A method, apparatus, and storage medium for separating vibration modulation signals in gear faults.

Abstract

This invention discloses a method, apparatus, and storage medium for separating vibration modulation signals in gear faults. The method includes: establishing a spatial coordinate system, where the X-axis represents the central axis of the gearbox, and the direction of the X-axis represents the direction from the input axis to the output axis along the central axis; based on the spatial coordinate system, acquiring time-domain vibration acceleration response signals using an accelerometer, and calculating the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency; calculating the target frequency modulation signal based on the vibration modulation sideband signal; and calculating the amplitude modulation signal based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal. The amplitude modulation signal and the target frequency modulation signal are used as the vibration modulation signal separation result and applied to gear fault diagnosis. This invention achieves modulation signal separation, improving accuracy and noise immunity. This invention can be widely applied in the field of rotating machinery signal processing technology.

Description

Technical Field

[0001] This invention relates to the field of rotating machinery signal processing technology, and in particular to a method, apparatus and storage medium for separating vibration modulation signals of gear faults. Background Technology

[0002] Gears are used in various rotating machinery, where the working environment is relatively harsh, making them prone to failure. Vibration signals from gear failures often contain rich amplitude modulation (AM) and frequency modulation (FM) components, which can serve as effective fault diagnosis indicators for monitoring and diagnosing the operating status of gear systems. Traditional vibration signal demodulation methods typically extract the AM signal first, then the FM signal. This results in the FM signal extraction accuracy being affected by the AM signal extraction, leading to low precision and poor noise immunity.

[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention

[0004] This invention provides a method, apparatus, and storage medium for separating gear fault vibration modulation signals, which effectively improves accuracy and noise immunity.

[0005] On one hand, embodiments of the present invention provide a method for separating vibration modulation signals in gear faults, comprising the following steps:

[0006] Establish a spatial coordinate system, wherein the X-axis of the spatial coordinate system is used to characterize the central axis of the gearbox, and the direction of the X-axis is used to characterize the direction from the input axis to the output axis along the central axis;

[0007] Based on the spatial coordinate system, calculate the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency;

[0008] Calculate the target frequency modulation signal based on the vibration modulation sideband signal;

[0009] Based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal, an amplitude modulation signal is calculated. The amplitude modulation signal and the target frequency modulation signal are used as the result of vibration modulation signal separation and for gear fault diagnosis.

[0010] In some embodiments, calculating the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency according to the spatial coordinate system includes:

[0011] After the unidirectional acceleration sensor is installed on the bearing housing surface of the gearbox, the sampling frequency is set, and the testing direction of the unidirectional acceleration sensor is the direction of the Z-axis in the spatial coordinate system.

[0012] Based on the sampling frequency, a data acquisition signal is generated. The data acquisition signal is used to control the unidirectional accelerometer to acquire data and obtain a time-domain vibration acceleration signal.

[0013] Extract the higher-order meshing frequency and modulation sideband width from the time-domain vibration acceleration signal;

[0014] Based on the higher-order engagement frequency and the modulation sideband width, calculate the phaseless bandpass filter parameters, which include the upper cutoff frequency, lower cutoff frequency, or order.

[0015] Based on the parameters of the phaseless bandpass filter, the time-domain vibration acceleration signal is filtered to obtain the meshing frequency to be corrected and the vibration modulation sideband signal.

[0016] Perform a discrete Fourier transform on the vibration-modulated sideband signal;

[0017] The target meshing frequency is obtained by correcting the meshing frequency to be corrected using a preset ratio correction method.

[0018] The target gear fault characteristic frequency is calculated based on the target meshing frequency, the number of gear teeth, and the vibration modulation sideband signal after discrete Fourier transform.

[0019] In some embodiments, calculating the target frequency modulation signal based on the vibration modulation sideband signal includes:

[0020] The vibration modulation sideband signal is subjected to Hilbert transform to obtain a normalized signal;

[0021] Extract the peaks, troughs, peak times, and trough times from the normalized signal;

[0022] Calculate the angular interval between adjacent peaks and troughs based on the peaks and troughs.

[0023] Based on the angle interval, the peak time, and the trough time, calculate the relationship curve between the input gear rotation angle and time;

[0024] Differentiating the curve of the relationship between the input gear rotation angle and time yields the curve of the relationship between the input gear speed and time.

