Virtual-real fusion control method and device for hydraulic system of engineering machinery

Abstract

The invention discloses a virtual-real fusion control method and device for an engineering machinery hydraulic system, and relates to the field of engineering machinery hydraulic control. The method comprises the following steps: constructing a digital twinborn body of the hydraulic system of the engineering machinery; according to a hydraulic cylinder displacement control signal of the hydraulic system of the engineering machinery and a hydraulic cylinder displacement twinborn signal output by the digital twinborn body, a PID algorithm is adopted to generate a flow control signal; and performing closed-loop control on the opening degree of the multi-way valve of the engineering machinery hydraulic system based on the flow control signal and the multi-way valve inlet and outlet pressure signal of the engineering machinery hydraulic system. Closed-loop control of the hydraulic system of the engineering machinery is realized by adopting displacement twin signals of the digital twin synchronous operation hydraulic cylinder, the precision is high, the cost is low, the reliability is high, on one hand, the defect that the open-loop control precision of a traditional hydraulic system is low is overcome, and on the other hand, the defects that an actuator is externally provided with a sensor and the reliability is low are overcome. And the sensor is easy to damage and poor in reliability under the severe working environment of the engineering machinery.

Description

Technical Field

[0001] The present application relates to the field of hydraulic control of engineering machinery, and in particular to a virtual-real fusion control method and device for a hydraulic system of engineering machinery. Background Art

[0002] Engineering machinery all use hydraulic control technology that uses internal combustion engines to drive hydraulic pumps as power sources and multi-way valves to control movement and distribute power. The flow rate of the hydraulic system determines the speed and position of the actuator. Therefore, as long as the flow rate is accurately controlled, high-precision control of the machine can be achieved. However, there are currently no low-cost, high-dynamic, and extremely low-pressure loss flow sensors on the market, and the variable loads in the hydraulic control process of engineering machinery increase the difficulty of control. In terms of hydraulic control of engineering machinery, there are generally shortcomings such as low control accuracy and poor real-time decision-making.

[0003] One existing method is to use a pressure compensator to reduce the impact of load changes on flow, but this increases the throttling loss of the multi-way valve, increases energy consumption, and has low control accuracy due to the influence of the compensator fluid force.

[0004] Another existing method is to install displacement, velocity, acceleration, inclination and other sensors on the outside of the actuator to directly perform closed-loop high-precision control. However, the cost is high and the installation is inconvenient. More importantly, construction machinery often works in the field, mines and other places. The working environment is extremely harsh, and the sensors are easily damaged, causing the machine to lose control, causing safety accidents and causing casualties. Summary of the invention

[0005] The purpose of this application is to provide a virtual-reality fusion control method and device for an engineering machinery hydraulic system, which can achieve high-precision and low-cost control of the engineering machinery hydraulic system.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a virtual-real fusion control method for a hydraulic system of an engineering machinery, comprising:

[0008] Build a digital twin of the hydraulic system of construction machinery;

[0009] According to the hydraulic cylinder displacement control signal of the construction machinery hydraulic system and the hydraulic cylinder displacement twin signal output by the digital twin, the PID algorithm is used to generate the flow control signal;

[0010] The opening of the multi-way valve of the hydraulic system of the engineering machinery is controlled in a closed loop based on the flow control signal and the inlet and outlet pressure signals of the multi-way valve of the hydraulic system of the engineering machinery.

[0011] In a second aspect, the present application provides a virtual-reality fusion control device for an engineering machinery hydraulic system, wherein the virtual-reality fusion control device for the engineering machinery hydraulic system applies the virtual-reality fusion control method for the engineering machinery hydraulic system, and the virtual-reality fusion control device for the engineering machinery hydraulic system comprises: a communication interaction module, a data storage module, a model management module, and a virtual-reality fusion control module;

[0012] The model management module is used to build and optimize the digital twin;

[0013] The engineering machinery hydraulic system and the model management module are both connected to the data storage module through the communication interaction module; the data storage module is used to store the hydraulic cylinder displacement control signal and the multi-way valve inlet and outlet pressure signal of the engineering machinery hydraulic system, and the hydraulic cylinder displacement twin signal output by the digital twin;

[0014] The virtual-reality fusion control module is connected to the data storage module, and the virtual-reality fusion control module is used to perform closed-loop control on the opening of the multi-way valve of the engineering machinery hydraulic system based on the hydraulic cylinder displacement control signal, the multi-way valve inlet and outlet pressure signal and the hydraulic cylinder displacement twin signal.

