Method and system for adjusting flow of high-temperature-resistant hydraulic pump

Abstract

The invention relates to the technical field of hydraulic control, and provides a high-temperature-resistant hydraulic pump flow adjusting method and system.The method comprises the steps that driving current is continuously monitored and obtained, and the viscosity degree is quantified according to current characteristics of the driving current; obtaining the viscosity degree of the valve element of the servo valve, and judging whether a fixation relieving program needs to be started or not according to the viscosity degree to obtain a fixation relieving judgment result; if the fixation relieving judgment result shows that the fixation relieving program needs to be started, driving current which is gradually increased at a preset uniform rate is applied to the servo valve; in the process that the driving current is gradually increased at the preset uniform rate, the actual position of the valve element of the servo valve is monitored in real time; and when it is monitored that the actual position of the servo valve element moves by a preset distance, the step-by-step increase of the uniform rate of the driving current is stopped immediately, and the driving current is adjusted. The hydraulic system has the effect of improving the stability and reliability of the hydraulic system.

Description

Technical Field

[0001] This invention relates to the field of hydraulic control technology, specifically to a method and system for regulating the flow rate of a high-temperature resistant hydraulic pump. Background Technology

[0002] In industrial production, high-precision hydraulic systems achieve precise control of actuator movements through the coordinated action of hydraulic pumps and electro-hydraulic servo valves. To ensure the responsiveness of the servo valve, a tiny vibration command, known as a "jitter signal," is typically superimposed on its drive signal to overcome the static friction and stickiness of the valve core. However, under certain specific and demanding operating conditions, this standard practice may actually present new challenges, affecting the long-term stability and control accuracy of the system.

[0003] However, when the accumulated drive current becomes large enough to overcome the "fixed resistance," the gel deposit layer is suddenly destroyed, and the valve core abruptly "jumps open." At this moment, the enormous electromagnetic thrust acting on the valve core no longer faces the extremely high fixed resistance, but rather the suddenly normalized, much smaller dynamic friction. This mismatch between the enormous thrust and the suddenly reduced resistance causes the valve core to burst open instantaneously at an extremely high speed, its displacement significantly exceeding the target position. This "overshoot" behavior causes the variable displacement mechanism angle of the hydraulic pump to become excessively large in a very short time, resulting in a destructive flow and pressure surge peak throughout the hydraulic system, far exceeding process requirements. This surge can not only damage hydraulic components such as pipelines, seals, or cylinders, but may even cause defects in the composite material products being molded, affecting their final quality and performance.

[0004] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0005] This application discloses a method and system for regulating the flow of a high-temperature hydraulic pump, which aims to solve the problem in the prior art where, after a long period of pressure holding, the servo valve core of a high-temperature hydraulic pump experiences difficulty in starting and overshoot in flow regulation due to the adhesion of gum, which in turn leads to system impact and product defects.

[0006] The technical solution of this application is as follows:

[0007] In a first aspect, this application discloses a method for regulating the flow rate of a high-temperature resistant hydraulic pump, comprising:

[0008] Continuously monitor and acquire the drive current corresponding to the servo valve, and quantify the viscosity of the servo valve core based on the current characteristics of the drive current.

[0009] When a command is received to switch the high-temperature hydraulic pump from the pressure holding state to the increased flow output mode, the viscosity of the servo valve core is obtained, and based on the viscosity, it is determined whether the fixation release procedure needs to be started, and the fixation release judgment result is obtained.

[0010] If the fixation release judgment result indicates that the fixation release procedure needs to be started, then a drive current is applied to the servo valve; the drive current gradually increases at a preset uniform rate.

[0011] The actual position of the servo valve core is monitored in real time as the drive current gradually increases at a preset uniform rate.

[0012] When the actual position of the servo valve core is detected to have moved by a preset distance, the uniform rate of the drive current is immediately stopped and the drive current is adjusted.

[0013] The technical solution can effectively identify and quantify the stickiness of the servo valve core, and initiate a controlled sticking release procedure when needed. This avoids the overshoot phenomenon caused by blindly increasing the drive current in traditional methods, thereby solving the problems of starting difficulties and flow shock caused by the sticking of the servo valve core after high temperature and high pressure holding.

[0014] Furthermore, this application also proposes a method for regulating the flow rate of a high-temperature hydraulic pump, wherein the steps of continuously monitoring and acquiring the drive current corresponding to the servo valve, and quantifying the viscosity of the servo valve core based on the current characteristics of the drive current, include:

[0015] The drive current of the servo valve is collected at a preset sampling rate to obtain current sampling data;

[0016] The current sampling data is filtered to extract the DC and AC components;

[0017] The DC component is compared with the preset reference average current value to obtain the current average current deviation;

[0018] When the current average current deviation exceeds the preset allowable fluctuation range, or the amplitude of the AC component is lower than the preset threshold, it is determined that the servo valve core is sticky.

[0019] The quantification of viscosity is calculated based on the relative ratio of the current average current deviation to the reference current value.

[0020] The quantified value of viscosity is updated and stored in real time.

[0021] Through this technical solution, the viscous state of the valve core can be accurately identified and quantified by refining the analysis of the servo valve drive current. This provides a reliable data foundation for subsequent determination of adhesion release and improves the accuracy and sensitivity of viscous judgment.

[0022] More specifically, in some preferred embodiments, when a preset distance of movement is detected in the actual position of the servo valve spool, the step of immediately stopping the gradual increase of the uniform rate of the drive current and adjusting the drive current includes:

[0023] While the drive current gradually increases at a preset uniform rate, the actual position of the servo valve core, the temperature of the hydraulic oil, and the pressure of the hydraulic oil are continuously monitored.

[0024] Based on the response characteristics corresponding to the actual position of the servo valve core, the temperature of the hydraulic oil, and the pressure of the hydraulic oil, it can be determined whether the servo valve core is in a smooth start state or a fixed breakthrough state.

[0025] If it is determined to be a smooth start-up state, immediately stop the uniform rate of gradual increase of the drive current, adjust the growth slope of the drive current, and make the drive current quickly increase to the current level required by the normal flow regulation mode.

[0026] If the condition is determined to be a fixed breakout state, the uniform rate of gradual increase of the drive current is immediately stopped, and an overshoot suppression strategy is executed. The overshoot suppression strategy includes instantaneously reducing the drive current to a preset safe value and activating damping control to stabilize the position of the servo valve core.

[0027] Through technical solutions, the valve core's starting mode can be intelligently distinguished based on its actual response characteristics and the hydraulic oil's operating parameters. Targeted strategies such as smooth start-up or overshoot suppression can be implemented to effectively avoid flow and pressure shocks during fixation failure, ensuring stable system operation.

[0028] Based on this, this application further proposes a step for determining whether the servo valve spool is in a smooth start state or a stuck breakout state based on the response characteristics corresponding to the actual position of the servo valve spool, the temperature of the hydraulic oil, and the pressure of the hydraulic oil, including:

[0029] Identify the response characteristics corresponding to the actual position of the servo valve spool; the response characteristics include the initial static zone length of the spool displacement, the spool displacement jump amplitude, and the spool displacement change rate;

[0030] Based on the temperature and pressure of the hydraulic oil, the initial static zone length, valve core displacement jump amplitude, and valve core displacement change rate are corrected.

[0031] Based on the corrected initial static zone length, valve core displacement jump amplitude, and valve core displacement change rate, it is determined whether the servo valve core is in a smooth start state or a fixed breakthrough state, and the fixed mode is identified as either an overall viscous state or a local fixed state.

[0032] Through technical solutions, the valve core displacement response characteristics can be refined and corrected in combination with the actual working conditions of the hydraulic oil, thus more accurately determining the valve core's fixation mode and providing a more reliable basis for subsequent precise control.

[0033] Based on the above, this application also proposes a method for regulating the flow rate of a high-temperature hydraulic pump. If a stuck-out state is detected, the uniform rate of gradual increase of the drive current is immediately stopped, and an overshoot suppression strategy is implemented. The overshoot suppression strategy includes the steps of instantaneously reducing the drive current to a preset safe value and activating damping control to stabilize the position of the servo valve spool.

[0034] Immediately stop the uniform rate of the drive current from gradually increasing;

[0035] Based on the valve core displacement change rate at the moment of breaking free from fixation, the temperature and pressure of the hydraulic oil, the overdrive energy and residual viscous force of the servo valve core are calculated.

[0036] Based on overdrive energy and residual viscous force, the target value and rate of fallback of the drive current are dynamically determined.

[0037] The drive current will instantly drop back to the target value at a drop rate;

[0038] The damping control parameters are dynamically adjusted based on the valve core displacement change rate at the moment the servo valve core breaks free from fixation, the temperature of the hydraulic oil, and the pressure of the hydraulic oil.

[0039] The damping control is activated to stabilize the servo valve spool position.

