A method and system for exhaust gas recirculation control

Abstract

The present application belongs to the technical field of exhaust gas recirculation control, and provides an exhaust gas recirculation control method and system. When the exhaust gas flow is obtained, the final exhaust gas flow set value is obtained through a correction coefficient. Specifically, the correction coefficient is 1 at steady state, the correction coefficient is less than 1 at transient acceleration, and the correction coefficient is greater than 1 at transient deceleration. The smoke degree is lower at transient state, which is more in line with the actual situation and has higher precision. The exhaust gas recirculation control is performed by combining proportional integral derivative control and feedforward control. Specifically, the feedforward control adopts switching between different feedforward maps. Under normal working conditions, the feedforward map accelerates the transient response of exhaust gas recirculation, so that the response of exhaust gas recirculation is better. Under the action of transient state, the feedforward map opening is reduced, which can prevent a large amount of exhaust gas from entering the engine through the exhaust gas recirculation pipeline at the moment, and reduce the smoke degree at sudden acceleration.

Description

Technical Field

[0001] This invention belongs to the field of waste gas recirculation control technology, and particularly relates to a waste gas recirculation control method and system. Background Technology

[0002] Exhaust Gas Recirculation (EGR) technology is one of the key technologies to meet non-four emission standards. EGR is the process of reintroducing exhaust gas from the exhaust pipe into the intake pipe and having it participate in combustion. EGR technology can effectively reduce NOx produced during combustion.

[0003] The inventors discovered that traditional exhaust gas recirculation (EGR) control does not adjust the control side according to the characteristics of NOx generation under different steady-state and transient operating conditions, resulting in low control accuracy and excessive NOx generation during EGR control. Furthermore, traditional EGR control methods do not consider the pulse spectrum settings under different operating conditions, making it impossible for the pulse spectrum settings to quickly adapt to the transient response of EGR. Under strong transient effects, a large amount of exhaust gas enters the engine instantly through the EGR pipeline, causing a sudden increase in smoke opacity. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes an exhaust gas recirculation control method and system. This invention employs a novel EGR rate closed-loop control strategy, corrects the charging efficiency, considers the differences between steady-state and transient operating conditions in the calibration strategy, and uses a proportional-integral-derivative control + feedforward control method to improve the responsiveness of EGR and make NOx control more precise.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0006] In a first aspect, the present invention provides a method for controlling exhaust gas recirculation, comprising:

[0007] Obtain the actual exhaust gas flow rate and the exhaust gas flow rate setpoint;

[0008] Based on the actual exhaust gas flow rate and the exhaust gas flow rate setpoint, exhaust gas recirculation control is performed using a combination of proportional-integral-derivative control and feedforward control.

[0009] The exhaust gas flow rate is calculated from the exhaust gas recirculation rate setpoint and the total intake air volume. The exhaust gas flow rate is then corrected by a correction coefficient to obtain the final exhaust gas flow rate setpoint. The correction coefficient is 1 in steady state, less than 1 during transient acceleration, and greater than 1 during transient deceleration. The feedforward control uses switching between different feedforward pulse spectra. Under normal operating conditions, the feedforward pulse spectrum is used to accelerate the transient response of exhaust gas recirculation. Under transient action, the feedforward pulse spectrum is used to reduce the opening of the exhaust gas recirculation valve.

[0010] Furthermore, when obtaining the exhaust gas flow rate setpoint, the charging efficiency is corrected by the actual intake temperature, intake pressure, and exhaust pressure.

[0011] Furthermore, the total intake volume m2 is:

[0012]

[0013] V = V _eng ·λ

[0014]

[0015] Where: R represents the molar gas constant; V _eng Represents engine displacement; λ0 represents engine charging efficiency under different operating conditions with the exhaust gas recirculation valve closed; T ref λ represents the reference temperature for different engine operating conditions under standard conditions; fac represents the temperature correction coefficient; f(n, P3-P2) represents the correction of the charging efficiency after the intake and exhaust pressure difference changes after the exhaust gas recirculation valve opens at each speed, n represents the engine speed, P3 represents the exhaust pressure, P2 represents the intake pressure; λ represents the actual charging efficiency under non-standard conditions.

