A high-pressure egr valve simulation model and a construction method and a calibration method thereof

Abstract

The application provides a high-pressure EGR valve simulation model and a construction method and a calibration method thereof, and belongs to the field of automobile calibration testing.The high-pressure EGR valve simulation model comprises a high-pressure EGR valve, upstream and downstream environment boundaries of the high-pressure EGR valve and a test data module, the high-pressure EGR valve gas circuit is connected between the upstream and downstream environment boundaries of the high-pressure EGR valve, and the test data module is connected to the high-pressure EGR valve and the upstream and downstream environment boundaries of the high-pressure EGR valve to transmit test data in the test data module.The calibration method of the high-pressure EGR valve simulation model comprises the following steps: obtaining a fitting function of the opening-flow coefficient of the high-pressure EGR valve, and importing the calibration MAP module to calibrate the high-pressure EGR valve simulation model.The application has the beneficial effect that the precision of the simulation model is greatly improved through the calibration of the change relationship between the flow coefficient of the high-pressure EGR valve and the opening of the high-pressure EGR valve, and the subsequent application requirements are met.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of automobile calibration test, and particularly relates to a high-pressure EGR valve simulation model and a construction method and a calibration method thereof. BACKGROUND

[0002] In order to meet the increasingly stringent requirements of emission regulations, vehicle manufacturers all over the world have begun to adopt new technologies and design schemes, making the control system and aftertreatment of the engine more and more complex. In addition, under the influence of environmental conditions such as altitude and temperature, the power and economy of diesel engines decrease, emissions deteriorate, which leads to an increase in diesel engine thermal load, and in addition, the turbocharger is overspeed and the in-cylinder pressure is out of limit, thereby doubling the engine calibration workload.

[0003] Virtual testbed (VTB) is a kind of vehicle virtual simulation testbed based on hardware-in-the-loop test system, which can replace real engine and vehicle. It mainly includes software simulation model, hardware-in-the-loop test system and high-quality test data. Except that the electronic control unit (ECU) and load are real, other modules of VTB are simulated by simulation model. The virtual calibration process mainly includes experimental design, virtual experiment, model construction, data optimization, management autonomy platform (MAP) generation and calibration result test. VTB virtual calibration can greatly reduce the calibration cycle and workload, thereby reducing the calibration cost.

[0004] The basic principle of exhaust gas recirculation (EGR) is to introduce part of the exhaust gas after combustion into the intake side for combustion again. The research on EGR technology abroad began in the 1960s, and the research shows that EGR technology has obvious effect on reducing NO X , and also has significant effect on combustion control and reducing knocking at idle speed. The widely used electronic control EGR system greatly improves the accuracy and response accuracy of EGR. The high-pressure EGR system is most widely used on diesel engines because its pipeline is relatively short, the pressure is relatively high, the air flow rate is relatively high, the EGR reaction rate is relatively high, and it does not damage the impeller and intercooler.

[0005] The establishment of the EGR valve simulation model is an indispensable part of the entire engine model, and the accuracy of the EGR valve simulation model also determines the accuracy of the entire engine simulation model. However, there is no related technology for simulating and calibrating the EGR system in the prior art, and therefore, there is an urgent need for an EGR valve simulation model that can be applied to a virtual calibration platform and a calibration method therefor. SUMMARY

[0006] Therefore, the present application aims to provide a high-pressure EGR valve simulation model and a construction method and a calibration method thereof. The accuracy of the simulation model is greatly improved by calibrating the relationship between the flow coefficient of the high-pressure EGR valve and the opening of the high-pressure EGR valve, thereby meeting the subsequent application requirements.

[0007] To achieve the above object, the technical scheme of the present application is as follows:

[0008] A high-pressure EGR valve simulation model, comprising a high-pressure EGR valve, a high-pressure EGR valve upstream environment boundary, a high-pressure EGR valve downstream environment boundary, and a test data module,

[0009] The high-pressure EGR valve upstream environment boundary is connected to the front end of the high-pressure EGR valve in the gas circuit, and is set as the pressure parameter and temperature parameter of the exhaust pipe rear end;

[0010] The high-pressure EGR valve upstream environment boundary is connected to the rear end of the high-pressure EGR valve in the gas circuit, and is set as the pressure parameter and temperature parameter of the front end of the intake pipe;

[0011] The test data module is connected to the high-pressure EGR valve, the high-pressure EGR valve upstream environment boundary, and the high-pressure EGR valve upstream environment boundary to transmit the test data in the test data module; wherein the test data module comprises at least one set of test data of calibration operating points, and the test data of the calibration operating points comprises the pressure parameter and temperature parameter of the exhaust pipe rear end, the pressure parameter and temperature parameter of the front end of the intake pipe, the opening of the high-pressure EGR valve, and the high-pressure EGR mass flow.

