Abnormal sound detection method and device

Abstract

The invention relates to an abnormal sound detection method, which comprises the following steps of: installing an abnormal sound detection device at a to-be-detected position of an automobile part, and detecting a vibration signal at an abnormal sound occurrence moment by using the abnormal sound detection device; and analyzing the vibration signal, determining an abnormal sound frequency band, performing noise reduction on the abnormal sound frequency band, and analyzing the to-be-detected position according to the vibration signal after noise reduction. The abnormal sound detection device is installed at the to-be-detected position of the automobile part, the abnormal sound detection device is used for detecting the vibration signal at the abnormal sound occurrence moment, then the vibration signal is analyzed, the abnormal sound frequency band is determined, the detection range of the vibration signal is reduced, noise reduction is conducted on the abnormal sound frequency band, the signal-to-noise ratio of the signal of the abnormal sound frequency band is increased, and the abnormal sound detection accuracy is improved. The interference of external noise is reduced, the feature information of the vibration signal is improved, and the technical problem that the fault position cannot be accurately judged due to the fact that the abnormal sound signal detected by the abnormal sound stethoscope in the vehicle driving process is interfered by other irrelevant signals in the related technology is solved.

Description

Technical Field

[0001] The present application relates to the technical field of detection equipment, and in particular to a method and device for detecting abnormal noise. Background Art

[0002] As people's requirements for automobile performance become higher and higher, the sound quality problems of automobile parts will cause sound interference and affect the environment inside the car. If abnormal noises occur in the components during operation, users need to ask maintenance personnel to detect and investigate. However, it is easy to make mistakes based on the subjective judgment of maintenance personnel, especially abnormal noises inside automobile parts. It is impossible to determine where the fault occurs in a timely and accurate manner, and the maintenance efficiency is extremely low.

[0003] In the related technology, the adsorption-type abnormal noise stethoscope can detect abnormal noise problems during vehicle driving. The stethoscope is mainly fixed on the structural parts to detect abnormal noise. It is difficult to detect abnormal noise inside the automobile parts. At the same time, the abnormal noise signal is easily interfered by other irrelevant signals during vehicle driving, and the interference signal will lead to incorrect judgment of the fault location.

[0004] Therefore, it is necessary to design a new abnormal sound detection device to overcome the above problems. Summary of the invention

[0005] The present application provides an abnormal noise detection method and device, which can solve the technical problem in the related art that the abnormal noise signal detected by the adsorption-type abnormal noise stethoscope during vehicle driving will be interfered by other irrelevant signals and the fault location cannot be accurately determined.

[0006] In a first aspect, an embodiment of the present application provides an abnormal sound detection method, which comprises the following steps:

[0007] S1: Install the abnormal sound detection device at the position to be tested of the automobile component, and use the abnormal sound detection device to detect the vibration signal when the abnormal sound occurs.

[0008] S2: Analyze the vibration signal, determine the abnormal sound frequency segment, reduce the noise of the abnormal sound frequency segment, and perform abnormal sound analysis on the position to be tested based on the vibration signal after noise reduction.

[0009] Among them, the abnormal sound detection device is installed at the position to be tested of the automobile component, and the abnormal sound detection device is used to detect the vibration signal at the time when the abnormal sound occurs, and then the vibration signal is analyzed to determine the abnormal sound frequency segment, narrow the detection range of the vibration signal, and reduce the noise of the abnormal sound frequency segment, improve the signal-to-noise ratio of the signal in the abnormal sound frequency segment, reduce the interference of external noise and improve the characteristic information of the vibration signal, and perform abnormal sound analysis on the position to be tested according to the vibration signal after noise reduction, and the automobile component can be set as a reduction box or other components.

[0010] In combination with the first aspect, in one implementation, analyzing the vibration signal to determine the abnormal sound frequency segment includes:

[0011] S201: Perform Fourier transform on the vibration signal to determine the frequency range of abnormal sound.