[0015] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0016] The present application provides a virtual-reality fusion control method and device for a hydraulic system of an engineering machinery. The present application uses a hydraulic cylinder displacement twin signal synchronously operated by a digital twin to realize closed-loop control of the hydraulic system of an engineering machinery, which has high precision, low cost, and high reliability. On the one hand, it overcomes the disadvantage of low precision of open-loop control of traditional hydraulic systems, and on the other hand, it overcomes the problem that the actuator external sensor is expensive, the sensor is easily damaged, and the reliability is poor in the harsh working environment of the engineering machinery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A flowchart of a virtual-real fusion control method for a hydraulic system of an engineering machinery provided in one embodiment of the present application;

[0019] Figure 2 for Figure 1 A flow chart of generating a flow control signal;

[0020] Figure 3A schematic diagram of the structure and principle of discrete point position feedback of a hydraulic cylinder provided in one embodiment of the present application;

[0021] Figure 4 for Figure 1 A schematic diagram of a flow chart for generating a flow control signal and performing closed-loop control on the opening of a multi-way valve of a hydraulic system of an engineering machinery;

[0022] Figure 5 A structural block diagram of a virtual-reality fusion control device for a hydraulic system of an engineering machinery provided in one embodiment of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0025] In an exemplary embodiment, a virtual-real fusion control method for a hydraulic system of an engineering machinery is provided, such as Figure 1 As shown, the process includes the following steps 101 to 103. Among them:

[0026] Step 101, constructing a digital twin of the hydraulic system of the construction machinery.

[0027] Step 102, using a PID algorithm to generate a flow control signal according to the hydraulic cylinder displacement control signal of the engineering machinery hydraulic system and the hydraulic cylinder displacement twin signal output by the digital twin.

[0028] Step 103 , performing closed-loop control on the opening of the multi-way valve of the hydraulic system of the engineering machinery based on the flow control signal and the inlet and outlet pressure signals of the multi-way valve of the hydraulic system of the engineering machinery.

[0029] By implementing the above steps 101 to 103 , high-precision and low-cost control of the hydraulic system of the construction machinery can be achieved.

[0030] In another exemplary embodiment of the present application, the above step 101 specifically includes:

[0031] Step 1: Collect the detailed geometric dimensions of each component of the engineering machinery hydraulic system entity, and use 3D drawing software to build a geometric model. Specifically, collect the detailed geometric dimensions of each component of the engineering machinery hydraulic system, and obtain the detailed dimensions of hydraulic pumps, multi-way valves, hydraulic cylinders, hydraulic pipelines and other components through point cloud scanning and other means, including but not limited to valve body size, valve core size, main valve stroke, spring stiffness, oil circuit interface size, valve core and valve body matching size, hydraulic pump distribution plate size, hydraulic pump plunger size, hydraulic cylinder piston rod size, etc. Use Creo, UG, SolidWorks and other 3D drawing software to build a geometric model.

[0032] Step 2: Test the hydraulic system of the construction machinery to obtain the component performance parameters and system performance characteristics of each component, and establish a performance model of the hydraulic system of the construction machinery. The component performance parameters refer to the performance of the component itself, such as the internal leakage of the hydraulic valve, the pressure loss characteristics, etc., such as the efficiency, pulsation, noise, etc. of the hydraulic pump. The system performance parameters refer to the overall dynamic response characteristics, stability, output power, efficiency, etc. of the hydraulic system of the construction machinery, which are affected by the coupling of the characteristics of each component. For example, the dynamic characteristics of the system will be affected by the response speed of the hydraulic pump, the response speed of the hydraulic valve, and the flow rate and pressure. The working stability of the hydraulic system is affected by factors such as fluid pressure, temperature, flow, leakage and pressure pulsation.

