Engine control method, device, equipment and medium based on exhaust temperature management

Abstract

The present invention discloses an engine control method, device, equipment and medium based on exhaust temperature management, which relates to the technical field related to engine control. The method includes setting a precondition for the exhaust temperature management function mode and entering the exhaust temperature management function mode when the precondition is met; controlling the throttle opening according to the throttle sonic flow model and the throttle output opening corresponding to the input flow, and setting the minimum throttle opening; controlling the exhaust back pressure valve opening according to the exhaust manifold pressure requirements at different engine speeds and the exhaust back pressure valve opening requirements obtained according to the characteristics of the supercharger turbine, and controlling the supercharger bleed valve actuator to be in a fully open state. The present application can effectively improve the thermal insulation capacity of the SCR after-treatment system, improve its conversion efficiency, and ensure the emission level of the engine after-treatment system.

Description

Technical Field

[0001] The present application relates to the technical field related to engine control, and specifically to an engine control method, device, equipment and medium based on exhaust temperature management. Background Art

[0002] Currently, the primary emission from diesel engines is NOx (nitrogen oxides). SCR (Selective Catalytic Reduction) after-treatment systems are typically used to consume NOx from engine emissions to meet relevant emission requirements. The level of NOx conversion by SCR is temperature-dependent. When the temperature is too low, the conversion efficiency is low, making it difficult to meet engine requirements. This is especially true in low-temperature environments, where SCR temperatures struggle to meet high efficiency requirements. Diesel engines equipped with throttles and using post-injection strategies can effectively increase exhaust temperatures to a certain extent in low-load operating ranges. This configuration strategy is widely used in the diesel engine industry, primarily to reduce intake air flow or increase post-combustion to increase engine exhaust temperatures.

[0003] Current diesel engine strategies using throttle or post-injection in low-load conditions can, to some extent, increase engine exhaust temperature and thus improve aftertreatment conversion efficiency. However, this does not address the issue of SCR temperature drop under certain engine operating conditions. For example, when the vehicle is driving downhill without the accelerator engaged, no fuel is burned. This can cause a sharp drop in engine exhaust temperature, which in turn causes the SCR temperature to drop too quickly, leading to low subsequent SCR conversion efficiency. Therefore, effectively managing the engine SCR aftertreatment temperature to improve SCR conversion efficiency has become a pressing issue. Summary of the Invention

[0004] The present application provides an engine control method, device, equipment and medium based on exhaust temperature management, which can effectively improve the thermal insulation capacity of the SCR after-treatment system, improve its conversion efficiency, and ensure the emission level of the engine after-treatment system.

[0005] In a first aspect, an embodiment of the present application provides an engine control method based on exhaust temperature management, the engine control method based on exhaust temperature management comprising:

[0006] Based on the preconditions set for the exhaust temperature management function mode, and when the preconditions are met, the exhaust temperature management function mode is entered;

[0007] The throttle opening is controlled by setting the throttle output opening corresponding to the throttle sonic flow model and the input flow rate, and by setting the minimum throttle opening;

[0008] According to the exhaust manifold pressure requirements at different engine speeds and the exhaust back-pressure valve opening requirements obtained according to the turbocharger turbine characteristics, the exhaust back-pressure valve opening is controlled, and the turbocharger bleed valve actuator is controlled to be in a fully open state.

[0009] In conjunction with the first aspect, in one embodiment,

[0010] The engine control method is adapted to an engine with an electronic throttle valve in front of the intake manifold and an exhaust back-pressure valve at the outlet of the turbocharger, and the opening degree of the throttle valve and the exhaust back-pressure valve is controlled by the ECU;

[0011] Pressure sensors are installed on the intake manifold and exhaust manifold of the engine, and a temperature sensor is installed at the SCR inlet.

[0012] In combination with the first aspect, in one embodiment, when the precondition is met, the exhaust temperature management function mode is entered, specifically:

[0013] Perform precondition judgment. When all conditions in the precondition are met, the exhaust temperature management mode needs to be activated. Otherwise, the exhaust temperature management mode does not need to be activated.