[0012] Among them, the time signal function can be projected on a set of specific basis functions through Fourier transform to obtain the components of the time signal function at each frequency, so as to determine the abnormal sound frequency segment of the vibration signal and narrow the detection range of the vibration signal.

[0013] In combination with the first aspect, in one implementation, the noise reduction of the abnormal sound frequency band includes:

[0014] S202: performing wavelet packet decomposition on the vibration signal, and selecting wavelet packets containing abnormal sound frequency bands.

[0015] S203: Reconstruct the wavelet packet signal to construct the first signal S1.

[0016] Among them, wavelet packet decomposition can decompose the low-frequency component and high-frequency component of the vibration signal, improve the time-frequency resolution of the vibration signal, the range of the vibration signal can be set to 0-3000Hz, and the vibration signal can be divided into six sections after wavelet packet decomposition, the first section is 0-500Hz, the second section is 500-1000Hz, the third section is 1000-1500Hz, the fourth section is 1500-2000Hz, the fifth section is 2000-2500Hz, and the sixth section is 2500-3000Hz. The wavelet packet containing the abnormal sound frequency section is selected, that is, the first section. Wavelet packet decomposition denoising is the first step of denoising. Demonstratively, the vibration signal can be decomposed into three layers, and the number of nodes in each layer can be set to 2 n (n=1, 2, 3), the decomposition relationship between the vibration signal S, the low-frequency signal A and the high-frequency signal D satisfies the following relationship:

[0017] S=A1+D1=AA2+DA2+AD2+DD2

[0018] =AAA3+DAA3+ADA3+DDA3+AAD3+DAD3+ADD3+DDD3 (1). In combination with the first aspect, in one implementation, the noise reduction of the abnormal sound frequency band further includes:

[0019] S204: Perform fully adaptive noise set empirical mode decomposition on the first signal S1 to obtain multiple intrinsic mode functions IMFs, solve the correlation coefficient between each intrinsic mode function IMF and the first signal S1, and select several groups of intrinsic mode function IMF signals with correlation coefficients greater than a set coefficient value to reconstruct the second signal S2.

[0020] Among them, the fully adaptive noise ensemble empirical mode decomposition (CEEMDAN) denoising is the second step of denoising, and CEEMDAN includes the following steps:

[0021] Step 1: Decompose the original signal with Gaussian white noise added to obtain the mean IMF of all decomposed first-order IMF components 1 :

[0022]

[0023] Among them, IMF 1 is the mean of the first-order IMF component, x(t) is the original signal, E j is the operator, w i is Gaussian white noise distributed in N(0,1), ε k is the noise amplitude,

[0024] Step 2: Obtain the first-order residual according to the mean of the original signal and the first-order IMF component. The first-order residual r 1 (t) satisfies the following relationship:

[0025] r 1 (t) = x(t) - IMF 1 (3)

[0026] Step 3: Obtain the mean of the second-order IMF component based on the first-order residual and the decomposed signal. The mean IMF of the second-order IMF component 2 The following relationship is satisfied:

[0027]

[0028] Among them, IMF 2 is the mean of the second-order IMF component, r 1 (t)+ε 1 E 1 (w i ) is the decomposed signal,

[0029] Step 4: Repeat the above steps k times to obtain the k-order residual, the k-order residual r k (t) satisfies the following relationship:

[0030] r k (t) = r k-1 (t)-IMF k (5)

[0031] Step 5: Substitute the decomposed signal and the k-order residual into formula (2) to obtain the mean of the k+1-order IMF component. The mean IMF of the k+1-order IMF component is k+1 The following relationship is satisfied:

[0032]

[0033] Among them, r k (t)+ε k E k (w i ) is the decomposed signal.

[0034] Step 6: When the components of the residual are less than two, the decomposition ends and the expression of the original signal is obtained:

[0035]

[0036] Among them, k is the total number of IMFs. CEEMDAN adds an adaptive noise related to the current IMF in the process of extracting each order of IMF. The adaptive noise is obtained by calculating the residual of the first-order IMF and the weighted value of the current noise. As the IMF is gradually extracted, the influence of the noise gradually decreases. Several groups of intrinsic mode function IMF signals with correlation coefficients greater than 0.5 can be selected to reconstruct the second signal S2, thereby obtaining a vibration signal with reduced interference signal influence.