[0033] Specifically, the hydraulic system of engineering machinery is tested, including but not limited to multi-way valve flow characteristic test, valve core displacement hysteresis test, multi-way valve dynamic characteristic test, multi-way valve mid-position leakage test, multi-way valve reversing position leakage test, multi-way valve steady-state load characteristic test, multi-way valve pressure characteristic test, multi-way valve pressure loss characteristic test, multi-way valve frequency response characteristic test, hydraulic pump volumetric efficiency characteristic test, hydraulic pump no-load displacement test, hydraulic pump dynamic response characteristic test, hydraulic pump impact test, hydraulic pump pressure-flow characteristic test, hydraulic pump repeatability test, etc. The performance parameters of each component and the overall performance parameters of the hydraulic system of engineering machinery are obtained, and a performance model of the hydraulic system of engineering machinery is established.

[0034] Step 3: Based on the working principle of the hydraulic system of engineering machinery and the coupling relationship between the components of the hydraulic system of engineering machinery during operation, as well as the influence of the performance parameters of the components on the performance parameters of the system, a behavioral model is constructed. Specifically, based on a large amount of test data and system operation data, feature extraction and data fusion are performed, and mathematical models of each component and system mathematical models are constructed based on the internal stress state of the component, friction and wear state, flow continuity equation, etc. Further, based on the coupling relationship between the system principle and the operating characteristics of each component, as well as the influence of the key parameters of the component on the system characteristics, a behavioral model is constructed. Further, the working principle of the hydraulic system of engineering machinery can be obtained by referring to the instructions for use of the hydraulic system of engineering machinery and related books, which is not limited here. The coupling relationship between the components of the hydraulic system of engineering machinery during operation can be obtained according to the structural relationship between the components and the working principle of the hydraulic system of engineering machinery, which is not limited here. The system performance parameters are affected by the coupling of each component. For example, the dynamic characteristics of the hydraulic system of engineering machinery will be affected by the response speed of the hydraulic pump, the response speed of the hydraulic valve, and the flow and pressure. The working stability of the hydraulic system of engineering machinery is affected by factors such as fluid pressure, temperature, flow, leakage and pressure pulsation. The influence of component performance parameters on system performance parameters can be obtained by analyzing the performance model, which is not limited here.

[0035] Step 4: Integrate the geometric model, performance model, and behavioral model of the construction machinery hydraulic system to build a digital twin of the construction machinery hydraulic system.

[0036] Step 5: The hydraulic system of construction machinery and the digital twin run synchronously online to obtain sensor detection data and twin data. The operation data of the hydraulic system of construction machinery detected by the sensor is compared and analyzed with the twin data, and the data is verified, and then the model of the digital twin is updated and optimized iteratively.

[0037] In another exemplary embodiment of the present application, Figure 2 As shown, the above step 102 specifically includes:

[0038] Step 6: The handle gives the hydraulic cylinder speed control signal v set , which is converted into the hydraulic cylinder displacement control signal x through the integral link set , the synchronous operation of the digital twin generates the flow control signal x back , x set and x back Make the difference and input it into the PID controller to achieve closed-loop control.

[0039] Step 7: A feedforward link is added to the PID control to feedback the discrete position signal of the hydraulic cylinder and the displacement control signal x of the hydraulic cylinder. setMake a differential input feedforward compensation controller, the output of the feedforward compensation controller is superimposed on the output of the PID controller, and input into the multi-way valve flow controller, such as Figure 2 shown.

