time.

[0096] It can be understood that when the compensation direction value at the target acquisition time is positive, compared with the change trend of the noise data at the target acquisition time and the previous adjacent acquisition time of the target acquisition time, the change trend of the values of the reverse sound wave emitted by the second speaker at the target acquisition time and the previous adjacent acquisition time of the target acquisition time is the same. At this time, the reverse sound wave emitted by the second speaker compensates too much for the noise generated by air flow, and it is necessary to reduce the intensity of the reverse sound wave emitted by the second speaker at the next acquisition time after the target acquisition time to improve the noise cancellation effect of active duct noise control; when the compensation direction value at the target acquisition time is negative, compared with the change trend of the noise data at the target acquisition time and the previous adjacent acquisition time of the target acquisition time, the change trend of the values of the reverse sound wave emitted by the second speaker at the target acquisition time and the previous adjacent acquisition time of the target acquisition time is different. At this time, the reverse sound wave emitted by the second speaker compensates too little for the noise generated by air flow, and it is necessary to increase the intensity of the reverse sound wave emitted by the second speaker at the next acquisition time after the target acquisition time to improve the noise cancellation effect of active duct noise control.

[0097] When the compensation direction value at the target acquisition moment is negative, the sum of the intensity of the reverse sound wave emitted by the second speaker at the acquisition moment after the target acquisition moment and the sound wave compensation value at the target acquisition moment is used as the intensity of the reverse sound wave emitted by the second speaker at the acquisition moment after the target acquisition moment; when the compensation direction value at the target acquisition moment is positive, the difference obtained by subtracting the sound wave compensation value at the target acquisition moment from the intensity of the reverse sound wave emitted by the second speaker at the acquisition moment after the target acquisition moment is used as the intensity of the reverse sound wave emitted by the second speaker at the acquisition moment after the target acquisition moment; when the compensation direction value at the target acquisition moment takes the value of 0, the intensity of the reverse sound wave emitted by the second speaker at the acquisition moment after the target acquisition moment is not adjusted.

[0098] Schematic diagram of the pipeline noise control effect is as Figure 2 shown. In Figure 2 , the abscissa is time, the ordinate is the noise amplitude, and the unit of the noise amplitude is dB. Figure 2 The upper side is the noise data graph of the negative pressure aspirator working for 60 seconds. Active pipeline noise control starts from 60 seconds. Figure 2 The lower side is the noise data graph of 60 seconds collected after active pipeline noise control. By comparing Figure 2 the two noise data graphs on the upper and lower sides, it can be seen that active pipeline noise control can significantly reduce the noise generated when the negative pressure aspirator is working.

[0099] Thus, active pipeline noise control is achieved.

[0100] The embodiment of the present invention also proposes an active pipeline noise control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above steps are implemented. Since an active pipeline noise control method is described in detail above, it will not be elaborated here.

[0101] It should be noted that: the above sequence of the embodiments of the present invention is only for description and does not represent the superiority or inferiority of the embodiments. And the above specific embodiments of this specification are described. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0102] Each embodiment in this specification is described in a progressive manner. The same or similar parts between each embodiment can be referred to each other, and the key points of each embodiment are the differences from other embodiments.

