Fuel injection control method, device, equipment and medium
By using an injection back pressure model based on engine operating parameters, the problems of insufficient accuracy in small fuel quantity and inaccurate mode switching in engine fuel injection control are solved, achieving high-precision fuel injection control, reducing calibration workload and improving system adaptability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-24
- Publication Date
- 2026-04-14
AI Technical Summary
Existing engine fuel injection control methods suffer from poor accuracy in controlling small fuel quantities, inaccurate fuel injection during operating mode switching, difficulty in calibration reuse after platform upgrades, and strong dependence on calibration.
Fuel injection control is achieved by determining the injection back pressure based on engine operating parameters, and then determining the actual injection pressure and energizing time by combining the injection demand pressure and flow rate. A dynamic injection back pressure model based on operating parameters is used for fuel injection control.
It improves control accuracy under low oil volume conditions, reduces calibration workload, enhances system robustness, and adapts to precise control in multi-mode operation scenarios.
Smart Images
Figure CN121854261A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of engines, specifically to a fuel injection control method, device, and medium. Background Technology
[0002] In current engine fuel injection control, the injector energizing pulse width (i.e., energizing time) is typically determined by looking up a table based on the required fuel injection quantity and the required injection pressure, in order to control the actual fuel injection quantity. Although this control method can meet the basic combustion and emission requirements of the engine under most operating conditions, it still has significant shortcomings in some typical scenarios.
[0003] First, when an engine undergoes a technical upgrade, such as an air system upgrade or combustion chamber optimization, even if the fuel supply system remains unchanged, the original calibration data is difficult to reuse directly. Second, for engines with exhaust temperature management, key parameters such as boost pressure differ significantly between different operating modes (e.g., high-altitude mode, regenerative mode). This variation indirectly affects the actual performance of the fuel injection process, and existing control strategies do not effectively compensate for the dynamic disturbances caused by mode switching, resulting in inaccurate fuel injection quantity control. Furthermore, under the same hardware configuration, the control accuracy for low injection pressure and low fuel injection quantity conditions is poor, affecting combustion stability.
[0004] Therefore, there is an urgent need for a fuel injection control method that has stronger environmental adaptability, reduces dependence on calibration, and can achieve high-precision fuel injection control under all operating conditions. Summary of the Invention
[0005] This application provides a fuel injection control method, apparatus, equipment, and medium, which can solve the technical problems of existing engine fuel injection control methods, such as poor control accuracy for small fuel quantities, inaccurate fuel injection when switching operating modes, difficulty in calibration reuse after platform upgrades, and reliance on test bench resources for initial calibration.
[0006] In a first aspect, embodiments of this application provide a fuel injection control method, the fuel injection control method comprising:
[0007] Determine the injection back pressure during engine fuel injection based on the engine's operating parameters; The actual injection pressure is determined based on the injection demand pressure during engine fuel injection and the injection back pressure. The actual injection energizing time of the engine injector is determined based on the actual injection pressure and the required injection flow rate.
[0008] In conjunction with the first aspect, in one embodiment, calculating the injection back pressure based on the engine's intake manifold pressure, the first cylinder volume before compression, the second cylinder volume after compression, and the adiabatic index of the fuel-air mixture includes:
[0009] The injection back pressure is calculated, wherein Indicates the injection back pressure. This indicates the intake manifold pressure. This indicates the first volume of the cylinder. This indicates the second volume of the cylinder. This indicates the adiabatic index.
[0010] In conjunction with the first aspect, in one embodiment, determining the injection back pressure during engine fuel injection based on engine operating parameters includes: Using the engine's speed and torque as input parameters, the corresponding injection back pressure is obtained by looking up the preset measured injection back pressure MAP table. The measured injection back pressure MAP table includes the mapping relationship between engine speed, engine torque and injection back pressure.
[0011] In conjunction with the first aspect, in one embodiment, the method further includes: establishing the measured injection back pressure MAP table, specifically including: Under steady-state conditions on the engine bench, the cylinder pressure, engine speed and engine torque were collected at multiple operating points. For each operating point, the in-cylinder pressure during the actual injection duration of the injector is averaged to obtain the injection back pressure at that operating point. Using the engine speed and engine torque as coordinate axes and the injection back pressure as the mapping value, a measured injection back pressure MAP table is constructed.
[0012] In conjunction with the first aspect, in one embodiment, determining the actual injection pressure based on the injection demand pressure during engine fuel injection and the injection back pressure includes: The actual injection pressure is obtained by subtracting the injection back pressure from the required injection pressure.
