An engine and a combustion control method and apparatus therefor
By configuring a residual gas coefficient relationship table under steady-state engine conditions, the engine is controlled to enter a lean combustion state, thus solving the problem of insufficient fuel economy and improving fuel economy and vehicle reliability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DONGFENG MOTOR GRP
- Filing Date
- 2023-10-31
- Publication Date
- 2026-07-21
AI Technical Summary
Existing lean-burn technology suffers from insufficient fuel economy in engines, especially in hybrid vehicles, where low-pressure EGR and high compression ratio technologies have limitations, resulting in inadequate fuel economy.
By acquiring the engine speed and intake air density under steady-state conditions, configuring the residual gas coefficient relationship table, controlling the engine to enter a lean combustion state when the lean combustion conditions are met, and ensuring combustion stability and economy by dynamically adjusting the fuel injection quantity and detection cycle.
It improves the fuel economy of the engine under steady-state conditions, reduces the amount of fuel injected, increases the driving range and reliability of hybrid vehicles, and reduces development costs.
Smart Images
Figure CN117662311B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of combustion control in engines, and more particularly to an engine and its combustion control method and apparatus. Background Technology
[0002] Lean combustion is an engine operating mode that increases the intake air volume and reduces the amount of fuel injected to achieve the desired air-fuel ratio. Because less fuel is used per combustion cycle, the engine becomes more efficient, economical, and environmentally friendly. However, because lean combustion affects vehicle performance, its application is currently limited, resulting in insufficient fuel economy during engine operation.
[0003] Therefore, improving engine fuel economy is a pressing technical problem that needs to be solved. Summary of the Invention
[0004] The present invention provides an engine and its combustion control method and apparatus, which can improve the fuel economy of the engine under steady-state operating conditions.
[0005] The embodiments of the present invention provide the following solutions: In a first aspect, embodiments of the present invention provide a combustion control method for an engine, the method comprising: Obtain the engine's first speed and first intake air density under steady-state operating conditions; The target residual gas coefficient of the engine is determined based on the first speed, the first intake air density and the preset first relationship table, wherein the first relationship table is a table showing the correspondence between different operating speeds, different intake air densities and residual gas coefficients. When the target residual gas coefficient is greater than the first residual gas coefficient under normal combustion conditions, the engine is controlled to enter a lean combustion state based on the target residual gas coefficient.
[0006] In one optional embodiment, controlling the engine to enter a lean combustion state based on a target residual gas coefficient includes: Based on the target residual gas coefficient, determine the slope of the residual gas coefficient when the engine transitions from normal combustion to lean combustion. The engine is controlled to enter a lean combustion state based on the slope of the residual gas coefficient until the engine's intake air volume reaches the intake air volume corresponding to the target residual gas coefficient.
[0007] In one optional embodiment, determining the slope of the residual gas coefficient as the engine transitions from a normal combustion state to a lean combustion state, based on a target residual gas coefficient, includes: Based on the target residual gas coefficient, determine the operating speed slope and intake air density slope of the engine when it transitions from normal combustion to lean combustion. The minimum value of the operating speed slope and the intake air density slope is determined as the residual gas coefficient slope.
[0008] In an optional embodiment, after controlling the engine to enter a lean combustion state according to the target residual gas coefficient, the method further includes: Obtain the engine's second speed and second residual gas coefficient under lean combustion conditions; Based on the second speed, the second residual gas coefficient, and the preset second relationship table, the target detection cycle for lean combustion of the engine is determined. The second relationship table is a table showing the correspondence between different speeds, different residual gas coefficients, and detection cycles. The engine is subjected to steady-state testing under lean combustion conditions according to the target testing cycle, and dynamic adjustments are made accordingly.