[0012] A construction method of a high-pressure EGR valve simulation model, applied to the above-mentioned high-pressure EGR valve simulation model, comprising:

[0013] Step S1: importing elements, selecting at least one high-pressure EGR valve in the element library and dragging it to the engineering window; wherein the engineering window comprises a high-pressure EGR valve upstream environment boundary and a high-pressure EGR valve downstream environment boundary;

[0014] Step S2: connecting element, connecting the high-pressure EGR valve gas path between the high-pressure EGR valve upstream environment boundary and the high-pressure EGR valve downstream environment boundary;

[0015] Step S3: import test data, import at least one set of test data of calibration working points, the test data of calibration working points including pressure parameters and temperature parameters of the rear end of the exhaust pipe, pressure parameters and temperature parameters of the front end of the intake pipe, and the opening of the high-pressure EGR valve; wherein the exhaust pipe is arranged on the front side of the high-pressure EGR valve, and the intake pipe is arranged on the rear side of the high-pressure EGR valve;

[0016] Step S4: element parameterization, based on the imported test data, parameterizing and setting the parameters of the high-pressure EGR valve upstream environment boundary, the parameters of the high-pressure EGR valve downstream environment boundary, and the opening of the high-pressure EGR valve, and setting the flow coefficient as a predetermined constant.

[0017] Further, the step S4 includes:

[0018] Step S41: data transmission,

[0019] transmit the pressure parameters and temperature parameters of the rear end of the exhaust pipe in the test data to the high-pressure EGR valve upstream environment boundary;

[0020] transmit the pressure parameters and temperature parameters of the front end of the intake pipe in the test data to the high-pressure EGR valve downstream environment boundary;

[0021] transmit the opening of the high-pressure EGR valve in the test data to the high-pressure EGR valve step S42: parameter setting,

[0022] set the parameters of the high-pressure EGR valve upstream environment boundary as the pressure parameters and temperature parameters of the rear end of the exhaust pipe in the test data;

[0023] set the parameters of the high-pressure EGR valve downstream environment boundary as the pressure parameters and temperature parameters of the front end of the intake pipe in the test data;

[0024] set the opening of the high-pressure EGR valve as the opening of the high-pressure EGR valve in the test data.

[0025] A high-pressure EGR valve simulation model calibration method applied to the above-mentioned high-pressure EGR valve simulation model, comprising:

[0026] Step A1: obtaining the fitting function of the opening-flow coefficient of the high-pressure EGR valve, and obtaining the relationship between the flow coefficient of the high-pressure EGR valve and the opening of the high-pressure EGR valve;

[0027] Step A2: Import the calibration MAP module and connect it between the test data module and the high-pressure EGR valve; wherein, the input of the calibration MAP module is the high-pressure EGR valve opening degree transmitted by the test data module, and the output of the calibration MAP module is the flow coefficient of the high-pressure EGR valve obtained based on the fitting function relationship of the high-pressure EGR valve opening degree-flow coefficient established in step A3.

[0028] Furthermore, step A1 includes:

[0029] Step A101: Import the PID EGR valve, wherein the specifications of the PID EGR valve are the same as those of the high-pressure EGR valve;

[0030] Step A102: Import the PID module and connect it between the test data module and the PID EGR valve. The input of the PID module includes the actual value and the designed value. The actual value is the upstream mass flow rate of the PID EGR valve, and the designed value is the high-pressure EGR mass flow rate transmitted by the test data module. The output of the PID module is used as the flow coefficient of the PID EGR valve. The proportional (P), integral (I), and derivative (D) terms of the PID module are set and adjusted, and simulation calculations are run. The PID module automatically adjusts according to the actual value and the designed value to output the flow coefficient of the high-pressure EGR valve.

[0031] Step A103: Obtain the fitting function of the opening degree-flow coefficient of the high-pressure EGR valve. Take the opening degree of the high-pressure EGR valve output by the test data module as the abscissa and the flow coefficient of the PID EGR valve output by the PID module as the ordinate. Perform piecewise function fitting on the two to obtain the fitting function of the opening degree-flow coefficient of the high-pressure EGR valve.

