Signal acquisition method and device for fault diagnosis of hydraulic pump

Abstract

The invention provides a signal acquisition method and device for fault diagnosis of a hydraulic pump, and belongs to the field of hydraulic pumps. The method comprises the following steps: identifying importance degrees of a plurality of diagnosis signals under various faults of the hydraulic pump; determining a core signal and an auxiliary signal based on the importance degree; determining a first acquisition frequency according to the change trend of the core signal; determining a second acquisition frequency set at least according to the first acquisition frequency and the change trend and historical fluctuation of the auxiliary signal; respectively calculating a first storage frequency and a second storage frequency according to the first acquisition frequency and a representative second acquisition frequency in the second acquisition frequency set; the core signals are collected based on the first collection frequency, the auxiliary signals are collected based on the second collection frequency, the core signals are stored based on the first storage frequency, and the auxiliary signals are stored based on the second storage frequency. According to the signal collection method and device for fault diagnosis of the hydraulic pump, the storage frequency of the non-core signals can be adjusted in a self-adaptive mode.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic pumps, and in particular to a signal acquisition method and device for hydraulic pump fault diagnosis. Background Art

[0002] With the continuous development of modern industry, hydraulic pumps are key power components in many mechanical equipment, and their reliability and stability are crucial to the normal operation of the entire system. In the fields of aviation, industrial manufacturing, etc., once a hydraulic pump fails, it may lead to serious consequences, such as aircraft flight safety issues, production line shutdowns, etc., so higher and higher requirements are placed on the fault diagnosis and operation status monitoring of hydraulic pumps.

[0003] Traditional hydraulic pump fault diagnosis mainly relies on manual periodic inspection and empirical judgment, which has many limitations. On the one hand, manual inspection is difficult to achieve real-time and continuous monitoring of hydraulic pumps. It can only be inspected when the equipment is shut down or undergoes regular maintenance, and it is impossible to capture sudden fault hazards during equipment operation in a timely manner. On the other hand, the accuracy of manual diagnosis depends largely on the experience level of technicians. Different people may have different judgments, which may easily lead to misjudgment or missed judgments.

[0004] At the same time, with the rapid development of electronic technology, information technology and sensor technology, intelligent monitoring and data management technologies have gradually emerged and have been widely used in various industrial fields. In the field of hydraulic pumps, it is also urgent to introduce these advanced technologies to achieve accurate monitoring of the operating status of hydraulic pumps, early warning of faults and efficient data management. Since hydraulic pumps have many parameters for fault diagnosis, and the online diagnostic function requires a lot of space resources and CPU performance during diagnosis and storage, it is impossible to process and transmit large amounts of data in real time. Therefore, it is necessary to study how to reduce the storage burden of the controller, improve the efficiency of diagnostic operations, extend the storage record time, and improve the final storage performance. Summary of the invention

[0005] In view of this, the present application provides a signal acquisition method and device for hydraulic pump fault diagnosis, which can adaptively adjust the storage frequency of non-core signals to improve storage performance.

[0006] Specifically, the present application is implemented through the following technical solutions: In a first aspect, the present application provides a signal acquisition method for hydraulic pump fault diagnosis, the method comprising: Identify the importance of multiple diagnostic signals under various faults of the hydraulic pump; Determining core signals and auxiliary signals based on the importance; Determining a first acquisition frequency according to a change trend of the core signal; Determine a second acquisition frequency set at least according to the first acquisition frequency, the change trend of the auxiliary signal and the historical fluctuation, wherein each second acquisition frequency in the second acquisition frequency set corresponds to an auxiliary signal, the second acquisition frequencies are not completely the same, and the first acquisition frequency is greater than the second acquisition frequency; Calculate a first storage frequency and a second storage frequency respectively according to a representative second acquisition frequency in the first acquisition frequency and the second acquisition frequency set, wherein the first storage frequency is calculated based on the first acquisition frequency, and the second storage frequency is calculated based on a relationship between the representative second acquisition frequency and a sampling rate threshold of the representative second acquisition frequency; The core signal is acquired based on the first acquisition frequency, the auxiliary signals are acquired based on the second acquisition frequency set, the core signal is stored based on the first storage frequency, and the auxiliary signals are stored based on the second storage frequency.

