Control Method, Device, Electronic Device and Storage Medium for Vehicle Exhaust Emissions

Abstract

The present invention discloses a control method, device, electronic device and storage medium for vehicle exhaust emissions, including: obtaining the current engine speed and fuel injection quantity; determining the working condition fluctuation value based on the engine speed and fuel injection quantity; judging whether the working condition fluctuation value is greater than a preset working condition fluctuation value; when the working condition fluctuation value is greater than the preset working condition fluctuation value, determining the NOx original emission model value of the engine based on the engine speed and fuel injection quantity; determining the urea injection quantity based on the NOx original emission model value; when the working condition fluctuation value is less than the preset working condition fluctuation value, obtaining the NOx original emission detection value detected by the NOx original emission sensor; determining the urea injection quantity based on the NOx original emission detection value. Through the current engine speed and fuel injection quantity of the present application, the current engine working condition fluctuation degree can be determined. When the working condition fluctuation value exceeds the preset value, it indicates that the NOx original emission value of the current engine is relatively large instantaneously. By using corresponding calculations, the accurate current NOx original emission value can be determined, avoiding excessive emissions caused by the detection delay of the NOx original emission sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engine exhaust gas purification, and particularly to a method, device, electronic device and storage medium for controlling vehicle exhaust emissions. Background Art

[0002] With the improvement of emission regulation requirements, SCR technology has been widely adopted in diesel engines to treat exhaust gas and reduce the emission of pollutant NOx.

[0003] In existing vehicles, the response time of the NOx sensor is about 2 - 5 s. Under transient engine conditions, there is a lag in the NOx measurement value, resulting in a delay in the urea injection amount. As a result, urea cannot react with NOx in the exhaust gas in a timely manner. Moreover, when the catalyst temperature is relatively high, the ammonia storage capacity decreases, and the increase in emissions caused by untimely urea injection is more obvious.

[0004] The time for the exhaust gas generated by the engine to pass through the SCR system is basically less than 0.1 s. The change range of the original NOx emission within a short time may reach more than 1000 ppm. The real - time accuracy of the original NOx emission detection has a significant impact on the real - time accuracy of urea injection. The current technical requirement for the NOx sensor is that the T90 response time is less than 3900 ms. Through experimental data analysis, it shows that the current response time of the NOx sensor is 2 s - 5 s, and the urea injection delay time is also 2 - 5 s. This leads to incorrect moments for increasing or decreasing the urea injection amount, resulting in the injected urea not being able to react with NOx in the exhaust gas in a timely manner and causing a relatively high tailpipe emission.

[0005] Therefore, the technical problem of how to improve the accuracy and response speed of the urea injection amount in the SCR system to reduce vehicle exhaust emissions urgently needs to be solved. Summary of the Invention

[0006] To solve the technical problem of how to improve the accuracy and response speed of the urea injection amount in the SCR system to reduce vehicle exhaust emissions as described in the above background art, the present invention provides a method, device, electronic device and storage medium for controlling vehicle exhaust emissions.

[0007] According to one aspect of the embodiments of the present application, a method for controlling vehicle exhaust emissions is provided, including: obtaining the current rotational speed and fuel injection quantity of the engine; determining a working condition fluctuation value based on the rotational speed and the fuel injection quantity, where the working condition fluctuation value characterizes the degree of working condition fluctuation of the engine; determining whether the working condition fluctuation value is greater than a preset working condition fluctuation value; when the working condition fluctuation value is greater than the preset working condition fluctuation value, determining a NOx raw emission model value of the engine based on the rotational speed and the fuel injection quantity; determining a urea injection quantity based on the NOx raw emission model value; when the working condition fluctuation value is less than the preset working condition fluctuation value, obtaining a NOx raw emission detection value detected by a NOx raw emission sensor; and determining the urea injection quantity based on the NOx raw emission detection value.

[0008] Optionally, the determining a working condition fluctuation value based on the rotational speed and the fuel injection quantity includes: obtaining a calibrated excess air coefficient of the engine; determining an actual excess air coefficient of the engine based on the rotational speed and the fuel injection quantity; and determining the working condition fluctuation value based on a ratio of the calibrated excess air coefficient to the actual excess air coefficient.