[0016] Furthermore, the method for obtaining the correction coefficient is as follows:

[0017] The actual Lambd at the set exhaust gas recirculation rate is obtained based on the set exhaust gas recirculation rate for each operating condition.

[0018] Fill the actual Lambd at each operating point into the set Lambd pulse spectrum;

[0019] The correction factor for transient conditions is obtained by dividing the set Lambd under each operating condition by the actual Lambd.

[0020] Furthermore, the actual Lambd is obtained by converting the exhaust oxygen concentration; exhaust oxygen concentration = ((total intake air volume - air volume consumed by engine combustion - pure exhaust gas volume) / (total intake air volume + fuel consumption)) * oxygen concentration.

[0021] Furthermore, the amount of pure exhaust gas in the exhaust gas is determined using a time delay module, with the delay time calibrated according to the operating conditions.

[0022] Furthermore, when the engine is running in normal mode, the feedforward value is obtained by looking up the normal feedforward pulse spectrum. When it is determined that the engine is in a strong transient state, the feedforward value is switched to strong transient feedforward. The strong transient state judgment process is as follows: determine whether the throttle change rate, engine torque change rate, and speed change rate exceed the calibration limit.

[0023] Secondly, the present invention also provides an exhaust gas recirculation control system, comprising:

[0024] The data acquisition module is configured to acquire the actual exhaust gas flow rate and the exhaust gas flow rate setpoint.

[0025] The control module is configured to control exhaust gas recirculation by using a combination of proportional-integral-derivative control and feedforward control based on the actual exhaust gas flow rate and the exhaust gas flow rate setpoint.

[0026] The exhaust gas flow rate is calculated from the exhaust gas recirculation rate setpoint and the total intake air volume. The exhaust gas flow rate is then corrected by a correction coefficient to obtain the final exhaust gas flow rate setpoint. The correction coefficient is 1 in steady state, less than 1 during transient acceleration, and greater than 1 during transient deceleration. The feedforward control uses switching between different feedforward pulse spectra. Under normal operating conditions, the feedforward pulse spectrum is used to accelerate the transient response of exhaust gas recirculation. Under transient action, the feedforward pulse spectrum is used to reduce the opening of the exhaust gas recirculation valve.

[0027] Thirdly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the exhaust gas recirculation control method described in the first aspect.

[0028] Fourthly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the exhaust gas recirculation control method described in the first aspect.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. In this invention, when acquiring the exhaust gas flow rate, a correction coefficient is applied to obtain the final exhaust gas flow rate setpoint. Specifically, the correction coefficient is 1 in steady state, less than 1 during transient acceleration, and greater than 1 during transient deceleration. This ensures lower smoke opacity under transient conditions, better reflecting reality and achieving higher accuracy. The invention employs a combination of proportional-integral-derivative (PID) control and feedforward control for exhaust gas recirculation control. Specifically, the feedforward control uses switching between different feedforward pulse spectra. Under normal operating conditions, the feedforward pulse spectra accelerates the transient response of exhaust gas recirculation, resulting in better responsiveness. Under transient conditions, the feedforward pulse spectra reduces the opening of the exhaust gas recirculation valve, preventing a large amount of exhaust gas from entering the engine through the exhaust gas recirculation pipeline and reducing smoke opacity during sudden acceleration.

[0031] 2. In this invention, the inflation efficiency is corrected by the actual intake temperature, intake pressure and exhaust pressure, making the intake volume calculation more accurate, thereby making the calculated exhaust gas flow rate more accurate.

[0032] 3. In this invention, the exhaust gas recirculation rate is used for closed-loop control instead of directly using the exhaust gas flow rate, which ensures better environmental adaptability. For example, in high-altitude environments or after the turbocharger ages, the intake pressure will change and the combustion state will change. Using the exhaust gas recirculation rate closed loop can adaptively adjust the exhaust gas volume to ensure that emissions are within reasonable limits.

[0033] 4. The real-time Lambd correction in this invention ensures lower smoke opacity under transient conditions. The actual Lambd calculation uses inert exhaust gas recirculation and a delay module, which is more realistic and has higher accuracy.