[0007] A second aspect of the present application provides a signal acquisition device for hydraulic pump fault diagnosis, the device comprising an identification module, a determination module, a calculation module and a storage module; wherein: The identification module is used to identify the importance of multiple diagnostic signals under various faults of the hydraulic pump; The determination module is used to determine the core signal and the auxiliary signal based on the importance; The determination module is further used to determine the first acquisition frequency according to the change trend of the core signal; The determination module is further used to determine a second acquisition frequency set based on at least the first acquisition frequency, the change trend of the auxiliary signal and the historical fluctuation, wherein each second acquisition frequency in the second acquisition frequency set corresponds to an auxiliary signal, the second acquisition frequencies are not completely the same, and the first acquisition frequency is greater than the second acquisition frequency; The calculation module is used to calculate a first storage frequency and a second storage frequency respectively according to a representative second acquisition frequency in the first acquisition frequency and the second acquisition frequency set, wherein the first storage frequency is calculated based on the first acquisition frequency, and the second storage frequency is calculated based on a relationship between the representative second acquisition frequency and a sampling rate threshold of the representative second acquisition frequency; The storage module is used to collect the core signal based on the first acquisition frequency, collect each of the auxiliary signals based on the second acquisition frequency set, store the core signal based on the first storage frequency, and store each of the auxiliary signals based on the second storage frequency.

[0008] The signal acquisition method and device for hydraulic pump fault diagnosis provided by the present application can accurately capture information that is crucial to fault diagnosis by identifying the importance of multiple diagnostic signals under various faults of the hydraulic pump, distinguishing between core signals and auxiliary signals, and determining the first acquisition frequency for the core signal according to its change trend. When determining the second acquisition frequency set of the auxiliary signal, comprehensively considering factors such as its change trend and historical fluctuations, it can ensure that various aspects of information related to the fault are obtained, and avoid collecting too much irrelevant data. In addition, the storage frequency is calculated based on different acquisition frequencies, and the core signal is stored at the first acquisition frequency, which ensures the integrity of the core data and provides a reliable basis for subsequent in-depth analysis and fault tracing. For the auxiliary signal, the storage frequency is adjusted according to the relationship between the representative second acquisition frequency and the sampling rate threshold, and the storage amount is reasonably controlled on the premise that the data has a certain value for fault diagnosis. This adaptive storage strategy can not only avoid wasting resources due to storing too much unimportant data, but also ensure that key information is not lost, effectively improve the utilization efficiency of storage resources, and enable the system to store historical data for a longer period of time. Therefore, this can accurately obtain valuable information for fault diagnosis, avoid collecting too much useless data, improve the pertinence and effectiveness of data collection, and effectively reduce storage space occupancy and avoid the storage of invalid data. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A flow chart of a first embodiment of a signal acquisition method for hydraulic pump fault diagnosis provided by the present application; Figure 2 This is a structural schematic diagram of Example 1 of a signal acquisition device for hydraulic pump fault diagnosis provided in the present application. DETAILED DESCRIPTION

[0010] Here, exemplary embodiments will be described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0011] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

[0012] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0013] Specific embodiments are given below to introduce the technical solution of the present application in detail.

[0014] Figure 1 This is a flow chart of the first embodiment of the signal acquisition method for hydraulic pump fault diagnosis provided by this application. Figure 1 , the method provided in this embodiment may include: S101. Identify the importance of multiple diagnostic signals under various faults of the hydraulic pump.

[0015] It should be noted that the method provided in the present application stores multiple diagnostic signals under various faults in the form of files. In the specific implementation, in the Linux system, a corresponding storage directory (for example, it can be / userdata / Store) is established, and the hydraulic pump is uniformly named with the prefix yyb. When the multiple diagnostic signals are axial vibration signal, radial vibration signal, return oil temperature, outlet temperature, return oil pressure and outlet pressure, they can be named in the following way: the axial vibration signal is named Vib_1, the radial vibration signal is named Vib_2, the return oil temperature is named T_oil, the outlet temperature is named T_out, the return oil pressure is named P_oil, and the outlet pressure is named P_out. In order to achieve granular refinement, avoid data coupling and reduce storage in minutes, six new files are created every minute to store the axial vibration signal, radial vibration signal, return oil temperature, return oil pressure, outlet temperature, and outlet pressure at the current moment. In each file, the corresponding data generation time, sampling rate, amount of data stored per second, corresponding storage interval and other information will be written.

[0016] Specifically, the importance of multiple diagnostic signals under various faults of the hydraulic pump is identified, including: (1) Obtaining historical data under multiple fault modes and determining multiple diagnostic signals based on the historical data.