[0040] Through this technical solution, the overshoot phenomenon after the fixation breakthrough can be addressed by calculating the overshoot impulse energy and residual viscous force, dynamically adjusting the drive current fallback strategy and damping control parameters, thereby achieving rapid stabilization of the valve core position, effectively suppressing overshoot, and protecting the system.

[0041] As a technical improvement, this application also proposes a method for regulating the flow rate of a high-temperature hydraulic pump, wherein the steps of calculating the overdrive energy and residual viscous force of the servo valve core based on the valve core displacement change rate at the moment of breaking free from fixation, the temperature of the hydraulic oil, and the pressure of the hydraulic oil include:

[0042] Real-time acquisition of servo valve spool displacement, drive current, hydraulic oil temperature, and hydraulic oil pressure;

[0043] Based on the valve core displacement, the motion state of the servo valve core is identified; the motion state includes the valve core displacement, valve core velocity, and valve core acceleration.

[0044] Based on the driving current, identify the driving force acting on the servo valve core;

[0045] Based on the temperature and pressure of the hydraulic oil, the corresponding physical properties of the hydraulic oil are obtained; the physical properties include the viscosity, density, and compressibility of the hydraulic oil.

[0046] By combining the motion state of the servo valve spool, the driving force, and the physical properties of the hydraulic oil, the overdrive energy and residual viscous force of the servo valve spool are dynamically calculated. The dynamic calculation process is iteratively corrected to match the calculation results with the actual motion trajectory and force state of the servo valve spool.

[0047] Through this technical solution, the overshoot energy and residual viscous force of the valve core can be accurately evaluated by real-time acquisition and dynamic calculation of multiple parameters, combined with iterative correction, providing a more accurate physical model support for overshoot suppression strategies.

[0048] Furthermore, this application also proposes a method for regulating the flow rate of a high-temperature hydraulic pump. This method dynamically calculates the overdrive energy and residual viscous force of the servo valve core by combining the motion state of the servo valve core, the driving force, and the physical properties of the hydraulic oil. The dynamic calculation process involves iterative correction to match the calculation results with the actual motion trajectory and force state of the servo valve core.

[0049] Based on the motion characteristics, driving force, and physical properties of hydraulic oil of the servo valve core in different stroke segments, the fixing force in the gap between the servo valve core and the valve sleeve is calculated in segments to obtain segmented fixing force data.

[0050] By comparing the segmented fixation data with the actual motion response of the servo valve core in the corresponding stroke segment, the fixation calculation parameters of each stroke segment are iteratively corrected until the fixation calculation results of each stroke segment match the actual motion response of the servo valve core in the corresponding stroke segment.

[0051] Through this technical solution, the fixation force of the valve core in different stroke segments can be simulated more accurately by segmented calculation and iterative correction, so that the calculation results are highly matched with the actual motion response, further improving the accuracy of overshoot suppression.

[0052] As a further improvement, this application also proposes a method for regulating the flow rate of a high-temperature hydraulic pump, wherein the step of dynamically adjusting the damping control parameters based on the valve core displacement change rate at the moment the servo valve core breaks free from fixation, the temperature of the hydraulic oil, and the pressure of the hydraulic oil includes:

[0053] Based on the valve core displacement change rate at the moment the servo valve core breaks free from fixation, the temperature and pressure of the hydraulic oil, calculate the instantaneous inertia of the servo valve core, the hydraulic damping coefficient, and the residual friction force.

[0054] Based on the instantaneous inertia of the valve core, the hydraulic damping coefficient, and the residual friction, adjust the proportional gain, integral time, and derivative time of the damping control.

[0055] Through this technical solution, the PID parameters of the damping control can be calculated and adjusted in real time based on the dynamic parameters of the valve core at the moment of breaking free from fixation. This makes the damping control more adaptable to the actual motion state of the valve core, thereby achieving faster and more stable position control.

[0056] Based on the above, this application also proposes a method for regulating the flow rate of a high-temperature resistant hydraulic pump, wherein the steps of adjusting the proportional gain, integral time, and derivative time of the damping control according to the instantaneous inertia of the valve core, the hydraulic damping coefficient, and the residual friction force include:

[0057] The degree of abrupt change in the physical properties of hydraulic oil is evaluated based on the instantaneous inertia of the valve core, the hydraulic damping coefficient, the residual friction, the real-time monitored rate of temperature change of hydraulic oil, and the rate of pressure change of hydraulic oil.

[0058] Based on the degree of abrupt change in physical characteristics, the proportional gain, integral time, and derivative time of the damping control are pre-compensated and adjusted.

[0059] After pre-compensation adjustment, continuously monitor the servo valve spool position and spool speed;

[0060] Based on the deviation between the actual motion response and the desired response of the servo valve spool, which is jointly reflected by the spool position and spool speed, the proportional gain, integral time, and derivative time of the damping control are adjusted in real time.

[0061] Through this technical solution, pre-compensation can be performed by considering the degree of abrupt changes in the physical properties of hydraulic oil, and real-time adjustments can be made in conjunction with the actual motion response of the valve core. This makes the parameter adjustment of damping control more precise and adaptive, further improving the stability of the valve core position and the control accuracy.

[0062] Secondly, this application also discloses a high-temperature resistant hydraulic pump flow regulation system for performing high-temperature resistant hydraulic pump flow regulation, comprising:

[0063] The viscosity quantification module is used to continuously monitor and acquire the drive current corresponding to the servo valve, and quantify the viscosity of the servo valve core based on the current characteristics of the drive current.

[0064] The adhesion release judgment module is used to obtain the viscosity of the servo valve core when it receives an instruction to switch the high-temperature hydraulic pump from the pressure holding state to the increased flow output mode, and to determine whether the adhesion release program needs to be started based on the viscosity, and to obtain the adhesion release judgment result.

[0065] The release procedure initiation module is used to apply a drive current to the servo valve if the fixation release judgment result indicates that the fixation release procedure needs to be initiated; the drive current gradually increases at a preset uniform rate.

[0066] The actual position monitoring module is used to monitor the actual position of the servo valve core in real time as the drive current gradually increases at a preset uniform rate.

[0067] The drive current adjustment module is used to immediately stop the uniform rate of gradual increase of the drive current and adjust the drive current when the actual position of the servo valve core is detected to have moved by a preset distance.

[0068] The technical solution provides a system for implementing the above-mentioned high-temperature hydraulic pump flow regulation method. Through modular design, it achieves intelligent identification of the stickiness of the servo valve core, controlled start-up of the stickiness release procedure, and precise adjustment of the drive current, thereby effectively solving the problems of starting difficulties and flow impact caused by the stickiness of the servo valve core after high temperature and high pressure holding.

[0069] Beneficial effects

[0070] The high-temperature hydraulic pump flow regulation method disclosed in this application can accurately quantify the viscosity of the servo valve core by continuously monitoring the drive current characteristics of the servo valve. Upon receiving a flow regulation command, it can intelligently determine whether a fixation release procedure needs to be initiated based on the actual viscosity of the valve core. When the fixation release procedure needs to be initiated, the method gradually increases the drive current at a preset uniform rate, while monitoring the actual position of the valve core in real time. Once a preset distance of movement of the valve core is detected, the uniform increase of the current is immediately stopped and adjustment is performed. This strategy effectively avoids the valve core overshoot phenomenon caused by blindly increasing the drive current in traditional methods, thus solving the technical problem of servo valve core gum fixation caused by hydraulic oil degradation products under high-temperature and high-pressure holding conditions, leading to starting difficulties and flow and pressure shocks. This method enables stable and precise regulation of the flow of the high-temperature hydraulic pump, significantly improving the stability and reliability of the hydraulic system and effectively protecting the quality of hydraulic components and the final product. Attached Figure Description

[0071] Figure 1 This is a flowchart of a high-temperature hydraulic pump flow regulation method according to one embodiment of the present invention;

[0072] Figure 2 This is one of the flowcharts of a high-temperature hydraulic pump flow regulation method according to another embodiment of the present invention;

[0073] Figure 3 This is a second flowchart of a high-temperature hydraulic pump flow regulation method according to another embodiment of the present invention;

[0074] Figure 4 This is a system block diagram of a high-temperature hydraulic pump flow regulation system according to another embodiment of the present invention;

[0075] Explanation of reference numerals in the attached figures:

[0076] 1. High-temperature resistant hydraulic pump flow regulation system; 11. Viscosity quantification module; 12. Fixation release judgment module; 13. Release program start module; 14. Actual position monitoring module; 15. Drive current adjustment module. Detailed Implementation

[0077] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0078] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0079] In industrial production, high-precision hydraulic systems achieve precise control of actuator movements through the synergistic action of hydraulic pumps and electro-hydraulic servo valves. However, under certain specific and harsh operating conditions, such as the high-temperature and high-pressure holding stage, the chemical degradation of hydraulic oil may lead to the precipitation of colloidal microparticles. These particles form a highly viscous deposit layer in the precise fit gap between the servo valve spool and the valve sleeve, causing the spool to "stick." This prevents the standard drive current from pushing the spool, resulting in spool overshoot and generating destructive flow and pressure surges, severely affecting system stability and control accuracy.