[0009] Optionally, when the working condition fluctuation value is greater than the preset working condition fluctuation value, the determining a NOx raw emission model value of the engine based on the rotational speed and the fuel injection quantity includes: determining a NOx raw emission calibration value based on the rotational speed and the fuel injection quantity; obtaining a first correction coefficient and a second correction coefficient; and determining the NOx raw emission model value based on the first correction coefficient, the second correction coefficient, and the NOx raw emission calibration value.

[0010] Optionally, obtaining the first correction coefficient includes: obtaining an intake air temperature value of the SCR system; and determining the first correction coefficient based on the intake air temperature value.

[0011] Optionally, obtaining the second correction coefficient includes: obtaining the rotational speed of the engine and the working condition fluctuation value; and determining the second correction coefficient based on the rotational speed and the working condition fluctuation value.

[0012] Optionally, after determining the urea injection quantity based on the NOx raw emission detection value, it includes: controlling the operation of a urea pump based on the urea injection quantity.

[0013] According to another aspect of the embodiments of the present application, a control device for vehicle exhaust emissions is further provided, including: an acquisition module that acquires the current rotational speed and fuel injection volume of the engine; a first analysis module that determines a working condition fluctuation value based on the rotational speed and the fuel injection volume; a second analysis module that determines whether the working condition fluctuation value is greater than a preset working condition fluctuation value; a third analysis module that, when the working condition fluctuation value is greater than the preset working condition fluctuation value, determines a NOx original emission model value of the engine based on the rotational speed and the fuel injection volume; a first execution module that determines a urea injection volume based on the NOx original emission model value; a fourth analysis module that, when the working condition fluctuation value is less than the preset working condition fluctuation value, acquires a NOx original emission detection value detected by a NOx original emission sensor; a second execution module that determines the urea injection volume based on the NOx original emission detection value.

[0014] Optionally, the control device for vehicle exhaust emissions further includes: a third execution module configured to control the operation of a urea pump based on the urea injection volume.

[0015] According to another aspect of the embodiments of the present application, an electronic device is further provided, including a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete mutual communication through the communication bus; among them, the memory is used to store a computer program; the processor is used to execute the method steps in any of the above embodiments by running the computer program stored on the memory.

[0016] According to another aspect of the embodiments of the present application, a computer-readable storage medium is further provided. A computer program is stored in the storage medium, and the computer program is configured to execute the method steps in any of the above embodiments when running.

[0017] The present application determines a working condition fluctuation value characterizing the fluctuation degree of the current working condition of the engine based on the current rotational speed and fuel injection volume of the engine. When the working condition fluctuation value is greater than the preset working condition fluctuation value, it indicates that the working condition of the engine undergoes a transient change at this time, and the original NOx emission value increases instantaneously. Since there is a delay in the detection of the NOx original emission sensor, in the present application, when the working condition of the engine undergoes a transient change, the current NOx original emission value is calibrated using the rotational speed and fuel injection volume, that is, the accurate NOx original emission model value is finally determined. The accurate urea injection volume is calculated using the calibrated NOx original emission model value with higher accuracy, increasing the reaction between urea and NOx compounds, and avoiding excessive vehicle exhaust emissions. When the working condition fluctuation value is less than the preset fluctuation value, it indicates that the working condition of the engine is in a steady state at this time, and the change amount of the NOx original emission value is small. At this time, even if there is a delay in the NOx original emission sensor, the impact is small within a few seconds. At the same time, when the engine is in a steady state, the change fluctuation of the NOx original emission value is small, but there may be an instantaneous increase in the NOx original emission value due to external environment or other working condition factors. If the NOx original emission value at this time is used as the basis for calculating the urea injection volume, it will cause an increase in the urea injection volume, which is not conducive to reducing vehicle tailpipe emissions. Therefore, when the working condition of the engine is in a steady state, the detected value of the NOx original emission sensor, that is, the NOx original emission detection value, is used for the NOx original emission value at this time, and the required urea injection volume is determined based on the NOx original emission detection value for exhaust gas treatment. Different NOx original emission value acquisition methods are applied when the engine is in different working conditions to ensure the accuracy and response speed of NOx original emission value detection under transient and steady states of the engine working condition, and effectively reduce the NOx tailpipe emissions of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings herein are incorporated into and constitute a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 is a schematic flowchart of an optional vehicle exhaust emission control method according to an embodiment of the present application;

