Engine combustion mode switching method and device, vehicle and storage medium

Abstract

The invention provides an engine combustion mode switching method and device, a vehicle and a storage medium, and belongs to the technical field of tail gas aftertreatment, engine combustion modes comprise a normal combustion mode and a low urea consumption mode, and the urea consumption of the low urea consumption mode is smaller than that of the normal combustion mode; the method comprises the steps that the urea-fuel ratio and the nitrogen oxide specific emission within the preset duration are determined; when the urine-fuel ratio is larger than a urine-fuel ratio threshold value and the nitrogen oxide specific emission amount is larger than a specific emission amount threshold value, the duration when the urine-fuel ratio is larger than the urine-fuel ratio threshold value and the nitrogen oxide specific emission amount is larger than the specific emission amount threshold value is obtained; and when the duration is longer than the calibrated duration, the combustion mode of the engine is switched from a normal combustion mode to a low urea consumption mode. According to the invention, the consumption of urea is reduced while the fuel economy is considered.

Description

Technical Field

[0001] The present invention relates to the technical field of exhaust gas aftertreatment, and in particular to an engine combustion mode switching method, device, vehicle and storage medium. Background Art

[0002] There is only one engine combustion mode in the prior art, and the combustion parameters of the engine combustion mode are calibrated according to factors such as emissions and fuel economy. The urea consumption is calculated based on the original nitrogen oxide concentration, exhaust flow, exhaust temperature, etc. of the engine after calibration. When the exhaust gas recirculation (EGR) system works normally, the urea consumption meets the requirements.

[0003] However, when the vehicle is running in the low-speed and medium-high load area, the EGR driving capacity is insufficient, which will lead to increased urea consumption. If the urea consumption is reduced, the fuel consumption will deteriorate, which will cause the overall fuel economy to deteriorate. If the fuel economy is ensured, the high urea consumption when the EGR driving capacity is insufficient cannot be improved.

[0004] Therefore, there is an urgent need to provide an engine combustion mode switching method, device, vehicle and storage medium to achieve fuel economy while reducing urea consumption. Summary of the invention

[0005] In view of this, it is necessary to provide an engine combustion mode switching method, device, vehicle and storage medium to solve the technical problems existing in the prior art of only setting one engine combustion mode, resulting in the inability to take into account both fuel economy and high urea consumption.

[0006] On the one hand, in order to solve the above technical problems, the present invention provides a method for switching an engine combustion mode, wherein the engine combustion mode includes a normal combustion mode and a low urea consumption mode, and the urea consumption of the low urea consumption mode is less than the urea consumption of the normal combustion mode; the method comprises: Determine the urine-to-fuel ratio and nitrogen oxides ratio emissions within a preset time period; When the urine-fuel ratio is greater than a urine-fuel ratio threshold and the nitrogen oxide specific emission is greater than a specific emission threshold, obtaining a duration in which the urine-fuel ratio is greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission is greater than the specific emission threshold; When the duration is greater than a calibrated duration, the engine combustion mode is switched from a normal combustion mode to a low urea consumption mode.

[0007] In a possible implementation, determining the nitrogen oxide emission ratio within a preset time period includes: Obtaining the accumulated nitrogen oxide mass and accumulated work within the preset time period; The ratio of the accumulated nitrogen oxide mass to the accumulated work is taken as the nitrogen oxide specific emission amount.

[0008] In a possible implementation, the accumulated nitrogen oxide mass is:

[0009] The accumulated work is:

[0010] In the formula, is the cumulative mass of nitrogen oxides; is the concentration of nitrogen oxides in ppm; is the exhaust flow rate, in kg / h; The initial time of the preset duration; The end time of the preset duration; To accumulate merit; is the engine speed; is the engine torque.