[0013] In conjunction with the first aspect, in one embodiment, determining the actual injection energizing time of the engine injector based on the actual injection pressure and the required injection flow rate includes: Using the actual injection pressure and the required injection flow rate as input parameters, the actual injection and energizing time of the injector is obtained by looking up the preset static energizing time MAP table. The static energizing time MAP table includes a mapping relationship between the actual injection pressure, the injection demand flow rate, and the actual injection energizing time.
[0014] Secondly, embodiments of this application provide a fuel injection control device, the fuel injection control device comprising: The first determining module is used to determine the injection back pressure during engine fuel injection based on the engine's operating parameters. The second determining module is used to determine the actual injection pressure based on the injection demand pressure during engine fuel injection and the injection back pressure. The third determining module is used to determine the actual injection energizing time of the engine injector based on the actual injection pressure and the required injection flow rate.
[0015] Thirdly, embodiments of this application provide a fuel injection control device, the fuel injection control device including a processor, a memory, and a fuel injection control program stored in the memory and executable by the processor, wherein when the fuel injection control program is executed by the processor, it implements the steps of the fuel injection control method as described in any of the preceding claims.
[0016] Fourthly, embodiments of this application provide a computer-readable storage medium storing a fuel injection control program, wherein when the fuel injection control program is executed by a processor, it implements the steps of the fuel injection control method as described in any of the preceding claims.
[0017] The beneficial effects of the technical solutions provided in this application include: By determining the injection back pressure during engine fuel injection based on engine operating parameters; determining the actual injection pressure based on the required injection pressure and the injection back pressure; and determining the actual injection energizing time of the engine injector based on the actual injection pressure and the required injection flow rate, this solution addresses technical issues such as insufficient fuel injection control accuracy under low injection pressure and low fuel volume conditions, fuel injection quantity deviation caused by boost pressure changes during engine operating mode switching, and high recalibration costs and long development cycles due to the inability to reuse calibration data after engine platform upgrades.
[0018] This invention introduces a dynamically determined injection back pressure based on operating parameters and calculates the actual injection pressure accordingly, thereby accurately reflecting the effective injection pressure difference in fuel injection control. This method not only significantly improves control accuracy and system robustness under low fuel volume conditions but also possesses excellent platform adaptability. When the engine undergoes product upgrades, only relevant parameters or the injection back pressure model need to be updated, without requiring repeated calibration of the entire engine's fuel injection strategy. Furthermore, this solution effectively addresses the exhaust temperature management requirements of modern engines, achieving precise fuel injection control in various operating modes even during multi-mode switching scenarios. Attached Figure Description
[0019] Figure 1 This is a schematic flowchart of an embodiment of the fuel injection control method of this application; Figure 2 This is a schematic diagram illustrating the logic of fuel injection control based on intake manifold pressure and compression ratio in this application. Figure 3 This is a schematic diagram illustrating the accuracy of the injection back pressure calculation in this application; Figure 4 This is a schematic diagram illustrating the logic of fuel injection control based on measured injection back pressure in this application. Figure 5 This is a schematic diagram of the cylinder pressure curve during fuel injection; Figure 6 This is a functional module diagram of an embodiment of the fuel injection control device of this application; Figure 7 This is a schematic diagram of the hardware structure of the fuel injection control device involved in the embodiments of this application. Detailed Implementation
[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.
[0021] First, in order to facilitate a clearer understanding of the technical solution of this application, the application scenario of the technical problem addressed by this application will be explained.
[0022] During the development of the engine electronic control system, it was discovered that despite using the standard MAP (Modular Appointment Time) of the fuel injector for fuel injection control, significant fuel injection quantity deviations still occurred in some scenarios. For example, under low fuel quantity conditions, the actual combustion state was unstable, resulting in large emission fluctuations; during engine operating mode switching (e.g., activating the throttle or adjusting the variable geometry turbocharger to achieve exhaust temperature management), the fuel injection response was either delayed or excessive; when migrating technologies between different engine platforms or hardware configurations, such as adjusting the compression ratio, optimizing the intake manifold, or upgrading the turbocharger system, the original calibration data could not be reused, requiring significant bench resources for recalibration. Initially, these problems were attributed to sensor accuracy, actuator response delay, or control algorithm lag. However, through in-depth combustion analysis and in-cylinder pressure testing, it was found that the root cause was the failure to consider the impact of injection back pressure on fuel injection.
