Method, device and electronic controller for controlling vehicle engine exhaust gas recirculation

Abstract

This application relates to a control method, apparatus, electronic controller, storage medium, and computer program product for exhaust gas recirculation (EGR) of a vehicle engine. The method includes: acquiring the current desired flow rate and the current actual flow rate of the target gas in a target cylinder of the vehicle engine; determining the current work fraction based on the number of cylinders performing work at the current time; determining a first mapping curve corresponding to the current work fraction; determining a current open-loop control quantity based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed; determining a target speed based on the difference between the current actual flow rate and the current desired flow rate, and the current open-loop control quantity; and controlling the target pump in the target cylinder to operate according to the target speed to achieve exhaust gas recirculation. This allows for precise control of exhaust gas recirculation.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a control method, device, electronic controller, storage medium, and computer program product for vehicle engine exhaust gas recirculation. Background Technology

[0002] With the development of vehicle technology, more and more people are buying and using vehicles to meet their travel needs. Since vehicles produce exhaust gases that are harmful to the environment when they are running, exhaust gas recirculation technology can be used to reduce exhaust emissions.

[0003] In related technologies, passive EGR (Exhaust Gas Recirculation) valves are typically used to increase the EGR rate (the ratio of recirculated exhaust gas to the total intake air volume into the cylinder), thereby reducing the amount of exhaust gas emitted. However, under different engine operating conditions, uneven power delivery can occur, making it difficult for related technologies to precisely control exhaust gas recirculation. Summary of the Invention

[0004] Therefore, it is necessary to provide a control method, device, electronic controller, computer-readable storage medium, and computer program product for vehicle engine exhaust gas recirculation that can accurately control exhaust gas recirculation, addressing the aforementioned technical problems.

[0005] In a first aspect, this application provides a control method for exhaust gas recirculation in a vehicle engine, comprising:

[0006] The current desired flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine are obtained, wherein the target gas is exhaust gas used for recirculation.

[0007] The current work fraction is determined based on the number of cylinders performing work in the current cycle.

[0008] A first mapping curve corresponding to the current work fraction is determined. The first mapping curve is a curve in which the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control.

[0009] The current open-loop control quantity is determined based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed.

[0010] Based on the difference between the current actual flow rate and the current expected flow rate, as well as the current open-loop control quantity, the target speed is determined, and the target pump in the target cylinder is controlled to operate according to the target speed to achieve exhaust gas recirculation.

[0011] Secondly, this application also provides a control device for exhaust gas recirculation in a vehicle engine, comprising:

[0012] The flow acquisition module is used to acquire the current expected flow rate and the current actual flow rate of the target gas in the target cylinder of the vehicle engine, wherein the target gas is exhaust gas used for recirculation.

[0013] The work fraction determination module is used to determine the current work fraction based on the number of cylinders performing work in a cycle at the current moment.

[0014] The mapping curve determination module is used to determine the first mapping curve corresponding to the current work fraction. The first mapping curve is the curve in which the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, the engine speed, and the desired flow rate under open-loop flow control.

[0015] The open-loop control quantity determination module is used to determine the current open-loop control quantity based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed.

[0016] The speed determination module is used to determine the target speed based on the difference between the current actual flow rate and the current expected flow rate, as well as the current open-loop control quantity, and to control the target pump in the target cylinder to operate according to the target speed in order to achieve exhaust gas recirculation.

[0017] Thirdly, this application also provides an electronic controller, including a memory and a microcontroller, wherein the memory stores a computer program, and the microcontroller executes the computer program to perform the following steps:

[0018] The current desired flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine are obtained, wherein the target gas is exhaust gas used for recirculation.

[0019] The current work fraction is determined based on the number of cylinders performing work in the current cycle.

[0020] A first mapping curve corresponding to the current work fraction is determined. The first mapping curve is a curve in which the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control.

[0021] The current open-loop control quantity is determined based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed.

[0022] Based on the difference between the current actual flow rate and the current expected flow rate, as well as the current open-loop control quantity, the target speed is determined, and the target pump in the target cylinder is controlled to operate according to the target speed to achieve exhaust gas recirculation.

[0023] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a microcontroller, performs the following steps:

[0024] The current desired flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine are obtained, wherein the target gas is exhaust gas used for recirculation.

[0025] The current work fraction is determined based on the number of cylinders performing work in the current cycle.

[0026] A first mapping curve corresponding to the current work fraction is determined. The first mapping curve is a curve in which the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control.

[0027] The current open-loop control quantity is determined based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed.

[0028] Based on the difference between the current actual flow rate and the current expected flow rate, as well as the current open-loop control quantity, the target speed is determined, and the target pump in the target cylinder is controlled to operate according to the target speed to achieve exhaust gas recirculation.

[0029] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a microcontroller, performs the following steps:

[0030] The current desired flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine are obtained, wherein the target gas is exhaust gas used for recirculation.

[0031] The current work fraction is determined based on the number of cylinders performing work in the current cycle.

[0032] A first mapping curve corresponding to the current work fraction is determined. The first mapping curve is a curve in which the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control.

[0033] The current open-loop control quantity is determined based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed.

[0034] Based on the difference between the current actual flow rate and the current expected flow rate, as well as the current open-loop control quantity, the target speed is determined, and the target pump in the target cylinder is controlled to operate according to the target speed to achieve exhaust gas recirculation.