[0021] Figure 2 is another schematic flowchart of an optional vehicle exhaust emission control method according to an embodiment of the present application;

[0022] Figure 3 is a structural block diagram of an optional vehicle exhaust emission control device according to an embodiment of the present application;

[0023] Figure 4 It is a structural block diagram of an optional electronic device according to an embodiment of the present application. Detailed implementation manners

[0024] In order to enable those skilled in the art of the present technology to better understand the solution of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0026] As described in the background art, the time for the exhaust gas generated by the engine to pass through the SCR system is basically less than 0.1 s, and the change range of the original NOx emission in a short time may reach more than 1000 ppm. The real-time accuracy of the original NOx emission detection has a significant impact on the real-time accuracy of urea injection. The current technical requirement for the NOx sensor is that the T90 response time is less than 3900 ms. Through experimental data analysis, it shows that the response time of the current NOx sensor is 2 s - 5 s, and the urea injection delay time is also 2 - 5 s, resulting in incorrect moments for the increase or decrease of the urea injection amount, so that the injected urea cannot react with the NOx in the exhaust gas in time, resulting in a high tailpipe emission.

[0027] Therefore, according to one aspect of the embodiments of the present application, a method for controlling vehicle exhaust emissions is provided. Refer to Figure 1 and Figure 2 As shown, the process of this method may include the following steps:

[0028] S10. Obtain the current rotational speed and fuel injection amount of the engine.

[0029] S20. Determine a working condition fluctuation value based on the rotational speed and the fuel injection quantity, where the working condition fluctuation value characterizes the degree of working condition fluctuation of the engine.

[0030] S30. Determine whether the working condition fluctuation value is greater than a preset working condition fluctuation value.

[0031] S40. When the working condition fluctuation value is greater than the preset working condition fluctuation value, determine a NOx raw emission model value of the engine based on the rotational speed and the fuel injection quantity.

[0032] S50. Determine a urea injection quantity based on the NOx raw emission model value.

[0033] S60. When the working condition fluctuation value is less than the preset working condition fluctuation value, obtain a NOx raw emission detection value detected by a NOx raw emission sensor.

[0034] S70. Determine the urea injection quantity based on the NOx raw emission detection value.

[0035] In this embodiment, a working condition fluctuation value characterizing the degree of fluctuation of the current working condition of the engine is determined by the current rotational speed and fuel injection quantity of the engine. When the working condition fluctuation value is greater than the preset working condition fluctuation value, it indicates that the working condition of the engine undergoes a transient change at this time, and the NOx raw emission value increases instantaneously. Since there is a delay in the detection of the NOx raw emission sensor, in this application, when the working condition of the engine undergoes a transient change, the rotational speed and fuel injection quantity are used to calibrate the current NOx raw emission value, that is, the NOx raw emission model value. After calibration, an accurate urea injection quantity is calculated using the NOx raw emission model value with higher accuracy, increasing the reaction between urea and NOx compounds, and avoiding excessive vehicle exhaust emissions. When the working condition fluctuation value is less than the preset fluctuation value, it indicates that the working condition of the engine is in a steady state at this time, and the change in the NOx raw emission value is small. At this time, even if there is a delay in the NOx raw emission sensor, the impact is small within a few seconds. At the same time, when the engine is in a steady state, the change in the NOx raw emission value fluctuates slightly, but there may be an instantaneous increase in the NOx raw emission value due to external environment or other working condition factors. If the NOx raw emission value at this time is used as the basis for calculating the urea injection quantity, it will cause an increase in the urea injection quantity, which is not conducive to reducing vehicle tail emissions. Therefore, when the working condition of the engine is in a steady state, the detection value of the NOx raw emission sensor, that is, the NOx raw emission detection value, is used for the NOx raw emission value at this time, and the required urea injection quantity is determined based on the NOx raw emission detection value for tail gas treatment. Different NOx raw emission value acquisition methods are applied when the engine is in different working conditions to ensure the accuracy and response speed of NOx raw emission value detection under transient and steady states of the engine working condition, and effectively reduce the NOx tail emissions of the engine.