[0040] In step 7, the discrete point position feedback signal of the hydraulic cylinder is provided on the piston rod of the hydraulic cylinder, and a groove with a special distribution pattern is provided. The groove is used as a discrete point, and a non-magnetic material is filled inside the groove. A Hall sensor is provided at the end of the cylinder barrel of the hydraulic cylinder to form a detection and signaling device, such as Figure 3 As the piston rod of the hydraulic cylinder moves, the detection and signaling device detects the discrete point passing by and immediately feeds back the discrete position information of the hydraulic cylinder. On the one hand, it generates the displacement twin signal x of the hydraulic cylinder. back The hydraulic cylinder displacement twin signal x is verified by using the hydraulic cylinder discrete point position feedback signal back Calibrate and correct to improve the hydraulic cylinder displacement twin signal x back The real-time and high fidelity of the twin data enable it to more realistically and effectively reflect the actual working state, thereby improving the accuracy of closed-loop control and the accuracy of the virtual-real fusion control method. On the other hand, the PID controller is superimposed with a feedforward link to optimize its dynamic characteristics and accuracy.

[0041] Furthermore, in step 7, the principle of the feedforward link is: the handle gives the hydraulic cylinder speed control signal v set , which is converted into the hydraulic cylinder displacement control signal x through the integral link set , and the hydraulic cylinder discrete point position feedback signal x L Make the difference and get the difference Δx L , input feedforward compensation controller, calculate correction coefficient Calculate the corrected velocity signal as v x =kv set , the feedforward compensation controller outputs the corrected flow signal q x =A A ·v x , added to the PID controller output, and then input into the multi-way valve flow controller; where A A is the effective area of ​​the hydraulic cylinder.

[0042] In step 7, a feedforward link may be superimposed on the basis of PID control, or the feedforward link may not be superimposed, and the output signal of the PID controller is directly input into the multi-way valve flow controller, which is not limited here.

[0043] In another exemplary embodiment of the present application, Figure 3 As shown, the above step 103 specifically includes:

[0044] Step 8: Based on the sensor detection data of the construction machinery hydraulic system, multi-way valve flow control is performed to drive the construction machinery hydraulic system to achieve high-precision control of the hydraulic system that integrates virtual and real elements.

[0045] In step 8, the flow control of the multi-way valve can be a flow soft measurement method or a pressure compensation method. Among them, the pressure compensation method is to set a pressure compensator in the valve so that the main valve pressure difference is a constant value, and the flow is only related to the valve opening. Figure 4 As shown, the temperature inside the valve and the inlet pressure p of the multi-way valve are detected through temperature, pressure and displacement sensors. i , multi-way valve outlet pressure p0, valve core displacement x m , through the operator (i.e. formula Among them, q m is the multi-way valve flow, C d is the multi-way valve flow coefficient, A(x m ) is the flow area of ​​the multi-way valve, Δp is the pressure difference between the inlet and outlet of the multi-way valve, and ρ is the oil density). The multi-way valve flow is calculated in real time and the difference is made with the flow control signal to perform closed-loop control. The flow calculation can be directly calculated by the operator, or by the neural network algorithm, or by the table lookup method, which is not limited here.

[0046] In an exemplary embodiment, Figure 5 As shown, a virtual-reality fusion control device for an engineering machinery hydraulic system is provided, and the virtual-reality fusion control device for the engineering machinery hydraulic system applies the virtual-reality fusion control method for the engineering machinery hydraulic system. The virtual-reality fusion control device for the engineering machinery hydraulic system includes: a communication interaction module, a data storage module, a model management module and a virtual-reality fusion control module; the model management module is used to construct and optimize a digital twin; the engineering machinery hydraulic system (i.e. Figure 5 The hydraulic system entity in the data storage module and the model management module are connected to the data storage module through the communication interaction module; the data storage module is used to store the hydraulic cylinder displacement control signal and the multi-way valve inlet and outlet pressure signal of the engineering machinery hydraulic system, and the hydraulic cylinder displacement twin signal output by the digital twin; the virtual-reality fusion control module is connected to the data storage module, and the virtual-reality fusion control module is used to perform closed-loop control on the opening of the multi-way valve of the engineering machinery hydraulic system based on the hydraulic cylinder displacement control signal, the multi-way valve inlet and outlet pressure signal and the hydraulic cylinder displacement twin signal.