[0035] The aforementioned vehicle engine exhaust gas recirculation control method, device, electronic controller, storage medium, and computer program product acquire the current desired flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine. The target gas is the exhaust gas used for recirculation. The current work fraction is determined based on the number of cylinders currently performing work recirculation. This current work fraction reflects the engine's work performance and effectively distinguishes whether it is in a non-uniform work state. A first mapping curve corresponding to the current work fraction is determined. This first mapping curve shows how the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control. Thus, based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed, the current open-loop control quantity matching the work performance can be accurately determined. Based on the difference between the current actual flow rate and the current desired flow rate, and the current open-loop control quantity, the target speed matching the work performance is accurately determined, and the target pump in the target cylinder is controlled according to the target speed to achieve exhaust gas recirculation. Therefore, the target speed is adaptively determined by considering the actual working conditions of the vehicle engine in order to achieve precise control of exhaust gas recirculation. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the internal structure of a vehicle engine in one embodiment;

[0038] Figure 2 This is an application environment diagram of a vehicle engine exhaust gas recirculation control method in one embodiment.

[0039] Figure 3 This is a flowchart illustrating a control method for exhaust gas recirculation in a vehicle engine, as shown in one embodiment.

[0040] Figure 4 This is a flowchart illustrating the steps for determining the enable flag in one embodiment;

[0041] Figure 5 This is a flowchart illustrating the determination of open-loop control quantities in one embodiment;

[0042] Figure 6 This is a schematic diagram illustrating the process of determining the current expected traffic in one embodiment;

[0043] Figure 7This is a schematic diagram illustrating the steps for determining the current actual traffic flow in one embodiment;

[0044] Figure 8 This is a flowchart illustrating the process of determining the target control quantity in one embodiment;

[0045] Figure 9 This is a schematic diagram illustrating the determination of the target rotational speed in one embodiment;

[0046] Figure 10 This is a structural block diagram of a vehicle engine exhaust gas recirculation control device in one embodiment;

[0047] Figure 11 This is a diagram of the internal structure of the electronic controller in one embodiment.

[0048] Explanation of reference numerals in the attached figures:

[0049] 010. Turbocharger; 020. Intercooler; 021. Intake throttle body; 030. Intake valve; 040. Diesel injector; 050. Exhaust valve; 060. Engine piston connecting rod; 070. Exhaust gas intercooler; 080. Electric EGR pump; 081. EGR pump power supply; 090. High-pressure fuel pump; 091. Common rail; 092. Rail pressure sensor; 093. High-pressure pump control valve; 011. Intake air flow sensor; 012. NOx sensor; 022. Intake air temperature and pressure sensor; 063. EGR pump upstream pressure sensor; 061. EGR pump downstream pressure sensor; 062. EGR pump downstream temperature sensor. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0051] To better understand the solution of this application, the structure of the vehicle engine provided in the embodiments of this application will be introduced first, such as... Figure 1 The diagram shown is a schematic representation of the internal structure of a vehicle engine in one embodiment. Figure 1For the meanings of the numbers in the diagram, please refer to the aforementioned annotations. Its core components include: turbocharger, intake throttle valve, intake valve, diesel injector, exhaust valve, engine piston connecting rod, electric EGR (Exhaust Gas Recirculation) pump, EGR pump power supply, high-pressure fuel pump, and common rail. Its core sensors include: intake air flow sensor, NOx (nitrogen oxides) sensor, intake air temperature and pressure sensor, upstream pressure sensor of EGR pump, downstream pressure sensor of EGR pump, and downstream temperature sensor of EGR pump. Its basic working principle is as follows: the intake air flow sensor determines the intake air sensor readings. Ambient air, after passing through the turbocharger and being cooled by the intercooler, is throttled by the intake throttle valve and then mixes with the cooled exhaust gas from the engine, which has passed through the intercooler and the electric EGR pump. During the intake stroke, this mixture enters the engine cylinders through the intake valves. The intake air temperature and pressure sensors, installed at the intake manifold, measure the intake air temperature and pressure, thereby calculating the total intake air volume. The upstream pressure sensor, downstream pressure sensor, and downstream temperature sensor of the EGR pump can measure the upstream pressure, downstream temperature, and pressure of the EGR pump in real time. Simultaneously, low-pressure fuel in the tank passes through the high-pressure pump control valve and is pressurized by the high-pressure pump before being pumped into the common rail. The rail pressure sensor on the common rail can measure the internal pressure. The diesel injector is connected to the common rail via a high-pressure fuel line. During the engine's compression stroke, when the piston reaches top dead center, the diesel injector injects high-pressure fuel into the engine cylinder to mix with the internal high-pressure air. During the power stroke, it performs work, releasing energy to drive the piston and crankshaft, outputting torque. During the exhaust stroke, the gas in the cylinder enters the exhaust pipe through the exhaust valve. The NOx sensor can measure the original exhaust air-fuel ratio. In operations where not all cylinders are performing power: during the intake stroke of the cylinder that is not performing power, the intake valve is closed to prevent the mixture in the intake manifold from entering the cylinder; during its compression process, the diesel injector does not inject fuel; during its exhaust stroke, the exhaust valve remains closed.

[0052] The vehicle engine exhaust gas recirculation control method provided in this application embodiment can be applied to, for example... Figure 2 In the application environment shown, the electronic controller 202 communicates with the vehicle engine 204. For example, the electronic controller 202 communicates with the vehicle engine 204 via a wired connection, such as a data cable in the vehicle. Specifically, the electronic controller 202 communicates with each device in the vehicle engine 204, which are the aforementioned devices. Figure 1 The sensor mentioned in the text.