[0080] In response, this application proposes a method for regulating the flow rate of a high-temperature resistant hydraulic pump, combined with... Figure 1 As shown, it includes:

[0081] S1 continuously monitors and acquires the drive current corresponding to the servo valve, and quantifies the viscosity of the servo valve core based on the current characteristics of the drive current.

[0082] S2, when receiving the instruction to switch the high-temperature hydraulic pump from the pressure holding state to the increased flow output mode, obtain the viscosity of the servo valve core, and determine whether the adhesion release procedure needs to be started based on the viscosity, and obtain the adhesion release judgment result;

[0083] S3, if the fixation release judgment result indicates that the fixation release procedure needs to be started, then apply a drive current to the servo valve; the drive current gradually increases at a preset uniform rate.

[0084] S4, while the drive current gradually increases at a preset uniform rate, monitor the actual position of the servo valve core in real time.

[0085] S5, when the actual position of the servo valve core is detected to have moved by a preset distance, immediately stop the uniform rate of the drive current gradually increasing and adjust the drive current.

[0086] Specifically, the "high-temperature resistant hydraulic pump" involved in this application refers to a hydraulic pump capable of stable operation in high-temperature environments, whose internal components and hydraulic oil are specially designed to withstand the challenges posed by high temperatures. A "servo valve" is an electro-hydraulic conversion element that receives electrical signals to control the flow and direction of hydraulic oil, thereby precisely controlling the movement of the actuator. The "valve core" is the core moving component inside the servo valve, and its position determines the flow cross-sectional area of ​​the hydraulic oil. The "drive current" is the electrical signal applied to the servo valve coil, used to generate electromagnetic force to drive the valve core to move. "Viscosity" refers to the magnitude of the resistance force experienced by the servo valve core during its movement, typically determined by static friction, dynamic friction, and the adhesive force formed by oil deterioration. The "adhesion release procedure" is a series of control strategies designed to overcome valve core viscosity and restore its normal movement. The "preset distance" is the minimum threshold at which the valve core's position changes during the adhesion release process; reaching this threshold indicates that adhesion has been effectively overcome.

[0087] The core of the high-temperature hydraulic pump flow regulation method of this application lies in the precise sensing and intelligent release of the viscous state of the servo valve core.

[0088] First, the method involves continuously monitoring and acquiring the drive current corresponding to the servo valve, and quantifying the viscosity of the servo valve spool based on the current characteristics of the drive current. In one embodiment, a high-precision current sensor can be connected in series in the drive circuit of the servo valve to acquire the current signal flowing through the servo valve coil in real time. The acquired current signal can be sent to a signal processing unit, which can perform a Fourier transform on the current signal to analyze its DC and AC components. For example, when the servo valve spool is in normal working condition, the DC component of its drive current should fluctuate around a preset reference value, while the AC component (usually caused by jitter) should have a certain amplitude. If the DC component is detected to continuously deviate from the reference value, or the amplitude of the AC component decreases significantly, it may indicate that the spool is viscous. The quantification of viscosity can be achieved by establishing a mathematical model, for example, calculating a viscosity index from 0 to 100 based on the degree to which the DC component deviates from the reference value or the degree of attenuation of the AC component amplitude, where 0 represents no viscosity and 100 represents complete adhesion.

[0089] Secondly, upon receiving a command to switch the high-temperature hydraulic pump from a pressure-holding state to an increased flow output mode, the system acquires the viscosity of the servo valve spool and determines whether a fixation release procedure needs to be initiated based on the viscosity level. For example, when the system switches from a prolonged pressure-holding state (where the hydraulic pump output flow is extremely low and the servo valve spool is near zero opening) to a mode requiring a rapid increase in flow output, the control system first queries the previously quantified valve spool viscosity. If the quantified viscosity value exceeds a preset threshold (e.g., viscosity index greater than 30), it determines that a fixation release procedure needs to be initiated. Conversely, if the viscosity is low, the system can directly enter the normal flow regulation mode. This judgment mechanism avoids unnecessary fixation release operations and improves system efficiency.

[0090] Furthermore, if the fixation release determination indicates that a fixation release procedure needs to be initiated, a drive current is applied to the servo valve; the drive current increases gradually at a preset uniform rate. For example, when it is determined that fixation release is required, the control system applies a special drive current to the servo valve. This current does not reach the target value instantaneously, but increases gradually at a preset, slow, and uniform rate. For example, the current can be set to increase by 0.1 mA per second until a certain upper limit is reached or the valve core begins to move. This slow increase strategy aims to gently overcome the fixation force and avoid shocks caused by sudden current changes.

[0091] Furthermore, as the drive current gradually increases at a preset uniform rate, the actual position of the servo valve spool is monitored in real time. For example, a high-precision displacement sensor (such as an LVDT linear displacement sensor) can be installed on the servo valve to obtain the precise position information of the spool in real time. This position data is continuously fed back to the control system so that the system can monitor the movement state of the spool in real time.

[0092] Finally, when a preset distance of movement is detected in the actual position of the servo valve spool, the uniform rate of gradual increase in the drive current is immediately stopped, and the drive current is adjusted. For example, when the drive current gradually increases to a certain level, and the displacement sensor detects a tiny movement of, for example, 0.05 mm, in the actual position of the valve spool, this indicates that the fixation has been broken. At this point, the control system immediately stops the uniform increase in the drive current and adjusts the drive current according to the actual response of the valve spool. This adjustment can be an instantaneous drop back to a safe value, or a smooth transition based on subsequent flow requirements to prevent valve spool overshoot.

[0093] Optional, combined Figure 2 As shown, the step of S1 continuously monitoring and acquiring the drive current corresponding to the servo valve, and quantifying the viscosity of the servo valve core based on the current characteristics of the drive current, may include the following operations:

[0094] S11, the drive current of the servo valve is collected at a preset sampling rate to obtain current sampling data;

[0095] S12 filters the current sampling data to extract the DC and AC components.

[0096] S13, compare the DC component with the preset reference average current value to obtain the current average current deviation;

[0097] S14. When the current average current deviation exceeds the preset allowable fluctuation range, or the amplitude of the AC component is lower than the preset threshold, it is determined that the servo valve core is sticky.

[0098] S15, Calculate the quantified value of viscosity based on the relative ratio of the current average current deviation to the reference current value;

[0099] S16 updates and stores the quantified value of viscosity in real time.

[0100] The sampling rate for acquiring the servo valve's drive current refers to periodically measuring the servo valve's power supply current using a sensor or ammeter and recording it digitally to form a continuous current sampling data stream. This preset sampling rate is typically set based on the servo valve's response speed and the system's real-time requirements for viscosity detection to ensure that subtle changes in the current signal can be captured.

[0101] Furthermore, the current sampling data is filtered to extract the DC and AC components. The purpose is to decompose the raw, potentially noisy, current signal into a stable DC component and a dynamically changing AC component. The DC component typically reflects the average driving force or average position of the servo valve under stable operating conditions, while the AC component may reflect minute vibrations, jitters, or response characteristics of the servo valve spool. A low-pass filter can extract the DC component, while a high-pass or band-pass filter can extract the AC component.

[0102] The DC component is compared with a preset reference average current value to obtain the current average current deviation. This is used to assess whether the servo valve experiences abnormal load or resistance under its current operating condition. The preset reference average current value is a reference value for the average current when the servo valve is operating under normal, non-sticky conditions; this value can be obtained through experimental calibration or theoretical calculation. When the actually measured DC component deviates from this reference value, it indicates that the servo valve may require additional driving force to overcome some resistance, which is usually an early sign of valve spool sticking.

[0103] Specifically, when the current average current deviation exceeds the preset allowable fluctuation range, or the amplitude of the AC component is lower than the preset threshold, the servo valve spool is determined to be sticky. The allowable fluctuation range defines the reasonable fluctuation range of the average current under normal operating conditions; exceeding this range indicates an anomaly. The amplitude of the AC component reflects the dynamic response capability or micro-motion state of the servo valve spool. When the spool sticks, its micro-motion capability is limited, leading to a decrease in the amplitude of the AC component. Therefore, either condition being met can be considered an indication of spool sticking.

[0104] Therefore, based on the relative ratio of the current average current deviation to the reference current value, a quantified value of the viscosity is calculated. This quantified value is a numerical indicator used to accurately describe the severity of valve core viscosity. For example, it can be calculated through the ratio of the deviation to the reference value or through a preset functional relationship, so that the viscosity can be quantified into a specific numerical value, facilitating subsequent judgment and processing.

[0105] Ultimately, the quantitative value of viscosity is updated and stored in real time. This aims to provide the latest and most accurate data support for subsequent fixation release judgments and to provide historical evidence for system performance analysis and fault diagnosis. Real-time updates ensure that the system can make decisions based on the latest valve core state, while storage helps track viscosity trends and evaluate the effectiveness of control strategies.