[0014] Based on the judgment result of the precondition, when entering the exhaust temperature management mode activation state, the duration of the exhaust temperature management mode activation state is judged. If the duration of the exhaust temperature management mode activation state is not greater than the preset time, the vehicle enters the exhaust temperature management function mode; otherwise, the vehicle does not enter the exhaust temperature management function mode;

[0015] The preconditions include that the engine throttle is 0, the actual SCR inlet temperature is lower than the set SCR inlet minimum temperature, the vehicle gear is not in neutral, or the vehicle gear is in neutral and the duration is greater than a set time.

[0016] In conjunction with the first aspect, in one embodiment, the throttle opening output corresponding to the throttle sonic flow model and the input flow rate, and setting the minimum throttle opening to achieve throttle opening control specifically include:

[0017] The minimum intake manifold pressure at the current engine speed is obtained by interpolation calculation based on the minimum intake manifold pressure;

[0018] Based on the calculated minimum intake manifold pressure, the current theoretical intake flow rate of the engine is calculated using the speed density method;

[0019] The throttle valve intake volume correction coefficient is calculated based on the throttle valve pressure ratio correction interpolation, and the input flow of the throttle valve sonic flow model is obtained based on the current theoretical intake flow of the engine and the throttle valve intake volume correction coefficient;

[0020] According to the input flow of the throttle sonic flow model, the throttle opening is obtained by interpolation calculation of the throttle sonic flow model;

[0021] Based on the calculated throttle opening and the set minimum throttle opening, a larger opening value is selected for throttle opening control.

[0022] In combination with the first aspect, in one embodiment, the current theoretical intake flow rate of the engine is calculated based on the calculated minimum intake manifold pressure using a speed density method, wherein the specific calculation method is:

[0023] The current theoretical intake flow of the engine = calculated minimum intake manifold pressure * engine displacement * current engine speed * R / current intake manifold temperature

[0024] Here, R represents a constant.

[0025] In conjunction with the first aspect, in one embodiment, the exhaust back-pressure valve opening control is implemented based on the exhaust manifold pressure requirements at different engine speeds and the exhaust back-pressure valve opening requirements obtained based on the turbocharger turbine characteristics, specifically including:

[0026] Interpolating the engine speed and the exhaust manifold pressure requirement to obtain the exhaust manifold pressure requirement at the current engine speed, and obtaining the theoretical turbine required pressure ratio based on the exhaust manifold pressure requirement;

[0027] The initial exhaust back-pressure valve required opening is calculated based on the turbine characteristic MAP, the theoretical turbine required pressure ratio, and the current engine speed;

[0028] Based on the calculated initial exhaust back-pressure valve required opening, the exhaust back-pressure valve is feedforward controlled;

[0029] Obtaining the current pressure of the exhaust manifold, and calculating the difference between the actual turbine required pressure ratio and the theoretical turbine required pressure ratio;

[0030] Based on the calculated difference, and when the difference is greater than the set value, the PID controller calculates and adjusts the corrected opening of the exhaust back-pressure valve. According to the initial exhaust back-pressure valve required opening and the calculated exhaust back-pressure valve corrected opening, the final exhaust back-pressure valve required opening is obtained, and the exhaust back-pressure valve opening is controlled based on the final exhaust back-pressure valve required opening.

[0031] In combination with the first aspect, in one embodiment, after the exhaust back-pressure valve opening is controlled based on the final exhaust back-pressure valve required opening, the method further includes:

[0032] The current pressure of the exhaust manifold is obtained, and the difference between the actual turbine required pressure ratio and the theoretical turbine required pressure ratio is calculated. If the difference is not greater than the set value, the exhaust back-pressure valve correction opening is adjusted to 0, and the exhaust back-pressure valve opening is controlled based on the initial exhaust back-pressure valve required opening.

[0033] In a second aspect, an embodiment of the present application provides an engine control device based on exhaust temperature management, the engine control device based on exhaust temperature management comprising:

[0034] A determination module, which is used to enter the exhaust temperature management function mode based on the preconditions set for the exhaust temperature management function mode and drive the execution module to work when the preconditions are met;

[0035] The execution module is used to control the throttle opening according to the throttle output opening corresponding to the throttle sonic flow model and the input flow, and to set the minimum throttle opening, and to control the exhaust back pressure valve opening according to the exhaust manifold pressure requirements at different engine speeds and the exhaust back pressure valve opening requirements obtained according to the characteristics of the turbocharger turbine, and at the same time control the turbocharger bleed valve actuator to be in a fully open state.

