Egr closed-loop exit control method based on supercharging control, storage medium and vehicle

Abstract

The application discloses an EGR closed-loop exit control method based on supercharging control, a storage medium and a vehicle, and comprises the following steps: reading an EGR closed-loop condition; when the EGR closed-loop condition changes from being satisfied to not being satisfied, obtaining an initial value of a time length during which an EGR valve target opening degree remains unchanged according to a pressure ratio coefficient and a real-time engine speed; and after the EGR closed-loop condition is not satisfied, updating and optimizing the remaining time during which the EGR valve target opening degree remains unchanged based on a supercharging pressure difference change amount and a hybrid valve outlet pressure change amount, to obtain an updated remaining time. The application determines the initial value of the time length during which the EGR valve target opening degree remains unchanged, optimizes the remaining time from the current time to the time when the EGR valve target opening degree remains unchanged, optimizes the control of the EGR valve target opening degree after the EGR closed loop is exited, identifies the fluctuation of the supercharging pressure deviation, optimizes the influence of the pressure fluctuation during the EGR closed loop exit process, and improves the supercharging control stability during the EGR closed loop exit process.

Description

Technical Field

[0001] This invention relates to the field of engine control, and more particularly to an EGR closed-loop exit control method based on boost control, a storage medium, and a vehicle. Background Technology

[0002] Exhaust gas recirculation (EGR) draws exhaust gas from the exhaust system and introduces it into the intake system. Studies have shown that EGR systems have certain advantages in improving emissions, reducing fuel consumption, and improving anti-knock capabilities. However, how to improve the smoothness and stability of boost control when the EGR closed-loop exits remains to be optimized. This patent proposes an EGR closed-loop exit control method that improves boost control stability, which is the subject of this patent's research. Summary of the Invention

[0003] Based on improving the stability of boost control, this invention provides an EGR closed-loop exit control method, a storage medium, and a vehicle based on boost control. The technical solution adopted by this invention is as follows:

[0004] An EGR closed-loop exit control method based on boost control, the method comprising:

[0005] Read the EGR closed-loop conditions. When the EGR closed-loop conditions change from being met to not being met, calibrate the initial value of the duration for which the target opening of the EGR valve remains unchanged based on the pressure ratio coefficient and the real-time engine speed.

[0006] After the EGR closed-loop condition is not met, the remaining time for the target opening of the EGR valve to remain unchanged is updated and optimized based on the change in the boost pressure difference and the change in the outlet pressure of the mixing valve, so as to obtain the updated final remaining time; the remaining time is the time from the current moment until the target opening of the EGR valve exits and remains unchanged.

[0007] According to the above scheme, the pressure ratio coefficient is obtained by multiplying the ratio of the actual pressure at the throttle outlet to the actual pressure at the throttle inlet by the pressure ratio coefficient correction factor; the pressure ratio coefficient correction factor is obtained by calibration.

[0008] According to the above scheme, the initial value of the duration for which the target opening of the EGR valve remains unchanged is obtained by calibration based on the pressure ratio coefficient and the real-time engine speed. The calibration basis is as follows: within several sampling cycles from the start of not meeting the EGR closed-loop condition to the end of the initial value of the duration, the fluctuation of the difference between the target boost pressure and the actual boost pressure is within the preset range.

[0009] According to the above scheme, the specific number of the sampling periods is determined by the turbocharger response time; the turbocharger response time is obtained by multiplying the turbocharger response initial time by the sum of the turbocharger response initial time self-learning coefficient and 1.

[0010] According to the above scheme, the initial response time of the turbocharger is specifically the time it takes for the air-fuel mixture to flow from the turbocharger compressor to the throttle outlet. It is obtained by setting different EGR rates and measuring the time under different engine speeds and different actual intake air densities entering the cylinder, and taking the average of multiple data.

[0011] According to the above scheme, the change in pressure difference is specifically the difference between the maximum and minimum pressure difference in the most recent sampling periods.

