A Method for Collecting Fault Information of a Hydraulic Control Check Valve for a Hydraulic Support

Abstract

The present application relates to the technical field of data processing, and particularly to a method for collecting fault information of a hydraulic control one-way valve for a hydraulic support. The method includes: recording the oil inlets and outlets of the hydraulic control one-way valve to be tested as each oil port, respectively obtaining the pressures at all times during the pressure boost period and the pressure holding period of each oil port, and recording them as the pressure boost section signals and the pressure holding section signals of each oil port; determining the signal similarity of any modal component; obtaining the denoised pressure boost section signals of each oil port; obtaining the pressure boost evaluation value of each oil port; obtaining the denoised pressure holding section signals of each oil port; determining the pressure holding evaluation value of each oil port; obtaining the fault degree of the hydraulic control one-way valve to be tested, and evaluating the leakage fault of the hydraulic control one-way valve to be tested. The present application can timely monitor the early weak leakage fault information hidden in the hydraulic control one-way valve to be tested, and reduce the risk of safety accidents occurring in the hydraulic support.

Description

Technical Field

[0001] This application relates to the technical field of data processing, and particularly relates to a method for collecting fault information of a hydraulic control check valve for a hydraulic support. Background Technique

[0002] A hydraulic support is a structure for controlling the mine pressure in a coal mining face, playing an important protective role in underground coal mining. A hydraulic control check valve is an important control component in a hydraulic support, and its sealing performance plays a role in maintaining pressure and positioning in the hydraulic support. Slight leakage of the hydraulic control check valve will cause the displacement of the hydraulic cylinder, and serious leakage will easily lead to safety accidents of the hydraulic support.

[0003] The existing hydraulic control check valve usually judges whether there is leakage by collecting its pressure signal and using the abnormal data in the pressure signal. However, the internal leakage fault signal in the hydraulic system is a weak signal under a typical strong background noise, making it difficult to directly detect abnormal data in the collected pressure of the hydraulic control check valve, and it is difficult to effectively extract early weak leakage fault information, and thus it cannot be detected in time when the hydraulic control check valve has an early weak leakage fault. Summary of the Invention

[0004] In order to solve the above technical problems, a method for collecting fault information of a hydraulic control check valve for a hydraulic support is provided to solve the existing problems.

[0005] The solution of this application to solve the technical problem is to provide a method for collecting fault information of a hydraulic control check valve for a hydraulic support, including the following steps:

[0006] Record the oil inlets and outlets of the hydraulic control check valve to be tested as each oil port, and respectively obtain the pressures at all times during the pressure increase period and the pressure holding period of each oil port, and record them as the pressure increase section signals and the pressure holding section signals of each oil port;

[0007] Extract the signals with trend terms and the signals after eliminating trend terms in the pressure increase section signals of each oil port; perform modal decomposition on the signals after eliminating trend terms, analyze the similarity of the signals in different time periods within any modal component corresponding to the signals after eliminating trend terms in the frequency domain, and determine the signal similarity of the any modal component; based on the signal similarity, filter the modal components and then perform signal reconstruction, and combine with the signals with trend terms to obtain the pressure increase section signals after denoising of each oil port;

[0008] Based on the change trend of the pressure increase section signals after denoising of each oil port, obtain the pressure increase evaluation value of each oil port;

[0009] Perform modal decomposition on the pressure-holding section signals of each oil port, analyze the correlation characteristics of each modal component corresponding to the pressure-holding section signals of each oil port, and after screening all modal components, obtain the pressure-holding section signals after denoising for each oil port through signal reconstruction;

[0010] Determine the pressure-holding evaluation value of each oil port based on the distribution of the pressure-holding section signals after denoising for each oil port in the frequency domain;

[0011] Based on the boost evaluation value and the pressure-holding evaluation value of all oil ports, obtain the fault degree of the to-be-tested hydraulic check valve, and evaluate the leakage fault of the to-be-tested hydraulic check valve.

[0012] Preferably, adopt the signal detrending method to separately extract the signal with a trend term and the signal after eliminating the trend term from the boost section signals of each oil port.