[0053] In some embodiments, the electronic controller 202 acquires sensing data sent by the vehicle engine 204. This sensing data is collected by various sensors in the vehicle engine 204 and includes the fuel injection quantity of each cylinder in the vehicle engine 204, the engine speed, and the number of cylinders currently performing power. After receiving sensor data, the electronic controller 202 acquires the current desired flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine. The target gas is the exhaust gas used for recirculation. The electronic controller 202 determines the current work fraction based on the number of cylinders performing work at the current moment. The electronic controller 202 determines a first mapping curve corresponding to the current work fraction. The first mapping curve is a curve showing how the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control. The electronic controller 202 determines the current open-loop control quantity based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed. Based on the difference between the current actual flow rate and the current desired flow rate, as well as the current open-loop control quantity, the electronic controller 202 determines the target speed and controls the target pump in the target cylinder to operate according to the target speed to achieve exhaust gas recirculation.

[0054] The electronic controller is used to control the exhaust gas recirculation process of the vehicle engine. The electronic controller 202 can be, but is not limited to, a controller in a vehicle or other electronic device, such as an electronic controller in a car.

[0055] In one exemplary embodiment, such as Figure 3 As shown, a control method for exhaust gas recirculation in a vehicle engine is provided, which is applied to... Figure 2 Taking the electronic controller 202 as an example, the explanation includes the following steps S302 to S310. Wherein:

[0056] Step S302: Obtain the current expected flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine. The target gas is the exhaust gas used for recirculation.

[0057] The target gas is the exhaust gas in the exhaust gas recirculation (EGR) system. The vehicle engine includes at least one cylinder, and the flow rate in this embodiment refers to the EGR flow rate. The current expected flow rate refers to the target EGR flow rate at the current moment, and the current actual flow rate refers to the actual EGR flow rate at the current moment.

[0058] Optionally, the electronic controller determines the enable flag of the target pump in the vehicle engine and determines the current desired flow rate based on the enable flag. The electronic controller also determines the current operating condition flag of the vehicle engine at the current moment and determines the current actual flow rate based on the current operating condition flag. Here, the target pump refers to the pump that performs exhaust gas recirculation, which can also be understood as the EGR pump.

[0059] For example, the step of determining the enable flag bit includes: the electronic controller acquiring the system fault flag bit, the engine transient condition flag bit, and the engine braking flag bit at the current moment, and determining the enable flag bit based on the system fault flag bit, the engine transient condition flag bit, and the engine braking flag bit.

[0060] For example, such as Figure 4 The diagram shown is a flowchart illustrating the steps for determining the enable flag in one embodiment. Figure 4 The OR gate is used based on the OR and NOT gates; that is, the enable flag is 1 only when all three conditions—system fault flag, engine transient condition flag, and engine braking flag—are not met, indicating that the system is in an enabled operating state. Specifically, a system fault flag not being met means no fault has occurred, while a meeting of these conditions indicates a fault has occurred; an engine transient condition flag not being met means the system is not in a transient state, while a meeting of these conditions indicates the system is in a transient state; and an engine braking flag not being met means the system is not in a braking state, while a meeting of these conditions indicates the system is in a braking state. For example, the enable flag is set to 1 if at least one of the following occurs: a serious fault in the target pump power supply; a low SOC (State of Charge) in the target pump power supply; a mechanical fault in the target pump itself or its controller; or an abnormal engine exhaust temperature.

[0061] Step S304: Determine the current work fraction based on the number of cylinders performing work in the current cycle.

[0062] In a vehicle engine with multiple cylinders, there may be a situation where all cylinders are working in a cycle, in which case the vehicle engine is working evenly; or there may be a situation where at least one cylinder is not working, in which case the vehicle engine is working unevenly.

[0063] The power fraction reflects whether the engine of a vehicle is performing work evenly.

[0064] Optionally, the electronic controller acquires the total number of cylinders in the vehicle engine, determines the number of cylinders performing work cycles at the current moment, and uses the ratio of this number to the total number of cylinders as the current work fraction. The higher the work fraction, the more cylinders are performing work cycles, and the closer it is to uniform work.

[0065] Step S306: Determine the first mapping curve corresponding to the current work fraction. The first mapping curve is the curve in which the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control.

[0066] Among them, multiple first mapping curves are pre-stored. Each mapping curve is a curve in which the open-loop control quantity changes with the fuel injection quantity of the target cylinder, the engine speed and the desired flow rate under open-loop flow control.

[0067] Optionally, the electronic controller acquires a plurality of pre-stored first mapping curves and determines from the plurality of first mapping curves the first mapping curve corresponding to the current work fraction.

[0068] For example, multiple score ranges for work done are pre-stored, each score range uniquely corresponding to a first mapping curve. The electronic controller determines the score range to which the current work done score belongs, and sets the first mapping curve corresponding to the determined score range as the first mapping curve corresponding to the current work done score.

[0069] Step S308: Determine the current open-loop control quantity based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed.

[0070] Among them, the open-loop control quantity refers to the flow rate required to perform open-loop control.

[0071] For example, the electronic controller acquires the current desired flow rate, the current fuel injection quantity of the target cylinder at the current moment, and the current engine speed, and uses the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed to determine the current open-loop control quantity.

[0072] For example, such as Figure 5 The diagram shown illustrates the process of determining the open-loop control quantity in one embodiment. For example, if a vehicle engine has four cylinders, and three cylinders are currently performing power operations, the power fraction is 3 / 4. There are four first mapping curves: first mapping curve 1, first mapping curve 2, first mapping curve 3, and first mapping curve 4. At this point, the fraction range corresponding to 3 / 4 is the third fraction range, and the first mapping curve 3 corresponds to this third fraction range. To ensure the stability of the open-loop control, if the first mapping curve determined at the previous moment is different from the first mapping curve determined at the current moment, there will be a transition period to ensure that the open-loop control quantity does not experience excessive jumps.