[0012] According to the above scheme, the updated final remaining time is calculated from the calibrated values ​​of the pressure ratio and the change in boost pressure difference, the calibrated values ​​of the change in the mixing valve outlet pressure and the change in the boost pressure difference, and the self-learning coefficient of the remaining time.

[0013] According to the above scheme, the calibration basis for the calibration values ​​of the pressure ratio and the change in boost pressure difference and the calibration values ​​of the change in the outlet pressure of the mixing valve and the change in the boost pressure difference is: to ensure that the fluctuation of the difference between the target boost pressure and the actual boost pressure is within a preset range within a preset time after the end of the final remaining time.

[0014] According to the above scheme, the fluctuation of the difference between the target boost pressure and the actual boost pressure is within a preset range, specifically determined by judging that the preset conditions are met in several sampling cycles from the first sampling cycle where the EGR closed-loop conditions are not met to the end of the initial duration value.

[0015] According to the above scheme, the self-learning coefficients for the initial response time and the remaining response time of the turbocharger are obtained in the following ways:

[0016] If the difference between the updated remaining time and the previous remaining time is greater than the preset value and the change in the mixing valve outlet pressure exceeds the preset value by one, and the number of consecutive occurrences exceeds the preset value, then the self-learning coefficient of the remaining time will be increased based on the self-learning coefficient of the previously stored remaining time, and the self-learning coefficient of the booster response initial time will be increased based on the self-learning coefficient of the previously stored booster response initial time.

[0017] If the difference between the remaining time after the update and the remaining time before the update is greater than a preset value of one, and the number of consecutive occurrences exceeds a preset value, then the self-learning coefficient of the remaining time will be increased based on the self-learning coefficient of the remaining time stored in the previous update.

[0018] If the difference between the updated remaining time and the previous remaining time is not greater than the preset value of 2, and the change in the outlet pressure of the mixing valve exceeds the preset value and the number of consecutive occurrences exceeds the preset value, then the self-learning coefficient of the remaining time is reduced based on the self-learning coefficient of the previously stored remaining time, and the self-learning coefficient of the booster response initial time is equal to the self-learning coefficient of the previously stored booster response initial time reduced.

[0019] If the difference between the remaining time after the update and the remaining time before the update is not greater than the preset value of 2, and the number of consecutive occurrences exceeds the preset value, then the self-learning coefficient of the remaining time is equal to the self-learning coefficient of the previously stored remaining time, reduced by the same factor.

[0020] If the difference between the remaining time after the update and the remaining time before the update is greater than the preset value one, and the difference between the remaining time after the last update and the remaining time before the update is not greater than the preset value two, then the self-learning coefficient of the remaining time is equal to the self-learning coefficient of the remaining time stored last time, plus the original value.

[0021] If the difference between the remaining time after the update and the remaining time before the update is not greater than the preset value two, and the difference between the remaining time after the update and the remaining time before the update is greater than the preset value one, then the self-learning coefficient of the remaining time is equal to the self-learning coefficient of the remaining time stored last time, reduced by the same factor.

[0022] In other cases, the self-learning coefficient for the remaining time and the self-learning coefficient for the initial time of the turbocharger response remain unchanged.

[0023] According to the above scheme, the initial value of the number of consecutive occurrences is 0, which can be saved after the vehicle is powered off, and can be updated at most once during each driving cycle.

[0024] A computer-readable storage medium having a computer program stored thereon, the computer program including executable instructions that, when executed by a processor, implement an EGR closed-loop exit control method based on boost control as described above.

[0025] A vehicle includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement an EGR closed-loop exit control method based on boost control as described above.