[0009] In one optional embodiment, steady-state detection of the lean-burn state of the engine is performed according to the target detection cycle, and dynamic adjustments are made, including: The crankshaft acceleration of the engine is acquired during the target detection cycle; When the crankshaft acceleration is within the preset acceleration range, the engine is controlled to perform lean combustion with the fuel injection quantity corresponding to the second residual gas coefficient. When the crankshaft acceleration is less than the acceleration range, the engine is controlled to reduce the amount of fuel injection at a preset first slope to achieve lean combustion until the crankshaft acceleration is within the acceleration range. When the crankshaft acceleration is greater than the acceleration range, the engine is controlled to increase the fuel injection quantity with a preset second slope to achieve lean combustion until the crankshaft acceleration is within the acceleration range.
[0010] In an optional embodiment, after controlling the engine to enter a lean combustion state according to the target residual gas coefficient, the method further includes: Obtain the engine's output power; The engine's third speed and second intake air density are determined based on the power output to be achieved. Determine whether the engine has exited the lean combustion state based on the third speed and the second intake air density; If so, the engine speed and intake air density are controlled to transition according to the corresponding preset slope until the engine enters normal combustion state.
[0011] Secondly, embodiments of the present invention also provide an engine, wherein combustion control is performed according to any of the methods in the first aspect.
[0012] Thirdly, embodiments of the present invention also provide a combustion control device for an engine, the device comprising: The first acquisition module is used to acquire the first engine speed and the first intake air density under steady-state operating conditions. The first determining module is used to determine the target residual gas coefficient of the engine based on the first speed, the first intake density and the preset first relationship table, wherein the first relationship table is a table of correspondence between different operating speeds, different intake densities and residual gas coefficients. The first control module is used to control the engine to enter a lean combustion state according to the target residual gas coefficient when the target residual gas coefficient is greater than the first residual gas coefficient under normal combustion conditions.
[0013] Fourthly, embodiments of the present invention also provide an electronic device, including a processor and a memory, the memory being coupled to the processor, the memory storing instructions that, when executed by the processor, cause the electronic device to perform the steps of any of the methods in the first aspect.
[0014] Fifthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the steps of any of the methods in the first aspect.
[0015] Compared with the prior art, the engine and combustion control method and device of the present invention have the following advantages: The combustion control method of this invention obtains the first engine speed and first intake air density under steady-state operating conditions, configures a first relationship table characterizing the correspondence between different operating speeds, different intake air densities, and the residual gas coefficient, and determines the target residual gas coefficient of the engine based on the first engine speed and first intake air density in the first relationship table. When the target residual gas coefficient is greater than the first residual gas coefficient under normal combustion conditions, it indicates that the conditions for lean combustion are met, and the engine is controlled to enter a lean combustion state according to the target residual gas coefficient. This method, by controlling the engine to perform lean combustion under steady-state operating conditions, reduces the amount of fuel injected during the combustion process, thereby improving the fuel economy of the engine under steady-state operating conditions. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 A flowchart illustrating an engine combustion control method provided in an embodiment of the present invention; Figure 2 A graph showing the lean combustion process of a vehicle during deceleration, provided in an embodiment of the present invention. Figure 3 A graph showing the lean-burn state of a vehicle during acceleration, provided as an embodiment of the present invention. Figure 4This is a schematic diagram of the structure of a combustion control device for an engine provided in an embodiment of the present invention. Detailed Implementation
[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the protection scope of the embodiments of the present invention.
[0019] In the context of dual carbon emissions, PHEVs (Plug-in Hybrid Electric Vehicles) and REVs (Range Extended Electric Vehicles) are gradually becoming the mainstream trend in the market. These are electric vehicles with dual power systems. REV models, in particular, use an engine to generate electricity to power the vehicle's battery, with the engine not directly involved in driving. This operating mode allows for selective energy management, enabling the engine to operate in a high thermal efficiency range. Meanwhile, existing engines employ technologies such as low-pressure EGR (Exhaust Gas Recirculation) and high compression ratios to further reduce fuel consumption and improve fuel economy. However, low-pressure EGR is limited by ambient temperature, water temperature, and altitude, and to ensure reliability, it suffers from limitations such as start-up delays and inability to operate at high and low temperatures, while also increasing costs. High compression ratios are also prone to durability issues such as knocking, leading to user complaints. Therefore, hybrid vehicles also urgently need to improve engine fuel economy. The following embodiments of the invention will specifically illustrate how to improve fuel economy during engine operation.