[0023] Specifically, injection back pressure refers to the pressure inside the engine cylinder when fuel injection occurs. Since the injector outlet is directly connected to the combustion chamber, the actual driving force for fuel injection is not the common rail pressure itself, but rather the difference between the common rail pressure and the injection back pressure, i.e., the effective injection pressure difference. Under low fuel volume conditions, the common rail pressure is low, while the in-cylinder compression pressure is relatively high, resulting in a significant proportion of injection back pressure. When switching modes or changing hardware, the intake charge and the final compression pressure change accordingly, causing dynamic fluctuations in injection back pressure. If the control strategy still uses a fixed strategy to look up a table to determine the injector's energizing time, systematic errors will inevitably be introduced.
[0024] Based on this, this application provides a fuel injection control method to solve the above-mentioned technical problems.
[0025] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0026] In a first aspect, embodiments of this application provide a fuel injection control method.
[0027] In one embodiment, reference is made to Figure 1 , Figure 1 This is a schematic flowchart of the first embodiment of the fuel injection control method of this application. Figure 1 As shown, the fuel injection control method includes: Step S1: Determine the injection back pressure during engine fuel injection based on the engine's operating parameters.
[0028] Step S2: Determine the actual injection pressure based on the injection demand pressure during engine fuel injection and the injection back pressure.
[0029] Step S3: Determine the actual injection energizing time of the engine injector based on the actual injection pressure and the required injection flow rate.
[0030] It is worth noting that this application identifies and dynamically compensates for injection back pressure, a key factor affecting the actual fuel injection characteristics, and incorporates injection back pressure into the fuel injection control logic, achieving adaptive capabilities to various engineering changes and operating scenarios. This control method can cover engine product upgrades (such as air system improvements and combustion chamber compression ratio optimization) without repeated calibration, while adapting to the needs of engine exhaust temperature management. It achieves precise fuel injection control in various operating modes, and can be achieved solely through pre-calibration using factory test data.
[0031] This application provides two methods for determining injection back pressure: the first is to calculate the theoretical injection back pressure based on the actual intake manifold pressure and compression ratio; the second is to obtain the measured injection back pressure by looking up a table.
[0032] In one embodiment, the first method obtains the theoretical injection back pressure based on the in-cylinder pressure estimation at the moment of engine fuel injection. The cylinder pressure estimation method uses theoretical calculations to determine the injection pressure, which in practice means: the in-cylinder pressure when the piston is at top dead center under the current operating conditions (assuming no combustion occurs), i.e., the maximum cylinder pressure that can be achieved during the theoretical adiabatic compression process.
[0033] Combination Figure 2 As shown, determining the injection back pressure during engine fuel injection based on engine operating parameters includes: calculating the injection back pressure based on the engine's intake manifold pressure, the first cylinder volume before compression, the second cylinder volume after compression, and the adiabatic index of the fuel-air mixture.
[0034] In the formula, This refers to the in-cylinder pressure at top dead center of the engine, which is the injection back pressure used in this application; This represents the cylinder pressure at the end of the intake manifold, but in engineering practice, it is replaced by the intake manifold pressure. This indicates the first volume of the cylinder. This indicates the second volume of the cylinder. Indicates the adiabatic index. This indicates the compression ratio of the engine combustion chamber. Specifically, the first cylinder volume refers to the total cylinder volume when the piston is at bottom dead center, and the second cylinder volume after compression refers to the combustion chamber volume when the piston is at top dead center.
[0035] Insulation Index Depending on the fuel type, EGR rate, and air-fuel ratio, the adiabatic index K has a definite physical value under specific operating conditions. This index can be obtained in various ways, including theoretical calculations, table lookup, experimental measurements, simulation software methods, or empirical formulas.
[0036] In this embodiment, the in-cylinder pressure curve of the compression section (i.e., injection back pressure) calculated by the above formula is compared with the measured in-cylinder pressure curve of the compression section. Figure 3 As shown, the verification results demonstrate that the accuracy of this estimation method meets the requirements of actual control. This application does not impose limitations on this method; the specific implementation can be flexibly selected based on actual development resources and accuracy requirements.