[0032] Furthermore, step A101 includes:

[0033] Step A1011: Copy the high-pressure EGR valve and import a valve with the same specifications as the high-pressure EGR valve as the PID EGR valve;

[0034] Step A1012: Connect the components to connect the PID EGR valve air circuit between the upstream environmental boundary of the high-pressure EGR valve and the downstream environmental boundary of the high-pressure EGR valve;

[0035] Step A1013: element parameterization, set the opening of the PID EGR valve to the opening of the high-pressure EGR valve in the test data, and the flow coefficient of the PID EGR valve is transmitted through the data bus.

[0036] The step A103 comprises:

[0037] Step A1301: plot the opening of the high-pressure EGR valve output by the test data module as the abscissa and the flow coefficient of the PID EGR valve output by the PID module as the ordinate.

[0038] Step A1302: piecewise fitting is performed on the plotting function in step A1301 to obtain a fitting function of the opening-flow coefficient of the high-pressure EGR valve, and the fitting function of the opening-flow coefficient of the high-pressure EGR valve is applied to the calibration MAP module.

[0039] An electronic device comprising a processor and a memory connected in communication with the processor and used for storing executable instructions of the processor, characterized in that the processor is used to execute the construction method of the high-pressure EGR valve simulation model and the calibration method of the high-pressure EGR valve simulation model.

[0040] A server comprising at least one processor and a memory connected in communication with the processor, wherein the memory stores executable instructions of the at least one processor, and the instructions are executed by the processor to make the at least one processor execute the construction method of the high-pressure EGR valve simulation model and the calibration method of the high-pressure EGR valve simulation model.

[0041] A computer-readable storage medium storing a computer program, characterized in that the computer program is executed by a processor to realize the construction method of the high-pressure EGR valve simulation model and the calibration method of the high-pressure EGR valve simulation model.

[0042] Compared with the prior art, the high-pressure EGR valve simulation model, the construction method thereof and the calibration method thereof have the following beneficial effects:

[0043] The high-pressure EGR valve simulation model, the construction method and the calibration method thereof, simulate the pressure parameters and the temperature parameters before and after the high-pressure EGR valve through the upstream environment boundary of the high-pressure EGR valve and the downstream environment boundary of the high-pressure EGR valve, so that the establishment of the high-pressure EGR valve simulation model is realized, and then the simulated high-pressure EGR valve can be applied to the VTB to replace the real high-pressure EGR valve for calibration, so that the time and cost pressure is reduced. At the same time, the accuracy of the simulation model is greatly improved by calibrating the change relationship between the flow coefficient of the high-pressure EGR valve and the opening of the EGR valve, so as to meet the subsequent application requirements. BRIEF DESCRIPTION OF DRAWINGS

[0044] The drawings constituting a part of this application are used to provide a further understanding of the application, and the illustrative embodiments of the application and the description thereof are used to explain the application, and do not constitute an improper limitation on the application. In the drawings:

[0045] Figure 1 The high-pressure EGR valve simulation model schematic diagram described in the embodiments of the application;

[0046] Figure 2 The function for fitting the opening-flow coefficient of the high-pressure EGR valve described in the embodiments of the application;

[0047] Figure 3 The high-pressure EGR valve simulation model schematic diagram using the calibration MAP module described in the embodiments of the application;

[0048] Figure 4 The high-pressure EGR valve simulation model calibration schematic diagram after importing the PID module and the PID EGR valve described in the embodiments of the application;

[0049] Figure 5 The comparison diagram of the high-pressure EGR mass flow simulated by the high-pressure EGR valve simulation model before and after calibration described in the embodiments of the application;

[0050] Figure 6 The high-pressure EGR valve flow coefficient diagram according to the flow coefficient output by the PID module described in the embodiments of the application.

[0051] Explanation of reference signs:

[0052] 1-high-pressure EGR valve; 2-high-pressure EGR valve upstream environment boundary; 3-high-pressure EGR valve upstream environment boundary; 4-test data module; 5-PID EGR valve; 6-PID module; 7-calibration MAP module. DETAILED DESCRIPTION

[0053] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0054] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0055] As shown in Figure 1 , Figure 1 The high-pressure EGR valve simulation model described in the embodiments of the present application is shown in the figure.