[0047] Among them, the digital twin and the hydraulic system of the construction machinery run synchronously, and the communication interaction module is used to realize the communication between the hydraulic system of the construction machinery and the digital twin. On the one hand, the actual operation data of the hydraulic system of the construction machinery and the data collected by the sensor are transmitted to the data storage module, and compared with the digital twin data for verification. The digital twin model is continuously updated and iterated in real time through the model management module to ensure its real-time and high fidelity in multiple dimensions and time scales. On the other hand, the synchronous operation data of the digital twin is transmitted to the data storage module, and the external closed-loop control of the hydraulic cylinder displacement is realized based on the twin data through the virtual-reality fusion control module, and the internal closed-loop control of the multi-way valve flow is realized based on the temperature, pressure, valve core displacement and other data detected by the sensor. The internal and external closed-loop closed-loops are nested, and the virtual and real are integrated to realize low-cost, high-precision and high-reliability dynamic closed-loop control of the system.

[0048] Among them, the communication interaction module includes interfaces such as the Internet of Things and wireless networks. The Internet of Things communication is mainly used for the control and signal acquisition of the hydraulic system of engineering machinery, including but not limited to CAN bus, serial port and other methods. The rest of the information is connected via a wireless communication interface, using protocols including but not limited to UDP, TCP / IP and other protocols.

[0049] The data storage module includes a real-time database and a cloud database. After receiving the real-time data of the hydraulic system of the construction machinery and the twin data of the synchronous operation of the digital twin, the real-time database performs data cleaning and classification. The physical data includes but is not limited to the temperature inside the valve, the inlet and outlet pressure of the multi-way valve, the valve core displacement, the discrete point position of the hydraulic cylinder, etc., and the twin data includes but is not limited to the multi-way valve flow, the hydraulic cylinder displacement, the hydraulic cylinder speed, the machine posture, etc. The physical data and the twin data are preprocessed, and the fused data is generated by the neural network hierarchical analysis method. The cloud database consists of data management and cloud data nodes. The data storage of the real-time database is uploaded to the cloud database for classification management and backup storage, and the data in the cloud database is read and downloaded according to demand.

[0050] The model management module includes a model training module and a model update module. It optimizes and trains the model based on test data and real-time sensor data, verifies and corrects the sensor data and digital twin data, evaluates the model accuracy, and then updates and iterates the digital twin model. The model management module is data-driven through the data storage module, and the model data of the model management module is also transmitted to the data storage module.

[0051] The virtual-real fusion control module performs closed-loop control of the hydraulic cylinder based on twin data and handle command signals, and realizes multi-way valve flow control based on sensor data, virtual-real fusion, drives the hydraulic system of engineering machinery, and achieves high-precision control. The virtual-real fusion control module is data-driven through the data storage module, and the control data of the virtual-real fusion control module is also transmitted to the data storage module.

[0052] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0053] 1. This application uses the twin data of the digital twin running synchronously to realize the closed-loop control of the system, which has high precision, low cost and high reliability. On the one hand, it overcomes the shortcomings of low open-loop control precision of traditional engineering machinery hydraulic systems. On the other hand, it overcomes the problem that the external sensors of the actuators are expensive, the sensors are easily damaged and have poor reliability in the harsh working environment of engineering machinery.

[0054] 2. This application uses the temperature, pressure and other sensors built into the multi-way valve to detect information and twin data verification, and updates and iterates the digital twin model in real time to ensure the real-time and high fidelity of the digital twin.

[0055] 3. This application uses the hydraulic cylinder discrete point feedback information, which is low cost and high reliability, to verify and correct the hydraulic cylinder displacement twin signal x output by the digital twin in real time back , thereby improving the accuracy of closed-loop control based on twin data.