[0025] The relationship curve between the input gear speed and time is fitted using the least squares method to obtain the speed signal equation;

[0026] Based on the speed signal equation, the relationship curve between the input gear speed and time is converted into a speed frequency signal;

[0027] Integrating the frequency conversion signal yields the gear meshing phase;

[0028] The target frequency modulation signal is calculated based on the meshing frequency modulation signal, the vibration modulation sideband signal, the gear meshing phase, the number of gear teeth, the meshing order, the amplitude of the speed fluctuation component, and the target gear fault characteristic frequency.

[0029] The calculation formula for the meshing frequency modulation signal is as follows:

[0030]

[0031]

[0032] In the formula, b(t) is the meshing frequency modulation signal, n(t) is the rotational speed signal, t is time, z is the number of gear teeth, k is the meshing order, and f nc kf is the characteristic frequency of the target gear fault. zc Let n be the k-th order target meshing frequency, n0 be the average speed of the input gear, I be the highest order of the speed fluctuation component, and c be the highest order of the input gear. i Let α be the amplitude of the i-th order speed fluctuation component. i Let be the phase of the i-th order speed fluctuation component, where i is the i-th order speed fluctuation component.

[0033] In some embodiments, calculating the amplitude modulation signal based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal includes:

[0034] Based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal, a mathematical model of the vibration modulation signal during gear fault is constructed.

[0035] Calculate the Fourier series fitting order based on the modulation sideband width;

[0036] Based on the Fourier series fitting order, the vibration modulation sideband signal, and the vibration modulation signal mathematical model, the amplitude and phase in the amplitude modulation component are calculated using the Fourier series fitting method.

[0037] The amplitude-modulated signal is generated based on the amplitude and the phase.

[0038] In some embodiments, the calculation formula for the vibration modulation sideband signal is:

[0039] y k (t)=A k [1+a k (t)]cos[2πkfz z t+φ k +b k (t)],

[0040] In the formula, yk (t) is the vibration modulation sideband signal, A k Let a be the amplitude of the k-th meshing frequency. k (t) is the amplitude modulation signal of the k-th meshing component, where k is the meshing order, and kf z Let φ be the k-th order meshing frequency, t be time, and φ be the frequency of engagement. k Let b be the phase of the k-th meshing frequency. k (t) is the frequency modulation signal of the k-th order meshing component.

[0041] In some embodiments, the expression for the rotational speed signal equation is:

[0042]

[0043] In the formula, n(t) is the rotational speed signal, n0 is the average rotational speed of the input gear, I is the highest order of the rotational speed fluctuation component, and c i Let f be the amplitude of the i-th order speed fluctuation component. nc Let α be the characteristic frequency of the target gear fault, t be time, and α be... i Let be the phase of the i-th order speed fluctuation component, where i is the i-th order speed fluctuation component.

[0044] In some embodiments, the mathematical model of the vibration modulation signal is expressed as follows:

[0045]

[0046] In the formula, y(t) is the mathematical model of the vibration modulation signal, and A k M is the amplitude of the k-th meshing frequency. f For the Fourier series fitting order, A k,m f is the amplitude of the m-th order characteristic frequency component of the gear fault to be corrected in the amplitude-modulated signal. nc The target gear fault characteristic frequency is t, where t is time. Let kf be the phase of the m-th order characteristic frequency component of the gear fault to be corrected in the amplitude-modulated signal. zc Let φ be the k-th order target meshing frequency. k Let z be the phase of the k-th meshing frequency, z be the number of gear teeth, k be the meshing order, I be the highest order of the speed fluctuation component, and c be the phase of the k-th meshing frequency. i Let α be the amplitude of the i-th order speed fluctuation component, where i is the i-th order speed fluctuation component. i Let be the phase of the i-th order rotational speed fluctuation component.

[0047] On the other hand, embodiments of the present invention provide a gear fault vibration modulation signal separation device, comprising:

[0048] The first module is used to establish a spatial coordinate system, wherein the X-axis of the spatial coordinate system is used to characterize the central axis of the gearbox, and the direction of the X-axis is used to characterize the direction from the input axis to the output axis on the central axis;

[0049] The second module is used to calculate the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency based on the spatial coordinate system.

[0050] The third module is used to calculate the target frequency modulation signal based on the vibration modulation sideband signal;

[0051] The fourth module is used to calculate an amplitude modulation signal based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal. The amplitude modulation signal and the target frequency modulation signal are used as the result of vibration modulation signal separation and for gear fault diagnosis.

[0052] On the other hand, embodiments of the present invention provide a computer device, including:

[0053] At least one processor;

[0054] At least one memory for storing at least one program;

[0055] When the at least one program is executed by the at least one processor, the at least one processor implements the method.

[0056] On the other hand, embodiments of the present invention provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described thereon.