[0056] The high-pressure EGR valve simulation model described in the present application comprises a high-pressure EGR valve 1, a high-pressure EGR valve upstream environment boundary 2, a high-pressure EGR valve downstream environment boundary 3, and a test data module 4,

[0057] The high-pressure EGR valve upstream environment boundary 2 is connected in gas circuit to the front end of the high-pressure EGR valve 1 and is set as the pressure parameter and temperature parameter of the rear end of the exhaust pipe;

[0058] The high-pressure EGR valve upstream environment boundary 2 is connected in gas circuit to the rear end of the high-pressure EGR valve 1 and is set as the pressure parameter and temperature parameter of the front end of the intake pipe;

[0059] The test data module 4 is connected with the high-pressure EGR valve 1, the high-pressure EGR valve upstream environment boundary 2, and the high-pressure EGR valve upstream environment boundary 2 to transmit the test data in the test data module 4; wherein the test data module 4 comprises at least one set of test data of calibration operating points, and the test data of the calibration operating points comprises the pressure parameter and temperature parameter of the rear end of the exhaust pipe, the pressure parameter and temperature parameter of the front end of the intake pipe, the opening of the high-pressure EGR valve 1, and the high-pressure EGR mass flow.

[0060] It should be noted that the pressure parameters and temperature parameters before and after the high-pressure EGR valve 1 are simulated by the high-pressure EGR valve upstream environment boundary 2 and the high-pressure EGR valve downstream environment boundary 3, thereby realizing the establishment of the high-pressure EGR valve simulation model, and the simulated high-pressure EGR valve 1 can be applied to a virtual bench as part of an engine model.

[0061] The construction method of the high-pressure EGR valve simulation model described in the present application is applied to the above-mentioned high-pressure EGR valve simulation model and comprises:

[0062] Step S1: import elements, select at least one high-pressure EGR valve 1 in the element library and drag to the engineering window; wherein the engineering window comprises a high-pressure EGR valve upstream environment boundary 2 and a high-pressure EGR valve downstream environment boundary 3;

[0063] Step S2: connecting element, connecting the high-pressure EGR valve 1 gas circuit between the high-pressure EGR valve upstream environment boundary 2 and the high-pressure EGR valve downstream environment boundary 3;

[0064] Step S3: import test data, import at least one set of test data of calibration working condition points, the test data of the calibration working condition points including the pressure parameters and temperature parameters of the rear end of the exhaust pipe, the pressure parameters and temperature parameters of the front end of the intake pipe and the opening of the high-pressure EGR valve 1; wherein the exhaust pipe is arranged on the front side of the high-pressure EGR valve 1, and the intake pipe is arranged on the rear side of the high-pressure EGR valve 1;

[0065] Step S4: element parameterization, based on the imported test data, parameterizing and setting the parameters of the high-pressure EGR valve upstream environment boundary 2, the parameters of the high-pressure EGR valve downstream environment boundary 3 and the opening of the high-pressure EGR valve 1, and setting the flow coefficient as a predetermined constant.

[0066] It should be noted that the construction method of the high-pressure EGR valve simulation model provided by the application is simulated by at least one high-pressure EGR valve 1 selected from the element library, wherein the high-pressure EGR valve 1 can be set as a throttle valve element to describe the gas flow in the circular throttle baffle; the pressure parameters and temperature parameters of the rear side of the exhaust pipe arranged on the front side of the high-pressure EGR valve 1 are simulated by the high-pressure EGR valve upstream environment boundary 2; and the pressure parameters and temperature parameters of the front side of the intake pipe arranged on the rear side of the high-pressure EGR valve 1 are simulated by the high-pressure EGR valve downstream environment boundary 3, so as to construct the simulation model of the high-pressure EGR valve 1.

[0067] In addition, the flow coefficient is closely related to the properties of the high-pressure EGR valve 1, and the flow coefficient in the prior art is usually set as a constant according to the experience of the person skilled in the art, and the constants of the flow coefficients set for high-pressure EGR valves 1 of different specifications can be different, so the constant of the flow coefficient is not limited in the application.

[0068] The construction method of the high-pressure EGR valve simulation model provided by the application simulates the pressure parameters and temperature parameters before and after the high-pressure EGR valve 1 through the high-pressure EGR valve upstream environment boundary 2 and the high-pressure EGR valve downstream environment boundary 3, so as to realize the establishment of the high-pressure EGR valve simulation model, and then the simulated high-pressure EGR valve 1 can be applied to a virtual test bench as part of an engine simulation model, to replace the real high-pressure EGR valve 1 for calibration work, thereby reducing the time and cost pressure.

[0069] The step S4 includes:

[0070] Step S41: Data transmission,

[0071] The pressure and temperature parameters at the rear end of the exhaust pipe in the test data are transmitted to the upstream environmental boundary 2 of the high-pressure EGR valve.

[0072] The pressure and temperature parameters at the front end of the intake pipe in the test data are transmitted to the downstream environmental boundary 3 of the high-pressure EGR valve.

[0073] The opening degree of the high-pressure EGR valve 1 in the test data is transmitted to the high-pressure EGR valve 1.