[0073] Step S310: Determine the target speed based on the difference between the current actual flow rate and the current expected flow rate, as well as the current open-loop control quantity, and control the target pump in the target cylinder to operate according to the target speed, so as to achieve exhaust gas recirculation.

[0074] Optionally, the electronic controller calculates the difference between the current actual flow rate and the current desired flow rate, determines the target speed based on the sum of the difference and the current open-loop control quantity, and controls the operation of the target pump in the target cylinder based on the target speed to achieve exhaust gas recirculation.

[0075] For example, after calculating the sum, if the sum is less than or equal to the control threshold, the target speed is determined based on the sum. If the sum is greater than the control threshold, the target speed is determined based on the control threshold.

[0076] In the aforementioned control method for exhaust gas recirculation (EGR) of a vehicle engine, the current desired flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine are obtained. The target gas is the exhaust gas used for recirculation. The current work fraction is determined based on the number of cylinders currently performing work recirculation. This current work fraction reflects the engine's work performance and effectively distinguishes whether it is in a non-uniform work state. A first mapping curve corresponding to the current work fraction is determined. This first mapping curve is a curve showing how the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control. Thus, based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed, the current open-loop control quantity matching the work performance can be accurately determined. Based on the difference between the current actual flow rate and the current desired flow rate, and the current open-loop control quantity, the target speed matching the work performance is accurately determined. The target pump in the target cylinder is then controlled according to the target speed to achieve exhaust gas recirculation. Therefore, by adaptively determining the matching target speed considering the actual work performance of the vehicle engine, precise control of exhaust gas recirculation can be achieved.

[0077] In some embodiments, the step of determining the current desired flow rate includes: when it is determined that the target pump is in an enabled operating state, acquiring the operating mode of the vehicle engine and the gas shut-off state of the target cylinder; selecting a second mapping curve from a plurality of second mapping curves that matches the operating mode and the gas shut-off state, wherein the second mapping curve is a curve in which the desired flow rate changes with the fuel injection quantity of the target cylinder, the engine speed, and the intake air fraction; determining the current intake air fraction based on the number of cylinders that are normally intakeing at the current moment; and determining the current desired flow rate based on the current fuel injection quantity, the current intake air fraction, the current engine speed, and the selected second mapping curve.

[0078] The vehicle engine's operating mode is a specific mode chosen to meet the specific requirements of the aftertreatment system. Even under the same engine operating conditions, the expected EGR flow rate will differ across operating modes. Operating modes include normal mode and aftertreatment heating mode. For example, an operating mode value of 0 represents normal mode, and an operating mode value of 1 represents aftertreatment heating mode. The gas shut-off status reflects whether the corresponding cylinder is shut off. The second mapping curve is used to determine the expected flow rate. The intake fraction is the ratio of the number of cylinders with normally functioning intake and exhaust valves in the current engine cycle to the total number of cylinders; that is, the intake fraction better reflects the engine's intake status.

[0079] Optionally, when the electronic controller determines that the target pump is in an enabled working state, the electronic controller selects multiple second mapping curves that match the operating mode from multiple preset second mapping curves according to the operating mode of the vehicle engine; according to the gas stop state of the target cylinder, it selects a second mapping curve that matches the gas stop state from the multiple second mapping curves that match the operating mode, and determines the selected second mapping curve that matches the gas stop state as the second mapping curve at the current moment.

[0080] The electronic controller determines the current desired flow rate based on the current fuel injection quantity, current intake air fraction, current engine speed, and the selected second mapping curve for the current moment.

[0081] For example, such as Figure 6 The diagram illustrates the process for determining the current desired flow rate in one embodiment. When the electronic controller determines that the enable flag is 0, meaning the target pump is not in an enabled operating state, it directly determines the current desired flow rate as 0.

[0082] When the electronic controller determines that the enable flag is 1, meaning the target pump is in an enabled operating state, the electronic controller will select the operating mode. If the operating mode is normal mode, then the operating mode selection will be confirmed. Figure 6 The value 0 indicates that the second mapping curve 1 and the second mapping curve 2 are the second mapping curves that match the normal mode. Based on the gas outage state, the second mapping curve that matches the gas outage state is determined from the second mapping curve 1 and the second mapping curve 2. Similarly, if the operation mode is the post-treatment heating mode, then the operation mode selection is determined. Figure 6 The value 1 in the diagram refers to the second mapping curves 3 and 4, which are the second mapping curves matched with the aftertreatment heating mode. Based on the gas shut-off state, the second mapping curve matching the gas shut-off state is determined from the second mapping curves 3 and 4. For a four-cylinder engine, if the intake mode value is '1100', it means that cylinders 1 and 2 are intake, and cylinders 3 and 4 are shut off.

[0083] In this embodiment, when the target pump is determined to be in an enabled operating state, the operating mode of the vehicle engine and the gas shut-off state of the target cylinder are acquired. From multiple second mapping curves, a second mapping curve matching the operating mode and gas shut-off state is selected. The second mapping curve is a curve showing how the desired flow rate changes with the fuel injection quantity, engine speed, and intake air fraction of the target cylinder. Thus, based on the current fuel injection quantity, current intake air fraction, current engine speed, and the selected second mapping curve, the current desired flow rate is determined, thereby accurately estimating the current desired flow rate adapted to the current intake conditions of the vehicle engine.

[0084] In some embodiments, the step of determining the current actual flow rate includes: obtaining the current operating condition flag of the vehicle engine at the current moment; if the current operating condition flag represents a transient operating condition, obtaining the actual rotational speed of the target pump in the target cylinder; calculating the ratio of the downstream pressure to the upstream pressure of the target pump, and determining the current actual flow rate based on the actual rotational speed and the ratio.