[0037] In combination with the first aspect, in one implementation, the noise reduction of the abnormal sound frequency band further includes:

[0038] S205: Construct the second signal S2 into a Hankel matrix A.

[0039] In this embodiment, singular value decomposition (SVD) denoising is the third step of denoising. For example, if the matrix A satisfies A∈R mxn , then A=USV T (8), where the orthogonal matrices U and V satisfy U∈R mxn , and V∈R mxn , discrete signal x(i) (i=1,2,…,N), where N is the number of sampling points, the second signal S2 is constructed into a Hankel matrix A:

[0040]

[0041] The Hankel matrix A can be subjected to singular value decomposition, singular values ​​with obvious fault characteristics can be selected, and singular values ​​with little correlation can be removed to reconstruct the matrix, thereby achieving the effect of reducing noise signal interference.

[0042] S206: Solve the singular values ​​of the Hankel matrix A, calculate the singular value differences, and select signals whose singular value differences are greater than the set difference to construct a third signal S3.

[0043] Among them, the Hankel matrix is ​​represented as a Hankel matrix, and the sequence S in the Hankel matrix A satisfies S=(diag(σ 1 ,σ 2,…,σ i ),0), where σ i is a singular value, and the singular values ​​are arranged from large to small. When the difference between two adjacent singular values ​​is greater than 20, the signal in the abnormal sound frequency band decomposed by the singular value will have a peak mutation. The mutation point contains important information. The signal with a singular value difference greater than the set value is selected to construct the third signal S3, thereby obtaining a vibration signal that eliminates the interference signal.

[0044] In the second aspect, an embodiment of the present application provides an abnormal sound detection device, which includes: a detection head connecting line and a conversion controller, one end of the detection head connecting line is provided with a vibration amplifier, and the vibration amplifier is fixed with a first electromagnet; the conversion controller is connected to the detection head connecting line, and the conversion controller is used to analyze the vibration signal, determine the abnormal sound frequency band, and reduce the noise of the abnormal sound frequency band.

[0045] Wherein, the vibration amplifier is used to receive and amplify the vibration signal, reduce the influence of interference signals in the environment, and facilitate the detection personnel to quickly find the abnormal sound location. The vibration amplifier is connected to a base, and the base is installed at one end of the detection head connecting line. The diameter of the base can be set to 2-4 mm, which is smaller than the probe diameter of 10-30 mm of the adsorption-type abnormal sound stethoscope, so that the abnormal sound detection device can detect the inside of the automobile part. The vibration amplifier is provided with the first electromagnet, and the first electromagnet is used to be adsorbed on the position to be tested of the automobile part. The detection head connecting line is provided with a plurality of second electromagnets at intervals, and the plurality of second electromagnets are used to adsorb the detection head connecting line to the automobile part in sections, which is convenient for the detection personnel to operate. The conversion controller is used to receive a voltage signal and convert the voltage signal into a sound signal. The conversion controller contains relevant preset algorithms. The conversion controller is also used to analyze the vibration signal, determine the abnormal sound frequency segment, and reduce the noise of the abnormal sound frequency segment. The conversion controller is connected to headphones, and the detection personnel can listen to the vibration signal through the headphones.

[0046] In combination with the second aspect, in one embodiment, a plurality of tungsten wires are provided in the detection head connecting line, each of the tungsten wires is connected to a first motor, and the first motor is configured to drive the tungsten wire to extend and retract.

[0047] Among them, the multiple tungsten wires can be set to four tungsten wires, the first motor can be set to a stepping motor, each of the tungsten wires is driven to retract and adjust its length by the first motor, and four first motors can be arranged side by side at the same position of the detection head connecting line. The four first motors adjust the direction of the vibration amplifier by adjusting the length of the four tungsten wires. The four first motors at the same position form four motors, and the detection head connecting line can be evenly distributed with multiple four motors along its length direction. The four motors can be installed on one side of the second electromagnet. The cooperation of multiple four motors can adjust the line shape of the detection head connecting line so that the detection head connecting line adapts to the internal structure of the automobile part, thereby realizing a large range of angle adjustment of the abnormal sound detection device, which is convenient for the detection personnel to adjust the fixed position of the abnormal sound detection device according to the internal morphology of the automobile part.