[0074] Step S42: Parameter settings,

[0075] Set the parameters of the upstream environmental boundary 2 of the high-pressure EGR valve to the pressure and temperature parameters of the exhaust pipe rear end in the test data;

[0076] Set the parameters of the downstream environmental boundary 3 of the high-pressure EGR valve to the pressure and temperature parameters of the inlet pipe in the test data;

[0077] Set the opening degree of the high-pressure EGR valve 1 to the opening degree of the high-pressure EGR valve 1 in the test data.

[0078] It should be noted that the test data includes at least one set of test data for calibration operating points; wherein, the test data for each set of calibration operating points corresponds to a set of simulated high-pressure EGR valve 1 components; and the test data for each set of calibration operating points is transmitted to the corresponding simulated high-pressure EGR valve 1 component set, namely, the upstream environmental boundary 2 of the high-pressure EGR valve, the downstream environmental boundary 3 of the high-pressure EGR valve, and the high-pressure EGR valve 1.

[0079] By transmitting the test data of the calibration operating point to the simulated high-pressure EGR valve 1 component group, that is, transmitting the pressure and temperature parameters of the exhaust pipe rear end, the pressure and temperature parameters of the intake pipe front end, and the opening degree of high-pressure EGR valve 1 to the upstream environmental boundary 2, the downstream environmental boundary 3, and high-pressure EGR valve 1 of high-pressure EGR valve respectively, the component parameterization of the high-pressure EGR valve simulation model can be achieved.

[0080] like Figure 2 and 3 As shown, Figure 2 The function used to fit the opening degree-flow coefficient of the high-pressure EGR valve as described in the embodiments of the present invention; Figure 3 This is a schematic diagram of a high-pressure EGR valve simulation model using the MAP module calibration described in an embodiment of the present invention.

[0081] The high-pressure EGR valve simulation model calibration method of the application is applied to the high-pressure EGR valve simulation model, and comprises the following steps:

[0082] Step A1: obtaining the fitting function of the opening-flow coefficient of the high-pressure EGR valve 1 to obtain the change relationship between the flow coefficient of the high-pressure EGR valve 1 and the opening of the high-pressure EGR valve 1.

[0083] Step A2: importing a calibration MAP module 7 connected between the test data module 4 and the high-pressure EGR valve 1; wherein the input of the calibration MAP module 7 is the high-pressure EGR valve opening transmitted by the test data module 4, and the output of the calibration MAP module 7 is the flow coefficient of the high-pressure EGR valve 1 obtained based on the fitting function relationship of the high-pressure EGR valve opening-flow coefficient established in step A3.

[0084] It should be noted that the high-pressure EGR valve 1 is set as a throttle valve element, wherein the effective flow area of the throttle valve element is obtained by calculating the valve diameter, shaft diameter, throttle gap angle and throttle opening, such as formula (1):

[0085]

[0086]

[0087] Wherein, A g represents the effective flow area (m2); D represents the valve diameter (m); d represents the shaft diameter (m); a0 represents the throttle gap angle (deg); and β represents the throttle opening (deg).

[0088] Wherein, the valve diameter, shaft diameter and throttle gap angle of each throttle valve are fixed, so the throttle opening directly affects the effective flow area. In addition, it can be known from the following formula (2) that the effective flow area of the throttle valve element is related to the mass flow of the throttle valve.

[0089]

[0090] Wherein, represents the mass flow; μ represents the flow coefficient; A geom represents the hole area; p up represents the upstream pressure; R up represents the upstream specific gas constant; T up represents the upstream temperature; and ψ represents the flow function.

[0091] When the subsonic flow, ψ is the following formula (3):

[0092]

[0093] wherein, κ represents the specific heat ratio. up represents the upstream pressure; p down represents the downstream pressure.

[0094] When the flow is sonic, ψ is the following formula (4):

[0095]

[0096] wherein, κ represents the specific heat ratio.

[0097] Therefore, the corresponding relationship between the throttle opening and the flow coefficient under different working conditions can be calibrated, so that the precision of the calibrated model can be greatly improved, and the subsequent application requirements can be met.

[0098] As Figure 4 shown, Figure 4 is a high-pressure EGR valve simulation model calibration schematic diagram after importing the PID module and the PID EGR valve 5 according to the embodiment of the application.