[0057] The beneficial effects of this invention are as follows:

[0058] In this embodiment of the invention, a spatial coordinate system is first established. The X-axis of the spatial coordinate system is used to characterize the central axis of the gearbox, and the direction of the X-axis is used to characterize the direction from the input axis to the output axis along the central axis. Then, based on the spatial coordinate system, the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency are calculated. Next, based on the vibration modulation sideband signal, the target frequency modulation signal is calculated. Finally, based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal, the amplitude modulation signal is calculated. The amplitude modulation signal and the target frequency modulation signal are used as the result of vibration modulation signal separation, thereby realizing modulation signal separation and improving accuracy and noise resistance.

[0059] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description and the drawings. Attached Figure Description

[0060] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0061] Figure 1 This is a flowchart of a method for separating vibration modulation signals in gear faults according to an embodiment of the present invention;

[0062] Figure 2 This is an overall flowchart illustrating the separation of frequency modulation (FM) and amplitude modulation (AM) signals according to an embodiment of the present invention.

[0063] Figure 3 This is a schematic diagram of a gear fault vibration modulation signal separation device according to an embodiment of the present invention;

[0064] Figure 4 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0066] It is understood that the terms “first,” “second,” etc., used in this application may be used herein to describe various concepts, but unless otherwise stated, these concepts are not limited by these terms. These terms are only used to distinguish one concept from another. For example, without departing from the scope of the embodiments of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the words “if,” “when,” or “in response to a determination” as used herein may be interpreted as “when…” or “when…” or “in response to a determination.”

[0067] As used in this application, the terms "at least one", "multiple", "each", "any", etc., "at least one" includes one, two or more, "multiple" includes two or more, "each" refers to each of the corresponding multiples, and "any" refers to any one of the multiples.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0069] Before providing a detailed description of the embodiments of this application, some of the nouns and terms involved in the embodiments of this application will be explained first. The nouns and terms involved in the embodiments of this application are subject to the following interpretations.

[0070] Gear fault vibration modulation signal: This refers to the change in vibration signal caused by faults (such as uniform wear, eccentricity, misalignment, local anomalies, etc.) during gear operation. These changes can be analyzed and diagnosed using time-domain and frequency-domain characteristics. Specifically, gear faults cause changes in the vibration waveform, which in turn affect the spectral structure, producing specific frequency components and amplitude changes. These changes can be used to identify and diagnose the type and severity of gear faults.

[0071] In related technologies, gears, as commonly used transmission mechanisms, are widely applied in various rotating machinery and key transmission equipment. However, their working environment is relatively harsh, and they are prone to failure during long-term use. Vibration signals from gear failures often contain rich amplitude modulation (AM) and frequency modulation (FM) components, which can serve as effective fault diagnosis indicators for monitoring and diagnosing the operating status of gear systems. Therefore, effectively extracting the vibration AM and FM signals closely related to gear conditions is of great significance for fault diagnosis and condition monitoring of gear systems. In recent years, typical methods for demodulating gear fault vibration signals include Hilbert transform demodulation, energy operator-based demodulation methods, and square amplitude demodulation. However, these demodulation methods typically extract the AM signal first and then the FM signal, resulting in the FM signal extraction accuracy being significantly affected by the AM signal extraction accuracy, leading to low precision and poor noise resistance.

[0072] In view of this, embodiments of the present invention effectively extract the speed fluctuation signal caused by gear faults from vibration signals, and then, by combining the mapping relationship between the speed fluctuation signal and the frequency modulation signal, accurately extract the vibration frequency modulation signal generated by the gear fault. Furthermore, based on the mathematical model of vibration amplitude modulation and frequency modulation signals, trigonometric function fitting is used to achieve accurate extraction of the amplitude modulation signal, ultimately realizing the effective separation of vibration amplitude modulation and frequency modulation signals from gear faults and the diagnosis of gear faults.

[0073] This application provides a method for separating vibration modulation signals in gear faults, relating to the field of rotating machinery signal processing technology. This method can be applied to a terminal, a server, or software running on either a terminal or a server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, smart speaker, smartwatch, or vehicle terminal, but is not limited to these. The server can be configured as an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network. The software can be an application implementing the method for separating vibration modulation signals in gear faults, but is not limited to the above forms.

[0074] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0075] The embodiments of this application will be explained in detail below with reference to the accompanying drawings:

[0076] Figure 1 This is an optional flowchart of a gear fault vibration modulation signal separation method provided in an embodiment of this application. Figure 1 The method may include, but is not limited to, steps S101 to S104.