[0020] Please see Figure 1 , Figure 1 This is a flowchart illustrating an engine combustion control method provided in an embodiment of the present invention. The control method can be applied to the engine's control terminal, such as the ECU (Engine Control Unit) of a gasoline vehicle or hybrid vehicle, or a controller containing the engine's power generation equipment, as long as it can implement the engine control steps. The control method specifically includes: S11. Obtain the engine's first speed and first intake air density under steady-state conditions.
[0021] Specifically, steady-state operating conditions refer to the engine's operation under constant speed and load. Steady-state operating conditions can be determined based on the vehicle's driving state. For example, in traditional gasoline vehicles, when driving on highways, the vehicle often maintains a constant, relatively high speed; the engine operating condition under this condition can be defined as a steady-state operating condition. In hybrid vehicles, when the REV model's battery charge is insufficient, the engine starts to replenish the battery with constant power; the engine operating condition in this scenario can be defined as a steady-state operating condition. The first speed characterizes the crankshaft speed during engine operation, which can be obtained from a speed sensor mounted on the engine crankshaft or from the generator speed of the hybrid vehicle. The first intake air density characterizes the amount of air intake into the engine cylinders under steady-state operating conditions, which can be calculated by the ECU. After obtaining the first speed and first intake air density, proceed to step S12.
[0022] S12. Determine the target residual gas coefficient of the engine based on the first speed, the first intake air density and the preset first relationship table, wherein the first relationship table is a table showing the correspondence between different operating speeds, different intake air densities and residual gas coefficients.
[0023] Specifically, the excess air coefficient (or excess air coefficient) is the ratio of the actual amount of air supplied for fuel combustion to the theoretical amount of air, and is an important parameter characterizing the fuel-air mixture ratio. The first relationship table can be set based on the experience of technical personnel or through calibration experiments. Please refer to Table 1, which is the first relationship table.
[0024] Table 1
[0025] In Table 1, the operating condition corresponding to a residual gas coefficient of 1 is the normal combustion state of the engine, where the ECU controls the engine to perform intake and fuel injection ignition according to the normal air-fuel ratio. The operating condition corresponding to a residual gas coefficient greater than 1 is the lean combustion state of the engine, where the ECU controls the engine to perform intake and fuel injection ignition according to the lean combustion air-fuel ratio. For example, a residual gas coefficient of 1.1 represents a 10% lean combustion. When the first relationship table is determined through calibration experiments, lean combustion tests can be performed on the engine on a test bench, and stability analysis can be performed with the COV (Coefficient of cyclic variation) parameters of the combustion analyzer to ensure that the engine can perform stable lean combustion when running at the residual gas coefficient set on the current test bench. The target residual gas coefficient is the residual gas coefficient determined in the first relationship table based on the first speed and the first intake air density. The target residual gas coefficient can be determined by traversing and searching. After obtaining the target residual gas coefficient, proceed to step S13.
[0026] S13. When the target residual gas coefficient is greater than the first residual gas coefficient under normal combustion conditions, the engine is controlled to enter a lean combustion state according to the target residual gas coefficient.
[0027] Specifically, the first residual gas coefficient under normal combustion conditions can be set according to the engine's properties, or it can be set to 1 based on the residual gas coefficient under normal combustion. When the target residual gas coefficient is greater than the first residual gas coefficient, it indicates that the engine has the conditions for lean combustion under steady-state conditions, and the engine is controlled to enter a lean combustion state according to the target residual gas coefficient. Conversely, when the residual gas coefficient is not greater than the first residual gas coefficient, the engine is controlled to perform normal combustion.