[0056] 4. This application is based on the digital twin of the hydraulic system of construction machinery, which can map the system operating characteristics and status in real time without the need for flow sensors, etc., and realize real-time and transparent online monitoring of system flow, power, energy, actuator posture and other information, thereby performing fault diagnosis, life prediction, and active operation and maintenance of each component, which is of great significance to the realization of intelligent construction machinery.

[0057] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A virtual-real fusion control method for a hydraulic system of an engineering machinery, characterized in that: include: Build a digital twin of the hydraulic system of construction machinery; According to the hydraulic cylinder displacement control signal of the construction machinery hydraulic system and the hydraulic cylinder displacement twin signal output by the digital twin, the PID algorithm is used to generate the flow control signal; The opening of the multi-way valve of the hydraulic system of the engineering machinery is controlled in a closed loop based on the flow control signal and the inlet and outlet pressure signals of the multi-way valve of the hydraulic system of the engineering machinery.

2. The virtual-real fusion control method for the hydraulic system of an engineering machinery according to claim 1 is characterized in that: Constructing a digital twin of the hydraulic system of construction machinery includes: Use 3D drawing software to build geometric models of hydraulic systems of construction machinery; Conducting tests on the hydraulic system of the construction machinery, obtaining the component performance parameters and system performance parameters of the hydraulic system of the construction machinery, and establishing a performance model of the hydraulic system of the construction machinery; the component performance parameters include the performance parameters of each component in the hydraulic system of the construction machinery, the system performance parameters are the performance parameters of the hydraulic system of the construction machinery as a whole, and the performance model represents the influence of the structural parameters of the hydraulic system of the construction machinery on the component performance parameters and the system performance parameters; Based on the working principle of the hydraulic system of construction machinery, the coupling relationship between the components of the hydraulic system of construction machinery during operation, and the influence of the performance parameters of the components on the performance parameters of the system, a behavioral model of the hydraulic system of construction machinery is constructed; among which, the influence of the performance parameters of the components on the performance parameters of the system is obtained by analyzing the performance model; Based on the geometric model, performance model and behavioral model of the construction machinery hydraulic system, a digital twin of the construction machinery hydraulic system is constructed.

3. The virtual-real fusion control method for the hydraulic system of an engineering machinery according to claim 2 is characterized in that: The test items for the hydraulic system of construction machinery include: One or more of the following: multi-way valve flow characteristic test, valve core displacement hysteresis test, multi-way valve dynamic characteristic test, multi-way valve mid-position leakage test, multi-way valve switching position leakage test, multi-way valve steady-state load characteristic test, multi-way valve pressure characteristic test, multi-way valve pressure loss characteristic test, multi-way valve frequency response characteristic test, hydraulic pump volumetric efficiency characteristic test, hydraulic pump no-load displacement test, hydraulic pump dynamic response characteristic test, hydraulic pump impact test, hydraulic pump pressure-flow characteristic test and hydraulic pump repeatability test.

4. The virtual-real fusion control method for the hydraulic system of an engineering machinery according to claim 1, characterized in that: Building a digital twin of the hydraulic system of construction machinery, which will then include: Acquire detection data of each sensor during the actual operation of the hydraulic system of the construction machinery and twin data generated by the digital twin during the synchronous operation process; the synchronous operation process is a process synchronized with the actual operation process of the hydraulic system of the construction machinery; The parameters of the digital twin are updated and optimized according to the detection data and the twin data so that the detection data and the twin data are consistent.

5. The virtual-real fusion control method for the hydraulic system of an engineering machinery according to claim 1, characterized in that: The opening of the multi-way valve of the hydraulic system of the engineering machinery is controlled in a closed loop based on the flow control signal and the inlet and outlet pressure signals of the multi-way valve of the hydraulic system of the engineering machinery, which also includes: When the piston rod of the hydraulic cylinder of the engineering machinery hydraulic system is located at a discrete point position, a discrete point position feedback signal of the hydraulic cylinder is obtained; Generate a corrected flow signal according to the hydraulic cylinder displacement control signal and the hydraulic cylinder discrete point position feedback signal; The flow control signal is corrected according to the corrected flow signal.