[0034] 5. The proportional-integral-derivative control + feedforward control method in this invention makes the response of exhaust gas recirculation better, and the dual MAP form of the feedforward makes the performance calibration selectivity greater under strong transient conditions, resulting in better performance. Attached Figure Description

[0035] The accompanying drawings, which form part of this embodiment, are used to provide a further understanding of this embodiment. The illustrative embodiments and their descriptions are used to explain this embodiment and do not constitute an improper limitation of this embodiment.

[0036] Figure 1 This is the exhaust gas recirculation system of Embodiment 1 of the present invention;

[0037] Figure 2 This is the overall EGR control strategy of Embodiment 1 of the present invention;

[0038] Figure 3 This is the method for obtaining the actual Lambd in Embodiment 1 of the present invention;

[0039] Figure 4 This is a schematic diagram of the feedforward control module in Embodiment 1 of the present invention;

[0040] Figure 5 This is the strong transient state judgment process of Embodiment 1 of the present invention. Detailed Implementation

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0042] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0043] EGR: Exhaust Gas Recirculation, is a process that recirculates exhaust gases from the engine into the intake manifold to mix with fresh air before entering the combustion chamber for combustion. This effectively reduces NOx emissions from the engine.

[0044] ECU: Electronic Control Unit.

[0045] EGR valve: Used to control the amount of recirculated exhaust gas. The one installed before the EGR cooler is called the hot end EGR valve, and the one installed after the EGR cooler is called the cold end EGR valve.

[0046] VNT: Variable Nozzle Turbine. The turbine exhaust inlet has a nozzle ring that can change the blade angle. The nozzle ring can be in any position between fully open and closed. This position can be set according to the signal sent by the ECU, thereby adjusting the turbocharger flow capacity at various engine speeds to ensure the turbocharger's working efficiency and response speed.

[0047] EGR drive pressure difference ΔP: P3-P2, where P3 is the exhaust pressure in front of the turbine and P2 is the intake pressure in the intake manifold (boost pressure of the turbocharger).

[0048] Example 1:

[0049] To address the problems of low control precision, excessive NOx generation during exhaust gas recirculation (EGR) control, and sudden increases in smoke due to a large influx of exhaust gas into the engine via the EGR pipeline in traditional methods, this embodiment provides an EGR control method, including:

[0050] Obtain the actual exhaust gas flow rate and the exhaust gas flow rate setpoint;

[0051] Based on the actual exhaust gas flow rate and the exhaust gas flow rate setpoint, exhaust gas recirculation control is performed using a combination of proportional-integral-derivative control and feedforward control.

[0052] The exhaust gas flow rate is calculated from the exhaust gas recirculation rate setpoint and the total intake air volume. The exhaust gas flow rate is then corrected by a correction coefficient to obtain the final exhaust gas flow rate setpoint. The correction coefficient is 1 in steady state, less than 1 during transient acceleration, and greater than 1 during transient deceleration. The feedforward control uses switching between different feedforward pulse spectra. Under normal operating conditions, the feedforward pulse spectrum is used to accelerate the transient response of exhaust gas recirculation. Under transient action, the feedforward pulse spectrum is used to reduce the opening of the exhaust gas recirculation valve.

[0053] Specifically, when acquiring the exhaust gas flow rate, a correction coefficient is used to obtain the final exhaust gas flow rate setpoint. Specifically, the correction coefficient is 1 in steady state, less than 1 during transient acceleration, and greater than 1 during transient deceleration; this ensures lower smoke opacity under transient conditions, is more realistic, and has higher accuracy. A combination of proportional-integral-derivative control and feedforward control is used for exhaust gas recirculation control. Specifically, the feedforward control switches between different feedforward pulse spectra. Under normal operating conditions, the feedforward pulse spectra accelerate the transient response of exhaust gas recirculation, making the response of exhaust gas recirculation better. Under transient conditions, the feedforward pulse spectrum opening is reduced to prevent a large amount of exhaust gas from entering the engine through the exhaust gas recirculation pipeline instantaneously, thus reducing smoke opacity during sudden acceleration.

