A method and device for real-time monitoring of the health status of a hydraulic plunger pump

Abstract

The present application provides a method and device for real-time monitoring of the health status of a hydraulic plunger pump, which belongs to the field of aviation hydraulics. The method includes: determining a first relationship between the total leakage of the hydraulic plunger pump and the operating parameters of the electrostatic actuator, and screening the follow-up parameters based on the dynamic change characteristics of the operating parameters with the working condition and health status of the hydraulic plunger pump; adjusting the first relationship of the total leakage of the plunger pump based on the follow-up parameters to obtain a second relationship; calculating the plunger pump torque based on the second relationship in combination with the law of conservation of energy; optimizing the plunger pump torque calculation formula based on the correlation between the viscous friction torque, the Coulomb friction torque and the follow-up parameters; monitoring the real-time operating parameters of the plunger pump, calculating the first coefficient and the second coefficient based on the real-time operating parameters, and inputting the first coefficient and the second coefficient into a neural network to construct a state monitoring model to evaluate the operating status of the plunger pump. The method and device provided by the present application can realize real-time monitoring of the operating status of the hydraulic plunger pump.

Description

Technical Field

[0001] The present application relates to the field of aviation hydraulic technology, and in particular to a method and device for real-time monitoring of the health status of a hydraulic plunger pump. Background Art

[0002] With the rapid advancement of aviation technology, the reliability and safety requirements for aircraft electromechanical systems are increasing. As a key component of an aircraft's hydraulic system, the performance of the electrostatic actuator (EHAP) directly impacts aircraft flight safety. The aircraft hydraulic piston pump is the core power element of the EHAP. However, in actual operation, due to factors such as harsh operating environments and frequent load fluctuations, the aircraft hydraulic piston pump is prone to failure, seriously affecting the normal operation of the EHAP. Therefore, real-time monitoring of the health of the aircraft hydraulic piston pump is crucial for ensuring safe flight.

[0003] Existing methods for monitoring the health of hydraulic piston pumps are mostly designed for traditional hydraulic systems and cannot meet the unique requirements of electrostatic actuators. Electrostatic actuators utilize closed hydraulic circuits, high motor speeds, short single-cycle operating times, and frequent start-stop and reversal cycles. This complicates the operating conditions of aircraft hydraulic piston pumps. Furthermore, electrostatic actuators have relatively few internal sensors. Currently, there is a lack of effective methods for monitoring the health of aircraft hydraulic piston pumps used in electrostatic actuators, making it impossible to leverage electrostatic actuator operating status data to monitor the hydraulic piston pump's operating status in real time. Summary of the Invention

[0004] In view of this, the present application provides a method and device for real-time monitoring of the health status of a hydraulic plunger pump, which can realize real-time monitoring of the operating status of the hydraulic plunger pump.

[0005] Specifically, this application is implemented through the following technical solutions:

[0006] A first aspect of the present application provides a method for real-time monitoring of the health status of a hydraulic plunger pump, the method comprising:

[0007] Determine a first relationship between the total leakage of the hydraulic plunger pump and the operating parameters of the electrostatic actuator, and select the servo parameters based on the dynamic change characteristics of the operating parameters with the working condition and health status of the hydraulic plunger pump;

[0008] Adjusting the first relationship of the total leakage of the plunger pump based on the servo parameter to obtain a second relationship;

[0009] According to the second relationship, the plunger pump torque is calculated in combination with the law of conservation of energy; the torque includes at least viscous friction torque and Coulomb friction torque;

[0010] Based on the correlation between the viscous friction torque, the Coulomb friction torque and the servo parameter, the plunger pump torque calculation formula is optimized; wherein the optimized plunger pump torque calculation formula includes a first coefficient and a second coefficient, and the first coefficient and the second coefficient are dynamically fitted coefficients and are dynamically adjusted as the health status of the plunger pump changes;

[0011] Monitor the real-time operating parameters of the plunger pump, calculate the first coefficient and the second coefficient based on the real-time operating parameters, and input the first coefficient and the second coefficient into a neural network to construct a state monitoring model to evaluate the operating state of the plunger pump.

[0012] A second aspect of the present application provides a device for real-time monitoring of the health status of a hydraulic plunger pump, the device comprising a screening module, an adjustment module, a calculation module, an optimization module, and a monitoring module;

[0013] The screening module is configured to determine a first relationship between a total leakage of the hydraulic plunger pump and an operating parameter of the electrostatic actuator, and to screen the servo parameter based on a dynamic change characteristic of the operating parameter with respect to a working condition and a health state of the hydraulic plunger pump;

[0014] The adjustment module is configured to adjust the first relationship of the total leakage of the plunger pump based on the servo parameter to obtain a second relationship;

[0015] The calculation module is used to calculate the torque of the plunger pump based on the second relationship and the law of conservation of energy; the torque includes at least viscous friction torque and Coulomb friction torque;

[0016] The optimization module is configured to optimize a plunger pump torque calculation formula based on a correlation between the viscous friction torque, the Coulomb friction torque, and the servo parameter; wherein the optimized plunger pump torque calculation formula includes a first coefficient and a second coefficient, wherein the first coefficient and the second coefficient are dynamically fitted coefficients and are dynamically adjusted as the health status of the plunger pump changes;

[0017] The monitoring module is used to monitor the real-time operating parameters of the plunger pump, calculate the first coefficient and the second coefficient based on the real-time operating parameters, and input the first coefficient and the second coefficient into a neural network to construct a state monitoring model to evaluate the operating state of the plunger pump.

