Method for simulating plateau performance test by applying virtual engine model
By constructing and debugging virtual engine models, the high cost and limitations of plateau scenario testing in traditional methods are solved, and efficient engine plateau performance simulation and calibration is achieved, saving costs and reducing development cycles.
Patent Information
- Application Number
- CN202411947845.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-05-02
AI Technical Summary
In the prior art, the method of using actual plateau scenes or real plateau simulation benches to test the engine is expensive and has great limitations, making it difficult to effectively simulate complex ECU control strategies and vehicle environments.
By obtaining engine parameter data, building a basic engine model and performing accuracy correction, adjusting it to a plateau simulated exhaust backpressure model, integrating it into a virtual development platform, debugging and boundary setting, and conducting plateau simulation experiments.
Effectively save development costs, reduce development cycles, avoid resource and environmental limitations in traditional methods, and can simulate more complex working conditions and ECU strategies, which can basically replace or partially replace plateau calibration work.
Smart Images
Figure CN119916775A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of simulation calculation, and more specifically, to a method for simulating plateau performance test by using a virtual engine model. Background Art
[0002] In the process of engine research and development, simulation computing has become an important development tool as a means of reproducing the engine's working process and performance results through the application of computing software and, to a certain extent, providing high-confidence prediction results through technical control.
[0003] In the process of modern engine development and use, in order to achieve comprehensive control under a variety of complex working conditions and environments, the engine often receives command control output by the electronic control unit (ECU) after complex logic judgment during actual vehicle driving. It is often difficult to achieve the true simulation of engine action under this complex control strategy in the model by using a single offline simulation method. At present, for the simulation of such a situation, the complex ECU control strategy is often simplified into a separate actuator execution logic, omitting the complex calculation logic and PID control in the logic path. This simplified processing will cause a certain difference between the simulation results and the actual results. Therefore, it is necessary to use a combination of software and hardware methods, with the help of a digital vehicle powertrain virtual development platform system, to achieve a method for simulating and reproducing the real driving process of the vehicle.
[0004] In the process of modern engine development, the actual application scenarios of the engine are divided into ordinary plain scenarios and non-standard scenarios (high temperature, plateau, and high cold). While the engine can work normally in the plain scenario, it also needs to be able to work normally in the non-standard environment that may be used. Among them, for the performance control and electronic control strategy calibration of the engine under the plateau, modern development work often adopts the actual plateau scenario or the real plateau simulation bench to carry out this work. However, the use of actual plateau scenarios or real plateau simulation benches will bring a lot of cost expenditures and are subject to great limitations. For example, the use of actual plateau scenarios for calibration has the problem of matching the engine with vehicle resources and modifying it, the calibration personnel must work with the vehicle, the working environment is poor, and the testable working conditions are limited. The use of real plateau simulation benches for calibration has the problem of having to increase the cost of converting the conventional performance bench into a plateau simulation bench based on the conventional performance bench, which is costly and can only indirectly simulate the plateau environment, resulting in possible distortion in the simulation. Summary of the invention
[0005] The technical problem to be solved by the present invention is to provide a method for simulating plateau performance tests using a virtual engine model in response to the deficiencies in the prior art, thereby solving the technical problems that the existing method of using actual plateau scenes or real plateau simulation benches to test engines is costly and has great limitations.
[0006] The method of simulating plateau performance test by using a virtual engine model according to the present invention comprises:
[0007] S11: Acquiring engine parameter data;
[0008] S12: constructing a basic engine model according to the engine parameter data, and performing precision correction on the basic engine model;
[0009] S13: adjusting the basic engine model to a plateau simulated exhaust back pressure model;
[0010] S14: integrating the plateau simulation exhaust back pressure model into a virtual development platform;
[0011] S15: debugging the plateau simulated exhaust back pressure model on the virtual development platform to generate a target model;
[0012] S16: Setting boundaries for the target model to carry out a plateau simulation experiment.