[0026] The beneficial effects of this invention are:

[0027] By determining the initial value of the duration for which the target opening of the EGR valve remains unchanged, and optimizing the remaining time from the current time point until the EGR valve exits with the target opening unchanged, the control of the target opening of the EGR valve after the EGR closed loop exits is optimized. At the same time, the fluctuation of the boost pressure difference is identified, and the impact of pressure fluctuation during the EGR closed loop exit process is optimized, thereby improving the stability of boost control during the EGR closed loop exit process. Attached Figure Description

[0028] Figure 1 This is a flowchart of a method according to an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of a system structure with EGR according to an embodiment of the present invention.

[0030] In the diagram, 1-air filter; 2-mixing valve; 3-compressor; 4-throttle body; 5-engine; 6-turbine; 7-catalyst; 8-particulate matter trap; 9-EGR cooler; 10-EGR valve; 11-temperature sensor; 12-differential pressure sensor. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] This invention primarily provides an EGR closed-loop exit control method based on boost control, a storage medium, and a vehicle. For example... Figure 1 As shown, the method includes:

[0033] S1. Read the EGR closed-loop conditions. When the EGR closed-loop conditions change from being met to not being met, the initial value of the duration for which the target opening of the EGR valve remains unchanged is obtained based on the pressure ratio coefficient and the real-time engine speed.

[0034] Assuming the EGR control demand is at its maximum, the target opening degree of the EGR valve is pct. EGRDsrd The opening degree is 100%; the target opening degree of the EGR valve is pct. EGRDsrd The opening range is 0%-100%.

[0035] Read the EGR closed-loop conditions. The EGR closed-loop conditions can be found in the activation conditions of EGR valve control in patent CN118128651A "Target Opening Control Method, Device, Equipment, Medium and Product of EGR Valve". Specifically, it can be to determine whether the target opening of the mixing valve is less than the opening threshold of the mixing valve.

[0036] When the EGR closed-loop condition is met, the target opening degree of the EGR valve is pct. EGRDsrdThe process is executed according to closed-loop control requirements, using a closed-loop control algorithm to control the actions of the mixing valve and EGR valve to achieve EGR rate tracking; this part is not within the scope of this patent.

[0037] When the EGR closed-loop condition changes from satisfied to unsatisfied, i.e., the previous sampling period detected a satisfied state and the current sampling period detects a unsatisfied state (the sampling period in this embodiment is 10ms), then according to the pressure ratio coefficient r PreRatio The initial value t is obtained by calibrating with the engine's real-time speed n to determine the duration t during which the target opening of the EGR valve remains constant. The target opening of the EGR valve remains constant, i.e., pct. EGRDsrd =pct EGRDsrd (z), where pct EGRDsrd (z) represents the target opening of the EGR valve in the previous sampling period (the last sampling period that satisfies the EGR closed-loop condition). Maintaining the target opening of the EGR valve constant aims to stabilize the EGR valve and thus avoid affecting the boost inlet pressure and consequently the boost control responsiveness. The initial duration t starts counting from the first sampling period when the EGR closed-loop condition is not satisfied.

[0038] Among them, pressure ratio coefficient The ratio of the actual pressure at the outlet of the mixing valve to the actual pressure at the inlet of the mixing valve can also be used in another embodiment of the present invention as the ratio of the actual pressure at the outlet of the EGR valve to the actual pressure at the inlet of the EGR valve. This is the ratio of the actual pressure at the throttle outlet to the actual pressure at the throttle inlet. This is a correction factor for the pressure ratio coefficient, mainly considering... The larger the throttle body, the worse its control capability, and the greater the risk to the turbocharger's pressure control accuracy. To avoid boost pressure control accuracy problems, improvements are made, which are obtained through calibration. The calibration parameters are shown in the table below:

[0039]

[0040]

[0041] Initial duration t = f(r) PreRatio The specific value of N is obtained through calibration, which is based on the following criteria: from the first sampling period where the EGR closed-loop condition is not satisfied to the end of the initial duration t. Boost Within each sampling period, the difference p between the target boost pressure and the actual boost pressure BoostErr The fluctuations are within the preset range. Where N... Boost for τ=τ Boost ×(1+r Boost ), where r is the turbocharger response time. BoostLet τ be the initial response time of the turbocharger. Boost The self-learning coefficient has a default value of 0 and can be saved after the vehicle is powered off.