[0036] In a third aspect, an embodiment of the present application provides an engine control device based on exhaust temperature management, wherein the engine control device based on exhaust temperature management includes a processor, a memory, and an engine control program based on exhaust temperature management stored on the memory and executable by the processor, wherein when the engine control program based on exhaust temperature management is executed by the processor, the steps of the above-mentioned engine control method based on exhaust temperature management are implemented.

[0037] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which an engine control program based on exhaust temperature management is stored. When the engine control program based on exhaust temperature management is executed by a processor, the steps of the above-mentioned engine control method based on exhaust temperature management are implemented.

[0038] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0039] By setting the preconditions for the exhaust temperature management function mode and entering the exhaust temperature management function mode when the preconditions are met, the throttle opening is controlled according to the throttle sonic flow model and the throttle output opening corresponding to the input flow, as well as setting the minimum throttle opening. Then, the exhaust back-pressure valve opening is controlled according to the exhaust manifold pressure requirements at different engine speeds and the exhaust back-pressure valve opening requirements obtained according to the turbocharger turbine characteristics. At the same time, the turbocharger bleed valve actuator is controlled to be in a fully open state, which can effectively improve the thermal insulation capacity of the SCR after-treatment system, improve its conversion efficiency, and ensure the emission level of the engine after-treatment system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of the engine control method based on exhaust temperature management in this application;

[0041] Figure 2 A schematic diagram of the configuration structure of the engine adapted by the engine control method of this application;

[0042] Figure 3 This is a functional module diagram of the engine control device based on exhaust temperature management in this application;

[0043] Figure 4 This is a schematic diagram of the hardware structure of the engine control device based on exhaust temperature management in this application. DETAILED DESCRIPTION

[0044] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0046] In a first aspect, an embodiment of the present application provides an engine control method based on exhaust temperature management, which can increase the engine SCR after-treatment temperature to a high-efficiency zone, thereby improving the SCR conversion efficiency.

[0047] In one embodiment, referring to Figure 1 , Figure 1 This is a flow chart of the engine control method based on exhaust temperature management in this application. Figure 1 As shown, the engine control method based on exhaust temperature management includes:

[0048] S1: Based on the preconditions set for the exhaust temperature management function mode, and when the preconditions are met, the exhaust temperature management function mode is entered;

[0049] See also Figure 2 The figure shows a schematic diagram of the configuration structure of the engine adapted by the engine control method of the present application. Specifically, an electronic throttle is provided in front of the intake manifold, an exhaust back-pressure valve is provided at the outlet of the turbocharger turbine end, and the opening control of the throttle and the exhaust back-pressure valve is realized by the ECU (Electronic Control Unit); pressure sensors are installed on the intake manifold and exhaust manifold of the engine to realize pressure measurement, and a temperature sensor is installed at the inlet of the SCR to realize temperature measurement. The data measured by the sensors are fed back to the ECU. Furthermore, the turbocharger bleed valve is controlled by the AVU control unit, and the ECU sends a control request to the AVU (a vehicle domain controller) control unit via the CAN (Controller Area Network) line. The AVU control unit controls the AVU actuator accordingly according to the received request.

[0050] Furthermore, in one embodiment, when the preconditions are met, the exhaust temperature management function mode is entered, specifically:

[0051] S101: Perform precondition judgment. If all conditions in the precondition are met, the exhaust temperature management mode needs to be activated. Otherwise, the exhaust temperature management mode does not need to be activated.

[0052] S102: Based on the judgment result of the precondition, when entering the exhaust temperature management mode and the state to be activated is required, the duration of the exhaust temperature management mode and the state to be activated is judged. If the duration of the exhaust temperature management mode and the state to be activated is not greater than the preset time, the whole vehicle enters the exhaust temperature management function mode; otherwise, the whole vehicle does not enter the exhaust temperature management function mode; wherein, the precondition includes that the engine throttle is 0, the actual SCR inlet temperature is less than the set SCR inlet minimum temperature, the whole vehicle gear is not in neutral, or the whole vehicle gear is in neutral and the duration is greater than the set time.