[0037] Explained, through the theoretical calculations described above, this scheme can effectively reflect the impact of the boost pressure generated by the air system and the compression ratio of the combustion chamber on the injection back pressure without increasing hardware costs. Since the model incorporates key physical factors affecting cylinder pressure, when using the same fuel injection unit (i.e., maintaining consistent injector specifications, especially flow characteristics), even if the engine platform changes (such as intake system optimization or compression ratio adjustment), there is no need for initial recalibration of the injectors or frequent full-engine bench calibration. This significantly reduces the calibration workload during the injector selection phase and the frequency of calibration in subsequent development, improving the versatility and development efficiency of the control strategy.
[0038] For example, such as Figure 2 As shown, the intake manifold pressure is obtained through the intake manifold pressure sensor equipped on the engine itself. Combined with the compression ratio of the combustion chamber and the adiabatic index of the fuel-air mixture, a theoretical model is used to estimate the injection back pressure at the moment of fuel injection. Then, the actual injection pressure is obtained by subtracting this injection back pressure from the required fuel injection pressure.
[0039] Furthermore, by using the actual injection pressure and the required injection flow rate as input parameters, and looking up the preset static energizing time MAP table, the actual injection energizing time of the injector can be determined. By controlling the injector according to the actual injection energizing time, precise control of fuel injection can be achieved.
[0040] The static energizing time MAP can be directly provided by the fuel injection system supplier or obtained through injector-specific bench testing. It stores the mapping relationship between actual injection pressure, injection demand flow rate, and energizing time. Therefore, high-precision fuel injection control can be achieved directly using static data obtained from supplier or component-level testing, without the need for recalibration of the entire machine platform.
[0041] The fuel injection control method of this embodiment is applicable to engines with various hardware configurations, and can fully utilize existing data (such as supplier data or specific test results) to complete the deployment of control strategies during the pre-calibration stage, significantly improving development efficiency. Furthermore, since this scheme is based on theoretical calculations using a physical model, it can dynamically reflect changes in injection back pressure under different operating conditions, thus effectively supporting multi-mode operating scenarios: for example, engines with exhaust temperature management functions can maintain good control accuracy and adaptability in all operating modes.
[0042] In one embodiment, combined with Figure 4 As shown, the second method obtains the measured injection back pressure by looking up a table, including: using the engine speed and torque as input parameters, looking up a preset measured injection back pressure MAP table to obtain the corresponding injection back pressure; wherein, the measured injection back pressure MAP table includes the mapping relationship between engine speed, engine torque and injection back pressure.
[0043] In one embodiment, establishing the measured injection back pressure MAP table specifically includes: under steady-state conditions on an engine bench, collecting in-cylinder pressure, engine speed, and engine torque corresponding to multiple operating points; for each operating point, averaging the in-cylinder pressure during the actual injection duration of the injector to obtain the injection back pressure at that operating point; and constructing the measured injection back pressure MAP table using the engine speed and engine torque as coordinate axes and the injection back pressure as the mapping value.
[0044] For example, the construction process of the measured injection back pressure MAP table is as follows: During the engine hardware finalization stage, the in-cylinder pressure curves during the actual injection duration at each steady-state operating point are collected using a combustion analysis system, such as... Figure 5 As shown, for each operating point, the collected cylinder pressure data is averaged within the time window from the injector opening to closing, and the resulting average value is the measured injection back pressure corresponding to that operating point. Subsequently, with engine speed and torque as the horizontal and vertical axes respectively, and the calculated injection back pressure as the mapping value, a complete two-dimensional measured injection back pressure MAP table is constructed.
[0045] This measured injection back pressure MAP table can be embedded in the engine control unit (ECU). During actual operation, the table can be quickly looked up by controlling engine speed and torque to obtain high-precision injection back pressure values, thereby providing key input parameters for fuel injection strategy optimization, rail pressure control, or combustion diagnostics.
[0046] Furthermore, the actual injection pressure is obtained by subtracting the injection back pressure from the required fuel injection pressure. Using the actual injection pressure and the required injection flow rate as input parameters, a preset static energizing time (MAP) table is consulted to determine the actual energizing time of the injector. By controlling the injector according to the actual energizing time, precise control of fuel injection can be achieved.
[0047] In an alternative implementation, the actual injection pressure is obtained by directly correcting the injection demand pressure based on the actual intake manifold pressure. This approach can adapt to precise control during various operating mode switching.
[0048] Specifically, using the intake manifold absolute pressure as the input parameter, a preset pressure compensation MAP table is consulted to obtain the corresponding pressure compensation parameters; these parameters include a pressure compensation coefficient or a pressure compensation amount. Subsequently, the injection demand pressure is compensated using these parameters to obtain the actual injection pressure. The pressure compensation MAP table contains a mapping relationship between the intake manifold pressure and the pressure compensation parameters, which can be generated through bench testing calibration.