[0017] In the fault diagnosis of hydraulic pumps, different fault modes (such as leakage, overload, pressure fluctuation, etc.) will show different diagnostic signals. In order to accurately determine the manifestation of these faults, it is necessary to first collect a variety of historical fault data. These data can be derived from the actual operation of the hydraulic pump. Sensors are used to record multiple signals such as pressure, flow, temperature, vibration, etc. of the hydraulic pump under different fault modes. Then, these data are analyzed, and by extracting the features of different fault modes, it is possible to identify which signals are the most significant or have the most diagnostic value in each fault situation. These signals are diagnostic signals.

[0018] (2) Calculate the sensitivity of each diagnostic signal under different fault modes.

[0019] For different fault modes, the sensitivity of each diagnostic signal is calculated, that is, the degree to which each signal responds to a specific fault. For example, for some mechanical faults, the vibration signal may be the most sensitive, while for hydraulic system pressure abnormalities, the pressure signal may be more sensitive.

[0020] Specifically, firstly, the diagnostic signal data under different fault modes are obtained through sensors. Secondly, for different diagnostic signals, the fault-related features are extracted, such as the mean, variance, frequency component, fluctuation amplitude, etc. of the signal, and the diagnostic signals under normal operation and fault conditions are compared. For example, the sensitivity of each signal to a certain fault is calculated through the rate of change (the percentage of change of the signal under normal state and fault state), signal-to-noise ratio (the ratio of fault signal to noise signal) or correlation analysis (correlation coefficient between signal and fault mode).

[0021] (3) Setting priorities based on the sensitivity, and determining the importance of multiple diagnostic signals under various types of faults based on the priorities.

[0022] Different signals are ranked according to their sensitivity. A signal with a higher sensitivity is more effective in diagnosing this type of fault and has a higher priority. It should be noted that the importance of diagnostic signals varies under different fault modes.

[0023] S102: Determine a core signal and an auxiliary signal based on the importance.

[0024] In combination with the above content, the core signal and auxiliary signal are determined based on the importance. Among them, the core signal is a high-priority signal, that is, it is a signal that is significantly sensitive to one or more faults and can quickly and accurately identify faults. It is a key indicator for fault diagnosis and can usually directly reflect the operating status and potential problems of the equipment. The auxiliary signal is a low-priority signal, that is, it is sensitive to faults but not decisive. It is a signal that can provide additional information for fault diagnosis. For example, in the vibration of hydraulic pump faults, the core signal is the vibration signal, and the auxiliary signals can be the return oil temperature signal, return oil pressure signal, outlet temperature signal, and outlet pressure signal. These signals do not need to be used as core signals for large-scale calculations in the time domain and frequency domain, but are only used as criteria and features.

[0025] S103: Determine a first acquisition frequency according to a change trend of the core signal.

[0026] It should be noted that determining the first acquisition frequency according to the change trend of the core signal includes: (1) Collect core signal data and analyze the changing trend of the core signal in real time.

[0027] After identifying the core signal in the corresponding fault mode, the core signal can be collected by using the corresponding sensor to obtain the core signal data. It should be noted that before analysis, the collected core signal can be pre-processed, such as filtering, denoising, etc., to eliminate measurement noise or interference signals and ensure the accuracy of the signal.

[0028] Use real-time data processing algorithms to analyze the core signal and observe whether the core signal has obvious trend changes, such as the rising or falling trend of the pressure signal, the sudden increase of the vibration signal, etc. It can also include analyzing the volatility of the core signal, such as the amplitude change, frequency change, oscillation mode, etc. of the core signal. During the analysis process, focus on extracting the key parameters of the core signal (such as the average value, maximum value, minimum value, frequency component of the vibration signal, etc.), track the changes of these parameters, and record them if large fluctuations or trend changes are found in the parameters.

[0029] (2) Obtain core signal historical data and determine the sampling rate threshold.

[0030] Obtain historical data of the core signal from the monitoring system or data recording device of the hydraulic pump, match the historical sampling frequency of the core signal within the corresponding time range and during the corresponding fluctuation or trend change from the historical data based on the above recorded data, perform statistical analysis based on the historical sampling frequency, calculate the basic statistical characteristics of the core signal (such as mean, variance, maximum value, minimum value, etc.), analyze the fluctuation range (upper and lower limits) and change frequency of the core signal under normal operating conditions, set empirical values ​​based on relevant industry experience, and determine the sampling rate threshold in combination with frequency response analysis (such as using Fourier transform and other methods to analyze the frequency domain characteristics of the core signal).

[0031] (3) adjusting the sampling rate threshold based on the collected core signal data, and taking the sampling rate threshold as the first collection frequency; increasing the sampling rate threshold when the change trend of the core signal is greater than a preset value; and decreasing the sampling rate threshold when the change trend amplitude of the core signal is less than a preset value.