[0053] That is, confirm whether the exhaust temperature management function is needed according to the engine demand, and realize whether it is turned on and enter the exhaust temperature management function mode by calibrating the main function switch of the module. Specifically, 3. When the main function switch is calibrated to be on, the following logical judgment is performed: 1. The engine throttle is 0; 2. The actual SCR inlet temperature is less than the set SCR inlet minimum temperature (this temperature is calibrated according to the model demand); 3. The current engine combustion is in a mode that requires exhaust temperature management (defined according to actual needs); 4. The vehicle gear is not in neutral or the vehicle gear is in neutral and the duration is greater than the set time; when all the above conditions are met, the exhaust temperature management mode enters the activation state. After entering the activation state, if the duration of the activation state of the exhaust temperature management mode is not greater than the maximum activation time of the exhaust temperature management function, the vehicle enters the exhaust temperature management function mode and executes steps S2 and S3.

[0054] S2: Control the throttle opening by determining the throttle output opening corresponding to the throttle sonic flow model and the input flow rate, and by setting the minimum throttle opening;

[0055] Furthermore, in one embodiment, the throttle opening is controlled based on the throttle sonic flow model and the throttle output opening corresponding to the input flow rate, and a minimum throttle opening is set, specifically including:

[0056] S201: Obtaining the minimum intake manifold pressure at the current engine speed based on the minimum intake manifold pressure interpolation calculation;

[0057] When the vehicle enters exhaust temperature management mode, the minimum intake manifold pressure at the current engine speed is interpolated based on the minimum intake manifold pressure. The interpolated minimum intake manifold pressure values ​​corresponding to various engine speeds are shown in Table 1 below. In this interpolation, the x-axis represents engine speed, and the y-axis represents minimum intake manifold pressure.

[0058] Table 1

[0059] 700 800 1000 1200 1400 1600 1800 2000 2200 60 62 64 66 68 70 72 74 76

[0060] For all tabular data in this application, interpolation calculation is used to determine the intermediate values.

[0061] S202: Based on the calculated minimum intake manifold pressure, a velocity density method is used to calculate the current theoretical intake flow rate of the engine;

[0062] Specifically, based on the calculated minimum intake manifold pressure, the speed density method is used to calculate the current theoretical intake flow rate of the engine. The specific calculation method is:

[0063] The current theoretical intake flow of the engine = calculated minimum intake manifold pressure * engine displacement * current engine speed * R / current intake manifold temperature

[0064] Where R represents a constant, which is obtained according to the model calibration definition.

[0065] S203: Obtaining a throttle intake volume correction coefficient based on the throttle pressure ratio correction interpolation calculation, and obtaining an input flow rate of a throttle sonic flow model based on the current theoretical intake flow rate of the engine and the throttle intake volume correction coefficient;

[0066] That is, the throttle intake correction coefficient is calculated based on the throttle pressure ratio correction interpolation. The throttle intake correction coefficient is interpolated based on its own characteristics and is calibrated based on its characteristics. The corresponding relationship between the throttle pressure ratio and the throttle intake correction coefficient is shown in Table 2 below. In this interpolation, the x-axis represents the gas pressure ratio between the throttle outlet and the inlet, and the y-axis represents the throttle intake correction coefficient.

[0067] Table 2

[0068]

[0069] For the calculation of the input flow of the throttle sonic flow model in the current state, the current theoretical intake flow of the engine is divided by the calculated throttle intake amount correction coefficient to obtain the input flow of the throttle sonic flow model.

[0070] S204: Obtaining a throttle opening by interpolation calculation of the throttle sonic flow model according to an input flow rate of the throttle sonic flow model;

[0071] That is, based on the input flow rate of the throttle sonic flow model, the throttle opening can be calculated by interpolating the throttle sonic flow model. The throttle sonic flow model has its own characteristics and is calibrated based on these characteristics. The corresponding relationship between the input flow rate and the throttle opening is shown in Table 3 below.

[0072] Table 3

[0073]

[0074] S205: Based on the calculated throttle opening and the set minimum throttle opening, the ECU selects the larger throttle opening value for throttle opening control. That is, based on the calculated throttle opening and the set minimum throttle opening, the ECU selects the larger throttle opening value for throttle opening control.