[0011] In a possible implementation, determining the urine-to-fuel ratio within a preset time period includes: Obtaining the urea injection amount per unit time and the fuel consumption per unit time; Based on the preset time, the urea injection amount per unit time and the fuel consumption per unit time are respectively integrated to obtain a urea volume and a fuel volume respectively; The ratio of the urea volume to the fuel volume is taken as the urea-to-fuel ratio.

[0012] In a possible implementation, before determining the urine-to-fuel ratio and nitrogen oxide ratio emissions within a preset time period, the method further includes: Obtaining vehicle operating parameters within the preset time; Inputting the vehicle operating condition parameters into a pre-built operating condition determination model to obtain the vehicle operating condition; the vehicle operating condition includes a stable operating condition and an unstable operating condition; The determination of the urine-to-fuel ratio and the nitrogen oxide ratio emissions within a preset time period includes: When the vehicle operating condition is a stable condition, the urine-fuel ratio and nitrogen oxide ratio emissions within a preset time period are determined.

[0013] In a possible implementation, the method further includes: Obtaining a median urine-fuel ratio, and determining a urine-fuel ratio difference between the median urine-fuel ratio and the urine-fuel ratio; The calibration time duration is determined based on the urine-to-fuel ratio difference and a mapping relationship between the urine-to-fuel ratio difference and the calibration time duration.

[0014] In a possible implementation, the method further includes: Acquiring real-time operating condition parameters, and determining the real-time operating condition based on the real-time operating condition parameters and the operating condition determination model; When the real-time operating condition is an unstable operating condition, or the continuous operation time of the low urea consumption mode is greater than the preset operation time, or the continuous driving mileage of the low urea consumption mode is greater than the preset driving mileage, the engine combustion mode is switched from the low urea consumption mode to the normal combustion mode.

[0015] On the other hand, the present invention further provides an engine combustion mode switching device, wherein the engine combustion mode includes a normal combustion mode and a low urea consumption mode, wherein the urea consumption of the low urea consumption mode is less than the urea consumption of the normal combustion mode; the device comprises: a parameter determination unit, for determining urine-to-fuel ratio and nitrogen oxide ratio emissions within a preset time period; a switching condition judgment unit, for obtaining a duration of the urine-fuel ratio being greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission being greater than the specific emission threshold when the urine-fuel ratio is greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission is greater than the specific emission threshold; The combustion mode switching unit is used to switch the engine combustion mode from a normal combustion mode to a low urea consumption mode when the duration is greater than a calibrated duration.

[0016] In another aspect, the present invention further provides a vehicle, comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the engine combustion mode switching method described in any one of the possible implementations above.

[0017] On the other hand, the present invention also provides a computer-readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps in the engine combustion mode switching method described in any possible implementation method mentioned above are implemented.

[0018] The beneficial effects of the present invention are as follows: the engine combustion mode switching method provided by the present invention first sets the engine combustion mode to include a normal combustion mode and a low urea consumption mode, and secondly sets a reasonable switching logic. When the urea consumption is at a high level, the engine combustion mode is switched from the normal combustion mode to the low urea consumption mode, which can reduce the urea consumption of the vehicle, thereby achieving the purpose of reducing urea consumption while taking into account the fuel economy of the entire vehicle.

[0019] Furthermore, the present invention determines whether urea consumption is at a high level based on parameters of the two dimensions of urea-to-fuel ratio and nitrogen oxide emission ratio, thereby improving the accurate judgment of the urea consumption level and further improving the accuracy of the switching timing of the engine combustion mode, that is, improving the timeliness of entering the low urea consumption mode, thereby further reducing urea consumption.