[0036] Among them, the preset working condition fluctuation value is configured as the critical value for the engine to switch from a steady state working condition to a transient working condition, and can be measured through a bench test.

[0037] As an exemplary embodiment, determining the operating condition fluctuation value based on the rotational speed and the fuel injection quantity includes: obtaining the calibrated excess air coefficient of the engine; determining the actual excess air coefficient of the engine based on the rotational speed and the fuel injection quantity; and determining the operating condition fluctuation value based on the ratio of the calibrated excess air coefficient to the actual excess air coefficient.

[0038] In this embodiment, the operating condition fluctuation value characterizes the degree of operating condition fluctuation of the engine. During bench tests, the calibrated excess air coefficient corresponding to the rotational speed and fuel injection quantity when the engine is in a steady state can be measured. During actual detection, the actual excess air coefficient is determined based on the actual rotational speed and actual fuel injection quantity of the current engine. The ratio of the calibrated excess air coefficient to the actual excess air coefficient is used as the operating condition fluctuation value. According to the magnitude of the ratio, the deviation degree of the current operating condition of the engine from the operating condition when the engine is in a steady state can be determined, and then which state the current operating condition of the engine is in can be determined.

[0039] As an exemplary embodiment, when the operating condition fluctuation value is greater than a preset operating condition fluctuation value, determining the NOx raw emission model value of the engine based on the rotational speed and the fuel injection quantity includes: determining the NOx raw emission calibration value based on the rotational speed and the fuel injection quantity; obtaining a first correction coefficient and a second correction coefficient; and determining the NOx raw emission model value based on the first correction coefficient, the second correction coefficient, and the NOx raw emission calibration value.

[0040] In this embodiment, when determining the NOx raw emission calibration value based on the rotational speed and the fuel injection quantity, since the intake air temperature and air volume of the SCR system will affect the value of ammonia storage, and thus affect the reaction quantity of NOx compounds, therefore, the NOx raw emission calibration value can be corrected based on parameters such as the intake air temperature of the SCR system, the engine rotational speed, and the operating condition fluctuation value, that is, the NOx raw emission calibration value is corrected using the first correction coefficient and the second correction coefficient, so as to obtain the accurate current NOx raw emission value of the engine, that is, the NOx raw emission model value, and further improve the accuracy of NOx raw emission value detection.

[0041] As an exemplary embodiment, obtaining the first correction coefficient includes: obtaining the intake air temperature value of the SCR system; and determining the first correction coefficient based on the intake air temperature value. Obtaining the second correction coefficient includes: obtaining the rotational speed and the operating condition fluctuation value of the engine; and determining the second correction coefficient based on the rotational speed and the operating condition fluctuation value.

[0042] In this embodiment, the first correction coefficient can be determined based on the intake air temperature value. During bench tests, the corresponding first correction coefficient is measured based on the intake air temperature values of different SCR systems to form a table of intake air temperature values and the first correction coefficient, which is then input into the vehicle's control unit or ECU. During actual detection, the vehicle can directly look up the corresponding first correction coefficient according to the current intake air temperature value, reducing the amount of computation. Similarly, for the determination of the second correction coefficient, during bench tests, the corresponding second correction coefficient can be determined based on different engine speeds and operating condition fluctuation values, and a MAP table is formed and input into the value control unit or ECU. When the engine speed and operating condition fluctuation values are obtained, the corresponding second correction coefficient can be determined by looking up the MAP diagram, reducing the amount of computation.

[0043] As an exemplary embodiment, after determining the urea injection amount based on the NOx raw emission detection value, it includes: controlling the urea pump to operate based on the urea injection amount.

[0044] In this embodiment, after determining the corresponding NOx raw emission value based on the current engine operating condition and then determining the current required urea injection amount, the vehicle's control unit or ECU controls the urea pump to perform corresponding injection based on the calculated urea injection amount to complete the catalysis of NOx compounds and reduce the vehicle's tailpipe emissions.