[0013] As a further improvement, in S12, the method for performing precision correction on the basic engine model is:
[0014] S21: calibrating the basic engine model to obtain initial accuracy;
[0015] S22: Compare the initial accuracy with a preset target accuracy. When the initial accuracy is equal to the target accuracy, determine that the initial accuracy meets the accuracy requirement. When the initial accuracy is not equal to the target accuracy, return to S21 to recalibrate the basic engine model.
[0016] Furthermore, the basic engine model is constructed and calibrated based on the MOBEO Cylinder class model.
[0017] Furthermore, in S22, when the initial accuracy meets the accuracy requirement, the calibration content of the basic engine model module is solidified.
[0018] Furthermore, in S13, the method for adjusting the basic engine model to the plateau simulated exhaust back pressure model is to perform specialized processing on the basic engine model, and construct a plateau simulated exhaust back pressure model based on the specialized engine model.
[0019] Furthermore, the method for specializing the basic engine model is to open a state adjustment interface to the basic engine model, associate the state adjustment interface with the environmental state, establish an association module through the associated state adjustment interface, and construct a plateau simulated exhaust back pressure model through the association module and the basic engine model.
[0020] Furthermore, in S14, the method for integrating the plateau simulated exhaust back pressure model into the virtual development platform is to set a matching engineering file, and integrate the plateau simulated exhaust back pressure model into the virtual development platform through the matching engineering file.
[0021] Furthermore, in S15, the method for debugging the plateau simulated exhaust back pressure model is to issue instructions to the plateau simulated exhaust back pressure model to obtain action performance, logic performance and precision performance, and when the action performance meets the preset action target performance and the logic performance meets the preset logic target performance and the precision performance meets the preset precision target performance, the target model is generated; otherwise, instructions continue to be issued to the target model.
[0022] Furthermore, the method for setting the boundary of the target model is to change the state adjustment interface into a corresponding plateau state interface, and modify the environmental state parameters of the plateau state interface into plateau environmental state parameters.
[0023] Furthermore, the target model includes a high-precision engine model and a model of a real-time hardware control unit.
[0024] Beneficial Effects
[0025] The advantages of the present invention are:
[0026] 1. The present invention obtains engine parameter data, constructs a basic engine model according to the engine parameter data, and performs precision correction on the basic engine model, so as to adjust the basic engine model to a plateau simulated exhaust back pressure model; the plateau simulated exhaust back pressure model is integrated into a virtual development platform; the plateau simulated exhaust back pressure model is debugged on the virtual development platform to generate a target model, and the boundary of the target model is set to carry out plateau simulation experiments, which can replace the actual simulation bench or partially replace the real plateau vehicle to carry out experiments and development work, effectively saving development costs and shortening development cycles.
[0027] 2. The present invention performs specialized processing related to plateau simulation tests on the basic engine and constructs a plateau simulation exhaust back pressure model. Compared with other existing technologies, the present invention realizes plateau simulation by adopting a virtual engine model, avoiding the various limitations and resource requirements required for traditional plateau simulation benches or real-scene calibration. Compared with traditional plateau simulation methods, the simulated working conditions are less restricted, the complexity of the real ECU strategy is taken into account, the simulation results can be debugged by model engineers online, the simulation results are linked with the ECU strategy, and the engine performance and actual simulation effect applied to the whole vehicle are taken into consideration. It can basically replace or partially replace the plateau calibration work.
[0028] 3. The present invention integrates the plateau simulated exhaust back pressure model into the virtual development platform, and debugs the plateau simulated exhaust back pressure model on the virtual development platform to generate a target model, thereby avoiding the resource problems in the existing plateau calibration based on a real simulation bench or a whole vehicle, and avoiding the problems of being unable to consider the control strategy when using the existing simulation method, which affects the work effect, and is very different from the actual calibration environment. The calibration engineers feel very disconnected, and cannot fully simulate the real engine action and cannot simulate the whole vehicle environment. This makes it a feasible method to use the simulation method to fully simulate the plateau performance test and support the calibration work.