[0018] The present invention provides a method and device for real-time monitoring of the health status of a hydraulic plunger pump. By combining the law of conservation of energy with the relationship between operating parameters related to an electrostatic actuator, a formula for calculating the plunger pump's torque is established. Torque is one of the key indicators reflecting the operating status of a hydraulic plunger pump. Accurately calculating torque provides a deeper understanding of the internal stresses of the hydraulic plunger pump and, consequently, its health status assessment. By analyzing the relationship between viscous friction torque, Coulomb friction torque, and servo parameters, the plunger pump torque calculation formula is optimized, resulting in a formula containing dynamic fitting coefficients. These coefficients dynamically adjust as the health status of the plunger pump changes, making torque calculation more accurate and more sensitive to changes in the health status of the hydraulic plunger pump. The present invention, through screening servo parameters, first locates parameters related to the health status of the total leakage volume, i.e., finds associated variables for the health status parameters. Based on these associated variables, the relationship between the associated variables and the operating parameters of the hydraulic plunger pump is then determined. The corresponding health status can then be directly determined using the operating parameters, simplifying the health assessment process. Furthermore, by integrating the operating conditions and structural characteristics of the electrostatic actuator, the present invention avoids the need for additional sensors and reduces costs. By using a neural network to construct a condition monitoring model, and by inputting first and second coefficients, the current operating status of the hydraulic plunger pump can be monitored in real time, providing strong support for fault diagnosis and prediction. The method provided in this application can comprehensively and accurately monitor the health status of aviation hydraulic plunger pumps used in electrostatic hydraulic actuators, adapt to complex operating conditions, and ensure the reliable operation of electrostatic hydraulic actuators. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Flowchart of Example 1 of the real-time monitoring method for the health status of a hydraulic plunger pump provided in this application;

[0020] Figure 2 This is a control flow chart for monitoring the real-time operating parameters of the plunger pump shown in this application;

[0021] Figure 3 This is a structural diagram of Example 2 of the real-time monitoring device for the health status of a hydraulic plunger pump provided in this application. DETAILED DESCRIPTION

[0022] Exemplary embodiments are described in detail herein, with examples illustrated in the accompanying drawings. When the following description refers to the drawings, identical numerals in different drawings represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with this application.

[0023] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms "a," "the," and "the" used in this application are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0024] It should be understood that although the terms first, second, third, etc. may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0025] Specific embodiments are given below to introduce the technical solutions of the present application in detail.

[0026] Figure 1 This is a flow chart of the first embodiment of the method for real-time monitoring of the health status of a hydraulic plunger pump provided by this application. Figure 1 The method provided in this embodiment may include:

[0027] S101. Determine a first relationship between a total leakage of a hydraulic plunger pump and an operating parameter of an electrostatic actuator, and select a follow-up parameter based on a dynamic change characteristic of the operating parameter with a working condition and a health state of the hydraulic plunger pump.

[0028] It should be noted that the first relationship between the total leakage of the hydraulic plunger pump and the operating parameters of the electrostatic actuator is determined, and the following parameters are screened according to the dynamic change characteristics of the operating parameters with the working condition and health status of the hydraulic plunger pump, including:

[0029] (1) Calculate the total leakage of the electrostatic hydraulic actuator.

[0030] It should be noted that total leakage is a key indicator of the operating status of an electrostatic hydraulic actuator, and its magnitude directly impacts system performance and efficiency. Calculating total leakage provides fundamental data for subsequent analysis of leak causes and assessment of system health. The total leakage can be approximated by measuring the amount of oil replenished in the hydraulic system over a given period of time, or by using pressure sensors and flow sensors to calculate the total leakage based on the relationship between system pressure and flow changes. The specific calculation method can be selected based on actual needs and is not limited in this embodiment.

[0031] (2) Determining an operating parameter of the electrostatic hydraulic actuator associated with the total leakage.

[0032] It's important to identify operating parameters that are closely related to total leakage. Changes in these parameters can directly or indirectly affect total leakage, providing a basis for leak analysis and control. For example, operating parameters can include the electrostatic actuator's motor current signal, the actuator cylinder's displacement signal, and the encoder's speed signal. This is because these signals can reflect the operating status of the electrostatic actuator and its hydraulic piston pump from different perspectives.

[0033] The motor is the power source that drives the hydraulic piston pump. The magnitude and changes in the motor current can indirectly reflect the hydraulic piston pump's load, operating efficiency, and the presence of abnormal resistance. For example, if an internal fault in the hydraulic piston pump causes increased friction or abnormal load, the motor current may change accordingly. The displacement of the actuator is closely related to the hydraulic piston pump's output flow and pressure. By monitoring the actuator's displacement signal, the hydraulic piston pump's operating stroke and output performance can be understood, thereby determining whether it is functioning properly. The encoder can accurately measure the motor's speed, which directly affects the speed of the hydraulic piston pump. The speed of the hydraulic piston pump has a significant impact on its performance and operating stability, so the speed signal is also one of the important criteria for evaluating the health of the hydraulic piston pump.