[0054] In this embodiment, the hardware configuration corresponding to the exhaust gas recirculation system is as follows: Figure 1 As shown:

[0055] Optionally, an intake air temperature and pressure sensor can be installed on the intake manifold (after EGR mixing) to measure the gas temperature T2 and gas pressure P2 entering the engine, respectively. A pressure sensor can be installed before the exhaust turbine to measure the exhaust pressure P3. An exhaust gas venturi can be used to measure the EGR exhaust gas volume. The turbocharger can be configured as a standard wastegate turbocharger, uncontrolled (the ECU cannot control the turbocharger), or a non-VNT turbocharger.

[0056] In this embodiment, the overall EGR control strategy is as follows: Figure 2 As shown:

[0057] Optionally, the overall control adopts the proportional-integral-derivative (PID) control method. The exhaust gas flow setpoint can be calculated from the EGR rate setpoint MAP (EGR rate MAP), which can be calibrated according to different operating conditions. The EGR rate can be understood as the ratio of the amount of recirculated exhaust gas to the total amount of intake air into the cylinder.

[0058] The intake air pressure P2 (turbocharger boost pressure) and intake air temperature T2 are measured by an intake air temperature and pressure sensor installed on the engine. The intake air temperature and pressure sensor calculates the total intake air volume m2 entering the engine using the following formula:

[0059]

[0060] V = V _eng ·λ (2)

[0061]

[0062] Where: R represents the molar gas constant; V _engThe engine displacement is a known value, calibrated based on actual conditions; λ0 represents the engine charging efficiency under different operating conditions with the EGR valve closed and in standard environmental conditions, which can be calibrated in a laboratory standard environment. Here, "standard environment" specifically refers to the intercooler after-temperature T. ref Under these conditions, for example, the temperature after cooling is 50℃ at the calibrated operating point; T ref The reference temperature representing the operating conditions of different engines under standard conditions can be obtained through calibration. For example, after fixing the calibration point at 50℃, each operating point will have a fixed temperature after the intercooler, T. ref MAP is based on engine speed n and fuel injection quantity; fac represents the temperature correction coefficient, which can be obtained through calibration; f(n, P3-P2) represents the correction of the charging efficiency after the intake and exhaust pressure difference changes after the EGR valve opens at each engine speed, which can be obtained through calibration, n represents engine speed; λ represents the actual charging efficiency under non-standard conditions, which can be determined by the actual intake air temperature T and f(n, P3-P2).

[0063] The actual exhaust gas flow rate can be obtained from the exhaust gas venturi tube installed on the engine EGR line. The calculation formula is shown in formula (4):

[0064]

[0065] Where: ΔP is the differential pressure measured by the differential pressure sensor installed on the Venturi tube; Cε is the discharge coefficient, which represents the coefficient between the actual flow rate and the theoretical flow rate through the device; β is the diameter ratio, which is the ratio of the Venturi tube throat diameter to the inlet diameter; d is the Venturi tube throat diameter; ρ is the density of the gas at the Venturi tube inlet, which is specifically calculated from the temperature and pressure of the inlet gas.

[0066] The exhaust gas flow rate is obtained from the EGR rate setpoint and the total intake air volume m2. The exhaust gas flow rate is then adjusted by the Lambd correction factor A to obtain the final exhaust gas flow rate setpoint. The Lambd correction factor is obtained as follows:

[0067] The ECU obtains the actual Lambd at the set EGR rate for each operating condition.

[0068] Fill the actual Lambd at each operating point into the set Lambd pulse spectrum (MAP);

[0069] The correction factor A under transient conditions is obtained by dividing the set Lambd under each operating condition by the actual Lambd.

[0070] The actual method for obtaining Lambd is as follows: Figure 3 As shown:

[0071] The exhaust gas volume Megr can be obtained from the exhaust gas venturi tube installed on the EGR line;

[0072] EGFVCtl_rO2AirRef_C represents the mass fraction of oxygen in the atmosphere, 0.2315; the conversion formula between exhaust oxygen concentration EGFVCtl_rO2ModVal and actual Lambd (EGFVCtl_rLamActVal) is as follows:

[0073]

[0074] Where O2 is the exhaust oxygen concentration EGFVCtl_rO2ModVal.

[0075] The method for obtaining the exhaust oxygen concentration EGFVCtl_rO2ModVal is described in [link to documentation]. Figure 3 As shown:

[0076] EGFVCtl_rO2ModVal=((Intake volume m2 - Engine combustion consumption - Pure exhaust gas in EGR exhaust gas) / (Intake volume m2 + Fuel consumption))*Oxygen concentration.