[0029] 4. The present invention sets the boundary of the target model to carry out plateau simulation experiments, which can replace the actual simulation bench or partially replace the real plateau vehicle to carry out experiments and development work, effectively saving development costs and reducing development cycles. It has strong autonomy and convenience, can efficiently support modern engine development work, and greatly reduce development costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 The present invention is a flow chart of a method for simulating plateau performance test by using a virtual engine model. DETAILED DESCRIPTION
[0031] The present invention will be further described below in conjunction with the embodiments, but it does not constitute any limitation to the present invention. Any limited number of modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.
[0032] See also Figure 1 The present invention discloses a method for simulating plateau performance tests using a virtual engine model. The method uses a high-precision engine model established by AVL CruiseM simulation software and applied to a digital vehicle powertrain virtual development platform system under a hardware system such as dSPACE or ETAS to perform plateau performance simulation tests. The method can be used to replace a real plateau simulation bench or partially replace a real plateau scene to carry out plateau calibration work required for engine development, effectively saving development costs and shortening development cycles.
[0033] Figure 1 The general method of using AVL CruiseM simulation software to build a high-precision engine model for a digital vehicle powertrain virtual development platform system under hardware systems such as dSPACE or ETAS for plateau performance simulation tests is demonstrated. This application will be based on Figure 1 Describes the process of developing a diesel engine model with a mechanical wastegate supercharger based on AVL CruiseM software, applying it to the digital vehicle powertrain virtual development platform, and conducting plateau simulation tests, including:
[0034] 101. Obtain engine parameter data and test data:
[0035] Engine data refers to the engine physical structure parameter data required to establish the engine model, such as cylinder diameter, stroke, compression ratio, injector parameters, pipeline volume and other engine parameters. The test data refers to the basic test data that can characterize the performance of this engine, such as engine universal test data, engine external characteristic test data, etc. Here, since the model to be developed will eventually be applied to the digital vehicle powertrain virtual development platform system and controlled by a real ECU, the test data should also include all engine actuator control parameters (such as oil volume, timing, rail pressure, injection pulse width and other information).
[0036] 102. Complete the construction of the basic engine model based on the engine parameter data:
[0037] The model building process specifically refers to the model building process based on the MOBEO Cylinder (Engineering Enhanced) model, which needs to establish a basic engine model based on the actual engine parameters obtained in 101. This type of engine model can be based on certain empirical models and physical models, and the performance of the engine can be calculated through the actions of the real engine actuators. This type of model must be used in the digital vehicle powertrain virtual development platform system, and the model mechanism content in the software will not be expanded too much here.
[0038] 103. Model calibration under single engine model:
[0039] The calibration process is a specific model calibration process based on the MOBEO Cylinder (Engineering Enhanced) model. The calibration of the basic engine model aims to make the basic engine model have higher accuracy through calibration, so as to reflect the performance of the real engine. Since there are similar methods in this field, we will not elaborate on them here.
[0040] 104. Determine whether the accuracy meets the requirements:
[0041] Since the model finally developed for the digital vehicle powertrain virtual development platform system is a complex model composed of multiple systems, each module work completed must be confirmed during the model development work to avoid errors that are difficult to locate. After completing the calibration work described in 103, the basic engine model results need to be tested for accuracy to ensure that there are no abnormalities in the single engine model results and that the accuracy meets the requirements. The method for accuracy correction of the basic engine model is to calibrate the basic engine model to obtain an initial accuracy; compare the initial accuracy with a preset target accuracy, and when the initial accuracy is equal to the target accuracy, it is judged that the initial accuracy meets the accuracy requirements; when the initial accuracy is not equal to the target accuracy, the basic engine model is recalibrated.
[0042] 105. Recalibrate the engine model to meet the accuracy requirements:
[0043] If the initial accuracy of the basic engine model does not meet the target accuracy requirements, the initial accuracy of the basic engine model needs to be continuously adjusted until it meets the requirements.