[0099] The step A1 comprises:

[0100] Step A101: importing a PID EGR valve 5, wherein the specification of the PID EGR valve 5 is the same as that of the high-pressure EGR valve 1;

[0101] Step A102: importing a PID module 6, which is connected between the test data module 4 and the PID EGR valve 5, the input of the PID module 6 includes an actual value Acrual Value and a design value Desired Value, wherein the actual value Acrual Value is the upstream mass flow of the PID EGR valve 5, the design value Desired Value is the high-pressure EGR mass flow transmitted by the test data module 4, and the output of the PID module 6 is used as the flow coefficient of the PID EGR valve 5; wherein the proportional term (P), the integral term (I) and the differential term (D) of the PID module 6 are set and adjusted, and the simulation calculation is run, wherein the PID module 6 automatically adjusts according to the actual value Actual Value and the design value Desired Value, and outputs the flow coefficient of the high-pressure EGR valve 1;

[0102] Step A103: Obtain the fitting function of the opening degree-flow coefficient of the high-pressure EGR valve 1. Take the opening degree of the high-pressure EGR valve 1 output by the test data module 4 as the abscissa and the flow coefficient of the PID EGR valve 5 output by the PID module 6 as the ordinate. Perform piecewise function fitting on the two to obtain the fitting function of the opening degree-flow coefficient of the high-pressure EGR valve 1.

[0103] It should be noted that by setting and adjusting the proportional (P), integral (I), and derivative (D) terms of the PID module 6 and running the simulation calculation, the PID module 6 will adjust according to the designed value and the actual value. Therefore, the output of the PID module 6 is the flow coefficient attribute of this high-pressure EGR valve 1. Calibration is performed by analyzing the relationship between the flow coefficient of the high-pressure EGR valve 1 and its opening degree, which significantly improves the accuracy of the simulation model and meets the requirements of subsequent applications.

[0104] like Figure 5 As shown, Figure 5 This is a comparison chart of the high-pressure EGR mass flow rate simulated by the high-pressure EGR valve simulation model before and after calibration, as described in this embodiment of the invention.

[0105] Step A101 includes:

[0106] Step A1011: Copy the high-pressure EGR valve 1, and import a valve with the same specifications as the high-pressure EGR valve 1 as the PID EGR valve 5;

[0107] Step A1012: Connect the components to connect the air path of the PID EGR valve 5 between the upstream environmental boundary 2 and the downstream environmental boundary 3 of the high-pressure EGR valve;

[0108] Step A1013: Component parameterization, setting the opening degree of the PID EGR valve 5 to the opening degree of the high-pressure EGR valve 1 in the test data, and transmitting the flow coefficient of the PID EGR valve 5 through the data bus.

[0109] It should be noted that a copy of the high-pressure EGR valve 1 is used as a PID EGR valve and connected in parallel with it. The flow coefficient of the high-pressure EGR valve 1 is set to a function pre-defined by those skilled in the art based on experience. The flow coefficient of the PID EGR valve 5 is set based on the opening degree-flow coefficient fitting function of the high-pressure EGR valve 1, and determined according to the opening degree of the PID EGR valve. This facilitates a comparison of the high-pressure EGR mass flow rates simulated by the model before and after calibration.

[0110] As Figure 6 shown, Figure 6 The high-pressure EGR valve flow coefficient graph plotted according to the flow coefficient output by the PID module in the embodiment of the present application.

[0111] The step A103 comprises:

[0112] Step A1301: plot the opening of the high-pressure EGR valve 1 output by the test data module 4 as the horizontal coordinate and the flow coefficient of the PID EGR valve 5 output by the PID module 6 as the vertical coordinate;

[0113] Step A1302: segmentally fit the plotting function in step A1301 to obtain the fitting function of the opening-flow coefficient of the high-pressure EGR valve 1, and apply the fitting function of the opening-flow coefficient of the high-pressure EGR valve 1 to the calibration MAP module 7.

[0114] It can be understood that the fitting function of the opening-flow coefficient of the high-pressure EGR valve 1 obtained by the PID module 6 and the PID EGR valve 5 is the function corresponding to the input-output of the calibration MAP module 7.

[0115] The electronic device provided by the present application comprises a processor and a memory connected with the processor and used for storing executable instructions of the processor, characterized in that the processor is used for executing the high-pressure EGR valve simulation model construction method and the high-pressure EGR valve simulation model calibration method.

[0116] The server provided by the present application is characterized in that it comprises at least one processor and a memory connected with the processor, the memory stores executable instructions of the at least one processor, and the instructions are executed by the processor to make the at least one processor execute the high-pressure EGR valve simulation model construction method and the high-pressure EGR valve simulation model calibration method.

[0117] The computer readable storage medium provided by the present application stores a computer program, and the computer program is executed by the processor to realize the high-pressure EGR valve simulation model construction method and the high-pressure EGR valve simulation model calibration method.