[0075] S3: Based on the exhaust manifold pressure requirements at different engine speeds and the exhaust back-pressure valve opening requirements obtained based on the turbocharger turbine characteristics, the exhaust back-pressure valve opening is controlled, and the turbocharger bleed valve actuator is controlled to be in a fully open state.

[0076] Furthermore, in one embodiment, exhaust back-pressure valve opening control is implemented based on exhaust manifold pressure requirements at different engine speeds and exhaust back-pressure valve opening requirements obtained based on supercharger turbine characteristics, specifically including:

[0077] S301: interpolating the engine speed and the exhaust manifold pressure requirement to obtain the exhaust manifold pressure requirement at the current engine speed, and obtaining a theoretical turbine required pressure ratio based on the exhaust manifold pressure requirement;

[0078] That is, when entering the exhaust temperature management mode, the exhaust backpressure valve is controlled according to the control logic of step S3. First, the exhaust manifold pressure requirement at the current engine speed is interpolated based on the engine speed and exhaust manifold pressure requirement. The corresponding relationship between engine speed and exhaust manifold pressure is shown in Table 4 below. Of course, this interpolation value can be calibrated and defined according to the engine model.

[0079] Table 4

[0080]

[0081] After the exhaust manifold pressure requirement is obtained, the theoretical turbine required pressure ratio can be obtained based on the exhaust manifold pressure requirement. The exhaust manifold pressure requirement divided by the turbine outlet pressure is the theoretical turbine required pressure ratio.

[0082] S302: Calculating an initial exhaust back-pressure valve required opening based on the turbine characteristic MAP (map), the theoretical turbine required pressure ratio, and the current engine speed;

[0083] As shown in Table 5 below, it is the turbine characteristic MAP, where the x-axis is the engine speed and the y-axis is the turbine pressure ratio. The turbine characteristic MAP is calibrated according to the engine model and supercharger characteristics.

[0084] Table 5

[0085]

[0086]

[0087] S303: Based on the calculated initial exhaust back-pressure valve required opening, the exhaust back-pressure valve is feedforward controlled. Specifically, the ECU controls the exhaust back-pressure valve according to the calculated initial exhaust back-pressure valve required opening.

[0088] S304: Obtaining the current pressure of the exhaust manifold and calculating the difference between the actual turbine required pressure ratio and the theoretical turbine required pressure ratio; by obtaining the exhaust manifold pressure data through the sensor, the actual turbine pressure ratio in the current state can be obtained;

[0089] S305: Based on the calculated difference, and when the difference is greater than the set value, the PID (Proportional-Integral-Derivative) controller is used to calculate and adjust the corrected opening of the exhaust back-pressure valve. According to the initial exhaust back-pressure valve required opening and the calculated exhaust back-pressure valve corrected opening, the final exhaust back-pressure valve required opening is obtained, and the exhaust back-pressure valve opening is controlled based on the final exhaust back-pressure valve required opening.

[0090] That is, when the difference is greater than a certain value, the PID controller calculates the corrected opening of the exhaust back-pressure valve. The ECU adds the exhaust back-pressure valve correction opening based on the initial exhaust back-pressure valve demand opening to obtain the final exhaust back-pressure valve demand opening, and then controls the exhaust back-pressure valve opening based on the final exhaust back-pressure valve demand opening.

[0091] Furthermore, after the exhaust back-pressure valve opening is controlled based on the final exhaust back-pressure valve required opening, it also includes: obtaining the current pressure of the exhaust manifold, and calculating the difference between the actual turbine required pressure ratio and the theoretical turbine required pressure ratio. If the difference is not greater than the set value, the exhaust back-pressure valve correction opening is adjusted to 0, and the exhaust back-pressure valve opening is controlled based on the initial exhaust back-pressure valve required opening.

[0092] Furthermore, for controlling the supercharger bleed valve actuator to be in a fully open state, specifically, after entering the exhaust temperature management function mode, the ECU sends a request to the AVU control unit, requiring the AVU to use its maximum capacity for control. The AVU control unit controls the AVU actuator to make the supercharger bleed valve in the maximum opening position according to the received request, so as to increase the exhaust temperature level.