[0048] In combination with the second aspect, in one implementation, the detection head connecting line is also connected to a control panel, and the control panel is electrically connected to the conversion controller and the first motor.

[0049] Among them, the control tablet is used to control the first motor to adjust the angle of the abnormal sound detection device. The control tablet is also used to display the calculation results of the conversion controller or the image of the detection position, so as to facilitate the detection personnel to accurately determine the fault location according to the processed vibration signal.

[0050] In combination with the second aspect, in one implementation, the vibration amplifier is also equipped with a camera and a searchlight, and the camera and the searchlight are both electrically connected to the control panel.

[0051] Among them, the vibration amplifier is connected to the camera, the camera is used to observe the structure in a hidden position, the searchlight is arranged on both sides of the vibration amplifier, and the searchlight is used to illuminate the observation area. The camera and the searchlight can be used together to effectively observe the internal morphology of automobile parts and detect abnormal noises in hidden positions. The camera and the searchlight are both controlled by the control panel.

[0052] In combination with the second aspect, in one embodiment, a second motor is connected to one end of the detection head connection line away from the vibration amplifier, and the second motor is configured to drive the detection head connection line to extend and retract.

[0053] Among them, the second motor can be set as a rotating motor, the second motor is installed in the packaging box, one end of the detection head connecting line is fixed in the packaging box, the second motor is connected to a rotating shaft, and the rotating shaft is wound around the detection head connecting line. When the hidden position is deeper, the second motor can be turned on to drive the rotating shaft to rotate, and the detection head connecting line wound around the rotating shaft can be rotated out of the packaging box to extend the detection head connecting line, thereby realizing the length adjustment of the abnormal sound detection device.

[0054] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0055] The abnormal noise detection device is installed at the position to be tested of the automobile part, and the abnormal noise detection device is used to detect the vibration signal when the abnormal noise occurs, and then the vibration signal is analyzed to determine the abnormal noise frequency band, narrow the detection range of the vibration signal, and reduce the noise of the abnormal noise frequency band, thereby improving the signal-to-noise ratio of the signal in the abnormal noise frequency band, reducing the interference of external noise and improving the characteristic information of the vibration signal. The abnormal noise analysis can be performed on the position to be tested based on the vibration signal after noise reduction, which solves the technical problem in the related technology that the abnormal noise signal detected by the adsorption-type abnormal noise stethoscope during vehicle driving will be interfered by other irrelevant signals and cannot accurately determine the fault location. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0057] Figure 1 A flowchart of an abnormal sound detection method provided in an embodiment of the present application;

[0058] Figure 2 A flowchart for reducing noise in an abnormal sound frequency band provided in an embodiment of the present application;

[0059] Figure 3 A schematic diagram of the structure of an abnormal sound detection device provided in an embodiment of the present application;

[0060] Figure 4 A schematic diagram of the structure of a camera and a searchlight provided in an embodiment of the present application;

[0061] Figure 5 A schematic diagram of the structure inside the detection head connecting line provided in an embodiment of the present application;

[0062] Figure 6 A schematic diagram of the structure inside the packaging box provided in an embodiment of the present application.

[0063] In the figure: 1. detection head connecting line; 101. tungsten wire; 102. first motor; 2. vibration amplifier; 3. first electromagnet; 4. conversion controller; 5. control panel; 6. camera; 7. searchlight; 8. second motor; 9. base; 10. second electromagnet; 11. earphone; 12. packaging box. DETAILED DESCRIPTION

[0064] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0065] The embodiments of the present application provide an abnormal noise detection method and device, which can solve the technical problem that the abnormal noise signal detected by an adsorption-type abnormal noise stethoscope during vehicle driving may be interfered by other irrelevant signals and the fault location cannot be accurately determined.