[0077] Step S101: Establish a spatial coordinate system. The X-axis of the spatial coordinate system is used to characterize the central axis of the gearbox, and the direction of the X-axis is used to characterize the direction from the input axis to the output axis on the central axis.

[0078] Step S102: Calculate the vibration modulation sideband signal, target meshing frequency, and target gear fault characteristic frequency according to the spatial coordinate system;

[0079] Step S103: Calculate the target frequency modulation signal based on the vibration modulation sideband signal;

[0080] Step S104: Calculate the amplitude modulation signal based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal. The amplitude modulation signal and the target frequency modulation signal are used as the result of vibration modulation signal separation and are used for gear fault diagnosis.

[0081] Steps S101 to S104 as shown in the embodiments of this application realize the separation of modulation signals, thereby improving accuracy and noise immunity.

[0082] In some embodiments, in step S101, a spatial coordinate system XYZ can be established. The X-axis of the spatial coordinate system represents the central axis of the gearbox, and the direction of the X-axis represents the direction from the input axis to the output axis along the central axis; that is, the positive direction of the X-axis points from the input axis to the output axis along the central axis of the gearbox. More often, the positive Z-axis of the spatial coordinate system is vertically upward, and the positive Y-axis is determined by the right-hand rule.

[0083] In some embodiments, in step S102, calculating the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency according to the spatial coordinate system may include, but is not limited to, the following steps:

[0084] After the unidirectional accelerometer is installed on the bearing housing surface of the gearbox, the sampling frequency is set, and the testing direction of the unidirectional accelerometer is the direction of the Z-axis in the spatial coordinate system.

[0085] Based on the sampling frequency, a data acquisition signal is generated. The data acquisition signal is used to control the unidirectional accelerometer to acquire data and obtain the time-domain vibration acceleration signal.

[0086] Extracting higher-order meshing frequencies and modulation sideband widths from time-domain vibration acceleration signals;

[0087] Based on the higher-order meshing frequency and the modulation sideband width, calculate the phaseless bandpass filter parameters, which include the upper cutoff frequency, lower cutoff frequency, or order.

[0088] Based on the parameters of the phaseless bandpass filter, the time-domain vibration acceleration signal is filtered to obtain the meshing frequency to be corrected and the vibration modulation sideband signal.

[0089] Perform Discrete Fourier Transform on the vibration-modulated sideband signal;

[0090] The meshing frequency to be corrected is corrected using a preset ratio correction method to obtain the target meshing frequency;

[0091] The target gear fault characteristic frequency is calculated based on the target meshing frequency, the number of gear teeth, and the vibration modulation sideband signal after discrete Fourier transform.

[0092] In some embodiments, after a unidirectional accelerometer is mounted on the bearing housing surface of the gearbox, a sampling frequency can be set. The testing direction of the unidirectional accelerometer is the Z-axis direction in the spatial coordinate system. The unidirectional accelerometer can be connected sequentially to a sensor, a data acquisition unit, and a portable computer. Then, based on the sampling frequency, an acquisition signal is generated. This acquisition signal is used to control the unidirectional accelerometer to acquire data, obtaining a time-domain vibration acceleration signal y(t) in m / s². 2 Then, the higher-order meshing frequency and modulation sideband width are extracted from the time-domain vibration acceleration signal. Based on the higher-order meshing frequency and modulation sideband width, the phase-free bandpass filter parameters are calculated. These parameters include the upper cutoff frequency, lower cutoff frequency, or order. For example, the upper cutoff frequency can be set to kf. z +6f i The lower cutoff frequency can be set to kf. z -6f i The order can be set to 1500, k is the order of the meshing frequency, i.e., the meshing order, which can be 5, and f z f is the meshing frequency. i The input shaft rotation frequency. After calculating the parameters of the phaseless bandpass filter, filtering can be performed using the phaseless bandpass filter, which includes gear fault modulation sidebands on both sides of the 5th order meshing frequency. The time-domain vibration acceleration signal can be filtered according to the phaseless bandpass filter parameters to obtain the meshing frequency to be corrected and the vibration modulation sideband signal. The formula for calculating the vibration modulation sideband signal is: y k (t)=A k [1+a k (t)]cos[2πkf z t+φ k +b k [(t)], where y k (t) represents the vibration-modulated sideband signal, A k Let a be the amplitude of the k-th meshing frequency. k (t) is the amplitude modulation signal of the k-th meshing component, where k is the meshing order, and kf z Let φ be the k-th order meshing frequency, t be time, and φ be the frequency of engagement. k Let b be the phase of the k-th meshing frequency. k (t) is the frequency-modulated signal of the k-th order meshing component. M is the amplitude modulation signal a kThe highest order of the fault characteristic frequency in (t), A k,m For amplitude modulation signal a k The characteristic frequency f of the m-th order gear fault to be corrected in (t) n The amplitude of the component, f n The characteristic frequency of the gear fault to be corrected. For amplitude modulation signal a k The characteristic frequency f of the m-th order gear fault to be corrected in (t) n The phase of the component, where L is the frequency-modulated signal b. k The highest order of the fault characteristic frequency in (t), B k,l For frequency modulation signal b k The l-th order characteristic frequency of the gear fault to be corrected in (t) is f. n The amplitude of the component, θ k,l For frequency modulation signal b k The l-th order characteristic frequency of the gear fault to be corrected in (t) is f. n The phase of the component. Then modulate the vibrational sideband signal y. k (t) Perform a discrete Fourier transform, and finally use the preset ratio correction method to correct the meshing frequency to be corrected, so as to obtain the target meshing frequency kf of the kth order. zc Based on the target meshing frequency, the number of gear teeth, and the vibration modulation sideband signal after discrete Fourier transform, the characteristic frequency f of the target gear fault is calculated. nc For example, the preset ratio correction method can be set to the ratio correction method with a Hanning window.