[0077] Specifically, considering the actual situation of exhaust gas recirculation delay, the pure exhaust gas volume in the EGR exhaust gas uses a time delay module, and the delay time can be calibrated according to the operating conditions (Time delay). Exhaust gas contains oxygen, and EGR recirculation exhaust gas also contains a certain amount of oxygen: Megr / Lambd calculates the pure exhaust gas volume in the EGR (inert EGR volume).

[0078] The feedforward control module consists of two parts, such as Figure 4 As shown, the feedforward MAP under normal operating conditions and the strong transient feedforward MAP are obtained by looking up the table from the normal feedforward MAP when the engine is running in normal mode. When it is determined that the engine is in a strong transient state, the feedforward value is switched to the strong transient feedforward. Under normal circumstances, the calibration opening of the strong transient feedforward MAP is small, for example, 0%.

[0079] The process for determining strong transient states is as follows: Figure 5 As shown:

[0080] Determine whether the rate of change of throttle, the rate of change of engine torque, and the rate of change of engine speed exceed the calibrated limits respectively;

[0081] Based on the engine speed calibration state time delay cur, it is ensured that strong transient states can be delayed for a period of time (e.g., 1 second). This function setting can ensure the stability of EGR control during engine transients.

[0082] Advantages of using Lambd-based correction and feedforward control:

[0083] In steady state, the actual Lambd of the engine is filled into the set Lambd pulse spectrum, with a correction factor of 1, resulting in no correction. In transient state, the actual Lambd differs from the set Lambd, requiring a correction. For example, during acceleration, the actual Lambd will be smaller than the set Lambd for that condition, with a correction factor less than 1. This reduces the exhaust gas flow rate setpoint and the actual EGR opening, thus lowering the engine's transient smoke and improving acceleration performance. During deceleration, the intake air volume is relatively sufficient, leading to higher NOx levels. In this case, the correction factor is greater than 1, increasing the EGR opening and contributing to NOx reduction. The correction varies depending on the intensity of the transient; the stronger the transient, the more pronounced the correction.

[0084] The feedforward method uses switching between different MAPs. Under normal operating conditions, the setting and calibration of the feedforward MAP can accelerate the transient response of the EGR. Under strong transient conditions, the feedforward MAP is switched to a relatively small opening (e.g., 0%), which can make the EGR valve close quickly. This can prevent a large amount of exhaust gas from entering the engine through the EGR pipeline and reduce the smoke during sudden acceleration.

[0085] Example 2:

[0086] This embodiment provides an exhaust gas recirculation control system, including:

[0087] The data acquisition module is configured to acquire the actual exhaust gas flow rate and the exhaust gas flow rate setpoint.

[0088] The control module is configured to control exhaust gas recirculation by using a combination of proportional-integral-derivative control and feedforward control based on the actual exhaust gas flow rate and the exhaust gas flow rate setpoint.

[0089] The exhaust gas flow rate is calculated from the exhaust gas recirculation rate setpoint and the total intake air volume. The exhaust gas flow rate is then corrected by a correction coefficient to obtain the final exhaust gas flow rate setpoint. The correction coefficient is 1 in steady state, less than 1 during transient acceleration, and greater than 1 during transient deceleration. The feedforward control uses switching between different feedforward pulse spectra. Under normal operating conditions, the feedforward pulse spectrum is used to accelerate the transient response of exhaust gas recirculation. Under transient action, the feedforward pulse spectrum is used to reduce the opening of the exhaust gas recirculation valve.

[0090] The operating method of the system is the same as that of the exhaust gas recirculation control method in Example 1, and will not be repeated here.

[0091] Example 3:

[0092] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the exhaust gas recirculation control method described in Embodiment 1.

[0093] Example 4:

[0094] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps of the exhaust gas recirculation control method described in Embodiment 1.

[0095] The above description is merely a preferred embodiment of this practice and is not intended to limit the scope of this practice. Various modifications and variations can be made to this practice by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this practice should be included within the protection scope of this practice.