[0066] See also Figure 1 As shown, the embodiment of the present application provides an abnormal sound detection method, which includes the following steps:

[0067] S1: Install the abnormal sound detection device at the position to be tested of the automobile component, and use the abnormal sound detection device to detect the vibration signal when the abnormal sound occurs.

[0068] S2: Analyze the vibration signal, determine the abnormal sound frequency segment, reduce the noise of the abnormal sound frequency segment, and perform abnormal sound analysis on the position to be tested based on the vibration signal after noise reduction.

[0069] In this embodiment, the abnormal sound detection device is installed at the position to be tested of the automobile component, and the abnormal sound detection device is used to detect the vibration signal at the time when the abnormal sound occurs, and then the vibration signal is analyzed to determine the abnormal sound frequency segment, narrow the detection range of the vibration signal, and reduce the noise of the abnormal sound frequency segment to improve the signal-to-noise ratio of the signal in the abnormal sound frequency segment, reduce the interference of external noise and improve the characteristic information of the vibration signal. The abnormal sound analysis can be performed on the position to be tested according to the vibration signal after noise reduction. The automobile component can be set as a reduction box or other components, which solves the technical problem in the related art that the abnormal sound signal detected by the adsorption-type abnormal sound stethoscope during vehicle driving will be interfered by other irrelevant signals and the fault location cannot be accurately determined.

[0070] Further, see Figure 1 and Figure 2As shown, in some embodiments, analyzing the vibration signal to determine the abnormal sound frequency segment includes:

[0071] S201: Perform Fourier transform on the vibration signal to determine the frequency range of abnormal sound.

[0072] In this embodiment, the time signal function can be projected onto a set of specific basis functions through Fourier transform to obtain the components of the time signal function at each frequency, so as to determine the abnormal sound frequency segment of the vibration signal and narrow the detection range of the vibration signal.

[0073] Further, see Figure 1 and Figure 2 As shown, in some embodiments, the noise reduction of the abnormal sound frequency band includes:

[0074] S202: performing wavelet packet decomposition on the vibration signal, and selecting wavelet packets containing abnormal sound frequency bands.

[0075] S203: Reconstruct the wavelet packet signal to construct the first signal S1.

[0076] In this embodiment, wavelet packet decomposition can decompose the low-frequency component and high-frequency component of the vibration signal, improve the time-frequency resolution of the vibration signal, the range of the vibration signal can be set to 0-3000Hz, and the vibration signal can be divided into six sections after wavelet packet decomposition, the first section is 0-500Hz, the second section is 500-1000Hz, the third section is 1000-1500Hz, the fourth section is 1500-2000Hz, the fifth section is 2000-2500Hz, and the sixth section is 2500-3000Hz. The wavelet packet containing the abnormal sound frequency section is selected, that is, the first section. Wavelet packet decomposition and noise reduction are the first step of noise reduction. Demonstratively, the vibration signal can be decomposed into three layers, and the number of nodes in each layer can be set to 2 n (n=1, 2, 3), the decomposition relationship between the vibration signal S, the low-frequency signal A and the high-frequency signal D satisfies the following relationship:

[0077] S=A1+D1=AA2+DA2+AD2+DD2

[0078] =AAA3+DAA3+ADA3+DDA3+AAD3+DAD3+ADD3+DDD3 (1).

[0079] Further, see Figure 1 and Figure 2 As shown, in some embodiments, the noise reduction of the abnormal sound frequency band further includes:

[0080] S204: Perform fully adaptive noise set empirical mode decomposition on the first signal S1 to obtain multiple intrinsic mode functions IMFs, solve the correlation coefficient between each intrinsic mode function IMF and the first signal S1, and select several groups of intrinsic mode function IMF signals with correlation coefficients greater than a set coefficient value to reconstruct the second signal S2.