[0034] (3) Obtain the correlation between the operating parameters and the structural parameters of the hydraulic plunger pump, and determine the fixed parameters.

[0035] It's important to note that fixed parameters are determined by the hydraulic pump's structural design properties. These properties can include structural dimensions, the geometry of moving parts, component connections and fits, and material properties. Their values ​​remain essentially unchanged during normal operation. For example, structural parameters such as the plunger diameter, plunger distribution circle radius, and swash plate angle are fixed parameters. These parameters primarily affect the basic performance and operating range of the hydraulic pump and serve as reference values ​​during monitoring to determine whether changes in other parameters are normal.

[0036] (4) Obtain the dynamic change characteristics of the operating parameters related to the operating state and health level of the hydraulic plunger pump, and determine the follow-up parameters.

[0037] It should be noted that the purpose of analyzing the collected operating parameters and identifying the dynamic change characteristics related to the operating status of the hydraulic plunger pump according to a preset algorithm is to extract the most valuable information for monitoring the health status of the hydraulic plunger pump. These algorithms can be based on signal processing technology, machine learning algorithms, or methods from other related fields. For example, a spectrum analysis algorithm can be used to analyze the frequency components of the motor current signal to detect whether there are abnormal frequency components, which may be related to the failure mode of the hydraulic plunger pump. For another example, a wavelet transform algorithm can be used to process the displacement signal of the actuator to extract the mutation points and characteristic waveforms in the signal, thereby determining whether the working status of the hydraulic plunger pump has changed.

[0038] Dynamic characteristic changes refer to signal characteristics that change significantly over time or with changing operating conditions during the operation of a hydraulic piston pump. Examples include amplitude fluctuations and frequency changes in the motor current signal, velocity changes and acceleration changes in the actuator displacement signal, and fluctuations in the encoder speed signal.

[0039] Specifically, the follow-up parameters are determined according to the changes in dynamic characteristics, wherein the follow-up parameters change as the working environment and / or health status of the piston pump changes, and they can directly reflect the actual working status and performance changes of the hydraulic piston pump. For example, parameters such as leakage, friction coefficient, and volumetric efficiency are follow-up parameters. Changes in leakage will affect the output flow and pressure of the hydraulic piston pump, changes in friction coefficient will lead to energy loss and reduced efficiency, and changes in volumetric efficiency reflect the degree of internal leakage and wear of the hydraulic piston pump. By monitoring the changes in the follow-up parameters, potential faults of the hydraulic piston pump can be discovered in a timely manner, and the degree of deterioration of its health status can be evaluated. S102. The first relationship of the total leakage of the piston pump is adjusted based on the follow-up parameters to obtain a second relationship.

[0040] It should be noted that the second relationship is obtained by adjusting the first relationship of the total leakage of the plunger pump based on the servo parameter, including:

[0041] (1) Determining a first relationship of a total leakage of a plunger pump; the first relationship includes a relationship between the total leakage and a fixed parameter and a follower parameter of an electrostatic hydraulic actuator.

[0042] It should be noted that the first relationship of the total leakage of the plunger pump is a mathematical expression describing the relationship between the total leakage and related parameters. Specifically, the first relationship of the total leakage of the plunger pump is as follows:

[0043] ;

[0044] in, is the gap leakage flow of the sliding shoe pair, is the gap leakage flow of the plunger ball joint pair, is the gap leakage flow of the plunger pair, It is the gap leakage flow of the distribution pair.

[0045] During actual operation, a plunger pump, a high-speed, high-pressure, rotating hydraulic machine, experiences long-term wear and tear on its internal components, as well as alternating pressure loads. This can lead to certain performance degradation. In the above formula, all parameters related to the leakage rate of the plunger pump can be divided into fixed parameters and dynamic parameters.

[0046] (2) Extracting a follow-up parameter from the first relationship, and adjusting the first relationship of the total leakage of the plunger pump based on the follow-up parameter to obtain a second relationship.

[0047] It should be noted that the purpose of extracting the servo parameters from the first relationship is to clarify which parameters change dynamically with the working state of the plunger pump, and which parameters have a more significant impact on the total leakage.

[0048] The second relationship, derived from the first relationship for the total leakage of the plunger pump, is based on the servo parameter to more accurately reflect the variations in total leakage during actual operation. Since the servo parameter varies with time and operating conditions, incorporating it into the total leakage relationship for adjustment makes the resulting second relationship more consistent with actual operating conditions, thereby improving the accuracy of plunger pump health status monitoring.

[0049] Specifically, the second relationship of the total leakage of the plunger pump is as follows:

[0050] ;

[0051] in, is the eccentricity, is the outlet oil pressure, is the oil return pressure, is the total leakage coefficient of all friction pairs of the hydraulic piston pump, They are the oil film clearance of the sliding shoe swash plate friction pair, the oil film clearance of the plunger sliding shoe ball joint pair, the clearance between the plunger and the cylinder plunger hole, and the oil film clearance of the cylinder distribution plate friction pair.