[0044] 106. Solidify the module content of the basic engine model:
[0045] After completing debugging task 105 or confirming in item 104 that the initial accuracy of the basic engine model meets the requirements, task 106 can be carried out to fix part of the engine model content (mainly the content involved in the engine model calibration part).
[0046] 107. Specialized processing related to plateau simulation test:
[0047] According to 102, the basic engine model built is a MOBEO model that calculates the engine performance through the real engine actuator action. Therefore, it is only necessary to define the boundary difference changes and actuator action differences caused by the engine switching from the plain environment to the plateau environment to carry out the plateau simulation test. And because the built model will eventually be applied to the digital vehicle powertrain virtual development platform and run in the form of ECU in the loop, the actuator actions directly controlled by the ECU (such as injection oil volume, injection timing, injection pulse width, rail pressure and other information) can be processed in the offline model building link. Therefore, the work that needs to be done at this time is only to specialize the engine boundaries in the model and the actuator actions that cannot be directly controlled by the ECU (such as the mechanical supercharger wastegate valve). The specific processing operations are as follows: by opening the interface to the basic engine model, the intake and exhaust air states of the basic engine model are adjustable (ambient pressure, temperature, air humidity); by associating the charging efficiency that characterizes the intake level of the model in the basic engine model with the ambient pressure, it can feedback the intake level changes caused by the changes in the air boundary under the plateau; by establishing an association module that strongly associates the flow characteristics of the mechanical wastegate valve of the supercharger with its physical characteristics, it can feedback the changes in the working state of the supercharger caused by the performance changes caused by the changes in the intake environment under the plateau. The plateau simulated exhaust back pressure model is constructed through the association module and the basic engine model.
[0048] 108. Construction of plateau simulation exhaust back pressure model:
[0049] In order to meet the requirements of emission regulations, non-clean energy engines developed by modern enterprises (such as the diesel engine described in this article) must generally be equipped with an after-treatment system to achieve road use based on the vehicle environment. The basic engine model constructed as described in Preamble 102 is generally a single engine model without an after-treatment system. There is a certain difference between its exhaust back pressure state and that of the engine with an after-treatment system. Therefore, before conducting the plateau simulation test, it is necessary to adjust it to the exhaust back pressure state with an after-treatment system. This part of the content can be achieved by building a complete after-treatment model through CruiseM, or by directly simplifying the after-treatment model into a valve component, that is, using a flow characteristic map to simulate its impact on exhaust back pressure.
[0050] 109. Vehicle model construction (optional):
[0051] Whether this part is carried out depends on the model test form that is ultimately expected to be achieved. If the plateau simulation test form you want to simulate is a steady-state test of the engine on the test bench, you do not need to carry out this part of the vehicle model construction work. If the plateau simulation test you want to simulate is a transient scene in which the engine is assembled on the whole vehicle and in a real plateau scene, you need to build a whole vehicle model and couple the whole vehicle model with the engine basic model. There are relatively mature methods for building a whole vehicle model, so this article will not go into details.
[0052] 110. Build the matching engineering files required to integrate the full model into the digital vehicle assembly virtual development platform:
[0053] After completing the work described in item 109, it is necessary to further construct the matching engineering files required for integrating the full model into the digital vehicle assembly virtual development platform so that the model has an environment that meets the hardware-in-the-loop operation. The matching engineering files are engineering files that use hardware and software to convert the physical / digital signals received or sent by the real control unit into digital / physical signals to meet the environment required for the model and actuator to work normally in the hardware-in-the-loop state. For example, in this embodiment, after the completed full model is integrated into the digital vehicle assembly virtual development platform, it will receive instructions from the real ECU control unit and feedback the signals required by the ECU. At the same time, the ECU will also issue instructions to control the hardware actions such as the real injector and throttle. Among them, in this embodiment, the injection amount signal required by the model is determined by the ECU through the engine state fed back by the model and the engine speed and load signal requirements received (if the integrated vehicle model, this part of the signal comes from the driver model, if the vehicle model is not integrated, this part of the signal comes from the dynamometer model), the current required injection amount is determined and an electro-physical signal is generated to make the real injector actuate. At this time, the generated electrical signal is monitored and converted into a digital signal, which is synchronously transmitted to the model to make the model actuate. The matching engineering file should meet all the signals required by the hardware-in-the-loop system formed by the model and the external hardware, and the conversion process of other signals will not be repeated one by one. Obviously, the signal conversion content and matching engineering file described here will vary depending on the type of hardware actually connected to the hardware-in-the-loop system.