[0081] In this embodiment, fully adaptive noise ensemble empirical mode decomposition (CEEMDAN) denoising is the second step of denoising, and CEEMDAN includes the following steps:

[0082] Step 1: Decompose the original signal with Gaussian white noise added to obtain the mean IMF of all decomposed first-order IMF components 1 :

[0083]

[0084] Among them, IMF 1 is the mean of the first-order IMF component, x(t) is the original signal, E j is the operator, w i is Gaussian white noise distributed in N(0,1), ε k is the noise amplitude,

[0085] Step 2: Obtain the first-order residual according to the mean of the original signal and the first-order IMF component. The first-order residual r 1 (t) satisfies the following relationship:

[0086] r 1 (t) = x(t) - IMF 1 (3)

[0087] Step 3: Obtain the mean of the second-order IMF component based on the first-order residual and the decomposed signal. The mean IMF of the second-order IMF component 2 The following relationship is satisfied:

[0088]

[0089] Among them, IMF 2 is the mean of the second-order IMF component, r 1 (t)+ε 1 E 1 (w i ) is the decomposed signal,

[0090] Step 4: Repeat the above steps k times to obtain the k-order residual, the k-order residual r k (t) satisfies the following relationship:

[0091] r k (t) = r k-1 (t)-IMF k(5)

[0092] Step 5: Substitute the decomposed signal and the k-order residual into formula (2) to obtain the mean of the k+1-order IMF component. The mean IMF of the k+1-order IMF component is k+1 The following relationship is satisfied:

[0093]

[0094] Among them, r k (t)+ε k E k (w i ) is the decomposed signal.

[0095] Step 6: When the components of the residual are less than two, the decomposition ends and the expression of the original signal is obtained:

[0096]

[0097] Among them, k is the total number of IMFs. CEEMDAN adds an adaptive noise related to the current IMF in the process of extracting each order of IMF. The adaptive noise is obtained by calculating the residual of the first-order IMF and the weighted value of the current noise. As the IMF is gradually extracted, the influence of the noise gradually decreases. Several groups of intrinsic mode function IMF signals with correlation coefficients greater than 0.5 can be selected to reconstruct the second signal S2, thereby obtaining a vibration signal with reduced interference signal influence.

[0098] Further, see Figure 1 and Figure 2 As shown, in some embodiments, the noise reduction of the abnormal sound frequency band further includes:

[0099] S205: Construct the second signal S2 into a Hankel matrix A.

[0100] In this embodiment, singular value decomposition (SVD) denoising is the third step of denoising. For example, if the matrix A satisfies A∈R mxn , then A=USV T (8), where the orthogonal matrices U and V satisfy U∈R mxn , and V∈R mxn , discrete signal x(i) (i=1,2,…,N), where N is the number of sampling points, the second signal S2 is constructed into a Hankel matrix A:

[0101]

[0102] The Hankel matrix A can be subjected to singular value decomposition, singular values ​​with obvious fault characteristics can be selected, and singular values ​​with little correlation can be removed to reconstruct the matrix, thereby achieving the effect of reducing noise signal interference.

[0103] S206: Solve the singular values ​​of the Hankel matrix A, calculate the singular value differences, and select signals whose singular value differences are greater than the set difference to construct a third signal S3.

[0104] In this embodiment, the Hankel matrix is ​​represented as a Hankel matrix, and the sequence S in the Hankel matrix A satisfies S=(diag(σ 1 ,σ 2 ,…,σ i ),0), where σ i is a singular value, and the singular values ​​are arranged from large to small. When the difference between two adjacent singular values ​​is greater than 20, the signal in the abnormal sound frequency band decomposed by the singular value will have a peak mutation. The mutation point contains important information. The signal with a singular value difference greater than the set value is selected to construct the third signal S3, thereby obtaining a vibration signal that eliminates the interference signal.

[0105] See also Figure 3 As shown, an embodiment of the present application provides an abnormal sound detection device, which includes: a detection head connection line 1 and a conversion controller 4, one end of the detection head connection line 1 is provided with a vibration amplifier 2, and the vibration amplifier 2 is fixed with a first electromagnet 3; the conversion controller 4 is connected to the detection head connection line 1, and the conversion controller 4 is used to analyze the vibration signal, determine the abnormal sound frequency band, and reduce the noise of the abnormal sound frequency band.