[0106] Optionally, when a preset distance is detected as a movement in the actual position of the servo valve spool, the steps of immediately stopping the gradual increase of the drive current at a uniform rate and adjusting the drive current include:

[0107] While the drive current gradually increases at a preset uniform rate, the actual position of the servo valve core, the temperature of the hydraulic oil, and the pressure of the hydraulic oil are continuously monitored.

[0108] Based on the response characteristics corresponding to the actual position of the servo valve core, the temperature of the hydraulic oil, and the pressure of the hydraulic oil, it can be determined whether the servo valve core is in a smooth start state or a fixed breakthrough state.

[0109] If it is determined to be a smooth start-up state, immediately stop the uniform rate of gradual increase of the drive current, adjust the growth slope of the drive current, and make the drive current quickly increase to the current level required by the normal flow regulation mode.

[0110] If the condition is determined to be a fixed breakout state, the uniform rate of gradual increase of the drive current is immediately stopped, and an overshoot suppression strategy is executed. The overshoot suppression strategy includes instantaneously reducing the drive current to a preset safe value and activating damping control to stabilize the position of the servo valve core.

[0111] Specifically, as the drive current gradually increases at a preset uniform rate, in addition to real-time monitoring of the actual position of the servo valve spool, the temperature and pressure of the hydraulic oil are also continuously monitored. The actual position of the servo valve spool can be acquired in real time using a displacement sensor (e.g., an LVDT linear displacement sensor); the temperature of the hydraulic oil can be measured using a temperature sensor; and the pressure of the hydraulic oil can be measured using a pressure sensor. This continuous monitoring of parameters provides comprehensive data support for subsequent judgment of the spool's motion state.

[0112] Furthermore, based on the response characteristics corresponding to the actual position of the servo valve spool, the temperature and pressure of the hydraulic oil, it can be determined whether the servo valve spool is in a smooth start state or a stuck-break state. The response characteristics corresponding to the actual position of the servo valve spool refer to the law of spool displacement change over time, such as the initial static zone length of the spool displacement, the amplitude of the spool displacement jump, and the rate of change of the spool displacement. The temperature and pressure of the hydraulic oil affect its physical properties such as viscosity, density, and compressibility, thus affecting the movement resistance of the spool. By comprehensively analyzing these parameters, it is possible to accurately distinguish whether the spool slowly and smoothly breaks out of the viscous state (smooth start state) or suddenly and violently breaks through the stuck state (stuck-break state).

[0113] When a smooth start-up is detected, it indicates that the viscous force of the valve core is small or has been gradually overcome, and the valve core moves smoothly. At this point, immediately stop the gradual, uniform increase of the drive current and adjust the growth slope of the drive current to quickly increase it to the current level required for the normal flow regulation mode. This is intended to rapidly regulate the hydraulic pump flow to the target value, improving the system's response speed and operating efficiency.

[0114] When a fixation failure is detected, it indicates that the valve spool suddenly releases after overcoming a large viscous force, which may cause the valve spool position to overshoot. In this case, the gradual, uniform increase of the drive current is immediately stopped, and an overshoot suppression strategy is implemented. This overshoot suppression strategy consists of two key parts: First, the drive current is instantaneously reduced to a preset safe value to rapidly decrease the driving force acting on the valve spool and prevent excessive valve spool movement; second, damping control is activated, dynamically adjusting control parameters to ensure the servo valve spool position quickly stabilizes at the desired position, preventing oscillation and secondary fixation.

[0115] Optionally, the steps for determining whether the servo valve spool is in a smooth start state or a stuck breakout state based on the response characteristics corresponding to the actual position of the servo valve spool, the temperature of the hydraulic oil, and the pressure of the hydraulic oil include:

[0116] Identify the response characteristics corresponding to the actual position of the servo valve spool; the response characteristics include the initial static zone length of the spool displacement, the spool displacement jump amplitude, and the spool displacement change rate;

[0117] Based on the temperature and pressure of the hydraulic oil, the initial static zone length, valve core displacement jump amplitude, and valve core displacement change rate are corrected.

[0118] Based on the corrected initial static zone length, valve core displacement jump amplitude, and valve core displacement change rate, it is determined whether the servo valve core is in a smooth start state or a fixed breakthrough state, and the fixed mode is identified as either an overall viscous state or a local fixed state.

[0119] Specifically, identifying the response characteristics corresponding to the actual position of the servo valve spool refers to extracting key kinematic parameters through analysis of the actual displacement data of the spool. Among these, the initial resting zone length of the spool displacement refers to the length of the displacement interval during which the spool remains stationary before the drive current begins to increase but before significant displacement occurs; it reflects the minimum driving force or displacement threshold required to overcome initial friction. The spool displacement jump amplitude refers to the amount of displacement when the spool suddenly starts from a stationary state or undergoes a significant displacement change during movement; it can indicate the severity of fixation breakthrough. The spool displacement change rate refers to the rate at which the spool displacement changes over time, i.e., the spool velocity; it can reflect the smoothness or abruptness of the spool movement. These response characteristics can be calculated from real-time acquired spool position sensor data.

[0120] Furthermore, the above response characteristics are corrected by incorporating the temperature and pressure of the hydraulic oil. This is because the physical properties of the hydraulic oil (such as viscosity, density, and compressibility) change significantly with temperature and pressure, thus affecting the motion response of the servo valve spool. For example, in high-temperature environments, the viscosity of the hydraulic oil decreases, which may cause the valve spool to displace more easily, thereby affecting the initial resting zone length and jump amplitude. In high-pressure environments, the compressibility of the hydraulic oil may affect the response speed of the valve spool. Therefore, correction coefficients can be constructed using pre-established physical models or experimental data to dynamically adjust the identified initial resting zone length, valve spool displacement jump amplitude, and valve spool displacement change rate, thereby eliminating the interference of environmental factors on the accuracy of the judgment.

[0121] Therefore, based on the corrected initial stationary zone length, valve spool displacement jump amplitude, and valve spool displacement change rate, it is possible to more accurately determine whether the servo valve spool is in a smooth start-up state or a fixation breakthrough state. For example, if the initial stationary zone length is long and a large valve spool displacement jump amplitude subsequently occurs, while the valve spool displacement change rate increases sharply in a short period of time, it is more likely to be judged as a fixation breakthrough state. Conversely, if the initial stationary zone length is short, the valve spool displacement jump amplitude is small, and the valve spool displacement change rate is stable, it is more likely to be judged as a smooth start-up state. In addition, by conducting a more detailed analysis of these corrected response characteristics, such as combining the response differences of the valve spool in different stroke segments, it is possible to further identify whether the fixation mode is a global viscous state or a local fixation state. A global viscous state may be characterized by a large initial stationary zone length throughout the entire stroke segment, while a local fixation state may only show a large jump amplitude or abnormal change rate in a specific stroke segment.

[0122] In some preferred embodiments, a specific example is given below. Assume that when the high-temperature hydraulic pump switches from a pressure-holding state to an increased flow output mode, the system begins to apply a drive current to the servo valve and gradually increases it.

[0123] First, the actual position data of the servo valve spool is acquired in real time. When the drive current increases from zero, the spool position remains unchanged for a period of time. The point at which the spool begins to move when the drive current reaches a certain value is recorded; the length of the spool displacement interval corresponding to this drive current is identified as the initial resting zone length. For example, if the spool only starts to move when the drive current reaches 100mA, and the spool displacement was 0 before that, then the initial resting zone length is determined.

[0124] Next, when the valve core begins to move, the jump and rate of change of its displacement are monitored. For example, if the valve core displacement jumps from 0mm to 0.5mm in a very short time (e.g., 50 milliseconds), then 0.5mm is recorded as the valve core displacement jump amplitude, and 0.5mm / 50ms is the valve core displacement rate of change.

[0125] Meanwhile, the system continuously monitors the temperature and pressure of the hydraulic oil. Assume the current hydraulic oil temperature is 150℃ and the pressure is 20MPa. According to a preset correction model, under these conditions (150℃ and 20MPa), the viscosity of the hydraulic oil may decrease, causing the valve core's actual response to be more sensitive than at normal temperature and pressure. Therefore, the identified initial static zone length, valve core displacement jump amplitude, and valve core displacement change rate are corrected. For example, the corrected initial static zone length may be adjusted to a slightly smaller value to reflect the lower starting resistance at higher temperatures.

[0126] Finally, a judgment is made based on the corrected response characteristics. If the corrected initial resting zone length is still large (e.g., still greater than a certain threshold after correction), and the valve core displacement jump amplitude is large, while the valve core displacement change rate is very high at the moment of breakthrough, the system determines that the servo valve core is in a fixed breakthrough state. Furthermore, if the valve core is found to exhibit similar large initial resting zone lengths and jump characteristics throughout the entire stroke range, it is identified as an overall viscous state; if abnormal jumps only occur in a specific stroke segment, it is identified as a local fixed state. Based on this judgment result, the system will trigger the corresponding fixed release procedure, such as executing an overshoot suppression strategy.