[0054] 111. Hardware signal access of real ECU control unit and other actuators:
[0055] After completing the 110 tasks, the whole vehicle model and the plateau simulated exhaust back pressure model can be integrated into the digital vehicle assembly virtual development platform, and connected to the real ECU control unit and other actuators to form a hardware-in-the-loop system.
[0056] 112. The hardware-in-the-loop system test based on the virtual development platform is normal:
[0057] After completing the work described in item 111, the full model includes the vehicle model and the plateau simulated exhaust back pressure model, and the full model can be tested in an online state (the state of the ECU and actuators of the real hardware control unit integrated). As in the model described in this embodiment, the model can be instructed to run a specified road spectrum vehicle test cycle (integrated vehicle model) or external characteristic test (not integrated vehicle model) on the digital vehicle assembly virtual development platform through AVL PUMA to test whether the actions, logic, accuracy, etc. during driving can continuously perform normally and meet the accuracy requirements.
[0058] The method for debugging the plateau simulated exhaust back pressure model is to issue instructions to the plateau simulated exhaust back pressure model to obtain action performance, logic performance and precision performance. When the action performance meets the preset action target performance and the logic performance meets the preset logic target performance and the precision performance meets the preset precision target performance, a target model is generated; otherwise, instructions continue to be issued to the target model.
[0059] Obviously, AVL PUMA is only a control system software for the digital vehicle assembly virtual development platform, and any other software that can achieve control is applicable to this method.
[0060] 113. The continuous debugging model performs normally in the online environment:
[0061] If the full model in 112 cannot continuously perform normally in the hardware-in-the-loop state, it is necessary to continuously debug the full model, or transmit the matching engineering file described in 110 to the full model, and debug the full model until the action performance, logic performance and accuracy performance are normal.
[0062] 114. Form a model that can achieve accurate control in an online environment:
[0063] After completing the debugging work in item 113 above or confirming that the model performs normally in the hardware-in-the-loop state in item 112, the work in item 114 can be carried out to solidify the debugged full model and related matching engineering files to form a model that contains both a high-precision engine model (or a vehicle model with a high-precision engine) and a real-time hardware control unit (ECU). This model can support real-time control calibration based on the digital vehicle assembly virtual development platform, accurately capture the engine status during real driving, and carry out subsequent simulation tests and development work based on this platform.
[0064] 115. Plateau environment boundary settings required by the model:
[0065] After completing the above 114 tasks, you can start the preparation work for the plateau simulation test. First, the model boundary state in the high-precision engine model (or the vehicle model with a high-precision engine) and the real-time hardware control unit (ECU) model should be changed to the corresponding plateau state through the reserved interface described in 107. For example, in this embodiment, the plateau test under the real Xining scene (2400m above sea level) can be simulated by changing the ambient temperature to 16°C and the ambient pressure to 76kPa (absolute pressure) (other influencing factors have been directly considered in the model as described in 103).