[0020] Furthermore, the present invention determines the switching timing based on the urine-fuel ratio and nitrogen oxide emission ratio within a preset time period, rather than determining the switching timing by the urine-fuel ratio and nitrogen oxide emission ratio at a certain moment, thereby avoiding the inaccuracy of short-term data and further improving the accuracy of the engine combustion mode switching timing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A schematic flow chart of an embodiment of the method for switching the combustion mode of an engine provided by the present invention; Figure 2 A schematic diagram of a flow chart of an embodiment of determining the specific emission of nitrogen oxides provided by the present invention; Figure 3 A schematic diagram of a flow chart of an embodiment of determining the urine-to-fuel ratio provided by the present invention; Figure 4 A schematic diagram of a flow chart of an embodiment of determining an engine operating condition provided by the present invention; Figure 5 A schematic diagram of a flow chart of an embodiment of determining the calibration duration provided by the present invention; Figure 6 A schematic diagram of a flow chart of an embodiment of switching from a low urea consumption mode to a normal combustion mode provided by the present invention; Figure 7 A schematic structural diagram of an embodiment of the engine combustion mode switching device provided by the present invention; Figure 8 A schematic structural diagram of an embodiment of a vehicle provided by the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0024] It should be understood that the schematic drawings are not drawn to scale. The flowchart used in the present invention shows the operations implemented according to some embodiments of the present invention. It should be understood that the operations of the flowchart can be implemented out of order, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present invention, can add one or more other operations to the flowchart, and can also remove one or more operations from the flowchart. Some of the block diagrams shown in the accompanying drawings are functional entities, which do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor systems and / or microcontroller systems.

[0025] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] The present invention provides an engine combustion mode switching method, device, vehicle and storage medium, which are described below respectively.

[0027] The embodiment of the present invention provides a method for switching an engine combustion mode, such as Figure 1 As shown, the engine combustion mode switching method includes: S101, determining the urine-to-fuel ratio and nitrogen oxide ratio emissions within a preset time period; S102, when the urine-fuel ratio is greater than the urine-fuel ratio threshold and the nitrogen oxide emission ratio is greater than the emission ratio threshold, obtaining a duration during which the urine-fuel ratio is greater than the urine-fuel ratio threshold and the nitrogen oxide emission ratio is greater than the emission ratio threshold; S103: When the duration is greater than the calibrated duration, the engine combustion mode is switched from the normal combustion mode to the low urea consumption mode.

[0028] It should be understood that the default mode of the engine combustion mode is the normal combustion mode.

[0029] Among them, the combustion parameters of the low urea consumption mode can be calibrated according to factors such as urea consumption and emissions, ensuring that the urea consumption in the low urea consumption mode is less than the urea consumption in the normal combustion mode.

[0030] It should be noted that the preset duration can be set or adjusted according to experience or actual application scenarios, and is not specifically limited here.

[0031] Compared with the prior art, the engine combustion mode switching method provided in the embodiment of the present invention first sets the engine combustion mode to include a normal combustion mode and a low urea consumption mode, and secondly sets a reasonable switching logic. When the urea consumption is at a high level, the engine combustion mode is switched from the normal combustion mode to the low urea consumption mode, which can reduce the urea consumption of the vehicle, thereby achieving the purpose of reducing urea consumption while taking into account the fuel economy of the entire vehicle.

[0032] Furthermore, the embodiment of the present invention determines whether urea consumption is at a high level based on the parameters of the two dimensions of urea-to-fuel ratio and nitrogen oxide emission ratio, thereby improving the accurate judgment of the urea consumption level and further improving the accuracy of the switching timing of the engine combustion mode, that is, improving the timeliness of entering the low urea consumption mode, thereby further reducing urea consumption.

[0033] Furthermore, the embodiment of the present invention determines the switching timing based on the urine-fuel ratio and nitrogen oxide emission ratio within a preset time period, rather than determining the switching timing by the urine-fuel ratio and nitrogen oxide emission ratio at a certain moment, thereby avoiding the inaccuracy of short-term data and further improving the accuracy of the engine combustion mode switching timing.

[0034] In some embodiments of the present invention, Figure 2 As shown, determining the nitrogen oxide emission ratio within a preset time period in step S101 includes: S201, obtaining the accumulated nitrogen oxide mass and accumulated work within a preset time period; S202. Taking the ratio of the accumulated nitrogen oxide mass to the accumulated work as the nitrogen oxide emission ratio.