[0049] Next, the actual injection pressure and the required injection flow rate are used as input parameters to look up the preset static energizing time MAP table, thereby determining the actual injection energizing time of the injector; finally, the opening duration of the injector is controlled according to the actual injection energizing time, so as to achieve precise control of fuel injection.
[0050] The fuel injection control method provided in this application can effectively achieve precise fuel control of the engine under various operating modes and with different configurations, significantly improving injection control accuracy. This advantage is particularly prominent in low injection pressure systems (such as those with a rail pressure below 500 bar). Furthermore, when the same type of fuel injector needs to be matched with multiple air systems (such as different turbocharger configurations), this method can significantly reduce calibration and adaptation workload while ensuring control accuracy. Simultaneously, this strategy enhances the system's robustness under multiple operating conditions, especially suitable for applications such as diesel engines with "same load, multiple boost requirements" (for example, due to exhaust temperature management requirements, different exhaust temperatures need to be achieved through throttle or boost adjustment under the same torque, resulting in differences in in-cylinder back pressure). Currently, the functional requirements definition and technical review of this control strategy have been completed, and it will be gradually applied to multiple engine platforms.
[0051] Secondly, embodiments of this application also provide a fuel injection control device.
[0052] In one embodiment, reference is made to Figure 6 , Figure 6 This is a functional block diagram of an embodiment of the fuel injection control device of this application. Figure 6 As shown, the fuel injection control device includes: The first determining module is used to determine the injection back pressure during engine fuel injection based on the engine's operating parameters. The second determining module is used to determine the actual injection pressure based on the injection demand pressure during engine fuel injection and the injection back pressure. The third determining module is used to determine the actual injection energizing time of the engine injector based on the actual injection pressure and the required injection flow rate.
[0053] Furthermore, in one embodiment, the first determining module is further configured to: The injection back pressure is calculated based on the engine's intake manifold pressure, the first cylinder volume before compression, the second cylinder volume after compression, and the adiabatic index of the fuel-air mixture.
[0054] Furthermore, in one embodiment, the device is also used for: calculating the injection back pressure based on the engine's intake manifold pressure, the first cylinder volume before compression, the second cylinder volume after compression, and the adiabatic index of the fuel-air mixture, including:
[0055] The injection back pressure is calculated, wherein Indicates the injection back pressure. This indicates the intake manifold pressure. This indicates the first volume of the cylinder. This indicates the second volume of the cylinder. This indicates the adiabatic index.
[0056] Furthermore, in one embodiment, the first determining module is further configured to: Using the engine's speed and torque as input parameters, the corresponding injection back pressure is obtained by looking up the preset measured injection back pressure MAP table. The measured injection back pressure MAP table includes the mapping relationship between engine speed, engine torque and injection back pressure.
[0057] Furthermore, in one embodiment, the device is also used for: Under steady-state conditions on the engine bench, the cylinder pressure, engine speed and engine torque were collected at multiple operating points. For each operating point, the in-cylinder pressure during the actual injection duration of the injector is averaged to obtain the injection back pressure at that operating point. Using the engine speed and engine torque as coordinate axes and the injection back pressure as the mapping value, a measured injection back pressure MAP table is constructed.
[0058] Furthermore, in one embodiment, the second determining module is further configured to: The actual injection pressure is obtained by subtracting the injection back pressure from the required injection pressure.
[0059] Furthermore, in one embodiment, the third determining module is further configured to: Using the actual injection pressure and the required injection flow rate as input parameters, the actual injection and energizing time of the injector is obtained by looking up the preset static energizing time MAP table. The static energizing time MAP table includes a mapping relationship between the actual injection pressure, the injection demand flow rate, and the actual injection energizing time.
[0060] The functions of each module in the above-mentioned fuel injection control device correspond to the steps in the above-mentioned fuel injection control method embodiment, and their functions and implementation processes will not be described in detail here.
[0061] Thirdly, embodiments of this application provide a fuel injection control device, which can be a personal computer (PC), laptop computer, server, or other device with data processing capabilities.
[0062] Reference Figure 7 , Figure 7 This is a schematic diagram of the hardware structure of the fuel injection control device involved in the embodiments of this application. In the embodiments of this application, the fuel injection control device may include a processor, a memory, a communication interface, and a communication bus.
[0063] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.