[0028] For example, when the ECU performs energy management, it selects the first engine speed under the current steady-state condition as 2000 rpm and the first intake air density as 1600 mg / L. A lookup in the first relationship table reveals that the engine's residual gas coefficient under the current steady-state condition is 1, which does not meet the conditions for lean combustion. Therefore, the ECU controls the engine to perform normal combustion. Due to changes in the vehicle's operating conditions, when the ECU performs energy management, it selects the first engine speed under the current steady-state condition as 2500 rpm and the first intake air density as 1200 mg / L. A lookup in the first relationship table reveals that the engine's residual gas coefficient under the current steady-state condition is 1.15, which meets the conditions for lean combustion. Therefore, the ECU controls the engine to enter a lean combustion state. In the lean combustion state, the engine's intake air volume follows the change in the residual gas coefficient to increase the engine's intake air volume and achieve lean combustion.
[0029] It should be noted that in hybrid vehicles, the ECU's energy management is based on the vehicle's battery charge. For example, with fluctuations in charge, if the output power at the wheels needs to be met, the engine's output power needs to be adjusted. The ECU can choose whether to control the engine to enter a lean-burn state based on the actual situation.
[0030] For example, controlling the engine to enter a lean combustion state based on a target residual gas coefficient includes: The first step is to determine the residual gas coefficient slope for the engine to transition from normal combustion to lean combustion based on the target residual gas coefficient. During normal combustion, the engine's residual gas coefficient is 1; during lean combustion, the residual gas coefficient is greater than 1. If the target residual gas coefficient is too large, directly controlling the engine to burn at the target residual gas coefficient will adversely affect combustion stability. Therefore, a corresponding residual gas coefficient slope can be set based on the target residual gas coefficient value to ensure a stable transition to lean combustion. Alternatively, the coefficient difference can be determined based on the difference between the target residual gas coefficient and the first residual gas coefficient. The residual gas coefficient slope is then determined based on the magnitude of this difference. The residual gas coefficient slope characterizes the change in intake air density during the transition from normal combustion to lean combustion and can be determined based on calibration experiments.
[0031] In practical applications, the stability of an engine transitioning from normal combustion to lean combustion is influenced by numerous factors, and empirical settings may lack accuracy, making calibration experiments time-consuming. Therefore, in one specific implementation, the slope of the residual gas coefficient as the engine transitions from normal combustion to lean combustion is determined based on the target residual gas coefficient, including: The operating speed slope and intake air density slope for the engine to transition from normal combustion to lean combustion are determined based on the target residual gas coefficient. Please refer to [link / reference]. Figure 2 , Figure 2 The graph shows the lean combustion curves during vehicle deceleration. Curve a represents the intake air density curve, curve b represents the engine speed curve, curve c represents the residual gas coefficient curve, and curve d represents the engine crankshaft acceleration curve. As the engine operating conditions change, the engine speed and intake air density will also change. The engine speed slope (r2 in the graph) can be obtained from the slope of the transition from the initial speed during normal combustion to the first speed; the intake air density slope (r1 in the graph) can be obtained from the slope of the transition from the initial intake air density during normal combustion to the first intake air density. The minimum value of the operating speed slope and the intake air density slope is determined as the residual gas coefficient slope, i.e., residual gas coefficient slope R = Min(R1, R2). Figure 2 In this case, the intake density slope R1 is less than the speed slope R2, so the speed slope R1 is determined as the residual gas coefficient slope R.
[0032] It is understandable that both the engine speed slope and the intake air density slope characterize the stable changes in engine speed and intake air density as engine operating conditions change. Determining the minimum value of these as the residual gas coefficient slope ensures a smooth transition in engine operating conditions and a smooth transition in fuel injection quantity, thus ensuring combustion stability. Similarly, Figure 3 The curve of the vehicle entering lean combustion during acceleration can also be obtained by determining the slope of the residual gas coefficient using the same method. After determining the slope of the residual gas coefficient, proceed to the next step.