[0042] The initial response time τ of the turbocharger Boost τ is the time it takes for the air-fuel mixture to flow from the turbocharger compressor to the throttle outlet. This part is obtained through bench calibration. In a preferred embodiment of the invention, it can be obtained by setting different EGR rates and measuring the time under different engine speeds and different actual intake air densities entering the cylinder, and then taking the average of multiple data points. Therefore, τ Boost It can be determined by the engine speed and the actual intake air density entering the cylinder.

[0043] Among them, the difference p between the target boost pressure and the actual boost pressure BoostErr The criteria for determining whether the fluctuation is within the preset range are:

[0044] |p BoostErrFilter (N)-p BoostErr (N)| <min[p BoostErr (N), p BoostErrFilter (N)]×r BoostErrLim The condition is defined from the first sampling period when the EGR closed-loop condition is not satisfied until the end of the Nth period after the initial duration t. Boost It is satisfied within each sampling period, where r BoostErrLim Take 0.1.

[0045] Where p BoostErrFilter (N)=K BoostErr ×[p BoostErr (N)-p BoostErrFilter [(N-1)]+p BoostErrFilter (N-1)

[0046] p BoostErr p is the original value of the difference between the target boost pressure and the actual boost pressure. BoostErr (N) represents the pressure difference p during the Nth sampling period. BoostErr Original value, p BoostErrFilter The pressure difference after first-order low-pass filtering, p BoostErrFilter (N) represents the filtered pressure difference after the Nth sampling period, p BoostErrFilter (N-1) represents the filtered pressure difference in the (N-1)th sampling period, where N = 1, 2, 3…, and p BoostErrFilter (0) equals the pressure difference p during the 0th sampling period. AftThrErr (0), specifically, the 0th sampling period occurs at the EGR system closed-loop enable time; the sampling period interval Δt is 10ms in this example, K BoostErr For coefficients, Where m is the number of engine cylinders, n is the engine speed, and k BoostErr The pressure difference filter coefficient is 0.2 in this example.

[0047] Based on the initial time value obtained from the calibration, under the same rotational speed n, if the pressure ratio r PreRatio The smaller the value, the smaller the initial duration t, in order to satisfy the difference p between the target boost pressure and the actual boost pressure. BoostErr The fluctuation is within the preset range; at the pressure ratio r PreRatio Under the same conditions, if the rotational speed n is smaller, the initial duration t will be larger, in order to satisfy the difference p between the target boost pressure and the actual boost pressure. BoostErr The fluctuations are within the preset range.

[0048] S2. After the EGR closed-loop condition is not met, the original remaining time for the EGR valve target opening to remain unchanged is updated and optimized based on the change in the boost pressure difference and the change in the mixing valve outlet pressure to obtain the updated remaining time; the remaining time is the time from the current moment until the EGR valve target opening exits and remains unchanged.

[0049] In actual testing, it is also necessary to update and optimize the original remaining time t1 from the current time point until the EGR valve exits with the target opening unchanged, to obtain the optimized original remaining time t1'. It should be noted that t1 is not necessarily equal to the initial time value t, because changes in the boost pressure difference may occur some time after the EGR closed-loop enabling condition has been exited.

[0050] t1'=t1×[1+f(r PreRatio , Δp BoostErr )]×[1+f(Δp AfMixAct , Δp BoostErr )]×(1+r t1 )

[0051] Where f(r) PreRatio , Δp BoostErr ) and f(Δp AfMixAct , Δp BoostErr The calibration was obtained based on a preset time after t1'. Internally ensure the difference p between the target boost pressure and the actual boost pressure. BoostErr The fluctuations are within the preset range.