[0118] In an embodiment of the present application, taking the AVL Cruise M (software for simulating fuel economy and emission performance) software as an example, the process of constructing the high-pressure EGR valve simulation model is as follows:

[0119] The test data module 4 imports test data of at least one calibration operating point, such as engine speed, torque, pressure and temperature at the rear end of the exhaust pipe, pressure and temperature at the front end of the intake pipe, high-pressure EGR valve 1 opening, high-pressure EGR mass flow, etc. under 217 operating points; the high-pressure EGR valve 1 is parameterized according to the actual specifications, in this embodiment, the high-pressure EGR valve has a pipe diameter of 39 mm and a shaft diameter of 7.8 mm, the flow coefficient is set to 0.34 according to experience, the valve opening is transmitted by data bus, and is set to the high-pressure EGR valve opening in the test data module 4, which is an array that changes with the operating point; the high-pressure EGR valve upstream environment boundary 2 is set by data bus data transmission, and is set to the pressure and temperature parameters at the rear end of the exhaust pipe in the test data module 4, which change with the operating point; the high-pressure EGR valve downstream environment boundary 3 is set by data bus data transmission, and is set to the pressure and temperature parameters at the front end of the intake manifold in the test data module 4, which change with the operating point. However, the high-pressure EGR valve simulation model described in the present application can also be used in other simulation software, and the pipe diameter and shaft diameter of the valve used can also be different, and the flow coefficient can also be set to other constants according to experience. That is, the simulation software, valve specifications and flow coefficient applied in the present application can be set according to actual conditions, and the present application does not limit this.

[0120] In addition, the calibration process of the above high-pressure EGR valve 1 model is as follows:

[0121] (1) Copy the high-pressure EGR valve 1 and name it PID EGR valve 5, the flow coefficient of the PID EGR valve 5 is set to data bus, and the other parameterized settings are exactly the same as those of the above high-pressure EGR valve 1, the PID EGR valve 5 is connected to the high-pressure EGR valve upstream environment boundary 2 and the high-pressure EGR valve downstream environment boundary 3, respectively, and the high-pressure EGR valve opening in the test data module 4 is transmitted to the PID EGR valve 5 by data bus;

[0122] (2) Establish PID module 6, the input of the PID module 6 has two, actual value Actual Value and design value Desired Value respectively.PID EGR valve 5 upstream mass flow is transmitted to PID module 6 as actual value Actual Value through data bus, and the high-pressure EGR mass flow of test data module 4 is transmitted to PID module 6 as design value Desired Value, and the output of PID module 6 is used as the flow coefficient of PID EGR valve 5, thereby forming a PID closed loop.Through setting and adjusting the proportional term (P), integral term (I) and differential term (D) of PID module 6, the simulation calculation is run, and the PID module 6 is adjusted according to the design value and the actual value, so that the output of the PID module 6 is the flow coefficient attribute of the high-pressure EGR valve.

[0123] (3) The test data high-pressure EGR valve 1 opening is used as the abscissa, and the output data of the PID module 6 is used as the ordinate, and the two are fitted by piecewise function, and the function obtained is the change relationship of the flow coefficient of the high-pressure EGR valve 1 with the opening of the high-pressure EGR valve 1.For example, the relationship between the two can be obtained.Paste the data into Excel and manually draw points, such as the abscissa high-pressure EGR valve opening from 0, 5, 10, 15 …… to 90, and the ordinate is calculated according to the curve trend, and the ordinate high-pressure EGR flow coefficient.

[0124] (4) The change function of the flow coefficient of the high-pressure EGR valve with the opening of the high-pressure EGR valve obtained by fitting is set as the abscissa and ordinate of the calibration MAP module 7.The high-pressure EGR valve opening of the calibration MAP module 7 comes from the test data module 4, and the flow coefficient of the high-pressure EGR valve is calculated by the corresponding relationship and output to the high-pressure EGR valve 1 as the flow coefficient of the high-pressure EGR valve 1, instead of the original 0.34 set by experience.

[0125] From the results comparison, it can be seen that the model precision after calibration in this way is greatly improved, and the subsequent application requirements are met. Figure 6

[0126] Those skilled in the art can realize that the units and method steps of the examples described in combination with the embodiments disclosed herein can be realized in electronic hardware, computer software or a combination of the two, and the components and steps of the examples have been described in the above description in general terms in order to clearly illustrate the interchangeability of hardware and software. Whether the functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application. ​

[0127] In several embodiments provided in the present application, it should be understood that the disclosed method and system can be implemented in other ways. For example, the division of the above-mentioned units is only a logical function division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The above-mentioned units can be or can not be physically separated, and the components displayed as units can be or can not be physical units, that is, they can be located in one place or can be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the present application.