[0013] Preferably, the determination of the signal similarity of any modal component includes:

[0014] Divide the any modal component into multiple signal segments; perform frequency-domain analysis on each signal segment to obtain the spectrogram of each signal segment;

[0015] The signal similarity is the average of the similarity degrees of the spectrograms corresponding to all any two signal segments in the any modal component.

[0016] Preferably, the process of obtaining the boost section signals after denoising for each oil port is as follows:

[0017] Obtain the segmentation threshold of the signal similarity of all modal components corresponding to the signal after eliminating the trend term, denoted as the first segmentation threshold; perform signal reconstruction on all modal components of each oil port whose signal similarity is greater than the first segmentation threshold;

[0018] Add the amplitudes of the reconstructed signal and the signal with a trend term at the same moment to obtain the boost section signals after denoising for each oil port.

[0019] Preferably, the boost evaluation value is the slope of the fitting line after linearly fitting the boost section signals after denoising for each oil port.

[0020] Preferably, the further measurement method of the correlation characteristics is: calculate the autocorrelation coefficient of each modal component corresponding to the pressure-holding section signals of each oil port.

[0021] Preferably, the process of obtaining the pressure-holding section signals after denoising for each oil port is as follows:

[0022] Obtain the segmentation threshold of the autocorrelation coefficient of all modal components corresponding to the pressure-holding section signals of each oil port, denoted as the second segmentation threshold;

[0023] Signal reconstruction is performed on all modal components of the autocorrelation coefficient of each oil port that is greater than the second segmentation threshold to obtain the pressure-holding section signal after denoising for each oil port.

[0024] Preferably, the determining of the pressure-holding evaluation value of each oil port includes:

[0025] Perform frequency-domain analysis on the pressure-holding section signal after denoising for each oil port to obtain a spectrogram, and use the sum of the products of all frequency components in the spectrogram and their corresponding energies as the pressure-holding evaluation value of each oil port.

[0026] Preferably, the obtaining of the fault degree of the to-be-tested hydraulic check valve includes:

[0027] Form a fault evaluation vector from the pressure-rise evaluation values and pressure-holding evaluation values of all oil ports of the to-be-tested hydraulic check valve;

[0028] Obtain the pressure-rise section signal and pressure-holding section signal of each oil port in the hydraulic check valve that has not leaked during the historical period, and calculate the pressure-rise evaluation value and pressure-rise evaluation value of each oil port in the non-leaking hydraulic check valve, and form a historical reference vector from them;

[0029] Calculate the difference between the fault evaluation vector and the historical reference vector as the fault degree of the to-be-tested hydraulic check valve.

[0030] Preferably, the evaluating of the leakage fault of the to-be-tested hydraulic check valve includes:

[0031] If the fault degree is greater than the preset threshold, the to-be-tested hydraulic check valve has a leakage fault; otherwise, the to-be-tested hydraulic check valve does not have a leakage fault.

[0032] This application has at least the following beneficial effects:

[0033] In this application, signals with the trend terms eliminated are extracted from the signals at the pressure boost stage of each oil port in the hydraulic control check valve to be tested. The similar change characteristics of the signals with the trend terms eliminated are analyzed under different frequency components, and the signal similarity of any modal component is calculated. The beneficial effect is that after eliminating the trend existing in the pressure boost stage signals, it is determined whether the signals are similar at the frequency corresponding to this modal component, so as to reflect the possibility that this modal component is a noise signal component. Secondly, through the signal similarity, the modal components of the noise signals are removed, the remaining modal components are signal-reconstructed, and then fused with the trend term signals to obtain the pressure boost stage signals after denoising for each oil port, and the pressure boost evaluation values for each oil port are obtained. The beneficial effect is that compared with the existing denoising algorithms, it effectively avoids the possibility that the true signal trend in the pressure boost stage signals is misidentified as noise and wrongly removed during the denoising process, improves the accuracy of subsequent evaluation of the change trend of the denoised pressure boost stage signals, and further extracts the latent leakage fault information of the hydraulic control check valve more accurately and effectively during its pressure boost process. Analyze the autocorrelation of the signals at the pressure holding stage of each oil port in the hydraulic control check valve to be tested, remove the modal components without autocorrelation characteristics, so as to remove the modal components containing noise components, and perform signal reconstruction on the remaining modal components to obtain the pressure holding stage signals after denoising for each oil port. The beneficial effect is that it reduces the influence of the noise in the pressure holding stage signals on the subsequent evaluation of the weak leakage fault information latent in the pressure holding stage signals. Through the frequency domain analysis of the pressure holding stage signals after denoising for each oil port, the pressure holding evaluation values for each oil port are determined. The beneficial effect is that it can extract the latent leakage fault information in the denoised pressure holding stage signals more accurately and effectively. Through the pressure boost evaluation values and the pressure holding evaluation values of all the oil ports of the hydraulic control check valve to be tested, the fault degree of the hydraulic control check valve to be tested is obtained, and the leakage fault of the hydraulic control check valve to be tested is evaluated. The beneficial effect is that by comparing the hydraulic control check valve to be tested with the non-leaking hydraulic control check valve, it can effectively monitor the latent early weak leakage fault information in the hydraulic control check valve to be tested, and then timely handle the leakage fault of the hydraulic control check valve to be tested, reducing the risk of safety accidents in the hydraulic support. Brief Description of the Drawings

[0034] The following further elaborates in detail a method for collecting fault information of a hydraulic control check valve for a hydraulic support according to this application with reference to the drawings.

[0035] Figure 1 It is a flowchart of the steps of a method for collecting fault information of a hydraulic control check valve for a hydraulic support provided by an embodiment of this application;

[0036] Figure 2 It is a flowchart of the steps of a method for obtaining the pressure holding evaluation values of each oil port provided by an embodiment of this application;

[0037] Figure 3The flowchart of the method for obtaining the fault degree provided by the embodiment of the present application. Detailed implementation manners

[0038] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the following further details a method for collecting fault information of a hydraulic control one-way valve for a hydraulic support proposed by the present application in combination with the accompanying drawings and implementation examples. It should be understood that the specific implementation examples described herein are only used to explain the present application and are not used to limit the present application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs.

[0040] Please refer to Figure 1 , which shows the flowchart of the steps of a method for collecting fault information of a hydraulic control one-way valve for a hydraulic support provided by an embodiment of the present application. The method includes the following steps:

[0041] Step 1: Denote the oil inlet and oil outlet of the hydraulic control one-way valve to be measured as each oil port, and respectively obtain the pressures at all times during the pressure increase period and the pressure holding period of each oil port, which are denoted as the pressure increase section signal and the pressure holding section signal of each oil port.

[0042] In a hydraulic system, a hydraulic control one-way valve is a commonly used direction control valve in the hydraulic system. It is mainly applied to occasions in the hydraulic system to prevent the reverse flow of oil. The hydraulic control one-way valve is often used for short-term pressure holding and locking of a hydraulic working circuit. When two hydraulic control one-way valves are used together, the function of mutual locking of two working circuits can be realized.

[0043] The hydraulic control one-way valve is very likely to fail and affect the normal operation of the shearer at the same time. Among them, the leakage of the hydraulic control one-way valve will have a certain impact on the performance of the shearer. The reasons for the leakage of the one-way valve are generally caused by sealing problems, such as damage to the oil hole sealing ring, damage to the sealing surface connected to the oil circuit, improper selection of the sealing ring, and unreasonable sealing form, etc.

[0044] To detect whether the hydraulic control one-way valve has a leakage phenomenon, a pressure sensor is respectively installed at the positions before and after the valve of the hydraulic control one-way valve in the hydraulic support to be measured, and the pressures of the oil inlet and oil outlet of the hydraulic control one-way valve to be measured at different times during the pressure increase period and the pressure holding period are collected;

[0045] Denote the pressures of the oil inlet of the hydraulic control one-way valve to be measured at all times during the pressure increase period and the pressure holding period as the pressure increase section signal and the pressure holding section signal of the oil inlet;

[0046] Denote the pressures of the oil outlet of the hydraulic control one-way valve to be measured at all times during the pressure increase period and the pressure holding period as the pressure increase section signal and the pressure holding section signal of the oil outlet.