[0052] It should be noted that in the first relationship of the total leakage of the plunger pump, we quantitatively define the first relationship of the total leakage of the plunger pump as the sum of the leakage of each important friction pair in the hydraulic plunger pump. However, in actual operation, the damage and degradation of internal components due to wear cannot be directly obtained from the first relationship. At the same time, the leakage of the above four friction pairs is a nonlinear expression of the above four gap values, that is, the size of the leakage is closely related to the gap value. Therefore, we adjust the total leakage flow to a combination of fixed parameters and variable parameters to facilitate monitoring of changes in the leakage of the hydraulic plunger pump.

[0053] S103. Calculate the plunger pump torque based on the second relationship and the law of conservation of energy; the torque at least includes viscous friction torque and Coulomb friction torque.

[0054] It should be noted that, according to the second relationship, combined with the law of conservation of energy, the calculation of the plunger pump torque includes:

[0055] (1) According to the law of conservation of energy, the energy balance equation of the plunger pump during operation is established.

[0056] It should be noted that according to the law of conservation of energy:

[0057] ;

[0058] in, is the output power, is the input power, is the torque loss, For flow loss.

[0059] It should also be noted that volumetric efficiency is an important indicator to characterize the output performance of hydraulic piston pumps. Its expression can generally be expressed as:

[0060] ;

[0061] in, is the input flow, is the output flow, is the instantaneous flow rate, is the total leakage flow.

[0062] Among them, for a certain hydraulic plunger pump, the plunger diameter can be determined according to the structural parameters , plunger distribution circle radius , swash plate inclination , to obtain its instantaneous theoretical flow rate:

[0063] ;

[0064] in, is the angular velocity of the plunger pump, is the number of plungers in the plunger pump.

[0065] By combining the law of conservation of energy and volumetric efficiency, the law of conservation of energy can be transformed into the form of a power balance expression, and the energy balance equation is obtained, as follows:

[0066] ;

[0067] in, For other traffic losses, is the damping torque related to the viscosity of the hydraulic oil, is the friction torque associated with the moving parts of the plunger pump, is the outlet oil pressure, For imported oil pressure, This is the return oil pressure. For the introduction of other parameters, please refer to the above description.

[0068] like , then the above formula can be simplified to obtain:

[0069] ;

[0070] in, .

[0071] (2) Substitute the second relational expression of the total leakage into the energy balance equation to obtain the formula for calculating the torque of the plunger pump.

[0072] It should be noted that the second relationship for total leakage is derived by considering the influence of the servo parameter on leakage. It more accurately describes the leakage situation of the plunger pump in actual operation. Substituting the second relationship for total leakage into the energy balance equation further analyzes the relationship between leakage and other parameters, thereby deriving the formula for calculating the plunger pump torque.

[0073] Specifically, by organizing and deriving the energy balance equation, torque can be expressed as a function of leakage, pressure, speed, and other relevant parameters. In this process, viscous friction torque and Coulomb friction torque, as part of the energy loss, are included in the torque calculation formula.

[0074] Specifically, the plunger pump torque calculation formula is as follows:

[0075] ;

[0076] The first half of the right side of the equal sign is defined as the equivalent torque of hydraulic pressure, where the friction torque is Can be divided into viscous friction torque and Coulomb friction torque For the meaning of other related parameters, please refer to the above introduction and will not be repeated here.

[0077] S104. Optimize the plunger pump torque calculation formula based on the correlation between the viscous friction torque, the Coulomb friction torque and the follow-up parameters; wherein the optimized plunger pump torque calculation formula includes a first coefficient and a second coefficient, and the first coefficient and the second coefficient are dynamic fitting coefficients, which are dynamically adjusted as the health status of the plunger pump changes.

[0078] It should be noted that, based on the correlation between the viscous friction torque, the Coulomb friction torque and the follow-up parameter, the plunger pump torque calculation formula is optimized, including:

[0079] (1) Analyze the relationship between the viscous friction torque, Coulomb friction torque and servo parameters under various piston pump states.

[0080] It should be noted that viscous friction torque is primarily related to the oil viscosity and the relative velocity of the moving parts within the plunger pump. The oil viscosity, a servo parameter, changes with operating conditions such as temperature and pressure, directly influencing the magnitude of the viscous friction torque. Coulomb friction torque is related to the normal pressure between the friction pairs and the friction coefficient. Changes in the load, a servo parameter, cause changes in the normal pressure between the friction pairs, thus affecting the Coulomb friction torque.

[0081] It should be noted that when monitoring the state of the plunger pump, we only need to pay attention to the amount that changes with the state of the plunger pump. Therefore, for the viscous friction torque , its expression can be written as:

[0082] ;

[0083] in, is the hydraulic dynamic viscosity, is the total friction torque of viscous friction, is the angular velocity of the hydraulic piston pump. For the meaning of other related parameters, please refer to the above introduction.

[0084] Similarly, for the Coulomb friction torque , its expression can be written as:

[0085] ;

[0086] in, is the workload pressure, is the total friction torque of Coulomb friction related to the pressure difference, is the Coulomb friction coefficient of the distribution pair under static pressure support, is the Coulomb friction coefficient of the sliding shoe pair under hydrostatic support, is the total friction torque of Coulomb friction related to the hydraulic piston pump structure, is the friction coefficient between the plunger and the cylinder plunger cavity wall, is the angular velocity of the hydraulic piston pump, is the plunger phase angle.