[0127] Optional, combined Figure 3 As shown, if a stuck-out state is detected, the uniform rate of gradual increase of the drive current is immediately stopped, and an overshoot suppression strategy is executed. The overshoot suppression strategy includes the steps of instantaneously reducing the drive current to a preset safe value and activating damping control to stabilize the position of the servo valve spool.

[0128] A1, immediately stop the uniform rate of the driving current gradually increasing;

[0129] This operation aims to quickly cut off the driving force that causes the valve core to accelerate continuously, creating conditions for subsequent precise control.

[0130] A2. Calculate the overdrive energy and residual viscous force of the servo valve core based on the valve core displacement change rate at the moment of breaking free from fixation, the temperature of the hydraulic oil, and the pressure of the hydraulic oil.

[0131] The valve spool displacement rate can be understood as the velocity of the valve spool at the moment of breaking free from fixation, directly reflecting the instantaneous momentum of the valve spool when it breaks free from fixation. The temperature and pressure of the hydraulic oil affect its physical properties such as viscosity and density, which in turn affect the resistance to valve spool movement and the performance of fixation forces within the hydraulic oil. By combining these parameters, we can more accurately assess the kinetic energy gained by the valve spool when breaking free from fixation and the residual viscous forces that may still exist after the breakthrough, hindering valve spool movement.

[0132] A3. Based on the overdrive energy and residual viscous force calculated above, dynamically determine the target value and rate of fallback of the drive current.

[0133] This means that the drive current does not simply fall back to a fixed preset safety value, but rather, based on the specific circumstances of the valve core overshoot, an optimal target value for the fallback and the best fallback rate to reach that target value are calculated. For example, if the overshoot energy is large, a lower target value for the fallback and a faster instantaneous fallback rate may be needed to quickly reduce the driving force and prevent excessive displacement of the valve core.

[0134] A4 will instantly reduce the drive current to the target value at a rate of decrease.

[0135] This step ensures that the adjustment of the drive current is fast and precise, and can respond promptly to dynamic changes after the valve core breaks free from fixation, thereby effectively suppressing overshoot.

[0136] A5. Based on the valve core displacement change rate at the moment the servo valve core breaks through the fixed position, the temperature and pressure of the hydraulic oil, the damping control parameters are dynamically adjusted, and the damping control is activated to stabilize the position of the servo valve core.

[0137] The parameters of damping control, such as proportional gain, integral time, and derivative time, are optimized in real time based on the specific dynamic characteristics of the valve core during overshoot. The purpose is to quickly and smoothly stabilize the valve core position at the desired position after the drive current recedes, through precise damping control, avoiding continuous oscillation or secondary overshoot, and ensuring the accuracy and stability of flow regulation.

[0138] In some preferred embodiments, a specific example is given below. Suppose that during the long-term operation of a high-temperature hydraulic pump, the servo valve spool exhibits varying degrees of viscosity due to hydraulic oil aging or impurity accumulation.

[0139] For example, in one scenario, the valve spool might be in a slightly localized fixed state. When the system receives a command to increase the flow output and determines that a fixation release procedure needs to be initiated, the drive current begins to increase uniformly. At the moment the valve spool breaks free from fixation, its displacement rate of change might be relatively small, and the temperature and pressure of the hydraulic oil are within normal ranges. At this point, according to the scheme of this application, the system calculates a small overdrive energy and residual viscous force. Based on these calculations, the target value for the drive current reduction might be dynamically determined to be a relatively high safety value, and the reduction rate might be relatively gentle. Simultaneously, the damping control parameters will be adjusted accordingly to provide appropriate damping, ensuring a smooth transition of the valve spool to the target position.

[0140] In another scenario, the valve core may be in a state of severe overall viscous adhesion, or it may break free of adhesion under high temperature and pressure. In this case, the rate of displacement change of the valve core at the moment of breakthrough may be very large, indicating that it has acquired a large instantaneous kinetic energy. The temperature and pressure of the hydraulic oil may also cause a significant decrease in the viscosity of the hydraulic oil, further exacerbating the overshoot tendency. According to the scheme of this application, the system will calculate the large overshoot kinetic energy and residual viscous force. Based on these calculation results, the target value of the drive current reduction will be dynamically determined to a lower safety value, and the reduction rate will be very fast to achieve the effect of "emergency braking" and quickly eliminate the overshoot. At the same time, the damping control parameters will also be dynamically adjusted to provide a stronger damping effect, quickly suppress the violent oscillation of the valve core, and make it stabilize quickly.

[0141] Optionally, the steps for calculating the overdrive energy and residual viscous force of the servo valve spool based on the rate of change of valve spool displacement at the moment of breaking free from fixation, the temperature of the hydraulic oil, and the pressure of the hydraulic oil include:

[0142] Real-time acquisition of servo valve spool displacement, drive current, hydraulic oil temperature, and hydraulic oil pressure;

[0143] Based on the valve core displacement, the motion state of the servo valve core is identified; the motion state includes the valve core displacement, valve core velocity, and valve core acceleration.

[0144] Based on the driving current, identify the driving force acting on the servo valve core;

[0145] Based on the temperature and pressure of the hydraulic oil, the corresponding physical properties of the hydraulic oil are obtained; the physical properties include the viscosity, density, and compressibility of the hydraulic oil.

[0146] By combining the motion state of the servo valve spool, the driving force, and the physical properties of the hydraulic oil, the overdrive energy and residual viscous force of the servo valve spool are dynamically calculated. The dynamic calculation process is iteratively corrected to match the calculation results with the actual motion trajectory and force state of the servo valve spool.

[0147] The system involves real-time acquisition of the servo valve spool displacement, drive current, hydraulic oil temperature, and hydraulic oil pressure to provide accurate real-time data input for subsequent calculations. The servo valve spool displacement can be measured using a displacement sensor, the drive current can be monitored using a current sensor, and the hydraulic oil temperature and pressure are acquired using temperature and pressure sensors, respectively. The real-time nature of this data is crucial for accurately capturing the moment the servo valve spool breaks free from its fixed state.

[0148] Furthermore, based on the collected servo valve spool displacement data, the motion state of the servo valve spool can be identified. This motion state includes not only the spool displacement amount, but also the spool velocity obtained by performing a first-order derivative on the displacement data, and the spool acceleration obtained by performing a second-order derivative on the velocity data. These motion parameters collectively describe the dynamic behavior of the servo valve spool during the process of breaking free from fixation.

[0149] Simultaneously, based on the real-time monitored drive current, the driving force acting on the servo valve spool can be identified. This driving force is the direct force that causes the servo valve spool to overcome viscous forces and generate displacement, and its magnitude has a specific functional relationship with the drive current.

[0150] Furthermore, by acquiring the real-time temperature and pressure of the hydraulic oil, its corresponding physical properties can be determined. These physical properties, such as the viscosity, density, and compressibility of the hydraulic oil, change with temperature and pressure, directly affecting the motion resistance of the servo valve spool and the response characteristics of the hydraulic system.

[0151] Finally, by combining the motion state of the servo valve spool (including spool displacement, spool velocity, and spool acceleration), the driving force acting on the servo valve spool, and the physical properties of the hydraulic oil (including hydraulic oil viscosity, hydraulic oil density, and hydraulic oil compressibility), the overdrive energy and residual viscous force of the servo valve spool can be dynamically calculated. This dynamic calculation process is carried out through iterative correction to ensure that the calculation results can highly match the actual motion trajectory and force state of the servo valve spool. For example, a dynamic model of the servo valve spool motion can be established, real-time acquired data can be substituted into the model for calculation, and the model parameters or calculation process can be repeatedly adjusted according to the deviation between the actual observed servo valve spool response and the model prediction until the preset matching accuracy is achieved.

[0152] Optionally, the steps for dynamically calculating the overdrive energy and residual viscous force of the servo valve spool, combining the motion state of the servo valve spool, driving force, and physical properties of the hydraulic oil, and for iteratively correcting the calculation process to match the calculation results with the actual motion trajectory and force state of the servo valve spool, include:

[0153] Based on the motion characteristics, driving force, and physical properties of hydraulic oil of the servo valve core in different stroke segments, the fixing force in the gap between the servo valve core and the valve sleeve is calculated in segments to obtain segmented fixing force data.

[0154] By comparing the segmented fixation data with the actual motion response of the servo valve core in the corresponding stroke segment, the fixation calculation parameters of each stroke segment are iteratively corrected until the fixation calculation results of each stroke segment match the actual motion response of the servo valve core in the corresponding stroke segment.