[0093] The engine control method of this application regulates the engine intake volume by equipping the engine with a throttle and an exhaust back-pressure valve. The corresponding pressure is obtained through the exhaust manifold pressure sensor, and the corresponding inlet temperature is obtained through the SCR inlet temperature sensor. The exhaust temperature management function master switch is calibrated according to the model requirements to confirm whether the current model requires the configuration of the exhaust temperature management function strategy. After the exhaust temperature management function strategy is configured, the exhaust temperature management function mode is activated when the engine throttle is 0, the actual SCR temperature is less than the minimum SCR inlet temperature, the engine is in a reasonable combustion mode, and the engine is not in neutral or the neutral time is greater than a certain period.

[0094] By calibrating the minimum pressure of the intake manifold, the speed density method is used to calculate the engine intake flow rate under this state, and then the corresponding correction amount is obtained through the throttle pressure ratio correction curve, and the input flow of the throttle sonic flow model is calculated. The throttle output opening is calculated through the throttle sonic flow model and the input flow, and compared with the minimum throttle opening of the model. The opening is controlled by the ECU according to the larger value of the two.

[0095] By calibrating the exhaust manifold pressure requirements at different engine speeds, the corresponding pressure requirements are obtained using the engine speed, and then the opening requirements of the exhaust back-pressure valve are obtained based on the turbine characteristics of the engine supercharger; finally, the ECU controls its opening according to this requirement.

[0096] At the same time, the ECU sends a control request to the supercharger AVU control unit, fully opening the supercharger purge valve actuator to increase exhaust temperature. This strategy effectively improves the thermal insulation capacity of the SCR after-treatment system, increases its conversion efficiency, and ensures the emission level of the engine after-treatment system.

[0097] The engine control method based on exhaust temperature management of the embodiment of the present application enters the exhaust temperature management function mode based on the preconditions set for the exhaust temperature management function mode, and when the preconditions are met, and then implements throttle opening control according to the throttle sonic flow model and the throttle output opening corresponding to the input flow, and sets the minimum throttle opening. Then, implements exhaust back-pressure valve opening control according to the exhaust manifold pressure requirements at different engine speeds and the exhaust back-pressure valve opening requirements obtained according to the supercharger turbine characteristics, and at the same time controls the supercharger bleed valve actuator to be in a fully open state, which can effectively improve the thermal insulation capacity of the SCR after-treatment system, improve its conversion efficiency, and ensure the emission level of the engine after-treatment system.

[0098] In a second aspect, an embodiment of the present application also provides an engine control device based on exhaust temperature management.

[0099] In one embodiment, referring to Figure 3 , Figure 3 This is a functional module diagram of the engine control device based on exhaust temperature management in this application. Figure 3 As shown, the engine control device based on exhaust temperature management includes: a determination module and an execution module.

[0100] The judgment module is used to enter the exhaust temperature management function mode based on the preconditions set for the exhaust temperature management function mode, and drive the execution module to work when the preconditions are met; the execution module is used to realize throttle opening control according to the throttle output opening corresponding to the throttle sonic flow model and the input flow, and set the minimum throttle opening, and realize exhaust back pressure valve opening control according to the exhaust manifold pressure requirements at different engine speeds, and the exhaust back pressure valve opening requirements obtained according to the characteristics of the supercharger turbine, and at the same time control the supercharger bleed valve actuator to be in a fully open state.

[0101] Among them, the functional implementation of each module in the above-mentioned engine control device based on exhaust temperature management corresponds to the various steps in the above-mentioned engine control method embodiment based on exhaust temperature management, and their functions and implementation processes will not be repeated here one by one.

[0102] On the third aspect, an embodiment of the present application provides an engine control device based on exhaust temperature management. The engine control device based on exhaust temperature management can be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0103] Reference Figure 4 , Figure 4 Schematic diagram of the hardware structure of the engine control device based on exhaust temperature management involved in the embodiment of the present application. In the embodiment of the present application, the engine control device based on exhaust temperature management may include a processor, a memory, a communication interface and a communication bus.

[0104] The communication bus may be of any type and is used to interconnect the processor, memory, and communication interface.

[0105] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces, used to interconnect components within the exhaust temperature management-based engine control device, as well as interfaces used to interconnect the exhaust temperature management-based engine control device with other devices (such as other computing devices or user devices). Physical interfaces can include Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc. User devices can include displays, keyboards, etc.