[0106] In this embodiment, the vibration amplifier 2 is used to receive and amplify the vibration signal, reduce the influence of interference signals in the environment, and facilitate the detection personnel to quickly find the abnormal sound location. The vibration amplifier 2 is connected to a base 9, and the base 9 is installed at one end of the detection head connecting line 1. The diameter of the base 9 can be set to 2 to 4 mm, which is smaller than the probe diameter of the adsorption-type abnormal sound stethoscope of 10 to 30 mm, so that the abnormal sound detection device can detect the inside of the automobile part. The vibration amplifier 2 is provided with the first electromagnet 3, and the first electromagnet 3 is used to be adsorbed on the position to be tested of the automobile part. The detection head connecting line 1 is provided with a plurality of second electromagnets 10 at intervals. The plurality of second electromagnets 10 are used to adsorb the detection head connecting line 1 to the automobile parts in sections, so as to facilitate the operation of the detection personnel. The conversion controller 4 is used to receive the voltage signal and convert the voltage signal into a sound signal. The conversion controller 4 contains relevant preset algorithms. The conversion controller 4 is also used to analyze the vibration signal, determine the abnormal sound frequency segment, and reduce the noise of the abnormal sound frequency segment. The conversion controller 4 is connected to the earphone 11, and the detection personnel can listen to the vibration signal through the earphone 11.

[0107] Further, see Figure 3 and Figure 5As shown, in some embodiments, a plurality of tungsten wires 101 are provided in the detection head connecting line 1 , each of the tungsten wires 101 is connected to a first motor 102 , and the first motor 102 is configured to drive the tungsten wire 101 to extend and retract.

[0108] In this embodiment, the multiple tungsten wires 101 can be set to four tungsten wires 101, and the first motor 102 can be set to a stepping motor. Each tungsten wire 101 is driven to retract and adjust its length by the first motor 102. Four first motors 102 can be arranged side by side at the same position of the detection head connecting line 1. The four first motors 102 adjust the direction of the vibration amplifier 2 by adjusting the length of the four tungsten wires 101. The four first motors 102 at the same position form four motors. The detection head connecting line 1 can evenly distribute multiple four motors along its length direction. The four motors can be installed on one side of the second electromagnet 10. The cooperation of multiple four motors can adjust the line shape of the detection head connecting line 1, so that the detection head connecting line 1 adapts to the internal structure of the automobile part, thereby realizing a large range of angle adjustment of the abnormal sound detection device, which is convenient for the detection personnel to adjust the fixed position of the abnormal sound detection device according to the internal morphology of the automobile part.

[0109] Further, see Figure 3 As shown, in some embodiments, the detection head connecting line 1 is also connected to a control panel 5 , and the control panel 5 is electrically connected to the conversion controller 4 and the first motor 102 .

[0110] In this embodiment, the control tablet 5 is used to control the first motor 102 to adjust the angle of the abnormal sound detection device. The control tablet 5 is also used to display the calculation results of the conversion controller 4 or the image of the detection position, so as to facilitate the detection personnel to accurately determine the fault location according to the processed vibration signal.

[0111] Further, see Figure 3 and Figure 4 As shown, in some embodiments, the vibration amplifier 2 is also equipped with a camera 6 and a searchlight 7 , and the camera 6 and the searchlight 7 are both electrically connected to the control panel 5 .

[0112] In this embodiment, the vibration amplifier 2 is connected to the camera 6, and the camera 6 is used to observe the structure in a hidden position. The searchlights 7 are arranged on both sides of the vibration amplifier 2, and the searchlights 7 are used to illuminate the observation area. The camera 6 and the searchlight 7 can be used to effectively observe the internal morphology of automobile parts and detect abnormal noises in hidden positions. The camera 6 and the searchlight 7 are both controlled by the control panel 5.