[0047] In this embodiment, the acquisition frequency of the pressure sensor is set to 1KHz, wherein the acquisition duration of the pressure holding section signal is set to 8s. As other implementation methods, the implementer can set them according to actual conditions, and this embodiment does not impose any special restrictions on this.

[0048] At this point, the pressure-rising section signal and the pressure-maintaining section signal of the oil inlet of the hydraulically controlled one-way valve to be tested, as well as the pressure-rising section signal and the pressure-maintaining section signal of the oil outlet are obtained.

[0049] Step 2, extracting the signal with trend item and the signal with trend item eliminated from the boost section signal of each oil port; performing modal decomposition on the signal with trend item eliminated, analyzing the similarity of signals in different time periods in any modal component corresponding to the signal with trend item eliminated in the frequency domain, and determining the signal similarity of any modal component; based on the signal similarity, reconstructing the signal after filtering the modal components, and obtaining the boost section signal of each oil port after denoising in combination with the signal with trend item; obtaining the boost evaluation value of each oil port based on the changing trend of the boost section signal of each oil port after denoising.

[0050] Due to the noise interference in the process of collecting and transmitting pressure data, some useful information features will be covered. When the hydraulic control one-way valve has an early weak leakage caused by the wear or tear of its valve core and sealing ring, it is difficult to detect such early weak leakage fault by monitoring the abnormal pressure data in the control chamber of the hydraulic control one-way valve. However, this early weak leakage will slow down the pressure increase speed of the pressure in the control chamber of the hydraulic control one-way valve during its pressure increase process, which is smaller than the pressure increase speed of the hydraulic control one-way valve without leakage during its pressure increase process; and the greater the leakage degree of this early weak leakage fault, the smaller the pressure increase speed during the pressure increase process. However, the pressure collected during the pressure increase process cannot accurately evaluate the pressure increase rate of the pressure increase process due to the mixing of noise signals, which leads to the inability to effectively extract the leakage information carried by the pressure of the hydraulic control one-way valve during the pressure increase process.

[0051] Secondly, since the pressure data of the hydraulically controlled one-way valve has an obvious upward trend during the boost process, the traditional denoising algorithm will mistake some real change trends in the pressure data as noise during the denoising process and remove them incorrectly, which will affect the subsequent evaluation accuracy of the change trend of the denoised pressure data. Therefore, after eliminating the trend in the boost signal, the noise information contained therein is analyzed and the noise in the signal is removed. The specific process is as follows:

[0052] The oil inlet and outlet of the hydraulically controlled one-way valve to be tested are recorded as the oil ports;

[0053] The signal trend elimination method is adopted to extract the signal with trend item and the signal with trend elimination item from the boost section signal of each oil port.

[0054] In this embodiment, a detrending method based on the least squares method is adopted. Among them, the detrending method based on the least squares method is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the prior art. For example, a detrending method based on an sgolay filter, etc. This embodiment does not make special restrictions on this.

[0055] During the pressure increase process of the hydraulic check valve, the control pressure oil will enter the control chamber of the hydraulic check valve from the control port to push the spool to move. During this pressure increase process, the movement of the spool of the hydraulic check valve is usually continuous and in the same direction. Secondly, the control pressure of the spool will gradually increase during the pressure increase process, and the movement of the spool is relatively smooth, so that the pressure data collected during the pressure increase process has a similar signal frequency distribution in different time periods, while the noise usually destroys this distribution due to its time-varying characteristics.

[0056] Therefore, analyze the similarity of the frequency characteristics of the detrended signal and calculate the signal similarity. Specifically:

[0057] Perform modal decomposition on the detrended signal to obtain multiple modal components;

[0058] In this embodiment, a variational mode decomposition algorithm is adopted for modal decomposition. Among them, the variational mode decomposition algorithm is a well-known technology and will not be elaborated here; secondly, the number of modal components is 10. As other implementation manners, implementers can set it by themselves according to the actual situation.