[0085] Among them, the operating condition indicator reflects whether it belongs to a steady-state operating condition.

[0086] Optionally, the electronic controller acquires the current operating condition flag of the vehicle's engine at the current moment. If the current operating condition is determined to be transient, the electronic controller acquires the actual rotational speed of the target pump in the target cylinder. The electronic controller calculates the square root of the ratio of the downstream temperature of the target pump to the standard temperature; this square root value is the temperature correction factor.

[0087] The electronic controller determines the standard speed of the target pump based on the ratio of the actual speed to the temperature correction factor, thus standardizing the speed. The electronic controller then maps this standard speed to the standard flow rate of the target gas. Finally, the electronic controller performs a corresponding mapping based on the downstream pressure and temperature to obtain a flow correction factor, and the product of this flow correction factor and the standard flow rate is determined as the current actual flow rate.

[0088] It should be noted that the above method of determining the current actual flow rate under transient conditions is one of several methods for determining the actual flow rate.

[0089] When the current operating condition is not a transient condition, the electronic controller selects the appropriate method for determining the actual flow rate at the current moment from among multiple methods for determining the actual flow rate.

[0090] For example, when the current operating condition is not a transient condition, the electronic controller determines a target determination method from multiple preset actual flow determination methods based on the current operating condition indicator, current engine speed, current fuel injection quantity, and current power fraction. The preset actual flow determination methods include a first determination method, a second determination method, and a third determination method. For instance, by acquiring the mapping relationship between the operating condition indicator, engine speed, fuel injection quantity, power fraction, and actual flow determination methods, the target determination method can be determined based on this mapping relationship.

[0091] like Figure 7 The diagram illustrates the steps for determining the current actual flow rate in one embodiment. First, the electronic controller determines the current operating condition flag. If the current operating condition flag indicates a transient operating condition, the electronic controller uses a second determination method to calculate the current actual flow rate, i.e., it returns to the step of obtaining the actual speed of the target pump in the target cylinder and continues execution.

[0092] When the current operating condition indicator represents a steady-state operating condition, the electronic controller maps the current operating condition indicator, current engine speed, current fuel injection quantity, and current power fraction to determine the corresponding target determination method.

[0093] If the target determination method is the first determination method, the electronic controller acquires the measurement values ​​obtained from the original exhaust air-fuel ratio related sensors, determines the fresh air quantity based on these measurement values, and determines the current actual flow rate based on the difference between the total intake air volume and the information air quantity. The measurement values ​​from the original exhaust air-fuel ratio related sensors can be the oxygen concentration measured by the NOx sensor or the oxygen concentration measured by the margin oxygen sensor. The engine's air-fuel ratio can be calculated based on the acquired oxygen concentration, and the fresh air quantity is obtained by multiplying the current cylinder injection quantity by the air-fuel ratio.

[0094] If the target determination method is the second determination method, the electronic controller will return to the above steps of obtaining the actual speed of the target pump in the target cylinder and continue to execute.

[0095] If the target determination method is the third determination method, the electronic controller will determine the current actual flow rate as the difference between the total intake air volume and the measurement value of the intake sensor. The intake sensor measurement value can obtain the intake air flow rate.

[0096] Therefore, it can be seen that the second determination method is more suitable for transient operating conditions. Of course, it can also be used under steady-state operating conditions. The first and second determination methods determine the air flow in different ways. The first determination method is determined by the air-fuel ratio, while the third determination method is obtained directly from the intake sensor.

[0097] Of course, to ensure the stability of the actual flow determination process, if the determination method at the previous moment is different from the determination method at the current moment, there will be a corresponding transition period to achieve a smooth transition of the determination method.

[0098] In this embodiment, under the condition that the current operating condition flag represents a transient operating condition, the actual rotational speed of the target pump in the target cylinder is obtained; the ratio of the downstream pressure to the upstream pressure of the target pump is calculated, and based on the actual rotational speed and the ratio, the current actual flow rate can be determined in real time and accurately. This ensures the accuracy of subsequent exhaust gas recirculation control.

[0099] In some embodiments, determining the target speed based on the difference between the current actual flow rate and the current desired flow rate, and the current open-loop control quantity, includes: determining the closed-loop control quantity for flow closed-loop control based on the difference between the current actual flow rate and the current desired flow rate; determining the target control quantity based on the sum of the closed-loop control quantity and the open-loop control quantity; acquiring a third mapping curve when the target pump is in an enabled operating state, the third mapping curve being a curve showing how the target pump speed changes with the control quantity and the exhaust flow rate; acquiring the current exhaust flow rate at the current moment, and determining the target speed based on the third mapping curve, the target control quantity, and the current exhaust flow rate.

[0100] The target control variable can be understood as the EGR control variable, which can be understood as the ideal flow rate.

[0101] Optionally, the electronic controller uses a closed-loop controller to determine the closed-loop control quantity for flow closed-loop control based on the difference between the current actual flow and the current expected flow, and then superimposes the closed-loop control quantity and the open-loop control quantity to obtain the sum.

[0102] The electronic controller acquires the fourth mapping curve, which shows how the control quantity threshold changes with engine speed, fuel injection quantity, and power fraction. Based on the current engine speed, current fuel injection quantity, and current power fraction, the control quantity threshold for the current moment is determined.

[0103] Based on the control threshold and the sum, the target control quantity is determined. With the target pump in the enabled operating state, the third mapping curve is obtained, which is the curve showing how the target pump speed changes with the control quantity and exhaust flow rate. The current exhaust flow rate at the current moment is obtained, and the target speed is determined based on the third mapping curve, the target control quantity, and the current exhaust flow rate.