[0155] Specifically, based on the motion characteristics, driving force, and physical properties of the hydraulic oil in different stroke segments of the servo valve spool, the fixation force within the gap between the servo valve spool and the valve sleeve is calculated in segments to obtain segmented fixation force data. This means dividing the entire stroke of the servo valve spool into several independent stroke segments. For example, based on the physical structure of the spool, the machining accuracy of the valve sleeve, the flow characteristics of the hydraulic oil, and empirical patterns of fixation force distribution in historical data, the 0-1mm stroke of the spool can be defined as the first stroke segment, the 1-2mm stroke as the second stroke segment, and so on. Within each stroke segment, the fixation force within the gap between the servo valve spool and the valve sleeve is independently calculated by combining the real-time acquired motion characteristics of the servo valve spool (such as displacement, velocity, and acceleration), the driving force acting on the spool, and the physical properties of the hydraulic oil (such as viscosity, density, and compressibility). The purpose of this segmented calculation is to more precisely capture the changes in fixation force at different locations, because the fixation force may not be uniformly distributed throughout the entire stroke, but is affected by factors such as local friction, oil film characteristics, and microstructure. Thus, a series of fixation calculation results for different travel segments can be obtained, namely segmented fixation data.

[0156] The process involves iteratively correcting the calculated parameters of the fixed force for each stroke segment by comparing the segmented fixed force data with the actual motion response of the servo valve core in the corresponding stroke segment. This correction continues until the calculated fixed force results for each stroke segment match the actual motion response of the servo valve core in that segment. After obtaining the initial segmented fixed force data, the system monitors the actual motion response of the servo valve core as it passes through each stroke segment in real time. The actual motion response can include parameters such as the actual displacement, velocity, and acceleration of the valve core. Subsequently, the previously calculated segmented fixed force data is compared and analyzed with the actual motion response of the valve core in the corresponding stroke segment. If a discrepancy exists, the parameters in the fixed force calculation model for that stroke segment are iteratively corrected. For example, parameters such as the friction coefficient and viscosity coefficient in the model can be adjusted until the fixed force calculation results for that stroke segment can accurately predict or explain the actual motion response of the valve core in that stroke segment. This iterative correction process continues until the fixed force calculation results for all stroke segments achieve the preset matching accuracy requirements with the actual motion response of the servo valve core in the corresponding stroke segments.

[0157] In some preferred embodiments, a specific example is given below. Assume the entire stroke of the servo valve spool is 0-5mm, and empirically, the fixation force exhibits different characteristics in the 0-2mm and 2-5mm stroke segments. The system first divides the spool stroke into a first stroke segment (0-2mm) and a second stroke segment (2-5mm). When the spool begins to move during the fixation release process, for example, when the spool starts moving from the 0mm position and enters the first stroke segment, the system collects the spool's motion characteristics (such as displacement, velocity, and acceleration) as well as the driving force and hydraulic oil physical properties in real time during this stroke segment. Based on this data, the fixation force of the first stroke segment is initially calculated. Simultaneously, the system monitors the actual motion response of the spool in the first stroke segment. If there is a deviation between the calculated fixation force and the actual motion response—for example, if the calculated fixation force causes the predicted spool speed to be lower than the actual speed—the system iteratively corrects the fixation force calculation parameters for the first stroke segment until the calculation result matches the actual motion response. As the valve core continues to move and enters the second stroke segment, the system independently calculates and iteratively corrects the fixation force in this segment in a similar manner, ensuring that the calculated fixation force for this segment also closely matches the actual motion response. Through this segmented calculation and local iterative correction, even if the fixation force differs significantly across different stroke segments, the system can accurately quantify the fixation force at each position, thus providing high-precision basic data for subsequent calculations of overdrive energy and residual viscous force.

[0158] Optionally, the steps for dynamically adjusting the damping control parameters based on the valve core displacement change rate at the moment the servo valve core breaks free from fixation, the hydraulic oil temperature, and the hydraulic oil pressure include:

[0159] Based on the valve core displacement change rate at the moment the servo valve core breaks free from fixation, the temperature and pressure of the hydraulic oil, calculate the instantaneous inertia of the servo valve core, the hydraulic damping coefficient, and the residual friction force.

[0160] Based on the instantaneous inertia of the valve core, the hydraulic damping coefficient, and the residual friction, adjust the proportional gain, integral time, and derivative time of the damping control.

[0161] Specifically, the instantaneous inertia of a servo valve spool refers to the spool's ability to resist changes in motion state at the moment of breaking free from fixation. Its magnitude is affected by factors such as the spool's own mass, connecting components, and acceleration at the moment of breaking free. The hydraulic damping coefficient reflects the resistance of hydraulic oil to the spool's motion; its value is closely related to the hydraulic oil's viscosity, the clearance between the spool and the valve sleeve, and the fluid velocity. Residual friction refers to the nonlinear frictional force that remains in the spool's motion after breaking free from fixation. This force may be caused by localized viscosity, seal friction, or mechanical wear. These physical quantities are key factors affecting the spool's dynamic response, and accurate calculation of them is fundamental to achieving precise damping control. Among these, the proportional gain, integral time, and derivative time of damping control are typical parameters of a PID (Proportional-Integral-Derivative) controller. The proportional gain determines the controller's response strength to the current error; the integral time affects the controller's ability to eliminate steady-state errors; and the derivative time reflects the controller's ability to predict the rate of change of error, helping to suppress overshoot and accelerate response speed. By establishing a mapping relationship between the calculated instantaneous inertia of the valve spool, the hydraulic damping coefficient, and the residual friction force and these PID parameters, adaptive adjustment of the damping control parameters can be achieved. For example, when the instantaneous inertia of the valve spool is large, it may be necessary to appropriately reduce the proportional gain to avoid overshoot; when the hydraulic damping coefficient is high, it may be necessary to adjust the integral time to speed up the response; when the residual friction force is large, it may be necessary to adjust the derivative time to better suppress oscillations.

[0162] In some preferred embodiments, a specific example is given below. Suppose that when the high-temperature hydraulic pump switches from a pressure-holding state to an increased flow output mode, the servo valve spool becomes stuck. The system first executes a sticking-out procedure, gradually increasing the drive current. When a preset distance of movement of the valve spool is detected, indicating that the sticking has been broken, the system immediately stops the uniform increase of the drive current and enters an overshoot suppression strategy. In this strategy, to achieve rapid stabilization of the valve spool position, the system collects the displacement change rate of the valve spool, the temperature and pressure of the hydraulic oil in real time at the moment the sticking is broken. For example, if the valve spool displacement change rate is extremely high, and the hydraulic oil temperature is high (leading to reduced viscosity), the system calculates a lower hydraulic damping coefficient and potentially higher instantaneous valve spool inertia. Based on these calculations, the damping control module dynamically adjusts its PID parameters: for example, it may appropriately reduce the proportional gain to avoid severe overshoot, while increasing the derivative gain to quickly suppress oscillations, and adjusting the integral time to ensure rapid elimination of steady-state errors. Through this dynamic adjustment, even when the hydraulic oil characteristics change due to high temperature, the servo valve core can quickly and smoothly converge to the target position after breaking through the fixed position, avoiding the problems of continuous oscillation or slow response that may be caused by traditional fixed parameter control, thereby ensuring the accuracy of hydraulic pump flow regulation and the stability of system operation.

[0163] Optionally, the steps of adjusting the proportional gain, integral time, and derivative time of the damping control based on the instantaneous inertia of the valve core, the hydraulic damping coefficient, and the residual friction include:

[0164] The degree of abrupt change in the physical properties of hydraulic oil is evaluated based on the instantaneous inertia of the valve core, the hydraulic damping coefficient, the residual friction, the real-time monitored rate of temperature change of hydraulic oil, and the rate of pressure change of hydraulic oil.

[0165] Based on the degree of abrupt change in physical characteristics, the proportional gain, integral time, and derivative time of the damping control are pre-compensated and adjusted.

[0166] After pre-compensation adjustment, continuously monitor the servo valve spool position and spool speed;

[0167] Based on the deviation between the actual motion response and the desired response of the servo valve spool, which is jointly reflected by the spool position and spool speed, the proportional gain, integral time, and derivative time of the damping control are adjusted in real time.

[0168] Specifically, the degree of abrupt change in the physical properties of hydraulic oil refers to the extent to which key physical parameters such as viscosity, density, and compressibility of the hydraulic oil change significantly within a short period of time. This abrupt change is typically driven by the rate of temperature and pressure change of the hydraulic oil. For example, a rapid increase or decrease in temperature will significantly alter the viscosity of the hydraulic oil, while rapid fluctuations in pressure will affect its compressibility. By monitoring these rates of change in real time, potential abrupt changes in the physical properties of the hydraulic oil can be predicted in advance, thus providing forward-looking information for subsequent adjustments to control parameters.