[0033] The second step involves controlling the engine to enter a lean combustion state based on the residual gas coefficient slope, until the engine's intake air volume reaches the intake air volume corresponding to the target residual gas coefficient. Please continue reading. Figure 2 The slope of the residual gas coefficient characterizes the range of change from a normal combustion state to a lean combustion state with a target residual gas coefficient. Based on the slope of the residual gas coefficient, the engine can smoothly enter a lean combustion state.
[0034] In practical applications, the lean combustion of an engine is greatly affected by environmental factors, such as the ambient temperature and air pressure. If the engine does not meet the target residual gas coefficient, the stability of lean combustion will be poor. Therefore, in one specific embodiment, after controlling the engine to enter a lean combustion state according to the target residual gas coefficient, the method further includes steps S14-S16, as follows: S14. Obtain the second engine speed and the second residual gas coefficient when the engine is in lean combustion state. The second engine speed represents the operating speed of the engine when it is in lean combustion, and can be obtained based on the crankshaft sensor. The second residual gas coefficient is the residual gas coefficient of the engine when it enters the lean combustion process, for example, the current residual gas coefficient when entering lean combustion based on the residual gas coefficient slope; it can also be the target residual gas coefficient. After obtaining the second engine speed and the second residual gas coefficient, proceed to step S15.
[0035] S15. Based on the second engine speed, the second residual gas coefficient, and the preset second relationship table, determine the target detection cycle for lean combustion of the engine. The second relationship table corresponds to different engine speeds, different residual gas coefficients, and the detection cycle. The detection cycle ranges from 0.5 to 2 seconds and can be selected based on the engine's operating speed and residual gas coefficient. Alternatively, the second relationship table can be calibrated and generated. Please refer to Table 2, which is the second relationship table.
[0036] Table 2
[0037] The data filled in Table 2 represents the detection cycle. The corresponding target detection cycle can be found in the second relationship table based on the second rotational speed and the second residual gas coefficient. After obtaining the target detection cycle, proceed to step S16.
[0038] S16. Perform steady-state testing of the engine under lean combustion conditions according to the target testing cycle, and make dynamic adjustments. During the target testing cycle, it is necessary to determine whether lean combustion is stable. This can be determined by the engine's exhaust emission data or by fluctuations in the engine's crankshaft acceleration.
[0039] For example, steady-state detection of the lean-burn state of the engine is performed according to the target detection cycle, and dynamic adjustments are made, including: The first step is to acquire the crankshaft acceleration of the engine within the target detection cycle. Crankshaft acceleration can be characterized as the angular acceleration of crankshaft rotation. The crankshaft speed is collected based on a preset cycle. The speed difference is obtained by the crankshaft speed of adjacent cycles, and the crankshaft acceleration is obtained by dividing the speed difference by the preset cycle.
[0040] The second step involves controlling the engine to inject fuel at the preset acceleration range when the crankshaft acceleration is within a stable lean combustion state. The engine is then controlled to inject fuel at the amount corresponding to the second residual gas coefficient for lean combustion, and the crankshaft acceleration is monitored in real-time based on the target detection cycle. If the crankshaft acceleration is less than the acceleration range, it indicates excessive fuel injection causing unstable lean combustion. The engine is then controlled to reduce the fuel injection at a preset first slope to achieve lean combustion until the crankshaft acceleration falls within the acceleration range. Conversely, if the crankshaft acceleration is greater than the acceleration range, it indicates insufficient fuel injection causing unstable lean combustion. The engine is then controlled to increase the fuel injection at a preset second slope to achieve lean combustion until the crankshaft acceleration falls within the acceleration range. The first and second slopes can be the same or different. Figure 2 and Figure 3 The first and second slopes are both set to R3.
[0041] Please refer to Table 3, which shows the correspondence between engine speed, intake air density, and crankshaft acceleration.