[0087] (2) According to the analysis results, the calculation formula of the plunger pump torque is adjusted to obtain an optimized formula including the first coefficient and the second coefficient.

[0088] It should be noted that, based on the above analysis results, the plunger pump torque calculation formula has been adjusted. Based on the original formula, a first coefficient and a second coefficient are introduced to respectively reflect the relationship between the viscous friction torque and the Coulomb friction torque and the servo parameter. The first coefficient can be a function related to the oil viscosity, speed, and other factors. It dynamically adjusts as these servo parameters change, thereby accurately reflecting the impact of the viscous friction torque on the plunger pump torque. The second coefficient can be a function related to the load, friction coefficient, and other factors. It also dynamically adjusts according to changes in the servo parameter to reflect the impact of the Coulomb friction torque on the plunger pump torque.

[0089] Through this optimization, the resulting torque calculation formula, including the first and second coefficients, can more accurately describe the torque variations of the plunger pump under different operating conditions. When the health of the plunger pump changes, such as when wear or leakage occurs, the servo parameters will change accordingly, causing changes in the first and second coefficients. By monitoring the dynamic adjustment of these coefficients, health issues of the plunger pump can be promptly identified, improving the accuracy and reliability of monitoring.

[0090] Specifically, the adjusted plunger pump torque calculation formula is as follows:

[0091] ;

[0092] The meaning of each parameter is described above and will not be repeated here.

[0093] Let the first coefficient , the second coefficient , then the optimization formula including the first coefficient and the second coefficient can be obtained:

[0094] ;

[0095] From the above formula, we can see that if and Keep constant, the input torque T and load pressure is linearly related, where and All about angular velocity For the meaning of other related parameters, please refer to the above introduction.

[0096] S105. Monitor the real-time operating parameters of the plunger pump, calculate the first coefficient and the second coefficient based on the real-time operating parameters, and input the first coefficient and the second coefficient into a neural network to construct a state monitoring model to evaluate the operating state of the plunger pump.

[0097] Combined with the optimization formula, it can be seen that in order to monitor the status of the plunger pump, it is only necessary to measure the input torque value under the current load condition to obtain the parameter and These two parameters directly represent the health status of the hydraulic piston pump. Therefore, in order to monitor the health status of the piston pump, it is also necessary to extract the input torque T and input speed , the inlet oil pressure of the plunger pump and outlet oil pressure .

[0098] Figure 2 For the control flow chart of monitoring the real-time operating parameters of the plunger pump shown in this application, please refer to Figure 2 Specifically, the monitoring of the real-time operating parameters of the plunger pump includes: detecting the displacement signal of the actuator cylinder; calculating the derivative value of the displacement signal and time; calculating the flow rate of the plunger pump based on the product of the derivative value and the actuating area of ​​the actuator cylinder; and calculating the inlet oil pressure and outlet oil pressure of the plunger pump based on the flow rate. It should be noted that the displacement signal of the actuator cylinder is one of the important bases for reflecting the working state of the hydraulic plunger pump. By monitoring the displacement signal in real time, the output of the plunger pump can be indirectly obtained. In specific implementation, a displacement sensor can be used to detect the displacement signal of the actuator cylinder. The derivative value of the displacement signal and time is the speed signal of the actuator cylinder. Speed ​​is an important parameter for describing the motion state of an object. For a hydraulic plunger pump, the speed of the actuator cylinder is directly related to the flow output of the pump. Calculating the speed signal can further analyze the working performance of the pump. Combined with the above description, the flow rate of the plunger pump is calculated based on the product of the derivative value and the actuating area of ​​the actuator cylinder, which can be expressed as follows:

[0099] ;

[0100] in, is the actuating area of ​​the actuator, is the displacement velocity.

[0101] Furthermore, based on the basic principles and relevant formulas of the hydraulic system, combined with the flow rate of the plunger pump and other system parameters, the inlet oil pressure and outlet oil pressure of the plunger pump can be calculated.

[0102] It should also be noted that monitoring the real-time operating parameters of the plunger pump includes: calculating the output torque of the servo motor based on the excitation current; determining the input torque of the hydraulic plunger pump based on the output torque of the servo motor, wherein the servo motor and the main shaft of the hydraulic plunger pump are directly connected through a spline.

[0103] There is a certain relationship between the motor output torque and the excitation current. Based on this relationship, the motor output torque can be calculated according to the excitation current after the excitation current is measured. The motor is directly connected to the plunger pump, and the output torque of the motor will be transmitted to the plunger pump. Therefore, the torque of the plunger pump can be indirectly obtained by measuring the motor input signal. Among them, a common method is to use the current and voltage sensors in the motor drive circuit to measure the input current and input voltage of the motor, and then calculate the torque of the plunger pump based on the power balance equation of the motor. Specifically, the speed and torque of the plunger pump can be obtained through the motor input signal. The motor speed can be directly read by the encoder, where the motor output torque is:

[0104] ;

[0105] in, is a constant value, is the excitation current on the q-axis.

[0106] In specific implementation, in the electrostatic actuator, the servo motor and the hydraulic plunger pump main shaft are directly connected through a spline. Therefore, it can be considered that the input torque of the hydraulic plunger pump is equal to the output torque of the servo motor, and the output torque of the servo motor can be directly obtained through the excitation current.