Claims

1. A method for controlling waste gas recirculation, characterized in that, include: Obtain the actual exhaust gas flow rate and the exhaust gas flow rate setpoint; Based on the actual exhaust gas flow rate and the exhaust gas flow rate setpoint, exhaust gas recirculation control is performed using a combination of proportional-integral-derivative control and feedforward control. The exhaust gas flow rate is calculated from the exhaust gas recirculation rate setpoint and the total intake air volume. The exhaust gas flow rate is then corrected by a correction coefficient to obtain the final exhaust gas flow rate setpoint. The correction coefficient is 1 in steady state, less than 1 during transient acceleration, and greater than 1 during transient deceleration. The feedforward control uses switching between different feedforward pulse spectra. Under normal operating conditions, the feedforward pulse spectrum is used to accelerate the transient response of exhaust gas recirculation. Under transient action, the feedforward pulse spectrum is used to reduce the opening of the exhaust gas recirculation valve.

2. The waste gas recirculation control method as described in claim 1, characterized in that, When obtaining the exhaust gas flow rate setpoint, the charging efficiency is corrected by the actual intake temperature, intake pressure, and exhaust pressure.

3. The waste gas recirculation control method as described in claim 1, characterized in that, The total intake volume m2 is: V=V _eng ·λ Where: R represents the molar gas constant; V _eng Represents engine displacement; λ0 represents engine charging efficiency under different operating conditions with the exhaust gas recirculation valve closed; T ref λ represents the reference temperature for different engine operating conditions under standard conditions; fac represents the temperature correction coefficient; f(n, P3-P2) represents the correction of the charging efficiency after the intake and exhaust pressure difference changes after the exhaust gas recirculation valve opens at each speed, n represents the engine speed, P3 represents the exhaust pressure, P2 represents the intake pressure; λ represents the actual charging efficiency under non-standard conditions.

4. The waste gas recirculation control method as described in claim 1, characterized in that, The correction coefficient is obtained as follows: The actual Lambd at the set exhaust gas recirculation rate is obtained based on the set exhaust gas recirculation rate for each operating condition. Fill the actual Lambd at each operating point into the set Lambd pulse spectrum; The correction factor for transient conditions is obtained by dividing the set Lambd under each operating condition by the actual Lambd.

5. The waste gas recirculation control method as described in claim 4, characterized in that, The actual Lambd is obtained by converting the exhaust oxygen concentration; exhaust oxygen concentration = ((total intake air volume - air volume consumed by engine combustion - pure exhaust gas volume) / (total intake air volume + fuel consumption)) * oxygen concentration.

6. The waste gas recirculation control method as described in claim 5, characterized in that, The amount of pure exhaust gas in the exhaust gas is determined by a time delay module, and the delay time is calibrated according to the operating conditions.

7. The waste gas recirculation control method as described in claim 1, characterized in that, When the engine is running in normal mode, the feedforward value is obtained by looking up the normal feedforward pulse spectrum. When the engine is determined to be in a strong transient state, the feedforward value is switched to strong transient feedforward. The strong transient state judgment process is as follows: determine whether the throttle change rate, engine torque change rate, and speed change rate exceed the calibration limit.

8. A waste gas recirculation control system, characterized in that, include: The data acquisition module is configured to acquire the actual exhaust gas flow rate and the exhaust gas flow rate setpoint. The control module is configured to control exhaust gas recirculation by using a combination of proportional-integral-derivative control and feedforward control based on the actual exhaust gas flow rate and the exhaust gas flow rate setpoint. The exhaust gas flow rate is calculated from the exhaust gas recirculation rate setpoint and the total intake air volume. The exhaust gas flow rate is then corrected by a correction coefficient to obtain the final exhaust gas flow rate setpoint. The correction coefficient is 1 in steady state, less than 1 during transient acceleration, and greater than 1 during transient deceleration. The feedforward control uses switching between different feedforward pulse spectra. Under normal operating conditions, the feedforward pulse spectrum is used to accelerate the transient response of exhaust gas recirculation. Under transient action, the feedforward pulse spectrum is used to reduce the opening of the exhaust gas recirculation valve.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the exhaust gas recirculation control method as described in any one of claims 1-7.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the exhaust gas recirculation control method as described in any one of claims 1-7.

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