[0104] In some embodiments, determining a target control quantity based on the sum of the closed-loop control quantity and the open-loop control quantity includes: determining a control quantity threshold; if the sum is less than or equal to the control quantity threshold, determining the sum as the target control quantity; if the sum is greater than the control quantity threshold, determining the control quantity threshold as the target control quantity.

[0105] For example, such as Figure 8 The diagram illustrates the process of determining the target control quantity in one embodiment. The electronic controller determines the control quantity threshold for the current moment using a fourth mapping curve, based on the current engine speed, current fuel injection quantity, and current power fraction. The electronic controller then determines the closed-loop control quantity for flow closed-loop control using a closed-loop controller, based on the difference between the current actual flow rate and the current desired flow rate. The closed-loop control quantity and the open-loop control quantity are then superimposed to obtain a sum. The minimum value between the sum and the control threshold is determined and set as the target control quantity.

[0106] Based on this, by comparing the sum and the control threshold, the minimum value between the two is determined as the target control quantity. This avoids the target control quantity from exceeding the limit and ensures the effectiveness of exhaust gas recirculation.

[0107] In this embodiment, the closed-loop control quantity for flow control is determined based on the difference between the current actual flow rate and the current desired flow rate. The target control quantity for flow control can be accurately determined based on the sum of the closed-loop and open-loop control quantities. With the target pump in an enabled operating state, a third mapping curve is obtained, which shows how the target pump's rotational speed changes with the control quantity and exhaust flow rate. The current exhaust flow rate is obtained, and based on the third mapping curve, the target control quantity, and the current exhaust flow rate, a matching target rotational speed is quickly and efficiently determined. Thus, the exhaust gas recirculation process at the target rotational speed takes into account the vehicle engine's work output, enabling reasonable and efficient control.

[0108] In some embodiments, the method further includes: acquiring a fault flag bit when the target pump is not in an enabled operating state; determining the current fault type when the fault flag bit indicates a fault; determining the speed corresponding to the current fault type from pre-stored speed data, wherein the speed data stores the speed corresponding to each fault type; and determining the speed corresponding to the current fault type as the target speed of the target pump.

[0109] For example, such as Figure 9The diagram illustrates the determination of the target speed in one embodiment. When the target pump is in an enabled operating state (i.e., the enable flag is 1), the electronic controller determines the target speed based on the third mapping curve, the target control quantity, and the current exhaust flow rate. When the target pump is not in an enabled operating state (i.e., the enable flag is 0), the electronic controller determines the value of the fault flag. If the fault flag indicates a fault (i.e., the fault flag is 1), the current fault type is determined. The speed corresponding to the current fault type is determined from pre-stored speed data, which stores the speeds corresponding to each fault type. The speed corresponding to the current fault type is then determined as the target speed of the target pump.

[0110] If no fault is indicated by the fault flag, the electronic controller determines the current operating condition flag. If the current operating condition flag is 1, the current operating condition is determined to be a transient condition, and the electronic controller determines the speed corresponding to the transient condition that is stored in advance as the target speed.

[0111] If the current operating condition flag is not 1, indicating a steady-state condition, the electronic controller determines the engine braking flag. If the engine braking flag is 1, it means the engine is currently braking, and the speed corresponding to the pre-stored braking state is determined as the target speed. If the engine braking flag is not 1, it means the engine is currently malfunctioning, i.e., the fault flag should be 1, not 0. In this case, the current fault type is determined; the speed corresponding to the current fault type is determined from the pre-stored speed data, which stores the speed corresponding to each fault type; and the speed corresponding to the current fault type is determined as the target speed of the target pump.

[0112] In this embodiment, when the target pump is not in an enabled operating state, a fault flag is acquired; if the fault flag indicates a fault, the current fault type is determined; the speed corresponding to the current fault type is determined from pre-stored speed data, which stores the speed corresponding to each fault type; the speed corresponding to the current fault type is determined as the target speed of the target pump. Therefore, by adaptively determining the matching target speed considering the actual working conditions and fault conditions of the vehicle engine, precise control of exhaust gas recirculation can be achieved.

[0113] In one specific embodiment, the electronic controller, upon determining that the target pump is in an enabled operating state, acquires the vehicle engine's operating mode and the target cylinder's air-stop state. From multiple second mapping curves, a second mapping curve matching the operating mode and air-stop state is selected. This second mapping curve represents the desired flow rate varying with the target cylinder's fuel injection quantity, engine speed, and intake air fraction. The current intake air fraction is determined based on the number of cylinders currently receiving normal intake air. The current desired flow rate is determined based on the current fuel injection quantity, current intake air fraction, current engine speed, and the selected second mapping curve. The current operating condition flag of the vehicle engine at the current moment is acquired. Given that the current operating condition flag represents a transient operating condition, the actual speed of the target pump within the target cylinder is acquired. The ratio of the downstream pressure to the upstream pressure of the target pump is calculated, and the current actual flow rate is determined based on the actual speed and this ratio. The current power fraction is determined by the ratio of the number of cylinders currently performing work cycles to the total number of cylinders. A first mapping curve corresponding to the current work fraction is determined. This first mapping curve is the curve showing how the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control. Based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed, the current open-loop control quantity is determined.

[0114] Based on the difference between the current actual flow rate and the current expected flow rate, determine the closed-loop control quantity for flow closed-loop control, and calculate the sum of the closed-loop control quantity and the open-loop control quantity. Determine the control quantity threshold. If the sum is less than or equal to the control quantity threshold, the sum is determined as the target control quantity; if the sum is greater than the control quantity threshold, the control quantity threshold is determined as the target control quantity.