[0059] Divide each modal component corresponding to the detrended signal into multiple signal segments;

[0060] In this embodiment, each modal component corresponding to the detrended signal is evenly divided into 8 signal segments. As other implementation manners, implementers can set it by themselves according to the actual situation.

[0061] Perform frequency domain analysis on each signal segment to obtain the spectrogram of each signal segment;

[0062] In this embodiment, fast Fourier transform is adopted for frequency domain analysis to obtain the spectrogram. Among them, fast Fourier transform is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the prior art. For example, discrete Fourier transform, etc. This embodiment does not make special restrictions on this.

[0063] It should be noted that the abscissa in the spectrogram represents frequency and the ordinate represents energy. Therefore, each frequency corresponds to an energy. Denote each frequency as each frequency component, and the energy corresponding to each frequency component can be obtained.

[0064] The mean of the similarity degrees of the spectrograms corresponding to all arbitrary two signal segments in each modal component corresponding to the detrended signal is used as the signal similarity of each modal component corresponding to the detrended signal.

[0065] In this embodiment, the similarity degree is measured by calculating the cosine similarity of the energies of all frequency components in the spectrograms corresponding to any two signal segments. Among them, the calculation of the cosine similarity is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the existing technology, such as the Pearson correlation coefficient, etc. This embodiment does not make special restrictions on this.

[0066] It should be noted that the smaller the signal similarity, the less similar the frequency distribution characteristics of the pressure data of this modal component in different time periods, which reflects that this modal component is more likely to be the noise signal component in the detrended signal.

[0067] Furthermore, based on the signal similarity, the noise signal components are screened to eliminate the noise signals. Specifically:

[0068] Obtain the segmentation threshold of the signal similarities of all modal components corresponding to the detrended signal, denoted as the first segmentation threshold.

[0069] In this embodiment, the Otsu threshold segmentation algorithm is used to obtain the first segmentation threshold. Among them, the Otsu threshold segmentation algorithm is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the existing technology, such as the cross-validation method, etc. This embodiment does not make special restrictions on this.

[0070] Perform signal reconstruction on all modal components whose signal similarities are greater than the first segmentation threshold, and add the amplitudes of the reconstructed signals and the signals with trend terms at the same moment to obtain the boosted pressure section signals after denoising for each oil port.

[0071] It should be noted that the process of signal reconstruction is a well-known technology and will not be elaborated here.

[0072] Take the slope of the fitting straight line after linearly fitting the boosted pressure section signals of each oil port as the boosted pressure evaluation value of each oil port.

[0073] In this embodiment, the least squares method is used for linear fitting. Among them, the least squares method is a well-known technology and will not be elaborated here.

[0074] It should be noted that the boost evaluation value reflects the change in the boost speed of the oil inlet and the oil outlet during the boost process, and is used to evaluate the degree of early weak leakage fault information carried by the pressure data at the oil inlet and the oil outlet of the to-be-tested pilot-operated check valve during the boost process. The larger the boost evaluation value, the faster the boost speed of the oil inlet and the oil outlet during the boost process. The greater the difference between the boost evaluation value and that of the pilot-operated check valve during the non-leakage period, the greater the possibility that the to-be-tested pilot-operated check valve has a leakage fault.

[0075] Thus, the boost evaluation values of the oil inlet and the oil outlet of the to-be-tested pilot-operated check valve are obtained.

[0076] Step 3: Perform modal decomposition on the pressure-holding section signals of each oil port, analyze the correlation characteristics of each modal component corresponding to the pressure-holding section signals of each oil port. After screening all modal components and through signal reconstruction, obtain the pressure-holding section signals after denoising for each oil port; determine the pressure-holding evaluation values of each oil port based on the distribution of the pressure-holding section signals after denoising for each oil port in the frequency domain.