[0128] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application.

[0129] The above-mentioned is only the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high-pressure EGR valve simulation model calibration method for calibrating a high-pressure EGR valve simulation model, characterized in that: the high-pressure EGR valve simulation model comprises a high-pressure EGR valve (1), a high-pressure EGR valve upstream environment boundary (2), a high-pressure EGR valve downstream environment boundary (3), and a test data module (4); the high-pressure EGR valve upstream environment boundary (2) is connected in gas circuit to the front end of the high-pressure EGR valve (1) and is set as the pressure and temperature parameters of the exhaust pipe rear end; the high-pressure EGR valve upstream environment boundary (2) is connected in gas circuit to the rear end of the high-pressure EGR valve (1) and is set as the pressure and temperature parameters of the intake pipe front end; the test data module (4) is connected with the high-pressure EGR valve (1), the high-pressure EGR valve upstream environment boundary (2), and the high-pressure EGR valve upstream environment boundary (2) to transmit test data in the test data module (4); wherein the test data module (4) comprises at least one set of test data of calibration operating points, and the test data of the calibration operating points comprise the pressure and temperature parameters of the exhaust pipe rear end, the pressure and temperature parameters of the intake pipe front end, the opening of the high-pressure EGR valve (1), and the high-pressure EGR mass flow; the calibration method comprises: step A1: obtaining a fitting function of the opening-flow coefficient of the high-pressure EGR valve (1) to obtain the relationship between the flow coefficient of the high-pressure EGR valve (1) and the opening of the high-pressure EGR valve (1); step A2: importing a calibration MAP module (7) connected between the test data module (4) and the high-pressure EGR valve (1); wherein the input of the calibration MAP module (7) is the high-pressure EGR valve (1) opening transmitted by the test data module (4), and the output of the calibration MAP module (7) is the flow coefficient of the high-pressure EGR valve (1) obtained based on the fitting function relationship of the high-pressure EGR valve (1) opening-flow coefficient established in step A3; wherein the step A1 comprises: step A101: importing a PID EGR valve (5), wherein the specifications of the PID EGR valve (5) are the same as those of the high-pressure EGR valve (1); ​ ​ ​ ​ ​ ​ ​ ​ ​ Step A102: introducing a PID module (6) connected between the test data module (4) and the PID EGR valve (5), the input of the PID module (6) including an actual value Acrual Value and a desired value Desired Value, wherein the actual value Acrual Value is the mass flow upstream of the PID EGR valve (5), and the desired value Desired Value is the high-pressure EGR mass flow transmitted by the test data module (4), and the output of the PID module (6) is used as the flow coefficient of the PID EGR valve (5); wherein the proportional term (P), the integral term (I) and the differential term (D) of the PID module (6) are set and adjusted to run simulation calculation, wherein the PID module (6) automatically adjusts according to the actual value Actual Value and the desired value Desired Value, and outputs the flow coefficient of the high-pressure EGR valve (1); Step A103: obtaining the fitting function of the opening-flow coefficient of the high-pressure EGR valve (1), taking the opening of the high-pressure EGR valve (1) output by the test data module (4) as the abscissa, and taking the flow coefficient of the PID EGR valve (5) output by the PID module (6) as the ordinate, and performing piecewise function fitting on the two to obtain the fitting function of the opening-flow coefficient of the high-pressure EGR valve (1).

2. The method of claim 1, wherein, The step A101 includes: Step A1011: copying the high-pressure EGR valve (1), introducing a valve with the same specifications as the high-pressure EGR valve (1) as the PID EGR valve (5); Step A1012: connecting elements, connecting the PID EGR valve (5) to the high-pressure EGR valve upstream environment boundary (2) and the high-pressure EGR valve downstream environment boundary (3); Step A1013: element parameterization, setting the opening of the PID EGR valve (5) to the opening of the high-pressure EGR valve (1) in the test data.

3. The method of claim 1, wherein The step A103 includes: Step A1301: taking the opening of the high-pressure EGR valve (1) output by the test data module (4) as the abscissa, and taking the flow coefficient of the PID EGR valve (5) output by the PID module (6) as the ordinate to plot points; Step A1302: performing piecewise fitting on the point plotting function in step A1301 to obtain the fitting function of the opening-flow coefficient of the high-pressure EGR valve (1), and applying the fitting function of the opening-flow coefficient of the high-pressure EGR valve (1) to the calibration MAP module (7).

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