[0035] The embodiment of the present invention obtains the accumulated nitrogen oxide mass and accumulated work respectively, further avoiding the problem of inaccurate nitrogen oxide emission ratio caused by factors such as backdraft and data delay, which causes the calculation results of local data to be extremely large or extremely small, thereby improving the accuracy of the determined nitrogen oxide emission ratio.

[0036] In a specific embodiment of the present invention, the cumulative nitrogen oxide mass is:

[0037] The accumulated work is:

[0038] In the formula, is the cumulative mass of nitrogen oxides; is the nitrogen oxide concentration in ppm; is the exhaust flow rate, The unit is kg / h; The initial time of the preset duration; The end time of the preset duration; To accumulate merit; is the engine speed; is the engine torque.

[0039] Then the nitrogen oxide emission BSNOX is: BSNOX=

[0040] It should be understood that: multiple sampling points are set within a preset time period, the nitrogen oxide concentration, exhaust flow, engine speed, and engine torque of each sampling point are obtained, the nitrogen oxide mass and work of each sampling point are obtained based on the above parameters, the nitrogen oxide mass and work of multiple sampling points are superimposed, and the cumulative nitrogen oxide mass and cumulative work are obtained.

[0041] In some embodiments of the present invention, Figure 3 As shown, the step S101 of determining the urine-to-fuel ratio within a preset time period includes: S301, obtaining a urea injection amount per unit time and a fuel consumption per unit time; S302, integrating the urea injection amount per unit time and the fuel consumption per unit time based on a preset time period, and correspondingly obtaining a urea volume and a fuel volume; S303: Taking the ratio of the urea volume to the fuel volume as the urea-to-fuel ratio.

[0042] Similarly, the embodiment of the present invention can avoid the adverse effects of inaccurate short-term data by integrating the urea injection amount per unit time and the fuel consumption per unit time to obtain the urea volume and fuel volume accordingly, thereby ensuring the accuracy of the determined urea-fuel ratio.

[0043] Due to sudden changes in operating conditions, such as large potholes on the road surface and obvious differences in ambient temperature, urea consumption may fluctuate. In order to avoid the sudden changes in operating conditions affecting the switching of the engine combustion mode, in some embodiments of the present invention, Figure 4 As shown, before step S101, it also includes: S401, obtaining vehicle operating parameters within a preset time; S402, inputting the vehicle operating condition parameters into a pre-built operating condition determination model to obtain the vehicle operating condition; the vehicle operating condition includes a stable operating condition and an unstable operating condition; Then step S101 is specifically as follows: When the vehicle is in a stable operating condition, the urine-to-fuel ratio and nitrogen oxides emission ratio within a preset time period are determined.

[0044] Before determining the timing of switching the engine combustion mode, the embodiment of the present invention first determines whether the vehicle operating condition is a stable condition. When the vehicle operating condition is a stable condition, step S101 is executed to avoid the influence of the unstable condition on the judgment of the timing of switching the engine combustion mode, thereby further ensuring the accuracy of the timing of switching the engine combustion mode.

[0045] The operating condition determination model needs to be trained, tested and verified based on the sample set in advance, and when the model performance meets the requirements, step S402 is executed.

[0046] Since the purpose of the operating condition determination model in the embodiment of the present invention is to classify the operating conditions, and the support vector machine (SVM) has a good classification effect, therefore, in the specific embodiment of the present invention, the model structure of the operating condition determination model is SVM.

[0047] Specifically, when the output value of the operating condition determination model is greater than 0, it is a stable operating condition, otherwise it is an unstable operating condition.

[0048] In a specific embodiment of the present invention, the vehicle operating parameters of step S401 include but are not limited to speed, torque, power, cooling water temperature, ambient temperature, and ambient pressure.