[0032] It should be noted that the sampling rate threshold determined based on historical data is adjusted in combination with the analysis results of the core signal data actually collected, and the adjusted sampling rate threshold is used as the first acquisition frequency. The system uses this frequency to collect core signals in real time to ensure that potential fault information can be monitored in a timely manner. If the real-time analysis results show that the change trend of the core signal is greater than the preset value, it means that the hydraulic pump may have a large fluctuation or failure risk. At this time, increasing the sampling rate threshold can increase the data collection frequency, allowing the system to capture small changes more sensitively. If the change trend is less than the preset value, it means that the hydraulic pump is working relatively stably. At this time, lowering the sampling rate threshold will help reduce the amount of data, optimize storage space, and reduce the computational burden of the system.

[0033] S104. Determine a second acquisition frequency set at least according to the first acquisition frequency, the change trend of the auxiliary signal and the historical fluctuation, wherein each second acquisition frequency in the second acquisition frequency set corresponds to an auxiliary signal, the second acquisition frequencies are not completely the same, and the first acquisition frequency is greater than the second acquisition frequency.

[0034] It should be noted that the determining of the second acquisition frequency set at least according to the first acquisition frequency, the change trend and historical fluctuation of the auxiliary signal includes: (1) Obtaining a first acquisition frequency and historical fluctuations, collecting auxiliary signal data, and analyzing the change trend of the auxiliary signal in real time.

[0035] Obtain the first acquisition frequency, historical fluctuations (included in historical data), and start collecting auxiliary signals related to the core signal based on the first acquisition frequency. Perform real-time processing on the collected auxiliary signals, including filtering, denoising, and feature extraction, and use statistical tools and algorithms (such as autoregressive models and Fourier transforms) to analyze the change trends of the auxiliary signals. According to the change trends (such as rise, fall, and periodic fluctuations), determine whether the auxiliary signals have abnormal fluctuations or periodic changes, and record the changes of the auxiliary signals in real time.

[0036] (2) Determine the fluctuation characteristics of the auxiliary signal based on the analysis results and the historical fluctuations.

[0037] By combining the recorded analysis results and historical fluctuations and comparing the changes in the same time range, the fluctuation characteristics of the auxiliary signal can be obtained, that is, when it rises or falls or whether there are periodic fluctuations.

[0038] (3) Determining a second acquisition frequency based on the fluctuation characteristics and the first acquisition frequency.

[0039] According to the previous analysis, the fluctuation amplitude (such as mean, standard deviation, maximum and minimum) and frequency components (such as main frequency and periodicity) of the auxiliary signal are obtained. By observing the fluctuation characteristics, a specific frequency lower than the first acquisition frequency is selected as the second acquisition frequency to ensure that the second acquisition frequency can cover the main change characteristics of the auxiliary signal.

[0040] (4) The second acquisition frequencies corresponding to the auxiliary signals are counted to form a second acquisition frequency set.

[0041] It should be noted that the acquisition frequencies of different auxiliary signals are not completely the same, and therefore, a second acquisition frequency set can be formed by taking statistics of the second acquisition frequencies corresponding to all auxiliary signals.

[0042] S105. Calculate a first storage frequency and a second storage frequency respectively according to a representative second acquisition frequency in the first acquisition frequency and the second acquisition frequency set, wherein the first storage frequency is calculated based on the first acquisition frequency, and the second storage frequency is calculated based on a relationship between the representative second acquisition frequency and a sampling rate threshold of the representative second acquisition frequency.

[0043] It should be noted that the representative second acquisition frequency is extracted from multiple auxiliary signals and can represent the overall characteristics of the auxiliary signals of this category. This ensures that the acquisition frequency can effectively capture the trend and characteristics of signal changes, rather than relying on a certain sampling frequency that may not be representative.

[0044] Specifically, calculating the first storage frequency based on the first acquisition frequency, and calculating the second storage frequency based on the relationship between the representative second acquisition frequency and a sampling rate threshold of the representative second acquisition frequency, includes: (1) Acquire a first acquisition frequency of the core signal, and determine the first acquisition frequency as a first storage frequency.

[0045] It should be noted that the core signal contains key information about the operating status of the hydraulic pump. For example, the vibration signal is crucial for reflecting the wear, imbalance, resonance and other problems of the internal mechanical parts of the hydraulic pump. Slight changes in these signals may indicate potential fault hazards. Therefore, the first acquisition frequency is determined as the first storage frequency, and the storage is maintained at full rate, which ensures that these key information will not be missed at any time, providing the most complete data support for subsequent accurate diagnosis.