[0052] Δp BoostErr The most recent value is the change in the boost pressure difference. The difference between the maximum and minimum pressure difference before the next sampling period (each sampling period is 10ms) (if the maximum pressure difference occurs later than the minimum pressure difference, then the change in pressure difference Δp)BoostErr It is a positive value; if the maximum value of the boost pressure difference occurs earlier than the minimum value of the boost pressure difference, then the change in boost pressure difference Δp BoostErr It is a negative value; if the time when the maximum value of the boost pressure difference occurs is the same as the time when the minimum value of the boost pressure difference occurs, then the change in boost pressure difference Δp BoostErr (0). The change in boost pressure difference is considered because if the change is too large, it will have a deteriorating effect on the stability trend of boost control, thereby affecting the stability of subsequent boost pressure control.

[0053] In a preferred embodiment of the present invention, the original remaining time t1 is limited to a maximum value of 0.2s and a minimum value of 0s to avoid excessive adjustment that would result in poor robustness of the intake system control.

[0054] Where, r t1 This is the self-learning coefficient for time t1, with a default value of 0, and it can be saved after the vehicle is powered off. Its calculation method is as follows:

[0055] (1) If t1'-t1 is greater than the preset value C1 (indicating that the adjustment is too large due to excessive fluctuation of the boost pressure difference; in this example, C1 is taken as 0.1s), and Δp AfMixAct If the pressure difference exceeds the preset value (±20 kPa in this example) and the number of consecutive occurrences CNT1 (initially 0, but can be saved after the vehicle is powered off) exceeds the preset value (5 in this example), it indicates that the influence of the boost pressure difference is causing the duration t1 to continuously increase. To avoid reducing the impact on the fluctuation of the boost pressure difference, the self-learning state of time t1 is set to the upward learning state one, i.e., r t1 It needs to be increased. t1 =r t1 (z)+0.05, r Boost =r Boost (z)+0.1, where r t1 (z) represents the learning value stored at time t1 from the previous learning session, r Boost (z) represents the r stored from the previous learning session. Boost The learned value is set, and CNT1 is cleared to zero. The newly learned value is used the next time this situation is entered for judgment. CNT1 is updated at most once in each driving cycle.

[0056] (2) If t1'-t1 is greater than the preset value C1, and the number of consecutive occurrences CNT1 exceeds the preset value (5 in this example), it indicates that the influence of the boost pressure difference causes the duration t1 to keep increasing. In order to avoid reducing the influence on the fluctuation of the boost pressure difference, the self-learning state of time t1 is set to the upward learning state one, i.e., r t1 It needs to be increased. t1 =r t1(z) +0.03. Simultaneously, CNT1 is cleared. The newly learned value is used the next time this condition is entered for judgment. CNT1 is updated at most once during each driving cycle. Each driving cycle of the vehicle consists of the period from power-on to power-off.

[0057] (3) If t1'-t1 is not greater than the preset value -C2 (0.1s in this example), and Δp AfMixAct If the value exceeds the preset value (±10 kPa in this example) and the number of consecutive occurrences CNT2 (initially 0, but can be saved after the vehicle is powered off) exceeds the preset value (5 in this example), it indicates that the influence of the boost pressure difference is causing the duration t1 to continuously decrease. To avoid reducing the impact on the fluctuation of the boost pressure difference, the time t1 is set to the downward learning state one, i.e., r t1 It needs to be reduced. t1 =r t1 (z)-0.02, r Boost =r Boost (z)-0.1. Simultaneously, CNT2 is cleared to zero. The newly learned value is used the next time this condition is entered for judgment; CNT2 is updated at most once per driving cycle.

[0058] (4) If t1'-t1 is not greater than the preset value -C2, and the number of consecutive occurrences CNT2 exceeds the preset value, it indicates that the influence of the boost pressure difference causes the duration t1 to continuously decrease. To avoid reducing the impact on the fluctuation of the boost pressure difference, the time t1 is set to the downward learning state one, i.e., r t1 It needs to be reduced. t1 =r t1 (z)-0.04. Simultaneously, CNT2 is cleared to zero. The newly learned value is used the next time this condition is considered; CNT2 is updated at most once per driving cycle.