[0049] The embodiment of the present invention sets the whole vehicle operating condition parameters including the vehicle's own parameters (speed, torque, power, cooling water temperature) and environmental parameters (ambient temperature, ambient pressure) to perform operating condition judgment from multiple dimensions, thereby improving the accuracy of the operating condition judgment result.

[0050] From the description of step S103, it can be seen that the setting of the calibration time determines the switching timing of the engine combustion mode. In order to further improve the accuracy of the switching timing of the engine combustion mode, in some embodiments of the present invention, it is also necessary to determine the calibration time. Specifically, Figure 5 , determine the calibration duration, including: S501, obtaining a median urine-fuel ratio, and determining a urine-fuel ratio difference between the median urine-fuel ratio and the urine-fuel ratio; S502: Determine the calibration time duration based on the urine-to-fuel ratio difference and the mapping relationship between the urine-to-fuel ratio difference and the calibration time duration.

[0051] Among them, the median urine-fuel ratio refers to the statistics of all urine-fuel ratios of a certain model of vehicles, and all urine-fuel ratios are arranged from small to large or from large to small. If the number of all urine-fuel ratios is an odd number, the middle number is taken as the median urine-fuel ratio. If the number of all urine-fuel ratios is an even number, the average of the two middle numbers is taken as the median urine-fuel ratio.

[0052] The median value of the urea-to-fuel ratio represents the central trend of the statistical data. Therefore, using the median value of the urea-to-fuel ratio as a reference for the calibration duration can take into account the urea fuel consumption requirements of most vehicles in the market.

[0053] It should be noted that the principle of the mapping relationship between the urine-fuel ratio difference and the calibration time duration is: the larger the urine-fuel ratio difference, the shorter the calibration time duration. The specific mapping relationship can be set according to the actual application scenario and is not specifically limited here.

[0054] In other embodiments of the present invention, the calibration duration can be set according to project requirements. For example, if the project requirement is to reduce the urine-to-fuel ratio as much as possible, the calibration duration should be appropriately shortened.

[0055] Since the fuel consumption is worse when the urea consumption is smaller, the engine cannot work in the low urea consumption mode for a long time. Therefore, in some embodiments of the present invention, Figure 6 As shown, the engine combustion mode switching method also includes: S601, obtaining real-time operating condition parameters, and determining the real-time operating condition based on the real-time operating condition parameters and an operating condition determination model; S602: When the real-time operating condition is an unstable operating condition, or the continuous operation time of the low urea consumption mode is greater than the preset operation time, or the continuous driving mileage of the low urea consumption mode is greater than the preset driving mileage, the engine combustion mode is switched from the low urea consumption mode to the normal combustion mode.

[0056] The embodiment of the present invention is arranged that when the real-time operating condition is an unstable operating condition, or the continuous operation time of the low urea consumption mode is greater than the preset operation time, or the continuous driving mileage of the low urea consumption mode is greater than the preset driving mileage, the engine combustion mode is switched from the low urea consumption mode to the normal combustion mode, so as to avoid the engine combustion mode being in the low urea consumption mode for a long time, and at the same time of reducing urea consumption, avoid the long-term deterioration of fuel consumption, thereby ensuring fuel economy.

[0057] It should be understood that the preset operating time and the preset mileage can be set or adjusted according to the actual application scenario and are not specifically limited here.

[0058] In order to verify the effectiveness of the engine combustion mode switching method proposed in the embodiment of the present invention, experiments were conducted on actual vehicle models. The results showed that the application of the embodiment of the present invention can reduce the urea-fuel ratio of vehicles with high urea consumption by 1%-3%, which is closer to the median level, and effectively reduces users' complaints about high urea consumption.