[0093] In some embodiments, the step S103, calculating the target frequency modulation signal based on the vibration modulation sideband signal, may include, but is not limited to, the following steps:

[0094] The vibration-modulated sideband signal is subjected to Hilbert transform to obtain the normalized signal;

[0095] Extract peaks, troughs, peak times, and trough times from a normalized signal;

[0096] Calculate the angular interval between adjacent peaks and troughs based on the peaks and troughs;

[0097] Calculate the relationship curve between the input gear rotation angle and time based on the angle interval, peak time, and trough time;

[0098] Differentiate the curve of the relationship between the input gear rotation angle and time to obtain the curve of the relationship between the input gear speed and time;

[0099] The relationship curve between the input gear speed and time is fitted using the least squares method to obtain the speed signal equation;

[0100] Based on the speed signal equation, the relationship curve between the input gear speed and time is converted into a speed frequency signal;

[0101] Integrating the frequency conversion signal yields the gear meshing phase;

[0102] The target frequency modulation signal is calculated based on the meshing frequency modulation signal, vibration modulation sideband signal, gear meshing phase, number of gear teeth, meshing order, amplitude of speed fluctuation component, and target gear fault characteristic frequency.

[0103] In some embodiments, the vibration modulation sideband signal y can be first applied. k (t) A Hilbert transform is performed to obtain a normalized signal. Then, the peaks and troughs in the normalized signal and their corresponding times are found. The peaks, troughs, peak times, and trough times are extracted from the normalized signal. Based on the peaks and troughs, the fixed angular interval π / (kz) between adjacent peaks and troughs is calculated, where z is the number of teeth of the input gear. Then, based on the angular interval, peak times, and trough times, the relationship curve between the input gear rotation angle and time is calculated, i.e., the rotation angle signal. The derivative of the relationship curve between the input gear rotation angle and time (i.e., the rotation angle signal) is obtained to obtain the relationship curve between the input gear speed and time, i.e., the speed signal. The least squares method is then used to fit the relationship curve between the input gear speed and time (i.e., the speed signal) to obtain the speed signal equation. The expression of the speed signal equation is: In the formula, n(t) is the rotational speed signal, n0 is the average rotational speed of the input gear, I is the highest order of the rotational speed fluctuation component, and c i Let f be the amplitude of the i-th order speed fluctuation component. nc Let α be the characteristic frequency of the target gear fault, t be time, and α be... i Let α be the phase of the i-th order speed fluctuation component. Then, according to the speed signal equation, the relationship curve between the input gear speed and time is converted into a speed frequency signal. The speed frequency signal is then integrated to obtain the gear meshing phase. Finally, based on the meshing frequency modulation signal, vibration modulation sideband signal, gear meshing phase, number of gear teeth, meshing order, amplitude of the speed fluctuation component, and the target gear fault characteristic frequency, the target frequency modulation signal is calculated. The formula for calculating the meshing frequency modulation signal is:

[0104]

[0105] In the formula, b(t) is the meshing frequency modulation signal, n(t) is the rotational speed signal, t is time, z is the number of gear teeth, k is the meshing order, and f nc kf is the characteristic frequency of the target gear fault. zc Let n be the k-th order target meshing frequency, n0 be the average speed of the input gear, I be the highest order of the speed fluctuation component, and c be the highest order of the input gear. iLet α be the amplitude of the i-th order speed fluctuation component. i Let be the phase of the i-th order speed fluctuation component, where i is the i-th order speed fluctuation component.