[0106] The 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.

[0107] The processor may be a general-purpose processor that can call an exhaust temperature management-based engine control program stored in a memory and execute the exhaust temperature management-based engine control method provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the exhaust temperature management-based engine control program is called can be referenced to the various embodiments of the exhaust temperature management-based engine control method of the present application and will not be further described here.

[0108] Those skilled in the art will understand that Figure 4 The hardware structure shown in the figure does not constitute a limitation to the present application and may include more or fewer components than shown in the figure, or a combination of certain components, or a different arrangement of components.

[0109] In a fourth aspect, an embodiment of the present application also provides a computer-readable storage medium.

[0110] The computer-readable storage medium of the present application stores an engine control program based on exhaust temperature management, wherein when the engine control program based on exhaust temperature management is executed by a processor, the steps of the engine control method based on exhaust temperature management as described above are implemented.

[0111] Among them, the method implemented when the engine control program based on exhaust temperature management is executed can refer to the various embodiments of the engine control method based on exhaust temperature management in this application, and will not be repeated here.

[0112] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0113] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0114] In the description of the embodiments of this application, the words "exemplary," "for example," or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary," "for example," or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "for example," or "for example" is intended to present the relevant concepts in a concrete manner.

[0115] In the description of the embodiments of the present application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two.

[0116] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0117] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it 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 the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0118] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An engine control method based on exhaust temperature management, characterized in that: The engine control method based on exhaust temperature management includes: Based on the preconditions set for the exhaust temperature management function mode, and when the preconditions are met, the exhaust temperature management function mode is entered; The throttle opening is controlled by setting the throttle output opening corresponding to the throttle sonic flow model and the input flow rate, and by setting the minimum throttle opening; Based on the exhaust manifold pressure requirements at different engine speeds and the exhaust back-pressure valve opening requirements obtained based on the turbocharger turbine characteristics, the exhaust back-pressure valve opening is controlled, and the turbocharger bleed valve actuator is controlled to be in a fully open state. The throttle output opening corresponding to the throttle sonic flow model and the input flow rate, and setting the minimum throttle opening to achieve throttle opening control specifically include: The minimum intake manifold pressure at the current engine speed is obtained by interpolation calculation based on the minimum intake manifold pressure; Based on the calculated minimum intake manifold pressure, the current theoretical intake flow rate of the engine is calculated using the speed density method; The throttle valve intake volume correction coefficient is calculated based on the throttle valve pressure ratio correction interpolation, and the input flow of the throttle valve sonic flow model is obtained based on the current theoretical intake flow of the engine and the throttle valve intake volume correction coefficient; According to the input flow of the throttle sonic flow model, the throttle opening is obtained by interpolation calculation of the throttle sonic flow model; Based on the calculated throttle opening and the set minimum throttle opening, a larger opening value is selected for throttle opening control.

2. The engine control method based on exhaust temperature management according to claim 1, characterized in that: The engine control method is adapted to an engine with an electronic throttle valve in front of the intake manifold and an exhaust back-pressure valve at the outlet of the turbocharger, and the opening degree of the throttle valve and the exhaust back-pressure valve is controlled by the ECU; Pressure sensors are installed on the intake manifold and exhaust manifold of the engine, and a temperature sensor is installed at the SCR inlet.

3. The engine control method based on exhaust temperature management according to claim 2, characterized in that: When the preconditions are met, the exhaust temperature management function mode is entered, specifically: Perform precondition judgment. When all conditions in the precondition are met, the exhaust temperature management mode needs to be activated. Otherwise, the exhaust temperature management mode does not need to be activated. Based on the judgment result of the precondition, when entering the exhaust temperature management mode activation state, the duration of the exhaust temperature management mode activation state is judged. If the duration of the exhaust temperature management mode activation state is not greater than the preset time, the vehicle enters the exhaust temperature management function mode; otherwise, the vehicle does not enter the exhaust temperature management function mode; The preconditions include that the engine throttle is 0, the actual SCR inlet temperature is lower than the set SCR inlet minimum temperature, the vehicle gear is not in neutral, or the vehicle gear is in neutral and the duration is greater than a set time.