[0045] According to another aspect of the embodiments of the present application, a control device for vehicle exhaust emissions is provided. Refer to Figure 3 as shown, including:

[0046] An acquisition module 301, which acquires the current engine speed and fuel injection amount;

[0047] A first analysis module 302, which determines the operating condition fluctuation value based on the engine speed and the fuel injection amount;

[0048] A second analysis module 303, which determines whether the operating condition fluctuation value is greater than a preset operating condition fluctuation value;

[0049] A third analysis module 304, when the operating condition fluctuation value is greater than the preset operating condition fluctuation value, determines the NOx raw emission model value of the engine based on the engine speed and the fuel injection amount;

[0050] A first execution module 305, which determines the urea injection amount based on the NOx raw emission model value;

[0051] A fourth analysis module 306, when the operating condition fluctuation value is less than the preset operating condition fluctuation value, acquires the NOx raw emission detection value detected by the NOx raw emission sensor;

[0052] A second execution module 307, which determines the urea injection amount based on the NOx raw emission detection value.

[0053] It should be noted that the acquisition module 301 in this embodiment can be used to execute the above step S10, the first analysis module 302 in this embodiment can be used to execute the above step S20, the second analysis module 303 in this embodiment can be used to execute the above step S30, the third analysis module 304 in this embodiment can be used to execute the above step S40, the first execution module 305 in this embodiment can be used to execute the above step S50, the fourth analysis module 306 in this embodiment can be used to execute the above step S60, and the second execution module 307 in this embodiment can be used to execute the above step S70.

[0054] As an exemplary embodiment, the vehicle exhaust emission control device further includes: a third execution module for controlling the operation of the urea pump based on the urea injection amount.

[0055] According to another aspect of the embodiments of the present application, an electronic device is provided, including a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete mutual communication through the communication bus. The memory is used to store a computer program; the processor is used to execute the vehicle exhaust emission control method described in any one of the above embodiments by running the computer program stored on the memory.

[0056] Figure 4 is a structural block diagram of an optional electronic device according to an embodiment of the present application. As Figure 4 shown, it includes a processor 402, a communication interface 404, a memory 406, and a communication bus 408. Among them, the processor 402, the communication interface 404, and the memory 406 complete mutual communication through the communication bus 408. Among them,

[0057] The memory 406 is used to store a computer program;

[0058] When the processor 402 is used to execute the computer program stored on the memory 406, the following steps are implemented:

[0059] Obtain the current engine speed and fuel injection amount;

[0060] Determine a working condition fluctuation value based on the speed and the fuel injection amount, and the working condition fluctuation value characterizes the degree of working condition fluctuation of the engine;

[0061] Judge whether the working condition fluctuation value is greater than a preset working condition fluctuation value;

[0062] When the working condition fluctuation value is greater than the preset working condition fluctuation value, determine the NOx original emission model value of the engine based on the speed and the fuel injection amount;

[0063] Determine the urea injection amount based on the NOx raw emission model value;

[0064] When the operating condition fluctuation value is less than the preset operating condition fluctuation value, obtain the NOx raw emission detection value detected by the NOx raw emission sensor;

[0065] Determine the urea injection amount based on the NOx raw emission detection value.

[0066] Optionally, in this embodiment, the above communication bus may be a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For the sake of convenience of representation, Figure 4 only a thick line is used to represent it in the figure, but it does not mean that there is only one bus or one type of bus.

[0067] The communication interface is used for communication between the above electronic device and other devices.

[0068] The memory may include a RAM, and may also include a non-volatile memory, for example, at least one disk memory. Optionally, the memory may also be at least one storage device located far from the aforementioned processor.

[0069] According to another aspect of the embodiments of the present application, a computer-readable storage medium is provided, in which a computer program is stored, and the computer program is configured to execute the vehicle exhaust emission control method described in any one of the above embodiments when running.

[0070] Optionally, in this embodiment, the storage medium is configured to store program codes for executing the following steps:

[0071] Obtain the current engine speed and fuel injection amount;

[0072] Determine the operating condition fluctuation value based on the engine speed and the fuel injection amount, and the operating condition fluctuation value characterizes the degree of operating condition fluctuation of the engine;

[0073] Judge whether the operating condition fluctuation value is greater than the preset operating condition fluctuation value;

[0074] When the operating condition fluctuation value is greater than the preset operating condition fluctuation value, determine the NOx raw emission model value of the engine based on the engine speed and the fuel injection amount;

[0075] Determine the urea injection amount based on the NOx raw emission model value;

[0076] When the working condition fluctuation value is less than the preset working condition fluctuation value, obtain the NOx original emission detection value detected by the NOx original emission sensor;

[0077] Determine the urea injection amount based on the NOx original emission detection value.