[0077] Furthermore, during the pressure-holding process of the pilot-operated check valve in normal operation, the pressure in its control chamber is usually stable and unchanged, making the pressure change of the pilot-operated check valve during the pressure-holding process relatively stable, that is, having a small signal frequency and fluctuation amplitude. If the pilot-operated check valve has a leakage, the pressure in the control chamber of the pilot-operated check valve will slowly decrease due to the leakage. When the pressure drops to a certain value, the pressure gauge in the pressure-holding circuit will trigger a signal, causing the hydraulic pump to resume supplying oil to the control chamber to increase the pressure to maintain the pressure in the control chamber. After the hydraulic pump stops supplying oil, the pressure will drop again, resulting in an approximately periodic fluctuation in the pressure waveform of the pilot-operated check valve during its pressure-holding process. Moreover, the more serious the leakage phenomenon, the greater the degree and speed of pressure drop, and the higher the oil supply frequency, making the frequency and amplitude of the pressure signal also larger. However, during the pressure-holding process, the pressure will be affected by noise, masking this pressure change characteristic caused by the early weak leakage fault of the pilot-operated check valve. Therefore, it is necessary to perform denoising processing on the pressure data during the pressure-holding process.

[0078] Based on the above analysis, the pressure data of the pilot-operated check valve during the pressure-holding process has strong autocorrelation, while the noise does not have autocorrelation due to its randomness and complexity. Therefore, by analyzing the autocorrelation characteristics of the pressure-holding section signals, removing the noise signal components, and calculating the pressure-holding evaluation value, the step flow chart of the method for obtaining the pressure-holding evaluation values of each oil port provided in the embodiments of the present application is as Figure 2 shown, and specifically includes:

[0079] Perform modal decomposition on the pressure-holding section signals of each oil port to obtain multiple modal components;

[0080] In this embodiment, the variational mode decomposition algorithm is used for mode decomposition. Among them, the variational mode decomposition algorithm is a well-known technology and will not be elaborated here. Secondly, the number of mode components is 10. As other implementation manners, the implementer can set it according to the actual situation.

[0081] Calculate the autocorrelation coefficient of each mode component;

[0082] In this embodiment, when calculating the autocorrelation coefficient, the delay amount is set to 3. As other implementation manners, the implementer can set it according to the actual situation. Among them, the calculation of the autocorrelation coefficient is a well-known technology and will not be elaborated here.

[0083] It should be noted that the smaller the autocorrelation coefficient, the weaker the autocorrelation of the mode component and the more likely it is to be a noise component.

[0084] Obtain the segmentation threshold of the autocorrelation coefficients of all mode components corresponding to the pressure-holding section signals of each oil port, denoted as the second segmentation threshold;

[0085] In this embodiment, the Otsu threshold segmentation algorithm is used to obtain the second segmentation threshold. Among them, the Otsu threshold segmentation algorithm is a well-known technology and will not be elaborated here. As other implementation manners, the implementer can adopt other methods of the existing technology, such as the cross-validation method, etc. This embodiment does not make special restrictions on this. Secondly, the process of signal reconstruction is a well-known technology and will not be elaborated here.

[0086] Perform signal reconstruction on all mode components of each oil port whose autocorrelation coefficient is greater than the second segmentation threshold to obtain the pressure-holding section signals after denoising for each oil port;

[0087] It should be noted that the method of signal reconstruction is a well-known technology and will not be elaborated here.

[0088] Perform frequency-domain analysis on the pressure-holding section signals after denoising for each oil port to obtain a spectrogram, and take the sum of the products of all frequency components in the spectrogram and their corresponding energies as the pressure-holding evaluation value for each oil port;

[0089] In this embodiment, the fast Fourier transform is used for frequency-domain analysis. Among them, the fast Fourier transform is a well-known technology and will not be elaborated here.