[0103] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; modifying the technical solutions described in the foregoing embodiments, or equivalently replacing some of the technical features therein, does not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. An active pipeline noise control method, characterized in that, The method includes the following steps: Collect the noise data of the suction tube, obtain the spectrogram of the noise data, and mark the vibration characteristic peaks of the negative pressure aspirator, the air vibration characteristic peaks, and the frequency characteristic peaks in the spectrogram; According to the differences between the frequency characteristic peaks and the vibration characteristic peaks of the negative pressure aspirator in the spectrogram, screen the same-kind frequency characteristic peaks of the vibration characteristic peaks of the negative pressure aspirator. According to all the same-kind frequency characteristic peaks of the vibration characteristic peaks of the negative pressure aspirator, determine the vibration noise data of the negative pressure aspirator, as well as the corresponding intensity, phase, and frequency. Determine the intensity, phase, and frequency of the air vibration noise data. According to the intensity, phase, and frequency of the vibration noise data of the negative pressure aspirator and the air vibration noise data, use the first speaker and the second speaker to emit reverse sound waves respectively; Starting from the moment when the first speaker and the second speaker emit reverse sound waves respectively, extract the noise data within a preset acquisition time interval. According to the differences between the noise data at adjacent acquisition moments and the noise data from the moment when the first speaker and the second speaker emit reverse sound waves to the acquisition moment, compensate the noise data at the next adjacent acquisition moment after the acquisition moment with reverse sound waves to achieve active pipeline noise control; The specific method included in marking the vibration characteristic peaks of the negative pressure aspirator, the air vibration characteristic peaks, and the frequency characteristic peaks in the spectrogram is as follows: Identify all the maximum points in the spectrogram of the noise data, and mark the maximum point with the largest amplitude among all the maximum points as the vibration characteristic peak of the negative pressure aspirator; Mark the maximum point with the second largest amplitude among all the maximum points as the air vibration characteristic peak; Mark all the maximum points that are neither the vibration characteristic peak of the negative pressure aspirator nor the air vibration characteristic peak as frequency characteristic peaks; The screening method for the same-kind frequency characteristic peaks of the vibration characteristic peaks of the negative pressure aspirator is as follows: Mark any one frequency characteristic peak as the target frequency characteristic peak; mark the difference between the frequency of the target frequency characteristic peak and the frequency of the vibration characteristic peak of the negative pressure aspirator as the first difference between the target frequency characteristic peak and the vibration characteristic peak of the negative pressure aspirator; mark the difference between the amplitude of the target frequency characteristic peak and the amplitude of the vibration characteristic peak of the negative pressure aspirator as the second difference between the target frequency characteristic peak and the vibration characteristic peak of the negative pressure aspirator; mark the reciprocal of the absolute value of the product of the first difference and the second difference of the target frequency characteristic peak as the similarity between the target frequency characteristic peak and the vibration characteristic peak of the negative pressure aspirator; According to the similarities between the vibration characteristic peaks of the negative pressure aspirator and all the frequency characteristic peaks, screen the same-kind frequency characteristic peaks of the vibration characteristic peaks of the negative pressure aspirator.

2. The active pipeline noise control method according to claim 1, wherein The specific method included in screening the same-kind frequency characteristic peaks of the vibration characteristic peaks of the negative pressure aspirator according to the similarities between the vibration characteristic peaks of the negative pressure aspirator and all the frequency characteristic peaks is as follows: The mean similarity between the vibration characteristic peaks of the negative pressure aspirator and all frequency characteristic peaks is denoted as the threshold for classifying the vibration characteristic peaks of the negative pressure aspirator into the same category ; The similarity corresponding to the vibration characteristic peak of the negative pressure suction device that is greater than The corresponding frequency characteristic peak is denoted as the same type of frequency characteristic peak of the vibration characteristic peak of the negative pressure suction device.

3. The active pipeline noise control method according to claim 1, characterized in that, The determination method for the intensity, phase, and frequency of the vibration noise data of the negative pressure aspirator is as follows: Mark the value of the vibration noise data of the negative pressure aspirator as the intensity of the vibration noise data of the negative pressure aspirator; Conduct time-frequency analysis on the vibration noise data of the negative pressure aspirator. According to the time-frequency analysis results, obtain the time-frequency diagram of the same-kind frequency characteristic peaks of the vibration noise data of the negative pressure aspirator. According to the time-frequency diagram of the vibration noise data of the negative pressure aspirator, obtain the phase of the vibration noise data of the negative pressure aspirator; Obtain the spectrogram of the vibration noise data of the negative pressure aspirator according to the vibration noise data of the negative pressure aspirator; obtain the frequency of the vibration noise data of the negative pressure aspirator according to the spectrogram of the vibration noise data of the negative pressure aspirator.