[0107] In addition, monitoring the real-time operating parameters of the plunger pump also includes: obtaining the speed information of the servo motor based on the sensor; determining the output speed of the servo motor based on the speed information of the servo motor; and calculating the input speed of the hydraulic plunger pump based on the output speed of the servo motor, wherein the servo motor and the hydraulic plunger pump in the electrostatic actuator are rigidly connected through a spline.

[0108] Specifically, the servo motor and the hydraulic plunger pump in the electrostatic hydraulic actuator are rigidly connected via a spline, and the input speed of the hydraulic plunger pump depends on the output speed of the servo motor, while the speed of the servo motor can be directly read by a resolver sensor.

[0109] Furthermore, based on the obtained parameters such as input torque, input speed, inlet and outlet oil pressure, and the optimized plunger pump torque calculation formula (including the first and second coefficients), a system of equations can be established. By solving the system of equations, the values ​​of the first and second coefficients in the current state can be calculated.

[0110] In addition, it should be noted that the evaluation of the operating status of the plunger pump includes:

[0111] (1) The principal component analysis method is used to reduce the dimension of the feature matrix of the current signal of the driving motor of the electrostatic hydraulic actuator in normal operation, the displacement signal of the actuator cylinder, and the speed signal of the encoder.

[0112] It should be noted that principal component analysis (PCA) is used to reduce the dimensionality of the feature matrices representing the current signal of the electrostatic-hydraulic actuator's drive motor, the displacement signal of the actuator cylinder, and the speed signal of the encoder during normal operation. In actual monitoring, the acquired signal data often contains a large amount of feature information, some of which may be correlated or redundant. PCA projects this high-dimensional feature data into a low-dimensional space, extracting the primary characteristic components. This reduces the data's dimensionality and improves the efficiency of subsequent data analysis and processing.

[0113] (2) Determine the characteristic vector related to the operating state of the plunger pump based on the optimized torque calculation formula.

[0114] Based on the optimized torque calculation formula, the eigenvectors associated with the plunger pump's operating status are determined. These eigenvectors are key feature combinations that can reflect the health of the plunger pump. By analyzing the torque calculation formula, we can identify which parameters have a greater impact on torque and combine the features corresponding to these parameters to form a eigenvector. For example, if it is found that parameters such as inlet oil pressure, outlet oil pressure, and speed have a significant impact on torque calculation and the operating status of the plunger pump, the features corresponding to these parameters can be extracted to form a eigenvector, which can be used as input for the subsequent condition monitoring model.

[0115] (3) Build a state monitoring model based on the feature vector and long short-term memory neural network.

[0116] Long-term short-term memory (LSTM) neural networks (LSTMs) have excellent time series processing capabilities and can capture long-term dependencies in data. In the health monitoring of plunger pumps, since their operation is dynamic and there is a certain correlation between states at different times, LSTMs are well-suited for building condition monitoring models. By inputting feature vectors into the LSTM neural network for training, the model learns the mapping relationship between the plunger pump's health status and the feature vectors. During the training process, the model is optimized using a large amount of historical data and the network parameters are adjusted to improve the model's accuracy and generalization ability.

[0117] (4) Inputting historical state operation data into the state monitoring model to obtain state prediction results.

[0118] Inputting historical operating data into the established condition monitoring model, the model outputs predictions for the plunger pump's condition based on the input feature vectors and the learned mapping relationships. These predictions can reflect the pump's health trends over the coming period. For example, the model can predict whether the plunger pump is at risk of failure, as well as the likely time and severity of the failure. By analyzing the predicted results, appropriate maintenance measures can be taken in advance to avoid failures or reduce the resulting losses.

[0119] (5) Based on the residuals between the status monitoring results and the status prediction results, analyze the degree of deviation between the current status and the historical operating trend.

[0120] The residuals between the condition monitoring results and the condition prediction results are used to analyze the degree of deviation between the current condition and the historical operating trend. The residual refers to the difference between the actual monitoring results and the predicted results. It reflects the model's prediction error for the current condition. By analyzing the size and trend of the residual, we can determine whether the current condition is consistent with the historical operating trend. If the residual is small and stable, it indicates that the current condition is relatively consistent with the historical operating trend and the plunger pump is operating normally. If the residual is large or shows a significant trend, it indicates that the current condition may be abnormal and further analysis is required.

[0121] (6) Integrate prediction results and real-time monitoring data to evaluate the health status of the plunger pump.

[0122] Specifically, in actual applications, the health status of the plunger pump cannot be judged solely based on prediction results or real-time monitoring data. A comprehensive assessment must be conducted by combining the two. For example, if the prediction results indicate that the plunger pump is at risk of failure, but the real-time monitoring data does not show obvious abnormalities, further observation and analysis are required, and the monitoring frequency may need to be increased or more detailed testing may be required. Conversely, if the real-time monitoring data indicates that the plunger pump has an abnormality, but the prediction results do not indicate a failure, the prediction model also needs to be checked and optimized. By comprehensively considering the prediction results and real-time monitoring data, the health status of the plunger pump can be more accurately assessed, potential problems can be discovered in a timely manner, and appropriate measures can be taken.