[0115] With the target pump enabled, the third mapping curve is acquired. This curve shows how the target pump's speed changes with the control variable and exhaust flow rate. The current exhaust flow rate is acquired, and the target speed is determined based on the third mapping curve, the target control variable, and the current exhaust flow rate. With the target pump disabled, the fault flag is acquired. If the fault flag indicates a fault, the current fault type is determined. The speed corresponding to the current fault type is determined from pre-stored speed data, which stores the speeds corresponding to each fault type. The speed corresponding to the current fault type is set as the target speed for the target pump. The target pump in the target cylinder is controlled to operate according to the target speed to achieve exhaust gas recirculation.

[0116] In this embodiment, the current desired flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine are obtained. The target gas is the exhaust gas used for recirculation. The current work fraction is determined based on the number of cylinders performing work at the current moment. The current work fraction reflects the work performance of the vehicle engine and effectively distinguishes whether it is in a non-uniform work performance. A first mapping curve corresponding to the current work fraction is determined. The first mapping curve is a curve showing how the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control. In this way, the current open-loop control quantity matching the work performance can be accurately determined based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed. Based on the difference between the current actual flow rate and the current desired flow rate, as well as the current open-loop control quantity, the target speed matching the work performance is accurately determined, and the target pump in the target cylinder is controlled according to the target speed to achieve exhaust gas recirculation. Therefore, by considering the actual work performance of the vehicle engine, the matching target speed is adaptively determined to achieve precise control of exhaust gas recirculation.

[0117] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0118] Based on the same inventive concept, this application also provides a vehicle engine exhaust gas recirculation control device for implementing the above-described vehicle engine exhaust gas recirculation control method. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations of one or more vehicle engine exhaust gas recirculation control device embodiments provided below can be found in the limitations of the vehicle engine exhaust gas recirculation control method described above, and will not be repeated here.

[0119] In one exemplary embodiment, such as Figure 10 As shown, a control device 1000 for exhaust gas recirculation of a vehicle engine is provided, comprising: a flow rate acquisition module 1002, a work fraction determination module 1004, a mapping curve determination module 1006, an open-loop control quantity determination module 1008, and a speed determination module 1010, wherein:

[0120] The flow acquisition module 1002 is used to acquire the current expected flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine. The target gas is the exhaust gas used for recirculation.

[0121] The work fraction determination module 1004 is used to determine the current work fraction based on the number of cylinders performing work in a cycle at the current moment.

[0122] The mapping curve determination module 1006 is used to determine the first mapping curve corresponding to the current work fraction. The first mapping curve is the curve in which the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control.

[0123] The open-loop control quantity determination module 1008 is used to determine the current open-loop control quantity based on the first mapping curve, the current desired flow rate, the current fuel injection quantity, and the current engine speed.

[0124] The speed determination module 1010 is used to determine the target speed based on the difference between the current actual flow rate and the current expected flow rate, as well as the current open-loop control quantity, and to control the target pump in the target cylinder to operate according to the target speed in order to achieve exhaust gas recirculation.

[0125] In some embodiments, the apparatus further includes a flow rate determination module, configured to acquire the operating mode of the vehicle engine and the gas cut-off state of the target cylinder when it is determined that the target pump is in an enabled operating state. From a plurality of second mapping curves, a second mapping curve matching the operating mode and gas cut-off state is selected. The second mapping curve is a curve showing how the desired flow rate changes with the fuel injection quantity, engine speed, and intake air fraction of the target cylinder. The current intake air fraction is determined based on the number of cylinders currently receiving normal intake air. The current desired flow rate is determined based on the current fuel injection quantity, the current intake air fraction, the current engine speed, and the selected second mapping curve.

[0126] In some embodiments, the flow determination module is used to acquire the current operating condition flag of the vehicle engine at the current moment. If the current operating condition flag indicates a transient operating condition, the actual rotational speed of the target pump in the target cylinder is acquired. The ratio of the downstream pressure to the upstream pressure of the target pump is calculated, and the current actual flow rate is determined based on the actual rotational speed and the ratio.

[0127] In some embodiments, the speed determination module 1010 is used to determine the closed-loop control quantity for flow closed-loop control based on the difference between the current actual flow rate and the current expected flow rate, and to determine the target control quantity based on the sum of the closed-loop control quantity and the open-loop control quantity. When the target pump is in an enabled operating state, a third mapping curve is acquired, which is a curve showing how the target pump's speed changes with the control quantity and exhaust flow rate. The current exhaust flow rate at the current moment is acquired, and the target speed is determined based on the third mapping curve, the target control quantity, and the current exhaust flow rate.

[0128] In some embodiments, the rotational speed determination module 1010 is used to determine a control quantity threshold. If the sum is less than or equal to the control quantity threshold, the sum is determined as the target control quantity. If the sum is greater than the control quantity threshold, the control quantity threshold is determined as the target control quantity.

[0129] In some embodiments, the speed determination module 1010 is used to acquire a fault flag bit when the target pump is not in an enabled operating state. If the fault flag bit indicates a fault, the current fault type is determined. The speed corresponding to the current fault type is determined from pre-stored speed data, which stores the speed corresponding to each fault type. The speed corresponding to the current fault type is determined as the target speed of the target pump.

[0130] The various modules in the aforementioned vehicle engine exhaust gas recirculation control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the microcontroller of the electronic controller in hardware form or independent of it, or stored in the memory of the electronic controller in software form, so that the microcontroller can call and execute the corresponding operations of each module.