[0059] Furthermore, in order to verify that the embodiment of the present invention takes fuel economy into consideration while reducing urea consumption, the universal MAP, cycle comprehensive fuel consumption and user use cost of the method proposed in the embodiment of the present invention and the method proposed in the embodiment of the present invention are obtained. The results are as follows: the areas with good comprehensive economy in the universal MAP are basically the same, the cycle comprehensive fuel consumption is 228.1g / kwh and 228g / kwh respectively, which is basically unchanged, and the user use cost is also basically unchanged. This further illustrates that the engine combustion mode switching method proposed in the embodiment of the present invention takes fuel economy into consideration while reducing urea consumption.

[0060] In order to better implement the engine combustion mode switching method in the embodiment of the present invention, based on the engine combustion mode switching method, the embodiment of the present invention also provides an engine combustion mode switching device, the engine combustion mode includes a normal combustion mode and a low urea consumption mode, the urea consumption of the low urea consumption mode is less than the urea consumption of the normal combustion mode; Figure 7 As shown, the engine combustion mode switching device 700 includes: The parameter determination unit 701 is used to determine the urine-to-fuel ratio and the nitrogen oxide ratio emissions within a preset time period; The switching condition judgment unit 702 is used to obtain the duration of the urine-fuel ratio being greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission being greater than the specific emission threshold when the urine-fuel ratio is greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission is greater than the specific emission threshold; The combustion mode switching unit 703 is used to switch the engine combustion mode from the normal combustion mode to the low urea consumption mode when the duration is greater than the calibrated duration.

[0061] It should be noted that the engine combustion mode switching device 700 provided in the above embodiment can implement the technical solution described in the above engine combustion mode switching method embodiment. The specific implementation principles or specific implementation details of the above modules or units can refer to the corresponding contents in the above engine combustion mode switching method embodiment, which will not be described one by one here.

[0062] like Figure 8 As shown, the present invention also provides a vehicle 800. The vehicle 800 includes a processor 801, a memory 802 and a display 803. Figure 8 Only some of the components of vehicle 800 are shown, but it should be understood that implementation of all of the components shown is not a requirement, and more or fewer components may alternatively be implemented.

[0063] In some embodiments, the processor 801 is an electronic control unit (ECU) in the vehicle 800 , which is used to run program codes or process data stored in the memory 802 , such as the engine combustion mode switching method in the present invention.

[0064] The memory 802 may be an internal storage unit of the vehicle 800 , such as a hard disk or a memory of the vehicle 800 , in some embodiments.

[0065] Furthermore, the memory 802 may include both an internal storage unit of the vehicle 800 and an external storage device. The memory 802 is used to store application software installed in the vehicle 800 and various data.

[0066] In some embodiments, the display 803 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 803 is used to display information of the vehicle 800 and to display a visual user interface. The components 801-803 of the vehicle 800 communicate with each other via a system bus.

[0067] In some embodiments of the present invention, when the processor 801 executes the engine combustion mode switching program in the memory 802, the following steps may be implemented: Determine the urine-to-fuel ratio and nitrogen oxides ratio emissions within a preset time period; When the urine-fuel ratio is greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission is greater than the specific emission threshold, obtaining a duration during which the urine-fuel ratio is greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission is greater than the specific emission threshold; When the duration is greater than a calibrated duration, the engine combustion mode is switched from the normal combustion mode to the low urea consumption mode.

[0068] It should be understood that: when the processor 801 executes the engine combustion mode switching program in the memory 802, in addition to the above functions, other functions can also be implemented. For details, please refer to the description of the corresponding method embodiment above.

[0069] Correspondingly, an embodiment of the present invention also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, the steps or functions in the engine combustion mode switching method provided in the above-mentioned method embodiments can be implemented.

[0070] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0071] The above is a detailed introduction to an engine combustion mode switching method, device, vehicle and storage medium provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A method for switching an engine combustion mode, characterized in that: The engine combustion mode includes a normal combustion mode and a low urea consumption mode, and the urea consumption of the low urea consumption mode is less than the urea consumption of the normal combustion mode; the method includes: Determine the urine-to-fuel ratio and nitrogen oxides ratio emissions within a preset time period; When the urine-fuel ratio is greater than a urine-fuel ratio threshold and the nitrogen oxide specific emission is greater than a specific emission threshold, obtaining a duration in which the urine-fuel ratio is greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission is greater than the specific emission threshold; When the duration is greater than a calibrated duration, the engine combustion mode is switched from a normal combustion mode to a low urea consumption mode.