[0046] (2) Acquire a second acquisition frequency set of the auxiliary signal, determine the representative second acquisition frequency, and calculate a corresponding sampling rate threshold of the auxiliary signal according to the representative second acquisition frequency.

[0047] According to the determined second acquisition frequency set, a representative second acquisition frequency can be selected based on the characteristics of the signal and its sensitivity in the fault mode, and the representative second acquisition frequency can effectively reflect the change characteristics of all relevant auxiliary signals. It should be noted that the method for calculating the sampling rate threshold of the corresponding auxiliary signal according to the representative second acquisition frequency can be: obtaining the change trend and historical fluctuations of the current auxiliary signal; determining the representative second acquisition frequency of each auxiliary signal based on the change trend of the auxiliary signal; calculating the sampling rate threshold of the representative second acquisition frequency according to the representative second acquisition frequency and the historical fluctuations. Specifically, please refer to the introduction of determining the sampling rate threshold of the core signal above, which will not be repeated here.

[0048] (3) Determining a magnitude relationship between the second acquisition frequency and the sampling rate threshold, and when the second acquisition frequency is less than the sampling rate threshold, determining the second acquisition frequency as the second storage frequency.

[0049] It should be noted that when determining the magnitude relationship between the second acquisition frequency and the sampling rate threshold, the main purpose is to ensure that when the auxiliary signal is acquired, the sampling frequency is high enough to capture the key change information in the signal. If the acquisition frequency of the auxiliary signal is too low, information loss may occur; but if the acquisition frequency is too high, the storage and processing burden may be increased. Therefore, it is necessary to adjust to achieve the purpose of both capturing the key change information in the signal and reducing storage.

[0050] In specific implementation, the relationship between each second acquisition frequency in the second acquisition frequency set and the sampling rate threshold is analyzed, and when the second acquisition frequency is less than the sampling rate threshold, the second acquisition frequency is determined to be the second storage frequency. thres , the second acquisition frequency is fs, the second storage frequency is f store , then when the second acquisition frequency fs < sampling rate threshold f thres When f store =fs.

[0051] (4) When the second acquisition frequency is greater than or equal to the sampling rate threshold, determine the storage coefficient of the auxiliary signal, and determine the second storage frequency based on the product of the storage coefficient and the sampling rate threshold; wherein different acquisition frequency intervals have different storage coefficients.

[0052] It should be noted that determining the storage coefficient of the auxiliary signal includes: the storage resource manager obtains the first storage space occupied by the current processing task, and predicts the second storage space occupied by the processing task in the first time period in the future; based on the first storage space and the second storage space, the remaining available storage space of the storage resource manager is calculated; the storage space required for the core signal is obtained, and the size of the available storage space for the auxiliary signal is determined based on the difference between the remaining available storage space of the storage resource manager and the storage space required for the core signal; the storage coefficient is calculated based on the size of the available storage space for the auxiliary signal and the number of types of auxiliary signals. By obtaining the storage space occupied by the processing tasks of the storage resource manager in the current and future periods, the remaining available space can be accurately calculated. Combined with the space required for the core signal, the size of the available space for the auxiliary signal is determined to ensure that the storage resource allocation is closely matched with the actual available resources of the system to avoid waste or shortage of storage space.

[0053] In addition, during the calculation process, the storage space required for the core signal is first determined and guaranteed to ensure that the core signal is stored at a higher frequency, thereby ensuring the integrity of the core data. Furthermore, the storage coefficient is calculated based on the size of the available space for the auxiliary signal and the number of its types, and the storage frequency can be flexibly allocated according to the importance and data volume requirements of different auxiliary signals. For signals that play an important auxiliary role in fault diagnosis, a relatively high storage frequency is given; while for relatively minor auxiliary signals, the storage frequency is appropriately reduced, which can not only ensure the acquisition of sufficient auxiliary diagnostic information, but also avoid excessive storage of unimportant data, thereby improving the pertinence and effectiveness of fault diagnosis.

[0054] It should also be noted that the storage coefficient is calculated based on the size of the available storage space of the auxiliary signal and the number of types of the auxiliary signal. This process needs to consider not only the number of types of the auxiliary signal, but also the change of the second acquisition frequency of each auxiliary signal. For example, taking any auxiliary signal as an example, when an auxiliary signal has 4 second acquisition frequency intervals, there should also be 4 different storage coefficients, as follows: When the second acquisition rate is 2000Hz>fs>=500Hz, K store =1; When the second acquisition rate is 5000Hz>fs>=2000Hz, K store =1.2; When the second acquisition rate is 20000Hz>fs>=5000Hz, K store =1.8; When the second acquisition rate is 50000Hz>fs>=20000Hz, K store =2; The above division of the second acquisition frequency interval and the corresponding storage coefficient are only exemplary. In addition, the storage coefficient is a positive number, and the value of the storage coefficient can also be a range (for example, 1.2-1.5), which can be adjusted according to actual needs.