[0066] 116. Plateau environment boundary setting required by ECU:
[0067] After completing the work described in item 115, the model operating environment described in item 110-114 is the hardware-in-the-loop environment of the real control unit ECU, so the ECU must be set accordingly to ensure that the ECU and the ECU status in the real plateau scene are consistent. For example, in this embodiment, when simulating the plateau test under the real Xining scene (2400m altitude), since the ECU unit used integrates an environmental pressure sensor to directly obtain the environmental pressure, and the ambient temperature is obtained through the measurement results of an external temperature sensor, the ECU needs to be set differently corresponding to these two different acquisition methods. Among them, when the model is integrated into the digital vehicle assembly virtual development platform to carry out simulation tests, the real external ambient temperature sensor is cancelled, and the ambient temperature is set directly through the environmental status interface described in item 115 and fed back to the ECU control unit. The ambient pressure is written to the pressure at the simulated altitude by using the electronic control calibration software to rewrite the data of the ECU control unit.
[0068] 117. Carry out plateau simulation tests based on the digital vehicle powertrain virtual development platform:
[0069] After completing the 116 tasks mentioned above, plateau simulation tests can be carried out.
[0070] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.
Claims
1. A method for simulating plateau performance test using a virtual engine model, characterized in that: The method is, S11: Acquiring engine parameter data; S12: constructing a basic engine model according to the engine parameter data, and performing precision correction on the basic engine model; S13: adjusting the basic engine model to a plateau simulated exhaust back pressure model; S14: integrating the plateau simulation exhaust back pressure model into a virtual development platform; S15: debugging the plateau simulated exhaust back pressure model on the virtual development platform to generate a target model; S16: Setting boundaries for the target model to carry out a plateau simulation experiment.
2. The method for simulating plateau performance test using a virtual engine model according to claim 1, characterized in that: In S12, the method for correcting the accuracy of the basic engine model is: S21: calibrating the basic engine model to obtain initial accuracy; S22: Compare the initial accuracy with a preset target accuracy. When the initial accuracy is equal to the target accuracy, determine that the initial accuracy meets the accuracy requirement. When the initial accuracy is not equal to the target accuracy, return to S21 to recalibrate the basic engine model.
3. The method for simulating plateau performance test using a virtual engine model according to claim 2, characterized in that: The basic engine model is constructed and calibrated based on the MOBEO Cylinder class model.
4. The method for simulating plateau performance test using a virtual engine model according to claim 3, characterized in that: In S22, when the initial accuracy meets the accuracy requirement, the calibration content of the basic engine model module is solidified.
5. The method for simulating plateau performance test using a virtual engine model according to claim 1, characterized in that: In S13, the method for adjusting the basic engine model to the plateau simulated exhaust back pressure model is to perform specialized processing on the basic engine model, and construct a plateau simulated exhaust back pressure model based on the specialized engine model.
6. The method for simulating plateau performance test using a virtual engine model according to claim 5, characterized in that: The method for specializing the basic engine model is to open a state adjustment interface to the basic engine model, associate the state adjustment interface with the environmental state, establish an association module through the associated state adjustment interface, and construct a plateau simulated exhaust back pressure model through the association module and the basic engine model.
7. The method for simulating plateau performance test using a virtual engine model according to claim 1, characterized in that: In S14, the method for integrating the plateau simulated exhaust back pressure model into the virtual development platform is to set a matching engineering file, and integrate the plateau simulated exhaust back pressure model into the virtual development platform through the matching engineering file.
8. The method for simulating plateau performance test using a virtual engine model according to claim 1, characterized in that: In S15, the method for debugging the plateau simulated exhaust back pressure model is to issue instructions to the plateau simulated exhaust back pressure model to obtain action performance, logic performance and accuracy performance. When the action performance meets the preset action target performance and the logic performance meets the preset logic target performance and the accuracy performance meets the preset accuracy target performance, the target model is generated; otherwise, instructions continue to be issued to the target model.
9. The method for simulating plateau performance test using a virtual engine model according to claim 1, characterized in that: The method for setting the boundary of the target model is to change the state adjustment interface into a corresponding plateau state interface, and modify the environmental state parameters of the plateau state interface into plateau environmental state parameters.
10. The method for simulating plateau performance test using a virtual engine model according to claim 9, characterized in that: The target model includes a high-precision engine model and a model of a real-time hardware control unit.