[0078] Optionally, the specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be elaborated herein.

[0079] Optionally, in this embodiment, the above storage medium may include, but is not limited to: various media such as USB flash drives, ROMs, RAMs, mobile hard disks, magnetic disks, or optical discs that can store program codes.

[0080] The serial numbers of the embodiments of the present application above are only for description and do not represent the superiority or inferiority of the embodiments.

[0081] It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present application.

[0082] The above is only the preferred implementation manner of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A method for controlling vehicle exhaust emissions, characterized in that, Including: Obtain the current engine speed and fuel injection quantity; Determine a working condition fluctuation value based on the engine speed and the fuel injection quantity, where the working condition fluctuation value characterizes the degree of working condition fluctuation of the engine; Judge whether the working condition fluctuation value is greater than a preset working condition fluctuation value; When the working condition fluctuation value is greater than the preset working condition fluctuation value, determine the NOx raw emission model value of the engine based on the engine speed and the fuel injection quantity; Determine the urea injection quantity based on the NOx raw emission model value; When the working condition fluctuation value is less than the preset working condition fluctuation value, obtain the NOx raw emission detection value detected by a NOx raw emission sensor; Determine the urea injection quantity based on the NOx raw emission detection value; Wherein, the determining the working condition fluctuation value based on the engine speed and the fuel injection quantity includes: Obtain the calibrated excess air coefficient of the engine; Determine the actual excess air coefficient of the engine based on the engine speed and the fuel injection quantity; Determine the working condition fluctuation value based on the ratio of the calibrated excess air coefficient to the actual excess air coefficient; When the working condition fluctuation value is greater than the preset working condition fluctuation value, the determining the NOx raw emission model value of the engine based on the engine speed and the fuel injection quantity includes: Determine the NOx raw emission calibration value based on the engine speed and the fuel injection quantity; Obtain a first correction coefficient and a second correction coefficient; Determine the NOx raw emission model value based on the first correction coefficient, the second correction coefficient and the NOx raw emission calibration value; Obtaining the first correction coefficient includes: Obtain the intake air temperature value of the SCR system; Determine the first correction coefficient based on the intake air temperature value; Obtaining the second correction coefficient includes: Obtain the engine speed and the working condition fluctuation value; Determine the second correction coefficient based on the engine speed and the working condition fluctuation value.

2. The control method for vehicle exhaust emissions according to claim 1, wherein, After determining the urea injection quantity based on the NOx raw emission model value or the NOx raw emission detection value, it includes: Control the urea pump to work based on the urea injection quantity.

3. A control device for vehicle exhaust emissions, the device being controlled by using the control method for vehicle exhaust emissions described in claim 1 or 2, characterized in that, Including: An acquisition module, which acquires the current engine speed and fuel injection quantity; A first analysis module, which determines a working condition fluctuation value based on the engine speed and the fuel injection quantity; A second analysis module, which judges whether the working condition fluctuation value is greater than a preset working condition fluctuation value; A third analysis module, which determines the NOx raw emission model value of the engine based on the engine speed and the fuel injection quantity when the working condition fluctuation value is greater than the preset working condition fluctuation value; A first execution module, which determines the urea injection quantity based on the NOx raw emission model value; A fourth analysis module, which acquires the NOx raw emission detection value detected by a NOx raw emission sensor when the working condition fluctuation value is less than the preset working condition fluctuation value; A second execution module, which determines the urea injection quantity based on the NOx raw emission detection value.

4. The control device for vehicle exhaust emissions according to claim 3, characterized in that, It further includes: A third execution module, which is used to control the urea pump to work based on the urea injection quantity.

5. An electronic device, comprising a processor, a communication interface, a memory, and a communication bus, wherein, The processor, the communication interface and the memory complete communication with each other through the communication bus. It is characterized in that The memory is used to store computer programs; The processor is used to execute the control method for vehicle exhaust emissions according to claim 1 or 2 by running the computer programs stored on the memory.

6. A computer-readable storage medium, characterized in that, A computer program is stored in the storage medium, wherein the computer program is configured to execute the method for controlling vehicle exhaust emissions according to claim 1 or 2 when running.

Images