[0131] In one exemplary embodiment, an electronic controller is provided, which can be a controller in a vehicle or other electronic device, and its internal structure diagram can be as follows. Figure 11As shown, the electronic controller includes a microcontroller, memory, input / output (I / O) interfaces, and a communication interface. The microcontroller, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The microcontroller provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The I / O interfaces are used for exchanging information between the microcontroller and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the microcontroller, it implements a control method for exhaust gas recirculation in a vehicle engine.

[0132] Those skilled in the art will understand that Figure 11 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0133] In one embodiment, an electronic controller is also provided, including a memory and a microcontroller, wherein the memory stores a computer program, and the microcontroller executes the computer program to implement the steps in the above method embodiments.

[0134] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a microcontroller, implements the steps in the above method embodiments.

[0135] In one embodiment, a computer program product is provided, including a computer program that, when executed by a microcontroller, implements the steps in the above method embodiments.

[0136] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0137] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0138] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0139] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A control method for exhaust gas recirculation in a vehicle engine, characterized in that, The method includes: The current desired flow rate and current actual flow rate of the target gas in the target cylinder of the vehicle engine are obtained, wherein the target gas is exhaust gas used for recirculation. The current work fraction is determined based on the number of cylinders performing work in the current cycle. Based on the current work fraction, a first mapping curve corresponding to the current work fraction is selected from multiple first mapping curves. The first mapping curve is a curve in which the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control. The current open-loop control quantity is determined based on the first mapping curve corresponding to the current work fraction, the current expected flow rate, the current fuel injection quantity, and the current engine speed. Based on the difference between the current actual flow rate and the current expected flow rate, as well as the current open-loop control quantity, the target speed is determined, and the target pump in the target cylinder is controlled to operate according to the target speed to achieve exhaust gas recirculation. The target pump is an EGR pump.

2. The method according to claim 1, characterized in that, The steps for determining the current expected traffic volume include: If the target pump is determined to be in an enabled working state, the operating mode of the vehicle engine and the gas deprivation state of the target cylinder are obtained. From multiple second mapping curves, a second mapping curve that matches the operating mode and the gas stop state is selected. The second mapping curve is a curve showing how the desired flow rate changes with the fuel injection quantity of the target cylinder, the engine speed, and the intake air fraction. The current intake fraction is determined based on the number of cylinders that are currently receiving air normally. The current desired flow rate is determined based on the current fuel injection quantity, the current intake fraction, the current engine speed, and the selected second mapping curve. The current intake fraction is the ratio of the number of cylinders whose intake and exhaust valves are currently operating normally to the total number of cylinders in the current vehicle engine cycle.

3. The method according to claim 1, characterized in that, The steps for determining the current actual traffic flow include: Obtain the current operating condition flag of the vehicle's engine at the current moment; When the current operating condition indicator represents a transient operating condition, the actual rotational speed of the target pump inside the target cylinder is obtained; Calculate the ratio of the downstream pressure to the upstream pressure of the target pump, and determine the current actual flow rate based on the actual rotational speed and the ratio.

4. The method according to claim 1, characterized in that, The step of determining the target rotational speed based on the difference between the current actual flow rate and the current desired flow rate, and the current open-loop control quantity, includes: Based on the difference between the current actual flow and the current expected flow, the closed-loop control quantity for flow closed-loop control is determined, and the target control quantity is determined based on the sum of the closed-loop control quantity and the open-loop control quantity. With the target pump in the enabled working state, a third mapping curve is obtained, which is the curve of the target pump speed changing with the control quantity and exhaust flow rate. Obtain the current exhaust flow rate at the current moment, and determine the target speed based on the third mapping curve, the target control variable, and the current exhaust flow rate.

5. The method according to claim 4, characterized in that, The step of determining the target control quantity based on the sum of the closed-loop control quantity and the open-loop control quantity includes: Determine a control quantity threshold; if the sum is less than or equal to the control quantity threshold, determine the sum as the target control quantity. If the sum is greater than the control threshold, the control threshold is determined as the target control quantity.

6. The method according to claim 4, characterized in that, The method further includes: If the target pump is not in an enabled operating state, acquire the fault flag bit; When the fault flag indicates that a fault has occurred, the current fault type is determined; The rotational speed corresponding to the current fault type is determined from pre-stored rotational speed data, which stores the rotational speed corresponding to each fault type. The rotational speed corresponding to the current fault type is determined as the target rotational speed of the target pump.

7. A control device for exhaust gas recirculation in a vehicle engine, characterized in that, The device includes: The flow acquisition module is used to acquire the current expected flow rate and the current actual flow rate of the target gas in the target cylinder of the vehicle engine, wherein the target gas is exhaust gas used for recirculation. The work fraction determination module is used to determine the current work fraction based on the number of cylinders performing work in a cycle at the current moment. The mapping curve determination module is used to select the first mapping curve corresponding to the current work fraction from a plurality of first mapping curves based on the current work fraction. The first mapping curve is a curve in which the open-loop control quantity of the target gas changes with the fuel injection quantity of the target cylinder, engine speed, and desired flow rate under open-loop flow control. The open-loop control quantity determination module is used to determine the current open-loop control quantity based on the first mapping curve corresponding to the current work fraction, the current expected flow rate, the current fuel injection quantity, and the current engine speed; The speed determination module is used to determine the target speed based on the difference between the current actual flow rate and the current expected flow rate, as well as the current open-loop control quantity, and to control the target pump in the target cylinder to operate according to the target speed to achieve exhaust gas recirculation. The target pump is an EGR pump.

8. An electronic controller, comprising a memory and a microcontroller, wherein the memory stores a computer program, characterized in that, When the microcontroller executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the microcontroller, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the microcontroller, it implements the steps of the method according to any one of claims 1 to 6.

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