[0042] Table 3
[0043] As can be seen from Table 3, the crankshaft acceleration will change accordingly under different speeds and different intake air densities. In order to make the stable judgment of the lean combustion state accurate, taking the speed after entering lean combustion as 2500 rpm and the intake air density as 1200 mg / l as an example, the acceleration can be determined as E8 in the table above. Based on the preset fluctuation range M, a reasonable acceleration range E8±M is configured so that the crankshaft acceleration E corresponds to the accurate acceleration range for judgment and dynamic adjustment.
[0044] Please continue reading. Figure 2 When the crankshaft acceleration is not within the acceleration range, the residual gas coefficient K can be determined by dynamically adjusting it to the acceleration range. Fuel injection control is then performed based on this residual gas coefficient K under steady-state conditions. It should be noted that the above dynamic adjustment method can adaptively adjust fuel injection in real time based on factors such as the current engine fuel quality and variations in vehicle components, achieving linear control of the residual gas coefficient and ensuring stable engine operation after lean combustion.
[0045] To further improve the applicability of lean combustion, after controlling the engine to enter a lean combustion state based on the target residual gas coefficient, the method also includes: S17. Obtain the engine's output power. The output power is the power required by the engine based on the ECU's energy management. It can be calculated by the ECU. After obtaining the output power, proceed to step S18.
[0046] S18. Determine the third speed and second intake density of the engine based on the output power to be output. After the output power of the engine changes, its corresponding operating speed and intake density will change accordingly. The third speed and second intake density respectively represent the operating speed and intake density that the engine needs to execute after the output power is updated. After obtaining the third speed and second intake density, proceed to step S19.
[0047] S19. Determine whether the engine has exited the lean combustion state based on the third speed and the second intake air density. Similarly, the residual gas coefficient corresponding to the third speed and the second intake air density can be determined based on the first relationship table. When the residual gas coefficient is greater than 1, it means that the engine can continue to be controlled in the lean combustion state; when the residual gas coefficient is 1, it means that the engine does not meet the operating conditions for lean combustion and it is necessary to control the engine to exit the lean combustion state, then proceed to step S20.
[0048] S20. If so, control the engine speed and intake air density according to the corresponding preset slope to transition until the engine enters normal combustion. The preset slope can be set to the slope corresponding to the engine entering lean combustion, which can smoothly transition the engine from lean combustion to normal combustion.
[0049] Based on the same inventive concept as the control method, embodiments of the present invention also provide an engine, wherein the engine performs combustion control according to any of the control methods.
[0050] Based on the same inventive concept as the control method, embodiments of the present invention also provide a combustion control device for an engine. Please refer to [link to relevant documentation]. Figure 4 , Figure 4 This is a schematic diagram of the control device, which specifically includes: The first acquisition module 401 is used to acquire the first engine speed and the first intake air density under steady-state conditions. The first determining module 402 is used to determine the target residual gas coefficient of the engine based on the first speed, the first intake density and the preset first relationship table, wherein the first relationship table is a correspondence table between different operating speeds, different intake densities and residual gas coefficients. The first control module 403 is used to control the engine to enter a lean combustion state according to the target residual gas coefficient when the target residual gas coefficient is greater than the first residual gas coefficient under normal combustion.
[0051] In one optional embodiment, the first control module includes: The determination submodule is used to determine the slope of the residual gas coefficient when the engine transitions from normal combustion to lean combustion, based on the target residual gas coefficient. The first control submodule is used to control the engine to enter a lean combustion state according to the slope of the residual gas coefficient until the engine's intake air volume reaches the intake air volume corresponding to the target residual gas coefficient.
[0052] In one alternative embodiment, determining the submodule includes: The first determining unit is used to determine the operating speed slope and intake air density slope of the engine when it transitions from normal combustion to lean combustion, based on the target residual gas coefficient. The second determining unit is used to determine the minimum value of the operating speed slope and the intake density slope as the residual gas coefficient slope.