[0055] In a specific implementation, the relationship between each second acquisition frequency in the second acquisition frequency set and the sampling rate threshold is analyzed, and when the second acquisition frequency is greater than or equal to the sampling rate threshold, the second storage frequency is determined based on the product of the storage coefficient and the sampling rate threshold. For example, if the sampling rate threshold is f thres , the second acquisition frequency is fs, the second storage frequency is f store , the storage coefficient is K store， Then when the second acquisition frequency fs>=sampling rate threshold f thres When f store =f thres *K store .

[0056] S106: Acquire the core signal based on the first acquisition frequency, acquire each of the auxiliary signals based on the second acquisition frequency set, store the core signal based on the first storage frequency, and store each of the auxiliary signals based on the second storage frequency.

[0057] It should be noted that after the first acquisition frequency and the second acquisition frequency set are determined, the core signal is acquired based on the first acquisition frequency, and each of the auxiliary signals is acquired based on the second acquisition frequency set.

[0058] It should be noted that storing the core signal based on the first storage frequency and storing each auxiliary signal based on the second storage frequency includes: setting a memory buffer, the memory buffer is used to receive and temporarily store the data of the core signal and the auxiliary signal in real time; storing the core signal to the memory buffer based on the first storage frequency, and storing each auxiliary signal to the memory buffer based on the second storage frequency; obtaining the storage ratio relationship between the memory buffer and the actual storage area, and storing the core signal and the auxiliary signal based on the storage ratio relationship. The hydraulic pump continuously generates a large amount of diagnostic signal data during operation, and these data need to be processed and stored in time. Setting the memory buffer as a temporary storage area can receive the data of the core signal and the auxiliary signal in real time to avoid data loss due to the write speed limit of the storage device or other system delays. For example, when the hydraulic pump runs at a high speed and the data acquisition frequency is high, directly writing the data to the storage device may not be able to process all the data in time due to the I / O operation delay of the storage device, resulting in partial data loss or confusion. The memory buffer can first quickly cache these data to ensure the continuity of the data, and wait for the system to write them to the actual storage area in an orderly manner at the right time.

[0059] It should also be noted that the first storage frequency and the second storage frequency are determined based on the importance of the signal and the requirements for system resource optimization, and may not fully match the actual acquisition rate of the data acquisition device. The memory buffer can play a role in smoothing out this rate difference. For example, the acquisition device may acquire data at a relatively high fixed rate, but the storage system sets different storage frequencies according to the importance of different signals. The memory buffer can temporarily store excess data when the acquisition rate is higher than the storage rate to prevent data backlog; when the storage rate can keep up with the acquisition rate, the data in the buffer is written to the actual storage area according to the set storage frequency, thereby achieving a dynamic balance between data acquisition and storage and ensuring stable system operation.

[0060] The signal acquisition method for hydraulic pump fault diagnosis provided in this embodiment can more accurately obtain valuable information for fault diagnosis by identifying the importance of multiple diagnostic signals under various types of hydraulic pump faults, distinguishing core signals from auxiliary signals, and determining the acquisition frequency (such as the first acquisition frequency and the second acquisition frequency set) according to their respective change trends and historical fluctuations, avoiding the acquisition of too much useless data, and improving the pertinence and effectiveness of data acquisition. In addition, based on the adaptive storage scheme of sampling rate threshold and storage coefficient, the core signal is stored at full rate to ensure data integrity, and the auxiliary signal is stored at a variable rate according to the sampling rate, which greatly reduces the storage space occupied while ensuring the data required for fault diagnosis. And when the sampling frequency of the auxiliary signal is high, by reasonably setting the sampling rate threshold and storage coefficient, its storage frequency is reduced, unnecessary data duplication storage is avoided, storage efficiency is improved, and the system can store historical data for a longer time. It should also be noted that the file system is used to store data, and each file contains detailed information (such as generation time, sampling rate, amount of data stored per second, storage interval, etc.), which is convenient for data management, query and analysis. Compared with the traditional method of directly storing in the controller FLASH memory, the maintainability and reliability of the data are improved. At the same time, the collected signals are arranged in chronological order and stored after being extracted at preset time intervals according to actual needs, which not only facilitates real-time data processing, but also enables flexible acquisition of data fragments according to different analysis needs, improving the flexibility and efficiency of data processing. The setting of the memory buffer optimizes the data storage process, ensures efficient transmission and storage of data in the system by reasonably managing the storage ratio relationship between the buffer and the actual storage area, and reduces performance bottlenecks caused by poor data transmission or storage waiting.