[0169] Based on the assessed degree of abrupt change in physical characteristics, the proportional gain, integral time, and derivative time of the damping control are pre-compensated and adjusted. Pre-compensation adjustment refers to making preliminary, forward-looking corrections to the PID control parameters based on the predicted trend of changes in the physical characteristics of the hydraulic oil, before a significant deviation occurs in the actual motion response of the servo valve spool. For example, if a rapid decrease in hydraulic oil viscosity is predicted, the proportional gain can be appropriately increased or the integral time decreased in advance to avoid oscillations caused by an excessively fast valve spool response; conversely, if a rapid increase in viscosity is predicted, parameters may need to be adjusted in advance to enhance the response speed. The purpose is to optimize parameters in the early stages of dynamic changes in the hydraulic system, reducing system response lag.

[0170] After the pre-compensation adjustment is completed, the system continuously monitors the servo valve spool position and speed. Spool position and speed are key indicators that directly reflect the actual motion state of the servo valve spool. Continuous monitoring allows for the acquisition of real-time dynamic response data of the spool, providing a basis for subsequent fine-tuning.

[0171] Based on the deviation between the actual motion response and the desired response of the servo valve spool, reflected by both spool position and velocity, the proportional gain, integral time, and derivative time of the damping control are adjusted in real time. The deviation between the actual motion response and the desired response refers to the difference between the actual position and velocity of the servo valve spool and the target position and velocity set by the control system. For example, if the actual position of the spool exhibits continuous small oscillations, or its velocity response is slower than expected, it indicates a deviation. Real-time adjustment refers to dynamically fine-tuning the proportional gain, integral time, and derivative time based on these deviations using a feedback control mechanism (such as a PID algorithm) to eliminate the deviations, making the actual motion trajectory of the spool as close as possible to the desired trajectory, thus ensuring stable and precise control of the spool.

[0172] In some preferred embodiments, a specific example is given below. Suppose that after a prolonged period of pressure holding in a high-temperature hydraulic pump, the hydraulic oil temperature experiences a rapid localized increase due to uneven environmental heat dissipation or localized friction, leading to a rapid decrease in hydraulic oil viscosity. According to the method described above, the system monitors the rate of temperature change and the rate of pressure change of the hydraulic oil in real time and assesses any abrupt changes in the physical properties of the hydraulic oil. For example, when the rate of temperature change exceeds a preset threshold, the system determines that the hydraulic oil viscosity may decrease rapidly, and thus pre-compensates for any excessively rapid response of the valve core in a low-viscosity environment by appropriately increasing the proportional gain of the damping control and reducing the integral time.

[0173] After pre-compensation adjustment, when the fixation release procedure is initiated and the servo valve spool begins to move, the system continuously monitors the actual position and speed of the spool. If a deviation is detected between the actual motion response (e.g., spool speed) and the expected response—for example, the spool speed is slightly higher than expected—it indicates that there may still be room for fine-tuning the pre-compensation. The system immediately makes real-time adjustments to the proportional gain, integral time, and derivative time based on this deviation to ensure that the spool can accurately and smoothly reach the target position, avoiding any residual overshoot or oscillation. Through this combination of pre-compensation and real-time adjustment, even under complex operating conditions where the physical properties of the hydraulic oil change rapidly, precise control of the servo valve spool and stable system operation can be ensured.

[0174] This application also discloses a high-temperature resistant hydraulic pump flow regulation system for performing high-temperature resistant hydraulic pump flow regulation, combined with... Figure 4 As shown, the high-temperature resistant hydraulic pump flow regulation system 1 includes:

[0175] The viscosity quantification module 11 is used to continuously monitor and acquire the drive current corresponding to the servo valve, and quantify the viscosity of the servo valve core based on the current characteristics of the drive current.

[0176] The adhesion release judgment module 12 is used to obtain the viscosity of the servo valve core when it receives an instruction to switch the high-temperature hydraulic pump from the pressure holding state to the increased flow output mode, and to determine whether the adhesion release program needs to be started based on the viscosity, and to obtain the adhesion release judgment result.

[0177] The release procedure initiation module 13 is used to apply a drive current to the servo valve if the fixation release judgment result indicates that the fixation release procedure needs to be started; the drive current gradually increases at a preset uniform rate.

[0178] The actual position monitoring module 14 is used to monitor the actual position of the servo valve core in real time as the drive current gradually increases at a preset uniform rate.

[0179] The drive current adjustment module 15 is used to immediately stop the uniform rate of gradual increase of the drive current and adjust the drive current when the actual position of the servo valve core is detected to have moved by a preset distance.

[0180] Specifically, the "high-temperature resistant hydraulic pump" involved in this application refers to a hydraulic pump capable of stable operation in high-temperature environments, whose internal components and hydraulic oil are specially designed to withstand the challenges posed by high temperatures. A "servo valve" is an electro-hydraulic conversion element that receives electrical signals to control the flow and direction of hydraulic oil, thereby precisely controlling the movement of the actuator. The "valve core" is the core moving component inside the servo valve, and its position determines the flow cross-sectional area of ​​the hydraulic oil. The "drive current" is the electrical signal applied to the servo valve coil, used to generate electromagnetic force to drive the valve core to move. "Viscosity" refers to the magnitude of the resistance force experienced by the servo valve core during its movement, typically determined by static friction, dynamic friction, and the adhesive force formed by oil deterioration. The "adhesion release procedure" is a series of control strategies designed to overcome valve core viscosity and restore its normal movement. The "preset distance" is the minimum threshold at which the valve core's position changes during the adhesion release process; reaching this threshold indicates that adhesion has been effectively overcome. The names of each module, such as the viscosity quantification module and the adhesion release judgment module, refer to the hardware, software, or a combination of both that implement their respective functions.

[0181] The high-temperature hydraulic pump flow regulation system disclosed in this application can be implemented in various ways for each module.

[0182] The viscosity quantification module continuously monitors and acquires the drive current corresponding to the servo valve, and quantifies the viscosity of the servo valve spool based on the current characteristics of the drive current. This module can consist of one or more current sensors, a signal conditioning circuit, and a processing unit. For example, the current sensor can acquire the drive current signal of the servo valve in real time, the signal conditioning circuit performs preprocessing such as amplification and filtering on the signal, and then inputs the processed signal to the processing unit. The processing unit can be a microcontroller, digital signal processor, or field-programmable gate array, which runs a specific algorithm to analyze the DC and AC components of the current signal and calculate the quantized viscosity value of the valve spool according to a preset logic model. As one implementation method, the processing unit can use a general-purpose processor and implement the above functions through software programming.

[0183] The adhesion release judgment module is used to obtain the viscosity of the servo valve core when receiving a command to switch the high-temperature hydraulic pump from pressure holding mode to increased flow output mode. Based on the viscosity, it determines whether the adhesion release procedure needs to be initiated and obtains the adhesion release judgment result. This module can be integrated into the main controller or exist as an independent logic judgment unit. It receives mode switching commands from the system operation interface and viscosity data from the viscosity quantification module. Through internal judgment logic, such as comparing the quantified viscosity value with a preset threshold, it determines whether the adhesion release procedure needs to be activated.

[0184] The release procedure initiation module applies a drive current to the servo valve if the fixation release judgment result indicates that the fixation release procedure needs to be initiated; the drive current increases gradually at a preset uniform rate. This module can consist of a digital-to-analog converter and a power amplifier, or a pulse width modulation controller and a drive circuit. When a start command is received, the module generates a drive current signal, the amplitude of which increases gradually at a preset uniform rate and is applied to the coil of the servo valve to generate a gradually increasing electromagnetic force.

[0185] The actual position monitoring module is used to monitor the actual position of the servo valve spool in real time as the drive current gradually increases at a preset uniform rate. This module typically includes a high-precision displacement sensor, such as a linear variable differential transformer or a Hall effect sensor, along with corresponding signal acquisition and processing circuitry. The displacement sensor converts the mechanical displacement of the valve spool into an electrical signal, which, after signal conditioning, is digitized and analyzed by the processing unit to obtain the precise position information of the valve spool in real time.

[0186] The drive current adjustment module is used to immediately stop the uniform increase of the drive current and adjust it when a preset distance of movement in the actual position of the servo valve spool is detected. This module can share some hardware resources with the deprogramming module and is managed by the main controller or independent control logic. It continuously receives valve spool position data from the actual position monitoring module. Once the change in valve spool position is detected to reach a preset distance threshold, the module immediately issues a command to stop the uniform increase of the drive current and adjusts the drive current according to a preset strategy (e.g., instantaneously dropping back to a safe value or smoothly transitioning to a target value) to prevent valve spool overshoot.

[0187] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for regulating the flow rate of a high-temperature resistant hydraulic pump, characterized in that, include: The drive current corresponding to the servo valve is continuously monitored and acquired, and the viscosity of the servo valve core is quantified based on the current characteristics of the drive current. When a command is received to switch the high-temperature hydraulic pump from the pressure holding state to the increased flow output mode, the viscosity of the servo valve core is obtained, and based on the viscosity, it is determined whether the fixation release procedure needs to be started, and the fixation release judgment result is obtained. If the fixation release determination result indicates that the fixation release procedure needs to be initiated, a drive current is applied to the servo valve; the drive current gradually increases at a preset uniform rate. During the process of the drive current gradually increasing at a preset uniform rate, the actual position of the servo valve core is monitored in real time. When the actual position of the servo valve core is detected to have moved by a preset distance, the uniform rate of the drive current is immediately stopped and the drive current is adjusted.