6. The virtual-real fusion control method for the hydraulic system of an engineering machinery according to claim 5, characterized in that: According to the hydraulic cylinder displacement control signal and the hydraulic cylinder discrete point position feedback signal, the formula for generating the corrected flow signal is: q x =A A ·v x ; v x =kv set ; Δx L =x set -x L ; Among them, q x To correct the flow signal, A A is the hydraulic cylinder working area, v x is the corrected speed signal, k is the correction coefficient, v set is the speed control signal, x set is the hydraulic cylinder displacement control signal, Δx L is the difference between the hydraulic cylinder displacement control signal and the hydraulic cylinder discrete point position feedback signal, x L It is the discrete point position feedback signal of the hydraulic cylinder.

7. The virtual-real fusion control method for the hydraulic system of an engineering machinery according to claim 5, characterized in that: When the piston rod of the hydraulic cylinder of the engineering machinery hydraulic system is at a discrete point position, a discrete point position feedback signal of the hydraulic cylinder is obtained, and then: The hydraulic cylinder discrete point position feedback signal is used to update and optimize the parameters of the digital twin, so that the hydraulic cylinder displacement twin signal output by the digital twin is consistent with the hydraulic cylinder discrete point position feedback signal.

8. The virtual-real fusion control method for a hydraulic system of an engineering machinery according to claim 1, characterized in that: The opening of the multi-way valve of the hydraulic system of the engineering machinery is controlled in a closed loop based on the flow control signal and the inlet and outlet pressure signals of the multi-way valve of the hydraulic system of the engineering machinery, specifically including: According to the inlet and outlet pressure signals of the multi-way valve of the hydraulic system of the construction machinery, the flow rate of the multi-way valve of the hydraulic system of the construction machinery is calculated by using the flow soft measurement method or the pressure compensation method; The valve opening of the hydraulic system of the engineering machinery is controlled according to the difference between the multi-way valve flow and the flow control signal.

9. The virtual-real fusion control method for the hydraulic system of an engineering machinery according to claim 8, characterized in that: The flow soft measurement method is the operator method, neural network algorithm or table lookup method; The formula of the operator method is: Among them, q m is the multi-way valve flow, C d is the multi-way valve flow coefficient, A(x m ) is the flow area of ​​the multi-way valve, Δp is the pressure difference between the inlet and outlet of the multi-way valve, and ρ is the oil density; The neural network model used in the neural network algorithm and the table used in the table lookup method both represent the relationship between the inlet and outlet pressure signals of the multi-way valve and the flow rate of the multi-way valve.

10. A virtual-real fusion control device for a hydraulic system of an engineering machinery, characterized in that: The virtual-reality fusion control device of the engineering machinery hydraulic system applies the virtual-reality fusion control method of the engineering machinery hydraulic system according to any one of claims 1 to 9, and the virtual-reality fusion control device of the engineering machinery hydraulic system comprises: a communication interaction module, a data storage module, a model management module and a virtual-reality fusion control module; The model management module is used to build and optimize the digital twin; The engineering machinery hydraulic system and the model management module are both connected to the data storage module through the communication interaction module; the data storage module is used to store the hydraulic cylinder displacement control signal and the multi-way valve inlet and outlet pressure signal of the engineering machinery hydraulic system, and the hydraulic cylinder displacement twin signal output by the digital twin; The virtual-reality fusion control module is connected to the data storage module, and the virtual-reality fusion control module is used to perform closed-loop control on the opening of the multi-way valve of the engineering machinery hydraulic system based on the hydraulic cylinder displacement control signal, the multi-way valve inlet and outlet pressure signal and the hydraulic cylinder displacement twin signal.

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