[0090] It should be noted that the pressure-holding evaluation value reflects the degree of early weak leakage fault information characterized by the pressure data at the inlet and outlet ports of the to-be-tested hydraulic check valve during the pressure-holding process. The greater the difference between the pressure-holding evaluation value and that of the hydraulic check valve during the non-leakage period, the greater the possibility that the to-be-tested hydraulic check valve has a leakage fault this time, and the more early weak leakage fault information is contained in the pressure-holding section signal.

[0091] So far, the pressure-holding evaluation values of the oil inlet and the oil outlet of the hydraulic check valve to be tested are obtained.

[0092] Step 4: Based on the pressure-rise evaluation values and the pressure-holding evaluation values of all the oil ports, obtain the fault degree of the hydraulic check valve to be tested, and evaluate the leakage fault of the hydraulic check valve to be tested.

[0093] Furthermore, based on the pressure-rise evaluation values and the pressure-holding evaluation values of the oil inlet and the oil outlet of the hydraulic check valve to be tested, evaluate the leakage fault of the hydraulic check valve, specifically:

[0094] Combine the pressure-rise evaluation value of the oil inlet of the hydraulic check valve to be tested, the pressure-rise evaluation value of the oil outlet, the pressure-holding evaluation value of the oil inlet, and the pressure-holding evaluation value of the oil outlet to form a fault evaluation vector.

[0095] Through a pressure sensor, obtain the pressure-rise section signals and the pressure-holding section signals of the oil inlet and the oil outlet in the hydraulic check valve without leakage in the historical period, and based on the above method, calculate the pressure-rise evaluation value of the oil inlet of the hydraulic check valve without leakage, the pressure-rise evaluation value of the oil outlet, the pressure-holding evaluation value of the oil inlet, and the pressure-holding evaluation value of the oil outlet, and form a historical reference vector.

[0096] Calculate the normalized result of the difference between the fault evaluation vector and the historical reference vector, and denote it as the fault degree.

[0097] In this embodiment, calculate the DTW distance between the fault evaluation vector and the historical reference vector. The calculation of the DTW distance is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the prior art, such as the reciprocal of the cosine similarity, etc. Secondly, perform normalization processing using the sigmoid function. The sigmoid function is a well-known technology and will not be elaborated here. As other implementation manners, implementers can adopt other methods of the prior art, such as the tanh function, etc. This embodiment does not make special restrictions on this.

[0098] If the fault degree is greater than the preset threshold, the hydraulic check valve to be tested has a leakage fault. Otherwise, the hydraulic check valve to be tested does not have a leakage fault.

[0099] In this embodiment, the preset threshold is set to 0.6. As other implementation manners, implementers can set it according to the actual situation.

[0100] It should be noted that the greater the fault degree, the more serious the leakage fault of the hydraulic check valve to be tested. Among them, the step flow chart of the method for obtaining the fault degree provided by the embodiment of the present application is as Figure 3 shown.

[0101] It should be understood that although Figure 1The steps in the flowchart are shown in sequence according to the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise clearly stated in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least some of the steps in Figure 1 may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed alternately or in rotation with at least some of the other steps or sub-steps or stages of the other steps.

[0102] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as within the scope described in this specification.

[0103] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation to the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application all belong to the protection scope of the technical solution of the present application.

Claims

1. A method for collecting fault information of a hydraulically controlled one-way valve for a hydraulic support, characterized in that: The method comprises the following steps: The oil inlet and the oil outlet of the hydraulically controlled one-way valve to be tested are recorded as each oil port, and the pressure of each oil port at all times during the pressure-increasing period and the pressure-maintaining period are respectively obtained, which are recorded as the pressure-increasing section signal and the pressure-maintaining section signal of each oil port; Extract the signals with trend items and the signals with trend elimination items from the boost section signals of each oil port; perform modal decomposition on the signals with trend elimination items, analyze the similarity of signals in different time periods in any modal component corresponding to the signals with trend elimination items in the frequency domain, and determine the signal similarity of any modal component; based on the signal similarity, perform signal reconstruction after filtering the modal components, and obtain the boost section signals of each oil port after denoising in combination with the signals with trend items; The slope of the fitted straight line after performing linear fitting on the boost section signal of each oil port after denoising is recorded as the boost evaluation value of each oil port; Perform modal decomposition on the pressure holding section signal of each oil port, analyze the correlation characteristics of each modal component corresponding to the pressure holding section signal of each oil port, screen all modal components and reconstruct the signal to obtain the denoised pressure holding section signal of each oil port; Perform frequency domain analysis on the pressure holding signals of each oil port after denoising to obtain a spectrum diagram, and take the cumulative sum of the products between all frequency components in the spectrum diagram and their corresponding energies as the pressure holding evaluation value of each oil port; Based on the pressure increase evaluation value and the pressure maintenance evaluation value of all oil ports, the fault degree of the hydraulically controlled one-way valve to be tested is obtained, and the leakage fault of the hydraulically controlled one-way valve to be tested is evaluated.