4. The active pipeline noise control method according to claim 1, characterized in that The specific method included in respectively using the first speaker and the second speaker to emit reverse sound waves according to the intensity, phase and frequency of the vibration noise data of the negative pressure aspirator and the air vibration noise data is as follows: The sound wave with the same intensity and frequency as the vibration noise data of the negative pressure aspirator but with the opposite phase is denoted as the reverse sound wave emitted by the first speaker; The sound wave with the same intensity and frequency as the air vibration noise data but with the opposite phase is denoted as the reverse sound wave emitted by the second speaker.

5. An active pipeline noise control method according to claim 1, characterized in that The specific method included in compensating the noise data of the next adjacent acquisition moment of the acquisition moment with reverse sound waves according to the difference between the noise data at adjacent acquisition moments and the noise data from the moment when the first speaker and the second speaker emit reverse sound waves to the acquisition moment, so as to achieve active pipeline noise control is as follows: Denote any acquisition moment starting from the second acquisition moment as the target acquisition moment, and denote the absolute value of the difference between the noise data of the target acquisition moment and the noise data of the previous adjacent acquisition moment of the target acquisition moment as the noise absolute difference of the target acquisition moment; denote the ratio of the noise absolute difference of the target acquisition moment to the noise data of the previous adjacent acquisition moment of the target acquisition moment as the sound wave cancellation degree of the target acquisition moment; When the sound wave cancellation degree of the target acquisition moment is greater than or equal to the first constant value, compensate the noise data of the next adjacent acquisition moment of the target acquisition moment with reverse sound waves according to the noise data from the moment when the first speaker and the second speaker emit reverse sound waves to the target acquisition moment.

6. The active pipeline noise control method according to claim 5, characterized in that The specific content included in compensating the noise data of the next adjacent acquisition moment of the target acquisition moment with reverse sound waves according to the noise data from the moment when the first speaker and the second speaker emit reverse sound waves to the target acquisition moment is as follows: Denote the noise data of the target acquisition moment as the initial compensation value of the target acquisition moment; Obtain the cancellation noise spectrogram of the noise data from the moment when the first speaker and the second speaker emit reverse sound waves to the target acquisition moment, and denote the sum of all amplitudes with the same type of frequency peaks as the air vibration characteristic peaks in the frequency values of the cancellation noise spectrogram as the amplitude sum of the target acquisition moment; denote the sum of all amplitudes corresponding to all frequencies in the cancellation noise spectrogram as the total amplitude sum of the target acquisition moment; denote the ratio of the amplitude sum of the target acquisition moment to the total amplitude sum as the compensation weight of the target acquisition moment; Denote the product of the initial compensation value of the target acquisition moment and the compensation weight as the sound wave compensation value of the target acquisition moment; The difference between the noise data at the target acquisition moment and the noise data at the previous adjacent acquisition moment of the target acquisition moment is denoted as the noise difference at the target acquisition moment; the difference between the values of the reverse sound wave emitted by the second speaker at the target acquisition moment and the previous adjacent acquisition moment of the target acquisition moment is denoted as the reverse sound wave difference at the target acquisition moment; the product of the noise difference and the reverse sound wave difference at the target acquisition moment is denoted as the compensation direction value at the target acquisition moment. According to the value of the compensation direction value at the target acquisition moment, the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment is adjusted.

7. An active pipeline noise control method according to claim 6, characterized in that, The method of adjusting the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment according to the value of the compensation direction value at the target acquisition moment specifically includes: When the compensation direction value at the target acquisition moment is negative, the sum of the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment and the sound wave compensation value at the target acquisition moment is used as the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment; When the compensation direction value at the target acquisition moment is positive, the difference obtained by subtracting the sound wave compensation value at the target acquisition moment from the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment is used as the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment; When the value of the compensation direction value at the target acquisition moment is 0, the intensity of the reverse sound wave emitted by the second speaker at the next acquisition moment after the target acquisition moment is not adjusted.

8. An active pipeline noise control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of an active pipeline noise control method as described in any one of claims 1 to 7 are implemented.

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