[0061] Corresponding to the aforementioned embodiment of a signal acquisition method for hydraulic pump fault diagnosis, the present application also provides an embodiment of a signal acquisition device for hydraulic pump fault diagnosis.

[0062] Figure 2 This is a schematic diagram of the structure of the first embodiment of the signal acquisition device for hydraulic pump fault diagnosis provided by the present application. Figure 2 The device provided in this embodiment includes an identification module 210, a determination module 220, a calculation module 230 and a storage module 240; wherein: The identification module 210 is used to identify the importance of multiple diagnostic signals under various faults of the hydraulic pump; The determination module 220 is used to determine the core signal and the auxiliary signal based on the importance; The determination module 220 is further configured to determine a first acquisition frequency according to a change trend of the core signal; The determination module 220 is further configured to determine a second acquisition frequency set based at least on the first acquisition frequency, the change trend of the auxiliary signal and the historical fluctuation, wherein each second acquisition frequency in the second acquisition frequency set corresponds to an auxiliary signal, the second acquisition frequencies are not completely the same, and the first acquisition frequency is greater than the second acquisition frequency; The calculation module 230 is used to calculate a first storage frequency and a second storage frequency respectively according to a representative second acquisition frequency in the first acquisition frequency and the second acquisition frequency set, wherein the first storage frequency is calculated based on the first acquisition frequency, and the second storage frequency is calculated based on a relationship between the representative second acquisition frequency and a sampling rate threshold of the representative second acquisition frequency; The storage module 240 is configured to acquire the core signal based on the first acquisition frequency, acquire each of the auxiliary signals based on the second acquisition frequency set, store the core signal based on the first storage frequency, and store each of the auxiliary signals based on the second storage frequency.

[0063] The device of this embodiment can be used to perform Figure 1 The steps, specific implementation principles and implementation processes of the method embodiment shown are similar and will not be repeated here.

[0064] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0065] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0066] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A signal acquisition method for hydraulic pump fault diagnosis, characterized in that: The method comprises: Identify the importance of multiple diagnostic signals under various faults of the hydraulic pump; Determining core signals and auxiliary signals based on the importance; Determining a first acquisition frequency according to a change trend of the core signal; Determine a second acquisition frequency set at least according to the first acquisition frequency, the change trend of the auxiliary signal and the historical fluctuation, wherein each second acquisition frequency in the second acquisition frequency set corresponds to an auxiliary signal, the second acquisition frequencies are not completely the same, and the first acquisition frequency is greater than the second acquisition frequency; Calculate a first storage frequency and a second storage frequency respectively according to a representative second acquisition frequency in the first acquisition frequency and the second acquisition frequency set, wherein the first storage frequency is calculated based on the first acquisition frequency, and the second storage frequency is calculated based on a relationship between the representative second acquisition frequency and a sampling rate threshold of the representative second acquisition frequency; The core signal is acquired based on the first acquisition frequency, the auxiliary signals are acquired based on the second acquisition frequency set, the core signal is stored based on the first storage frequency, and the auxiliary signals are stored based on the second storage frequency.

2. The method according to claim 1, characterized in that The calculating the first storage frequency based on the first acquisition frequency, and calculating the second storage frequency based on the relationship between the representative second acquisition frequency and a sampling rate threshold of the representative second acquisition frequency, comprises: Acquire a first acquisition frequency of the core signal, and determine the first acquisition frequency as a first storage frequency; Acquire a second acquisition frequency set of the auxiliary signal, determine the representative second acquisition frequency, and calculate a corresponding sampling rate threshold of the auxiliary signal according to the representative second acquisition frequency; Determine the magnitude relationship between the second acquisition frequency and the sampling rate threshold, and when the second acquisition frequency is less than the sampling rate threshold, determine that the second acquisition frequency is the second storage frequency; When the second acquisition frequency is greater than or equal to the sampling rate threshold, a storage coefficient of the auxiliary signal is determined, and the second storage frequency is determined based on the product of the storage coefficient and the sampling rate threshold; wherein different acquisition frequency intervals have different storage coefficients.