2. A method for collecting fault information of a hydraulically controlled one-way valve for a hydraulic support as claimed in claim 1, characterized in that: The signal trend elimination method is adopted to extract the signal with trend term and the signal with trend elimination term from the boost section signal of each oil port.

3. A method for collecting fault information of a hydraulically controlled one-way valve for a hydraulic support as claimed in claim 1, characterized in that: The determining the signal similarity of any modal component comprises: Divide any modal component into multiple signal segments; perform frequency domain analysis on each signal segment to obtain a frequency spectrum of each signal segment; The signal similarity is the average of the similarities of the frequency spectrograms corresponding to all any two signal segments in any modal component.

4. A method for collecting fault information of a hydraulically controlled one-way valve for a hydraulic support as claimed in claim 1, characterized in that: The process of obtaining the boost section signal after denoising of each oil port is as follows: Obtaining a segmentation threshold of signal similarity of all modal components corresponding to the signal for eliminating the trend term, recorded as a first segmentation threshold; performing signal reconstruction on all modal components of each oil port whose signal similarity is greater than the first segmentation threshold; The amplitude of the reconstructed signal and the signal with trend term at the same time are added to obtain the boost section signal of each oil port after denoising.

5. A method for collecting fault information of a hydraulically controlled one-way valve for a hydraulic support as claimed in claim 1, characterized in that: A further measurement method of the correlation feature is: calculating the autocorrelation coefficient of each modal component corresponding to the pressure holding section signal of each oil port.

6. A method for collecting fault information of a hydraulically controlled one-way valve for a hydraulic support as claimed in claim 5, characterized in that: The process of obtaining the pressure holding section signal after denoising of each oil port is as follows: Obtaining the segmentation threshold of the autocorrelation coefficients of all modal components corresponding to the pressure-maintaining section signals of each oil port, recorded as the second segmentation threshold; Signal reconstruction is performed on all modal components of each oil port whose autocorrelation coefficient is greater than the second segmentation threshold to obtain a denoised pressure holding section signal of each oil port.

7. A method for collecting fault information of a hydraulically controlled one-way valve for a hydraulic support as claimed in claim 1, characterized in that: The step of obtaining the fault degree of the hydraulically controlled one-way valve to be tested comprises: The pressure increase evaluation values ​​and pressure maintenance evaluation values ​​of all oil ports of the hydraulically controlled one-way valve to be tested are used to form a fault evaluation vector; Obtain the pressure-rising section signal and the pressure-maintaining section signal of each oil port in the hydraulically-controlled one-way valve without leakage in the historical period, and calculate the pressure-rising evaluation value and the pressure-rising evaluation value of each oil port in the hydraulically-controlled one-way valve without leakage, and form them into a historical reference vector; The difference between the fault assessment vector and the historical reference vector is calculated as the fault degree of the hydraulically controlled one-way valve to be tested.

8. A method for collecting fault information of a hydraulically controlled one-way valve for a hydraulic support as claimed in claim 1, characterized in that: The leakage fault assessment of the hydraulically controlled one-way valve to be tested includes: If the fault degree is greater than a preset threshold, the hydraulically controlled one-way valve to be tested has a leakage fault; otherwise, the hydraulically controlled one-way valve to be tested does not have a leakage fault.

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