[0123] The method provided in this embodiment comprehensively reflects the operating status of a hydraulic plunger pump by collecting multiple operating parameters, such as motor current signals, actuator displacement signals, and encoder speed signals, and filtering out characteristic signals related to the operating status of the hydraulic plunger pump. By distinguishing between fixed and servo parameters, the method can better adapt to the complex and variable operating conditions of electrostatic hydraulic actuators. The introduction of servo parameters enables the monitoring method to capture changes in the hydraulic plunger pump's performance caused by varying operating conditions in real time, thereby more accurately assessing its health status. Furthermore, by combining the law of conservation of energy with the relationship between relevant operating parameters of electrostatic hydraulic actuators, a formula for calculating the plunger pump's torque is established. Torque is one of the key indicators reflecting the operating status of a hydraulic plunger pump. Accurately calculating torque provides a deeper understanding of the internal stresses of the hydraulic plunger pump and, therefore, assesses its health status. By analyzing the correlation between viscous friction torque, Coulomb friction torque, and servo parameters, the plunger pump torque calculation formula is optimized, resulting in a formula that includes dynamic fitting coefficients. These coefficients dynamically adjust as the health status of the plunger pump changes, making torque calculation more accurate and more sensitive to changes in the health status of the hydraulic plunger pump. It should also be noted that principal component analysis was used to reduce the dimensionality of the signal feature matrix, reducing data redundancy and complexity. The optimized torque calculation formula was used to determine the eigenvectors associated with the plunger pump's operating status, improving data processing efficiency and model accuracy. A condition monitoring model was constructed using a long-short-term memory neural network, which can effectively process time series data and capture changing trends in the plunger pump's health status. By learning and training from historical operating data, the model can accurately predict current and future operating states, providing strong support for fault diagnosis and prediction.

[0124] Based on the energy conversion relationship, this application derives the mapping relationship between the operating state parameters of the drive motor and the state parameters of the hydraulic plunger pump, and uses a mathematical model to analyze the change law of the plunger pump state parameters with the operating parameters of the drive motor and the actuator. Starting from the energy transfer relationship, it can solve the engineering problem of low reliability and difficulty in abnormal monitoring due to the small number of internal sensors in the electrostatic actuator and the inability to directly monitor the health status of the hydraulic plunger pump.

[0125] Corresponding to the aforementioned embodiment of a method for real-time monitoring of the health status of a hydraulic plunger pump, the present application also provides an embodiment of a device for real-time monitoring of the health status of a hydraulic plunger pump.

[0126] Figure 3 This is a structural diagram of the second embodiment of the real-time monitoring device for the health status of a hydraulic plunger pump provided by this application. Figure 3 , the device provided in this embodiment includes a screening module 310, an adjustment module 320, a calculation module 330, an optimization module 340 and a monitoring module 350;

[0127] The screening module 310 is configured to determine a first relationship between the total leakage of the hydraulic plunger pump and the operating parameters of the electrostatic actuator, and to screen the servo parameters based on the dynamic variation characteristics of the operating parameters with the working condition and health status of the hydraulic plunger pump;

[0128] The adjustment module 320 is configured to adjust the first relationship of the total leakage of the plunger pump based on the servo parameter to obtain a second relationship;

[0129] The calculation module 330 is used to calculate the torque of the plunger pump based on the second relationship and the law of conservation of energy; the torque includes at least viscous friction torque and Coulomb friction torque;

[0130] The optimization module 340 is configured to optimize a plunger pump torque calculation formula based on the correlation between the viscous friction torque, the Coulomb friction torque, and the servo parameter; wherein the optimized plunger pump torque calculation formula includes a first coefficient and a second coefficient, wherein the first coefficient and the second coefficient are dynamically fitted coefficients and are dynamically adjusted as the health status of the plunger pump changes;

[0131] The monitoring module 350 is used to monitor the real-time operating parameters of the plunger pump, calculate the first coefficient and the second coefficient based on the real-time operating parameters, and input the first coefficient and the second coefficient into a neural network to construct a state monitoring model to evaluate the operating state of the plunger pump.

[0132] 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.

[0133] 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.

[0134] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the partial description of the method embodiments. The device embodiments described above are merely 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.

[0135] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, 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 method for real-time monitoring of the health status of a hydraulic plunger pump, characterized in that: The method comprises: Determine a first relationship between the total leakage of the hydraulic plunger pump and the operating parameters of the electrostatic actuator, and select the servo parameters based on the dynamic change characteristics of the operating parameters with the working condition and health status of the hydraulic plunger pump; Adjusting the first relationship of the total leakage of the plunger pump based on the servo parameter to obtain a second relationship; According to the second relationship, the plunger pump torque is calculated in combination with the law of conservation of energy; the torque includes at least viscous friction torque and Coulomb friction torque; Based on the correlation between the viscous friction torque, the Coulomb friction torque, and the servo parameter, the plunger pump torque calculation formula is optimized; wherein the optimized plunger pump torque calculation formula includes a first coefficient and a second coefficient, the first coefficient and the second coefficient respectively reflecting the relationship between the viscous friction torque and the Coulomb friction torque and the servo parameter, and the first coefficient and the second coefficient are dynamic fitting coefficients and are dynamically adjusted as the health status of the plunger pump changes; Monitor the real-time operating parameters of the plunger pump, calculate the first coefficient and the second coefficient based on the real-time operating parameters, and input the first coefficient and the second coefficient into a neural network to construct a state monitoring model to evaluate the operating state of the plunger pump.