[0064] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting components within the fuel injection control equipment, as well as interfaces used for interconnecting the fuel injection control equipment with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.
[0065] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.
[0066] The processor can be a general-purpose processor, which can call the fuel injection control program stored in the memory and execute the fuel injection control method provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the fuel injection control program is called can be referred to in the various embodiments of the fuel injection control method of this application, and will not be repeated here.
[0067] Those skilled in the art will understand that Figure 7 The hardware structure shown does not constitute a limitation of this application and may include more or fewer components than shown, or combine certain components, or have different component arrangements.
[0068] Fourthly, embodiments of this application also provide a computer-readable storage medium.
[0069] The present application has a computer-readable storage medium storing a fuel injection control program, wherein when the fuel injection control program is executed by a processor, it implements the steps of the fuel injection control method as described above.
[0070] The method implemented when the fuel injection control program is executed can be referred to in various embodiments of the fuel injection control method of this application, and will not be repeated here.
[0071] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0072] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.
[0073] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.
[0074] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.
[0075] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.
[0076] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.
[0077] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A fuel injection control method, characterized in that, The fuel injection control method includes: Determine the injection back pressure during engine fuel injection based on the engine's operating parameters; The actual injection pressure is determined based on the injection demand pressure during engine fuel injection and the injection back pressure. The actual injection energizing time of the engine injector is determined based on the actual injection pressure and the required injection flow rate.
2. The fuel injection control method as described in claim 1, characterized in that, Determining the injection back pressure during engine fuel injection based on engine operating parameters includes: The injection back pressure is calculated based on the engine's intake manifold pressure, the first cylinder volume before compression, the second cylinder volume after compression, and the adiabatic index of the fuel-air mixture.
3. The fuel injection control method as described in claim 2, characterized in that, The injection back pressure is calculated based on the engine's intake manifold pressure, the first cylinder volume before compression, the second cylinder volume after compression, and the adiabatic index of the fuel-air mixture, including: The injection back pressure is calculated, wherein Indicates the injection back pressure. This indicates the intake manifold pressure. This indicates the first volume of the cylinder. This indicates the second volume of the cylinder. This indicates the adiabatic index.
4. The fuel injection control method as described in claim 1, characterized in that, Determining the injection back pressure during engine fuel injection based on engine operating parameters includes: Using the engine's speed and torque as input parameters, the corresponding injection back pressure is obtained by looking up the preset measured injection back pressure MAP table. The measured injection back pressure MAP table includes the mapping relationship between engine speed, engine torque and injection back pressure.
5. The fuel injection control method as described in claim 4, characterized in that, The method also includes: establishing the measured injection back pressure MAP table, specifically including: Under steady-state conditions on the engine bench, the cylinder pressure, engine speed and engine torque were collected at multiple operating points. For each operating point, the in-cylinder pressure during the actual injection duration of the injector is averaged to obtain the injection back pressure at that operating point. Using the engine speed and engine torque as coordinate axes and the injection back pressure as the mapping value, a measured injection back pressure MAP table is constructed.
6. The fuel injection control method as described in claim 1, characterized in that, The step of determining the actual injection pressure based on the injection demand pressure during engine fuel injection and the injection back pressure includes: The actual injection pressure is obtained by subtracting the injection back pressure from the required injection pressure.
7. The fuel injection control method as described in claim 1, characterized in that, Determining the actual injection energizing time of the engine injector based on the actual injection pressure and the required injection flow rate includes: Using the actual injection pressure and the required injection flow rate as input parameters, the actual injection and energizing time of the injector is obtained by looking up the preset static energizing time MAP table. The static energizing time MAP table includes a mapping relationship between the actual injection pressure, the injection demand flow rate, and the actual injection energizing time.
8. A fuel injection control device, characterized in that, The fuel injection control device includes: The first determining module is used to determine the injection back pressure during engine fuel injection based on the engine's operating parameters. The second determining module is used to determine the actual injection pressure based on the injection demand pressure during engine fuel injection and the injection back pressure. The third determining module is used to determine the actual injection energizing time of the engine injector based on the actual injection pressure and the required injection flow rate.
9. A fuel injection control device, characterized in that, The fuel injection control device includes a processor, a memory, and a fuel injection control program stored in the memory and executable by the processor, wherein when the fuel injection control program is executed by the processor, it implements the steps of the fuel injection control method as described in any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a fuel injection control program, wherein when the fuel injection control program is executed by a processor, it implements the steps of the fuel injection control method as described in any one of claims 1 to 7.