[0113] Further, see Figure 3and Figure 6 As shown, in some embodiments, the end of the detection head connecting line 1 away from the vibration amplifier 2 is connected to a second motor 8, and the second motor 8 is configured to drive the detection head connecting line 1 to retract.

[0114] In this embodiment, the second motor 8 can be set as a rotating motor, the second motor 8 is installed in the packaging box 12, one end of the detection head connecting line 1 is fixed in the packaging box 12, the second motor 8 is connected to a rotating shaft, and the rotating shaft is wound around the detection head connecting line 1. When the hidden position is deeper, the second motor 8 can be turned on to drive the rotating shaft to rotate, and the detection head connecting line 1 wound around the rotating shaft can be screwed out of the packaging box 12, so that the detection head connecting line 1 is extended, thereby realizing the length adjustment of the abnormal sound detection device.

[0115] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0116] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0117] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for detecting abnormal sound, characterized in that: It includes the following steps: The abnormal noise detection device is installed at the position to be tested of the automobile component, and the abnormal noise detection device is used to detect the vibration signal when the abnormal noise occurs; The vibration signal is analyzed to determine the abnormal sound frequency segment, and the noise of the abnormal sound frequency segment is reduced. The abnormal sound analysis is performed on the position to be tested based on the vibration signal after noise reduction.

2. The abnormal sound detection method according to claim 1, characterized in that: The analyzing of the vibration signal to determine the abnormal sound frequency segment includes: Perform Fourier transform on the vibration signal to determine the frequency range of abnormal sound.

3. The abnormal sound detection method according to claim 1, characterized in that: The noise reduction of the abnormal sound frequency band includes: Perform wavelet packet decomposition on the vibration signal and select the wavelet packet containing the abnormal sound frequency band; The wavelet packet is reconstructed to construct a first signal S1.

4. The abnormal sound detection method according to claim 3, characterized in that: The noise reduction of the abnormal sound frequency band also includes: Perform fully adaptive noise set empirical mode decomposition on the first signal S1 to obtain multiple intrinsic mode functions IMF, solve the correlation coefficient between each intrinsic mode function IMF and the first signal S1, and select several groups of intrinsic mode function IMF signals with correlation coefficients greater than a set coefficient value to reconstruct the second signal S2.

5. The abnormal sound detection method according to claim 4, characterized in that: The noise reduction of the abnormal sound frequency band also includes: Constructing the second signal S2 into a Hankel matrix A; Solve the singular values ​​of the Hankel matrix A, calculate the singular value differences, and select signals whose singular value differences are greater than the set difference to construct the third signal S3.

6. An abnormal sound detection device, characterized in that: It includes: A detection head connecting line (1), wherein one end of the detection head connecting line (1) is provided with a vibration amplifier (2), and the vibration amplifier (2) is fixedly provided with a first electromagnet (3); A conversion controller (4), the conversion controller (4) is connected to the detection head connection line (1), and the conversion controller (4) is used to analyze the vibration signal, determine the abnormal sound frequency segment, and reduce the noise of the abnormal sound frequency segment.

7. The abnormal sound detection device according to claim 6, characterized in that: A plurality of tungsten wires (101) are arranged in the detection head connecting line (1), each of the tungsten wires (101) is connected to a first motor (102), and the first motor (102) is configured to drive the tungsten wire (101) to extend and retract.

8. The abnormal sound detection device according to claim 7, characterized in that: The detection head connection line (1) is also connected to a control panel (5), and the control panel (5) is electrically connected to the conversion controller (4) and the first motor (102).

9. The abnormal sound detection device according to claim 8, characterized in that: The vibration amplifier (2) is also equipped with a camera (6) and a searchlight (7), and the camera (6) and the searchlight (7) are both electrically connected to the control panel (5).

10. The abnormal sound detection device according to claim 6, characterized in that: One end of the detection head connecting line (1) away from the vibration amplifier (2) is connected to a second motor (8), and the second motor (8) is configured to drive the detection head connecting line (1) to extend and retract.

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