2. The method for regulating the flow rate of a high-temperature resistant hydraulic pump according to claim 1, characterized in that, The step of continuously monitoring and acquiring the drive current corresponding to the servo valve, and quantifying the viscosity of the servo valve core based on the current characteristics of the drive current, includes: The drive current of the servo valve is collected at a preset sampling rate to obtain current sampling data; The current sampling data is filtered to extract the DC and AC components; The DC component is compared with a preset reference average current value to obtain the current average current deviation; When the current average current deviation exceeds the preset allowable fluctuation range, or the amplitude of the AC component is lower than the preset threshold, it is determined that the servo valve core is sticky. The quantification of viscosity is calculated based on the relative ratio of the current average current deviation to the reference current value. The quantified value of viscosity is updated and stored in real time.

3. The method for regulating the flow rate of a high-temperature resistant hydraulic pump according to claim 2, characterized in that, The step of immediately stopping the gradual increase of the uniform rate of the drive current and adjusting the drive current when the actual position of the servo valve core is detected to have moved by a preset distance includes: While the drive current gradually increases at a preset uniform rate, the actual position of the servo valve core, the temperature of the hydraulic oil, and the pressure of the hydraulic oil are continuously monitored. Based on the response characteristics corresponding to the actual position of the servo valve core, the temperature of the hydraulic oil, and the pressure of the hydraulic oil, it can be determined whether the servo valve core is in a smooth start state or a fixed breakthrough state. If it is determined to be a smooth start-up state, the uniform rate of gradual increase of the drive current is immediately stopped, and the growth slope of the drive current is adjusted so that the drive current is rapidly increased to the current level required by the normal flow regulation mode. If the condition is determined to be a fixed breakthrough state, the uniform rate of gradual increase of the driving current is immediately stopped, and an overshoot suppression strategy is executed. The overshoot suppression strategy includes instantaneously reducing the driving current to a preset safe value and activating damping control to stabilize the position of the servo valve core.

4. The method for regulating the flow rate of a high-temperature resistant hydraulic pump according to claim 3, characterized in that, The step of determining whether the servo valve spool is in a smooth start state or a stuck breakout state based on the response characteristics corresponding to the actual position of the servo valve spool, the temperature of the hydraulic oil, and the pressure of the hydraulic oil includes: Identify the response characteristics corresponding to the actual position of the servo valve spool; the response characteristics include the initial static zone length of the spool displacement, the spool displacement jump amplitude, and the spool displacement change rate; Based on the temperature and pressure of the hydraulic oil, the initial static zone length, valve core displacement jump amplitude, and valve core displacement change rate are corrected. Based on the corrected initial static zone length, valve core displacement jump amplitude, and valve core displacement change rate, it is determined whether the servo valve core is in a smooth start state or a fixed breakthrough state, and the fixed mode is identified as either an overall viscous state or a local fixed state.

5. The method for regulating the flow rate of a high-temperature resistant hydraulic pump according to claim 3, characterized in that, If the condition is determined to be a fixation failure state, the uniform rate of the driving current is immediately stopped from gradually increasing, and an overshoot suppression strategy is implemented. The overshoot suppression strategy includes the steps of instantaneously reducing the drive current to a preset safe value and activating damping control to stabilize the position of the servo valve spool. Immediately stop the uniform rate of the drive current from gradually increasing; Based on the valve core displacement change rate at the moment of breaking free from fixation, the temperature and pressure of the hydraulic oil, the overdrive energy and residual viscous force of the servo valve core are calculated. Based on the overdrive energy and residual viscous force, the target value and rate of fallback of the drive current are dynamically determined. The driving current is instantly reduced to the target value at the reduction rate; The damping control parameters are dynamically adjusted based on the valve core displacement change rate at the moment the servo valve core breaks free from fixation, the temperature of the hydraulic oil, and the pressure of the hydraulic oil. The damping control is activated to stabilize the servo valve spool position.

6. The method for regulating the flow rate of a high-temperature resistant hydraulic pump according to claim 5, characterized in that, The step of calculating the overdrive energy and residual viscous force of the servo valve spool based on the valve spool displacement change rate at the moment of breaking free from fixation, the temperature of the hydraulic oil, and the pressure of the hydraulic oil includes: Real-time acquisition of servo valve spool displacement, drive current, hydraulic oil temperature, and hydraulic oil pressure; Based on the valve core displacement, the motion state of the servo valve core is identified; the motion state includes valve core displacement, valve core velocity, and valve core acceleration. Based on the driving current, identify the driving force acting on the servo valve core; The physical properties of the hydraulic oil are obtained based on its temperature and pressure; these physical properties include the viscosity, density, and compressibility of the hydraulic oil. By combining the motion state of the servo valve spool, the driving force, and the physical properties of the hydraulic oil, the overdrive energy and residual viscous force of the servo valve spool are dynamically calculated. The dynamic calculation process is iteratively corrected to match the calculation results with the actual motion trajectory and force state of the servo valve spool.

7. The method for regulating the flow rate of a high-temperature resistant hydraulic pump according to claim 6, characterized in that, The dynamic calculation of the overdrive energy and residual viscous force of the servo valve core is achieved by combining the motion state of the servo valve core, the driving force, and the physical properties of the hydraulic oil. The dynamic calculation process, through iterative correction, ensures that the calculation results match the actual motion trajectory and force state of the servo valve core. The steps include: Based on the motion characteristics, driving force, and physical properties of hydraulic oil of the servo valve core in different stroke segments, the fixing force in the gap between the servo valve core and the valve sleeve is calculated in segments to obtain segmented fixing force data. By comparing the segmented fixation data with the actual motion response of the servo valve core in the corresponding stroke segment, the fixation calculation parameters of each stroke segment are iteratively corrected until the fixation calculation results of each stroke segment match the actual motion response of the servo valve core in the corresponding stroke segment.

8. The method for regulating the flow rate of a high-temperature resistant hydraulic pump according to claim 5, characterized in that, The steps for dynamically adjusting the damping control parameters based on the valve core displacement change rate at the moment the servo valve core breaks free from fixation, the hydraulic oil temperature, and the hydraulic oil pressure include: Based on the valve core displacement change rate at the moment the servo valve core breaks free from fixation, the temperature and pressure of the hydraulic oil, calculate the instantaneous inertia of the servo valve core, the hydraulic damping coefficient, and the residual friction force. Based on the instantaneous inertia of the valve core, the hydraulic damping coefficient, and the residual friction, adjust the proportional gain, integral time, and derivative time of the damping control.

9. The method for regulating the flow rate of a high-temperature resistant hydraulic pump according to claim 8, characterized in that, The step of adjusting the proportional gain, integral time, and derivative time of the damping control based on the instantaneous inertia of the valve core, the hydraulic damping coefficient, and the residual friction includes: The degree of abrupt change in the physical properties of the hydraulic oil is evaluated based on the instantaneous inertia of the valve core, the hydraulic damping coefficient, the residual friction force, the real-time monitored rate of temperature change of the hydraulic oil, and the rate of pressure change of the hydraulic oil. Based on the degree of abrupt change in the physical characteristics, the proportional gain, integral time, and derivative time of the damping control are pre-compensated and adjusted. After pre-compensation adjustment, continuously monitor the servo valve spool position and spool speed; Based on the deviation between the actual motion response and the desired response of the servo valve core, which is jointly reflected by the valve core position and valve core speed, the proportional gain, integral time, and derivative time of the damping control are adjusted in real time.

10. A high-temperature resistant hydraulic pump flow regulation system, used for regulating the flow of a high-temperature resistant hydraulic pump, characterized in that, include: The viscosity quantification module is used to continuously monitor and acquire the drive current corresponding to the servo valve, and quantify the viscosity of the servo valve core based on the current characteristics of the drive current. The adhesion release judgment module is used to obtain the viscosity of the servo valve core when it receives an instruction to switch the high-temperature hydraulic pump from the pressure holding state to the increased flow output mode, and to determine whether the adhesion release procedure needs to be started based on the viscosity, and to obtain the adhesion release judgment result. The release procedure initiation module is used to apply a drive current to the servo valve if the fixation release judgment result indicates that the fixation release procedure needs to be initiated; the drive current gradually increases at a preset uniform rate. The actual position monitoring module is used to monitor the actual position of the servo valve core in real time as the drive current gradually increases at a preset uniform rate. The drive current adjustment module is used to immediately stop the uniform rate of gradual increase of the drive current and adjust the drive current when the actual position of the servo valve core is detected to have moved by a preset distance.

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