2. The method according to claim 1, characterized in that The real-time operating parameters of the monitoring plunger pump include: Detecting the displacement signal of the actuator; Calculate the time derivative of the displacement signal; Calculating the flow rate of the plunger pump based on the product of the derivative value and the actuating area of ​​the actuator; The inlet oil pressure and the outlet oil pressure of the plunger pump are calculated based on the flow rate.

3. The method according to claim 1, characterized in that Monitoring of real-time operating parameters of the plunger pump includes: Calculate the output torque of the servo motor based on the excitation current; The input torque of the hydraulic plunger pump is determined according to the output torque of the servo motor, wherein the servo motor and the main shaft of the hydraulic plunger pump are directly connected through a spline.

4. The method according to claim 1, wherein Monitor the real-time operating parameters of the plunger pump, including: Obtain the speed information of the servo motor based on the sensor; Determining the output speed of the servo motor according to the speed information of the servo motor; The input speed of the hydraulic piston pump is calculated based on the output speed of the servo motor, wherein the servo motor and the hydraulic piston pump in the electrostatic actuator are rigidly connected through a spline.

5. The method according to claim 1, wherein The determining of the first relationship between the total leakage of the hydraulic plunger pump and the operating parameters of the electrostatic actuator, and screening the follow-up parameters according to the dynamic change characteristics of the operating parameters with the working condition and health status of the hydraulic plunger pump, includes: Calculating the total leakage of the electrostatic hydraulic actuator; determining an operating parameter of the electrostatic hydraulic actuator associated with the total leakage; Obtaining a correlation between the operating parameters and the structural parameters of the hydraulic plunger pump to determine fixed parameters; The dynamic change characteristics of the operating parameters related to the operating state and health level of the hydraulic plunger pump are obtained to determine the follow-up parameters.

6. The method according to claim 1, characterized in that The first relationship of adjusting the total leakage of the plunger pump based on the servo parameter to obtain the second relationship includes: Determining a first relationship of a total leakage of the plunger pump; the first relationship including a relationship between the total leakage and a fixed parameter and a follower parameter of the electrostatic hydraulic actuator; A servo parameter is extracted from the first relationship, and the first relationship of the total leakage of the plunger pump is adjusted based on the servo parameter to obtain a second relationship.

7. The method according to claim 1, characterized in that Calculating the plunger pump torque based on the second relationship and the law of conservation of energy includes: According to the law of conservation of energy, the energy balance equation of the plunger pump during operation is established; Substitute the second relational expression of the total leakage into the energy balance equation to obtain the plunger pump torque calculation formula.

8. The method according to claim 1, characterized in that The optimization of the plunger pump torque calculation formula based on the correlation between the viscous friction torque, the Coulomb friction torque and the follow-up parameter includes: Analyze the relationship between viscous friction torque, Coulomb friction torque and servo parameters under various piston pump states; The plunger pump torque calculation formula is adjusted according to the analysis results to obtain an optimized formula including the first coefficient and the second coefficient.

9. The method according to claim 1, characterized in that The evaluating the operating state of the plunger pump includes: The principal component analysis method is used to reduce the dimension of the feature matrix of the current signal of the driving motor of the electrostatic hydraulic actuator in normal operation, the displacement signal of the actuator cylinder and the speed signal of the encoder. Determine the characteristic vector related to the operating state of the plunger pump according to the optimized torque calculation formula; Building a condition monitoring model based on the feature vector and the long short-term memory neural network; Inputting historical state operation data into the state monitoring model to obtain state prediction results; Analyze the degree of deviation between the current state and the historical operating trend based on the residuals between the state monitoring results and the state prediction results; Combine prediction results and real-time monitoring data to assess the health status of the plunger pump.

10. A real-time monitoring device for the health status of a hydraulic plunger pump, characterized in that: The device includes a screening module, an adjustment module, a calculation module, an optimization module and a monitoring module; The screening module is configured to determine a first relationship between a total leakage of the hydraulic plunger pump and an operating parameter of the electrostatic actuator, and to screen the servo parameter based on a dynamic change characteristic of the operating parameter with respect to a working condition and a health state of the hydraulic plunger pump; The adjustment module is configured to adjust the first relationship of the total leakage of the plunger pump based on the servo parameter to obtain a second relationship; The calculation module is used to calculate the torque of the plunger pump based on the second relationship and the law of conservation of energy; the torque includes at least viscous friction torque and Coulomb friction torque; The optimization module is configured to optimize a plunger pump torque calculation formula based on a correlation between the viscous friction torque, the Coulomb friction torque, and the servo parameter; wherein the optimized plunger pump torque calculation formula includes a first coefficient and a second coefficient, wherein the first coefficient and the second coefficient respectively reflect a relationship between the viscous friction torque and the Coulomb friction torque and the servo parameter, and the first coefficient and the second coefficient are dynamically fitted coefficients and are dynamically adjusted as the health status of the plunger pump changes; The monitoring module is used to monitor the real-time operating parameters of the plunger pump, calculate the first coefficient and the second coefficient based on the real-time operating parameters, and input the first coefficient and the second coefficient into a neural network to construct a state monitoring model to evaluate the operating state of the plunger pump.

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