[0053] In an optional embodiment, the control device further includes: The second acquisition module is used to acquire the second engine speed and the second residual gas coefficient under lean combustion conditions. The second determining module is used to determine the target detection cycle for lean combustion of the engine based on the second speed, the second residual gas coefficient and the preset second relationship table, wherein the second relationship table is a table showing the correspondence between different speeds, different residual gas coefficients and detection cycles. The detection and adjustment module is used to perform steady-state detection of the engine under lean combustion conditions according to the target detection cycle and to make dynamic adjustments.
[0054] In one optional embodiment, the detection adjustment module includes: The acquisition submodule is used to acquire the crankshaft acceleration of the engine during the target detection cycle; The second control submodule is used to control the engine to perform lean combustion with the fuel injection quantity corresponding to the second residual gas coefficient when the crankshaft acceleration is in the preset acceleration range. The third control submodule is used to control the engine to reduce the amount of fuel injection at a preset first slope to achieve lean combustion when the crankshaft acceleration is less than the acceleration range, until the crankshaft acceleration is within the acceleration range. The fourth control submodule is used to control the engine to increase the fuel injection quantity at a preset second slope to achieve lean combustion when the crankshaft acceleration is greater than the acceleration range, until the crankshaft acceleration is within the acceleration range.
[0055] In an optional embodiment, the control device further includes: The third acquisition module is used to acquire the engine's output power; The third determining module is used to determine the engine's third speed and second intake air density based on the power to be output; The fourth determining module is used to determine whether the engine has exited the lean combustion state based on the third speed and the second intake air density. The second control module is used to determine when the engine exits the lean combustion state, and then control the engine's operating speed and intake air density to transition according to the corresponding preset slope until the engine enters the normal combustion state.
[0056] Based on the same inventive concept as the control method, embodiments of the present invention also provide an electronic device, including a processor and a memory, the memory being coupled to the processor, the memory storing instructions, which, when executed by the processor, cause the electronic device to perform the steps of any of the control methods.
[0057] Based on the same inventive concept as the control method, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of any one of the methods in the control method.
[0058] The technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: 1. The control method obtains the engine's first speed and first intake air density under steady-state conditions, configures a first relationship table representing the correspondence between different operating speeds, different intake air densities, and the residual gas coefficient, and determines the engine's target residual gas coefficient based on the first speed and first intake air density in the first relationship table. When the target residual gas coefficient is greater than the first residual gas coefficient under normal combustion conditions, it indicates that the conditions for lean combustion are met, and the engine is controlled to enter a lean combustion state according to the target residual gas coefficient. This method reduces the amount of fuel injected during combustion by controlling the engine to perform lean combustion under steady-state conditions, thereby improving the engine's fuel economy under steady-state conditions.
[0059] 2. When applied to hybrid vehicles, lean combustion can replenish the power battery, increasing the vehicle's driving range; at the same time, low-pressure EGR can be eliminated, and lean combustion alone can achieve the same fuel-saving rate; reducing the development costs for OEMs while improving the reliability of the vehicle during use.
[0060] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0061] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (modules, systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0062] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0063] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0064] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.
[0065] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.
Claims
1. A combustion control method for an engine, characterized in that, The method includes: Obtain the engine's first speed and first intake air density under steady-state operating conditions; The target residual gas coefficient of the engine is determined based on the first rotational speed, the first intake air density, and a preset first relationship table, wherein the first relationship table is a table showing the correspondence between different operating speeds, different intake air densities, and residual gas coefficients. When the target residual gas coefficient is greater than the first residual gas coefficient under normal combustion conditions, the engine is controlled to enter a lean combustion state according to the target residual gas coefficient. Obtain the second engine speed and the second residual gas coefficient under lean combustion conditions; Based on the second rotational speed, the second residual gas coefficient, and a preset second relationship table, the target detection cycle for lean combustion of the engine is determined, wherein the second relationship table is a table showing the correspondence between different rotational speeds, different residual gas coefficients, and detection cycles; The engine is subjected to steady-state detection of the lean combustion state according to the target detection cycle, and dynamic adjustments are made, including: The crankshaft acceleration of the engine is acquired during the target detection cycle; When the crankshaft acceleration is within a preset acceleration range, the engine is controlled to perform lean combustion with the fuel injection quantity corresponding to the second residual gas coefficient. When the crankshaft acceleration is less than the acceleration range, the engine is controlled to reduce the fuel injection quantity at a preset first slope to perform lean combustion until the crankshaft acceleration is within the acceleration range. When the crankshaft acceleration is greater than the acceleration range, the engine is controlled to increase the fuel injection quantity at a preset second slope to perform lean combustion until the crankshaft acceleration is within the acceleration range.