4. The engine control method based on exhaust temperature management according to claim 2, characterized in that: Based on the calculated minimum intake manifold pressure, the speed density method is used to calculate the current theoretical intake flow rate of the engine, wherein the specific calculation method is: The current theoretical intake flow of the engine = the calculated minimum intake manifold pressure * engine displacement * current engine speed * R / current intake manifold temperature Here, R represents a constant.

5. The engine control method based on exhaust temperature management according to claim 2, characterized in that: The exhaust back-pressure valve opening control is implemented based on the exhaust manifold pressure requirements at different engine speeds and the exhaust back-pressure valve opening requirements obtained based on the supercharger turbine characteristics, specifically including: Interpolating the engine speed and the exhaust manifold pressure requirement to obtain the exhaust manifold pressure requirement at the current engine speed, and obtaining the theoretical turbine required pressure ratio based on the exhaust manifold pressure requirement; The initial exhaust back-pressure valve required opening is calculated based on the turbine characteristic MAP, the theoretical turbine required pressure ratio, and the current engine speed; Based on the calculated initial exhaust back-pressure valve required opening, the exhaust back-pressure valve is feedforward controlled; Obtaining the current pressure of the exhaust manifold, and calculating the difference between the actual turbine required pressure ratio and the theoretical turbine required pressure ratio; Based on the calculated difference, and when the difference is greater than the set value, the PID controller calculates and adjusts the corrected opening of the exhaust back-pressure valve. According to the initial exhaust back-pressure valve required opening and the calculated exhaust back-pressure valve corrected opening, the final exhaust back-pressure valve required opening is obtained, and the exhaust back-pressure valve opening is controlled based on the final exhaust back-pressure valve required opening.

6. The engine control method based on exhaust temperature management according to claim 5, characterized in that: After the exhaust back pressure valve opening is controlled based on the final exhaust back pressure valve required opening, the following steps are also included: The current pressure of the exhaust manifold is obtained, and the difference between the actual turbine required pressure ratio and the theoretical turbine required pressure ratio is calculated. If the difference is not greater than the set value, the exhaust back-pressure valve correction opening is adjusted to 0, and the exhaust back-pressure valve opening is controlled based on the initial exhaust back-pressure valve required opening.

7. An engine control device based on exhaust temperature management, characterized in that: The engine control device based on exhaust temperature management includes: A determination module, which is used to enter the exhaust temperature management function mode based on the preconditions set for the exhaust temperature management function mode and drive the execution module to work when the preconditions are met; an execution module for controlling the throttle opening by outputting the throttle opening according to the throttle sonic flow model and the input flow rate, and setting a minimum throttle opening; and controlling the exhaust back-pressure valve opening according to the exhaust manifold pressure requirements at different engine speeds and the exhaust back-pressure valve opening requirements obtained based on the turbocharger turbine characteristics, while controlling the turbocharger bleed valve actuator to be in a fully open state; The throttle output opening corresponding to the throttle sonic flow model and the input flow rate, and setting the minimum throttle opening to achieve throttle opening control specifically include: The minimum intake manifold pressure at the current engine speed is obtained by interpolation calculation based on the minimum intake manifold pressure; Based on the calculated minimum intake manifold pressure, the current theoretical intake flow rate of the engine is calculated using the speed density method; The throttle valve intake volume correction coefficient is calculated based on the throttle valve pressure ratio correction interpolation, and the input flow of the throttle valve sonic flow model is obtained based on the current theoretical intake flow of the engine and the throttle valve intake volume correction coefficient; According to the input flow of the throttle sonic flow model, the throttle opening is obtained by interpolation calculation of the throttle sonic flow model; Based on the calculated throttle opening and the set minimum throttle opening, a larger opening value is selected for throttle opening control.

8. An engine control device based on exhaust temperature management, characterized in that: The engine control device based on exhaust temperature management includes a processor, a memory, and an engine control program based on exhaust temperature management stored on the memory and executable by the processor, wherein when the engine control program based on exhaust temperature management is executed by the processor, the steps of the engine control method based on exhaust temperature management as described in any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores an engine control program based on exhaust temperature management, wherein when the engine control program based on exhaust temperature management is executed by a processor, the steps of the engine control method based on exhaust temperature management according to any one of claims 1 to 6 are implemented.

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