[0106] The calculation formula for the meshing frequency modulation signal is the mapping relationship between the speed signal generated by the gear fault and the k-th order meshing frequency modulation signal b(t), which is obtained by comparing y k From b(t) and b(t), we can see that That is, the frequency modulation signal b that needs to be solved. k (t). This is because at this point the number of teeth z, the meshing order k, and the amplitude c of the oscillation speed... i and the target gear fault characteristic frequency f nc All are known; substitute them into... The frequency modulation signal b can be obtained from the expression. k (t), thus enabling the separation of the frequency modulation signal from the vibration modulation signal.

[0107] In some embodiments, step S104, calculating the amplitude modulation signal based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal, may include, but is not limited to, the following steps:

[0108] Based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal, a mathematical model of the vibration modulation signal during gear fault is constructed.

[0109] Calculate the Fourier series fitting order based on the modulation sideband width;

[0110] Based on the Fourier series fitting order, the vibration modulation sideband signal, and the mathematical model of the vibration modulation signal, the amplitude and phase in the amplitude modulation component are calculated using the Fourier series fitting method.

[0111] An amplitude-modulated signal is generated based on the amplitude and phase.

[0112] In some embodiments, a mathematical model of the k-th order vibration modulation signal during gear failure can be constructed first based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal. The expression for the vibration modulation signal mathematical model is as follows:

[0113] In the formula, y(t) is the mathematical model of the vibration modulation signal, and A k M is the amplitude of the k-th meshing frequency. f For the Fourier series fitting order, A k,m f is the amplitude of the m-th order characteristic frequency component of the gear fault to be corrected in the amplitude-modulated signal. nc Let t be the characteristic frequency of the target gear fault, and t be time. Let kf be the phase of the m-th order characteristic frequency component of the gear fault to be corrected in the amplitude-modulated signal. zcLet φ be the k-th order target meshing frequency. k Let z be the phase of the k-th meshing frequency, z be the number of gear teeth, k be the meshing order, I be the highest order of the speed fluctuation component, and c be the phase of the k-th meshing frequency. i Let α be the amplitude of the i-th order speed fluctuation component, where i is the i-th order speed fluctuation component. i Let M be the phase of the i-th order rotational speed fluctuation component. Then, based on the modulation sideband width, calculate the Fourier series fitting order M. f The order of the Fourier series fitting can be determined by the actual vibration modulation signal y. k The modulation sideband width in (t) is determined. Then, based on the Fourier series fitting order, the vibration modulation sideband signal, and the mathematical model of the vibration modulation signal, the amplitude and phase of the amplitude-modulated component are calculated using the Fourier series fitting method. The amplitude may include A... k and A k,m Phase can include φ k and A k The parameter range can be set to [0, max(y)]. k (t))],A k,m The parameter range can be set to [0, 1], max(y k (t) represents y k The maximum value of (t), φ k and The value range of can be set to [0, 2π].

[0114] Finally, based on the amplitude and phase, an amplitude-modulated (AM) signal is generated, enabling accurate separation of the AM signal. The AM signal and the target frequency-modulated (FM) signal are then used as the results of vibration modulation signal separation. Furthermore, after separating the AM signal and the target FM signal, gear fault diagnosis can be performed based on these signals.

[0115] In some embodiments, the overall process for separating the frequency modulation signal and the amplitude modulation signal is as follows: Figure 2 As shown, the vibration amplitude-frequency modulation (AM-FM) signal of gear faults (i.e., the time-domain vibration acceleration signal) can be obtained first, and then phaseless bandpass filtering and discrete spectrum correction can be performed to obtain the accurate target meshing frequency and the target gear fault characteristic frequency. Then, the extreme value search method is used to find the relationship curve between gear rotation angle and time (i.e., the rotation angle signal), and the derivative is used to obtain the relationship curve between rotation speed and time (i.e., the rotation speed signal). Then, the frequency modulation signal is obtained through the frequency modulation signal generation mechanism. Finally, a mathematical model of vibration amplitude-frequency modulation signal is constructed, and the amplitude modulation signal parameters are solved by the trigonometric function fitting method to calculate the amplitude modulation signal. Thus, the frequency modulation signal and the amplitude modulation signal can be separated from the vibration amplitude-frequency modulation signal of gear faults.