2. The combustion control method for an engine according to claim 1, characterized in that, The step of controlling the engine to enter a lean combustion state based on the target residual gas coefficient includes: Based on the target residual gas coefficient, determine the residual gas coefficient slope of the engine as it transitions from the normal combustion state to the lean combustion state. The engine is controlled to enter the lean combustion state according to the slope of the residual gas coefficient until the intake air volume of the engine reaches the intake air volume corresponding to the target residual gas coefficient.
3. The combustion control method for an engine according to claim 2, characterized in that, The step of determining the slope of the residual gas coefficient as the engine transitions from the normal combustion state to the lean combustion state based on the target residual gas coefficient includes: Based on the target residual gas coefficient, determine the operating speed slope and intake air density slope of the engine as it transitions from the normal combustion state to the lean combustion state; The minimum value of the operating speed slope and the intake air density slope is determined as the residual gas coefficient slope.
4. The combustion control method for an engine according to claim 1, characterized in that, After controlling the engine to enter a lean combustion state according to the target residual gas coefficient, the method further includes: Obtain the output power of the engine; The engine's third speed and second intake air density are determined based on the power to be output. Based on the third rotational speed and the second intake air density, determine whether the engine has exited the lean combustion state; If so, the engine's operating speed and intake air density are controlled to transition according to the corresponding preset slope until the engine enters the normal combustion state.
5. An engine, characterized in that, The engine performs combustion control according to any one of claims 1-4.
6. A combustion control device for an engine, characterized in that, The device includes: The first acquisition module is used to acquire the first engine speed and the first intake air density under steady-state operating conditions. The first determining module is used to determine the target residual gas coefficient of the engine based on the first rotational speed, the first intake air density and a preset first relationship table, wherein the first relationship table is a correspondence table between different operating speeds, different intake air densities and residual gas coefficients. The first control module is used to control the engine to enter a lean combustion state according to the target residual gas coefficient when the target residual gas coefficient is greater than the first residual gas coefficient of the normal combustion state. The second acquisition module is used to acquire the second engine speed and the second residual gas coefficient of the engine under lean combustion conditions. The second determining module is used to determine the target detection cycle for lean combustion of the engine based on the second rotational speed, the second residual gas coefficient and a preset second relationship table, wherein the second relationship table is a table showing the correspondence between different rotational speeds, different residual gas coefficients and detection cycles; The detection and adjustment module is used to perform steady-state detection of the lean combustion state of the engine according to the target detection cycle, and to make dynamic adjustments, including: An acquisition submodule is used to acquire the crankshaft acceleration of the engine during the target detection cycle; The second control submodule is used to control the engine to perform lean combustion with the fuel injection quantity corresponding to the second residual gas coefficient when the crankshaft acceleration is in the preset acceleration range. The third control submodule is used to control the engine to reduce the amount of fuel injection at a preset first slope to perform lean combustion when the crankshaft acceleration is less than the acceleration range, until the crankshaft acceleration is within the acceleration range. The fourth control submodule is used to control the engine to increase the fuel injection quantity at a preset second slope to perform lean combustion when the crankshaft acceleration is greater than the acceleration range, until the crankshaft acceleration is within the acceleration range.
7. An electronic device, characterized in that, It includes a processor and a memory, the memory being coupled to the processor, the memory storing instructions that, when executed by the processor, cause the electronic device to perform the steps of the method of any one of claims 1-4.
8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method described in any one of claims 1-4.