2. The engine combustion mode switching method according to claim 1, characterized in that: Determines specific NOx emissions for a preset period of time, including: Obtaining the accumulated nitrogen oxide mass and accumulated work within the preset time period; The ratio of the accumulated nitrogen oxide mass to the accumulated work is taken as the nitrogen oxide specific emission amount.

3. The engine combustion mode switching method according to claim 2, characterized in that: The cumulative nitrogen oxide mass is: The accumulated work is: In the formula, is the cumulative mass of nitrogen oxides; is the concentration of nitrogen oxides in ppm; is the exhaust flow rate, in kg / h; The initial time of the preset duration; The end time of the preset duration; To accumulate merit; is the engine speed; is the engine torque.

4. The engine combustion mode switching method according to claim 1, characterized in that: The step of determining the urine-to-fuel ratio within a preset time period includes: Obtaining the urea injection amount per unit time and the fuel consumption per unit time; Based on the preset time, the urea injection amount per unit time and the fuel consumption per unit time are respectively integrated to obtain a urea volume and a fuel volume respectively; The ratio of the urea volume to the fuel volume is taken as the urea-to-fuel ratio.

5. The engine combustion mode switching method according to claim 1, characterized in that: Before determining the urine-to-fuel ratio and nitrogen oxide ratio emissions within a preset time period, the method further includes: Obtaining vehicle operating parameters within the preset time; Inputting the vehicle operating condition parameters into a pre-built operating condition determination model to obtain the vehicle operating condition; the vehicle operating condition includes a stable operating condition and an unstable operating condition; The determination of the urine-to-fuel ratio and the nitrogen oxide ratio emissions within a preset time period includes: When the vehicle operating condition is a stable condition, the urine-fuel ratio and nitrogen oxide ratio emissions within a preset time period are determined.

6. The engine combustion mode switching method according to claim 1, characterized in that: The method further comprises: Obtaining a median urine-fuel ratio, and determining a urine-fuel ratio difference between the median urine-fuel ratio and the urine-fuel ratio; The calibration time duration is determined based on the urine-to-fuel ratio difference and a mapping relationship between the urine-to-fuel ratio difference and the calibration time duration.

7. The method for switching the engine combustion mode according to claim 5, characterized in that: The method further comprises: Acquiring real-time operating condition parameters, and determining the real-time operating condition based on the real-time operating condition parameters and the operating condition determination model; When the real-time operating condition is an unstable operating condition, or the continuous operation time of the low urea consumption mode is greater than the preset operation time, or the continuous driving mileage of the low urea consumption mode is greater than the preset driving mileage, the engine combustion mode is switched from the low urea consumption mode to the normal combustion mode.

8. An engine combustion mode switching device, characterized in that: The engine combustion mode includes a normal combustion mode and a low urea consumption mode, wherein the urea consumption in the low urea consumption mode is less than the urea consumption in the normal combustion mode; the device includes: a parameter determination unit, for determining urine-to-fuel ratio and nitrogen oxide ratio emissions within a preset time period; a switching condition judgment unit, for obtaining a duration of the urine-fuel ratio being greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission being greater than the specific emission threshold when the urine-fuel ratio is greater than the urine-fuel ratio threshold and the nitrogen oxide specific emission is greater than the specific emission threshold; The combustion mode switching unit is used to switch the engine combustion mode from a normal combustion mode to a low urea consumption mode when the duration is greater than a calibrated duration.

9. A vehicle, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the engine combustion mode switching method described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, the steps in the engine combustion mode switching method described in any one of claims 1 to 7 are implemented.

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