[0116] In some embodiments, this embodiment is based on the research of rotational speed extraction method and frequency modulation mechanism, and provides a method with higher accuracy and better noise resistance for separating amplitude modulation and frequency modulation signals of gear fault vibration. This embodiment has the following advantages: (1) High accuracy of modulation separation: By combining rotational speed extraction, the mapping relationship between frequency modulation signal and rotational speed signal generated by gear fault and trigonometric function fitting method, the extraction accuracy of frequency modulation signal and amplitude modulation signal can be improved, especially the influence of amplitude modulation signal extraction accuracy on frequency modulation signal extraction accuracy can be reduced, and the extraction accuracy of frequency modulation signal can be improved. (2) Good noise resistance: Based on the trigonometric function characteristics in gear fault vibration modulation signal, combined with the mathematical model of gear fault vibration signal and vibration modulation mechanism, the modulation signal parameters can be solved by trigonometric function fitting method, which can further improve the noise resistance of amplitude modulation and frequency modulation signal separation method.

[0117] The beneficial effects of implementing the embodiments of the present invention include: First, a spatial coordinate system is established. The X-axis of the spatial coordinate system is used to characterize the central axis of the gearbox, and the direction of the X-axis is used to characterize the direction from the input axis to the output axis in the central axis. Then, based on the spatial coordinate system, the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency are calculated. Then, based on the vibration modulation sideband signal, the target frequency modulation signal is calculated. Finally, based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal, the amplitude modulation signal is calculated. The amplitude modulation signal and the target frequency modulation signal are used as the result of vibration modulation signal separation, thereby realizing modulation signal separation and improving accuracy and noise resistance.

[0118] like Figure 3 As shown, this embodiment of the invention also provides a gear fault vibration modulation signal separation device, comprising:

[0119] The first module 801 is used to establish a spatial coordinate system. The X-axis of the spatial coordinate system is used to characterize the central axis of the gearbox, and the direction of the X-axis is used to characterize the direction from the input axis to the output axis in the central axis.

[0120] The second module 802 is used to calculate the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency according to the spatial coordinate system.

[0121] The third module 803 is used to calculate the target frequency modulation signal based on the vibration modulation sideband signal;

[0122] The fourth module 804 is used to calculate the amplitude modulation signal based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal. The amplitude modulation signal and the target frequency modulation signal are used as the result of vibration modulation signal separation and are used for gear fault diagnosis.

[0123] The content of the above method embodiments is applicable to the device embodiments. The specific functions implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0124] like Figure 4 As shown, embodiments of the present invention also provide a computer device, including:

[0125] At least one processor 901;

[0126] At least one memory 902 is used to store at least one program;

[0127] When at least one program is executed by at least one processor, such that at least one processor achieves Figure 1 The method shown.

[0128] The content of the above method embodiments is applicable to the device embodiments. The specific functions implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0129] This invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements... Figure 1 The method shown.