3. The method according to claim 1, characterized in that: Calculating the sampling rate threshold of the representative second acquisition frequency includes: Obtain the change trend and historical fluctuation of the current auxiliary signal; Determining a representative second acquisition frequency of each auxiliary signal based on a change trend of the auxiliary signal; A sampling rate threshold of the representative second acquisition frequency is calculated according to the representative second acquisition frequency and the historical fluctuation.

4. The method according to claim 1, characterized in that The determining the first acquisition frequency according to the change trend of the core signal includes: Collect core signal data and analyze the change trend of the core signal in real time; Obtain core signal historical data and determine the sampling rate threshold; The sampling rate threshold is adjusted based on the collected core signal data, and the sampling rate threshold is used as the first collection frequency; when the change trend of the core signal is greater than a preset value, the sampling rate threshold is increased; when the change trend amplitude of the core signal is less than a preset value, the sampling rate threshold is reduced.

5. The method according to claim 1, characterized in that The determining of the second acquisition frequency set at least according to the first acquisition frequency, the change trend and the historical fluctuation of the auxiliary signal comprises: Acquire the first acquisition frequency and historical fluctuations, collect auxiliary signal data and analyze the change trend of the auxiliary signal in real time; Determining fluctuation characteristics of the auxiliary signal based on the analysis results and the historical fluctuations; determining a second acquisition frequency based on the fluctuation characteristics and the first acquisition frequency; The second acquisition frequencies corresponding to the auxiliary signals are counted to form a second acquisition frequency set.

6. The method according to claim 1, characterized in that The importance of multiple diagnostic signals for various faults of the hydraulic pump is identified, including: Acquire historical data under multiple fault modes, and determine multiple diagnostic signals based on the historical data; Calculate the sensitivity of each diagnostic signal under different fault modes; Priorities are set based on the sensitivity, and importance of multiple diagnosis signals under various types of faults is determined based on the priorities.

7. The method according to claim 1, characterized in that The core signal and the auxiliary signal are collected simultaneously at a fixed frequency; the fixed frequency is the fastest frequency when collecting the core signal and the auxiliary signal; The collected signals are arranged in chronological order and stored after being extracted at preset time intervals according to actual needs.

8. The method according to claim 1, characterized in that: The storing of the core signal based on the first storage frequency and the storing of each auxiliary signal based on the second storage frequency include: Setting a memory buffer, wherein the memory buffer is used to receive and temporarily store data of the core signal and the auxiliary signal in real time; storing the core signal to the memory buffer based on the first storage frequency, and storing each auxiliary signal to the memory buffer based on the second storage frequency; A storage ratio relationship between the memory buffer and the actual storage area is obtained, and the core signal and the auxiliary signal are stored based on the storage ratio relationship.

9. The method according to claim 2, characterized in that: The determining of the storage coefficient of the auxiliary signal comprises: The storage resource manager obtains a first storage space occupied by a current processing task, and predicts a second storage space occupied by processing tasks in a first time period in the future; Calculating the remaining available storage space of the storage resource manager based on the first storage space and the second storage space; Acquire the storage space required by the core signal, and determine the size of the available storage space for the auxiliary signal based on the difference between the remaining available storage space of the storage resource manager and the storage space required by the core signal; The storage coefficient is calculated based on the size of the available storage space for the auxiliary signal and the number of types of the auxiliary signal.

10. A signal acquisition device for hydraulic pump fault diagnosis, characterized in that: The device comprises an identification module, a determination module, a calculation module and a storage module; wherein: The identification module is used to identify the importance of multiple diagnostic signals under various faults of the hydraulic pump; The determination module is used to determine the core signal and the auxiliary signal based on the importance; The determination module is further used to determine the first acquisition frequency according to the change trend of the core signal; The determination module is further used to determine a second acquisition frequency set based on at least the first acquisition frequency, the change trend of the auxiliary signal and the historical fluctuation, wherein each second acquisition frequency in the second acquisition frequency set corresponds to an auxiliary signal, the second acquisition frequencies are not completely the same, and the first acquisition frequency is greater than the second acquisition frequency; The calculation module is used to calculate a first storage frequency and a second storage frequency respectively according to a representative second acquisition frequency in the first acquisition frequency and the second acquisition frequency set, wherein the first storage frequency is calculated based on the first acquisition frequency, and the second storage frequency is calculated based on a relationship between the representative second acquisition frequency and a sampling rate threshold of the representative second acquisition frequency; The storage module is used to collect the core signal based on the first acquisition frequency, collect each of the auxiliary signals based on the second acquisition frequency set, store the core signal based on the first storage frequency, and store each of the auxiliary signals based on the second storage frequency.

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