[0130] The content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0131] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A method for separating vibration modulation signals in gear faults, characterized in that, Includes the following steps: Establish a spatial coordinate system, wherein the X-axis of the spatial coordinate system is used to characterize the central axis of the gearbox, and the direction of the X-axis is used to characterize the direction from the input axis to the output axis along the central axis; Based on the spatial coordinate system, calculate the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency; Calculate the target frequency modulation signal based on the vibration modulation sideband signal; Based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal, an amplitude modulation signal is calculated. The amplitude modulation signal and the target frequency modulation signal are used as the result of vibration modulation signal separation and for gear fault diagnosis. The calculation of the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency based on the spatial coordinate system includes: After the unidirectional acceleration sensor is installed on the bearing housing surface of the gearbox, the sampling frequency is set, and the testing direction of the unidirectional acceleration sensor is the direction of the Z-axis in the spatial coordinate system. Based on the sampling frequency, a data acquisition signal is generated. The data acquisition signal is used to control the unidirectional accelerometer to acquire data and obtain a time-domain vibration acceleration signal. Extract the higher-order meshing frequency and modulation sideband width from the time-domain vibration acceleration signal; Based on the higher-order engagement frequency and the modulation sideband width, calculate the phaseless bandpass filter parameters, which include the upper cutoff frequency, lower cutoff frequency, or order. Based on the parameters of the phaseless bandpass filter, the time-domain vibration acceleration signal is filtered to obtain the meshing frequency to be corrected and the vibration modulation sideband signal. Perform a discrete Fourier transform on the vibration-modulated sideband signal; The target meshing frequency is obtained by correcting the meshing frequency to be corrected using a preset ratio correction method. The target gear fault characteristic frequency is calculated based on the target meshing frequency, the number of gear teeth, and the vibration modulation sideband signal after discrete Fourier transform. The step of calculating the target frequency modulation signal based on the vibration modulation sideband signal includes: The vibration modulation sideband signal is subjected to Hilbert transform to obtain a normalized signal; Extract the peaks, troughs, peak times, and trough times from the normalized signal; Calculate the angular interval between adjacent peaks and troughs based on the peaks and troughs. Based on the angle interval, the peak time, and the trough time, calculate the relationship curve between the input gear rotation angle and time; Differentiating the curve of the relationship between the input gear rotation angle and time yields the curve of the relationship between the input gear speed and time. The relationship curve between the input gear speed and time is fitted using the least squares method to obtain the speed signal equation; Based on the speed signal equation, the relationship curve between the input gear speed and time is converted into a speed frequency signal; Integrating the frequency conversion signal yields the gear meshing phase; The target frequency modulation signal is calculated based on the meshing frequency modulation signal, the vibration modulation sideband signal, the gear meshing phase, the number of gear teeth, the meshing order, the amplitude of the speed fluctuation component, and the target gear fault characteristic frequency. The formula for calculating the meshing frequency modulation signal is as follows: In the formula, The meshing frequency modulation signal, This is the rotation speed signal. For time, This refers to the number of teeth on the gear. For meshing order, The target gear fault characteristic frequency, For the first k Target engagement frequency, The average speed of the input gear. This represents the highest order of the speed fluctuation component. For the first i The amplitude of the speed fluctuation component. For the first i The phase of the speed fluctuation component, For the first i Speed ​​fluctuation components; The step of calculating the amplitude modulation signal based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal includes: Based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal, a mathematical model of the vibration modulation signal during gear fault is constructed. Calculate the Fourier series fitting order based on the modulation sideband width; Based on the Fourier series fitting order, the vibration modulation sideband signal, and the vibration modulation signal mathematical model, the amplitude and phase in the amplitude modulation component are calculated using the Fourier series fitting method. The amplitude-modulated signal is generated based on the amplitude and the phase. The mathematical model of the vibration modulation signal is expressed as follows: ， In the formula, The mathematical model for the vibration modulation signal is as follows: For the first k The amplitude of the engagement frequency. The order of the Fourier series fitting is given. For the amplitude modulation signal, the first m The amplitude of the characteristic frequency components of the gear fault to be corrected. The target gear fault characteristic frequency, For time, For the amplitude modulation signal, the first m The phase of the characteristic frequency components of the gear fault to be corrected. For the first k Target engagement frequency, For the first k Phase of the engagement frequency, This refers to the number of teeth on the gear. For meshing order, This represents the highest order of the speed fluctuation component. For the first i The amplitude of the speed fluctuation component. For the first i Speed ​​fluctuation components, For the first i The phase of the speed fluctuation component.

2. The method according to claim 1, characterized in that, The formula for calculating the vibration-modulated sideband signal is as follows: ， In the formula, The vibration modulation sideband signal, For the first k The amplitude of the engagement frequency. For the first k Amplitude modulation signal of step meshing component, For meshing order, For the first k Meshing frequency, For time, For the first k Phase of the engagement frequency, For the first k Frequency modulation signal of step meshing component.

3. The method according to claim 1, characterized in that, The expression for the rotational speed signal equation is: ， In the formula, This is the rotation speed signal. The average speed of the input gear. This represents the highest order of the speed fluctuation component. For the first i The amplitude of the speed fluctuation component. The target gear fault characteristic frequency, For time, For the first i The phase of the speed fluctuation component, For the first i The speed fluctuation component.

4. An apparatus for implementing the gear fault vibration modulation signal separation method as described in any one of claims 1-3, characterized in that, include: The first module is used to establish a spatial coordinate system, wherein the X-axis of the spatial coordinate system is used to characterize the central axis of the gearbox, and the direction of the X-axis is used to characterize the direction from the input axis to the output axis on the central axis; The second module is used to calculate the vibration modulation sideband signal, the target meshing frequency, and the target gear fault characteristic frequency based on the spatial coordinate system. The third module is used to calculate the target frequency modulation signal based on the vibration modulation sideband signal; The fourth module is used to calculate an amplitude modulation signal based on the target meshing frequency, the target gear fault characteristic frequency, and the target frequency modulation signal. The amplitude modulation signal and the target frequency modulation signal are used as the result of vibration modulation signal separation and for gear fault diagnosis.

5. A computer device, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the method as described in any one of claims 1-3.

6. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-3.

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