[0059] (5) If t1'-t1 is greater than the preset value C1, and the previous occurrence of t1'-t1 was not greater than the preset value -C2, then the adjustment fluctuation is too large, which has a significant impact on pressure fluctuation. In this case, the self-learning state of time t1 is changed to the upward learning state two, i.e., r t1 It needs to be increased. t1 =r t1 (z)+0.02. The newly learned value is used when this condition is considered again.

[0060] (6) If t1'-t1 is not greater than the preset value -C2, and the last occurrence of t1'-t1 was greater than the preset value C1, then the adjustment fluctuation is too large, which has a significant impact on pressure fluctuation. In this case, the self-learning state of time t1 is changed to the downward learning state two, i.e., r t1 It needs to be reduced. t1 =rt1 (z)-0.02. The newly learned value is used when judging this situation the next time it is entered.

[0061] (7) In other cases, r t1 and r Boost It remains unchanged.

[0062] The priority of the above 7 conditions decreases from one to the next.

[0063] like Figure 2 As shown, the present invention also provides a system structure with EGR, including an air filter 1, a mixing valve 2, a compressor 3, a throttle valve 4, an engine 5, a turbine 6, a catalytic converter 7, a particulate filter 8 connected in sequence, and an EGR cooler 9, an EGR valve 10, a temperature sensor 11 installed between the EGR valve 10 and the EGR cooler 9, and a differential pressure sensor 12 connected to the EGR valve 10 forming a branch; the two ends of the branch are respectively connected to the outlet of the particulate filter 8 and the outlet of the mixing valve 2; wherein the mixing valve 2 is used to adjust the pressure at the outlet of the EGR valve 10 to increase the differential pressure across the EGR valve 10, the engine 5 is used to compress fresh air for boosting, the turbine 6 is used to control the opening of the exhaust bypass valve, the EGR cooler 9 is used to receive and cool the exhaust gas output from the particulate filter 8 to increase the exhaust gas flow rate, the EGR valve 10 is used to control the exhaust gas flow rate entering the cylinder, the temperature sensor 11 is used to detect the temperature of the exhaust gas entering the EGR valve 10, and the differential pressure sensor 12 is used to detect the pressure at the inlet and outlet of the EGR valve 10. The structure described in this embodiment is used to execute an EGR closed-loop exit control method based on boost control as described in the embodiment.

[0064] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that the computer program includes executable instructions, which, when executed by a processor, implement the EGR closed-loop exit control method based on boost control described above.

[0065] The present invention also provides a vehicle comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement an EGR closed-loop exit control method based on boost control as described above.

[0066] This invention optimizes the control of the target opening of the EGR valve after the EGR closed loop exits by determining an initial value for the duration during which the target opening of the EGR valve remains unchanged, and optimizing the remaining time from the current time to the exit when the target opening of the EGR valve remains unchanged. At the same time, it identifies the fluctuation of the boost pressure deviation and optimizes the impact of pressure fluctuation during the exit of the EGR closed loop, thereby improving the stability of boost control during the exit of the EGR closed loop.

[0067] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0068] The order of the steps in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0069] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A closed-loop EGR exit control method based on boost control, characterized in that, The method includes: Read the EGR closed-loop conditions. When the EGR closed-loop conditions change from being met to not being met, calibrate the initial value of the duration for which the target opening of the EGR valve remains unchanged based on the pressure ratio coefficient and the real-time engine speed. After the EGR closed-loop condition is not met, the remaining time for the EGR valve target opening to remain unchanged is updated and optimized based on the change in boost pressure difference and the change in mixing valve outlet pressure, resulting in the updated remaining time; the remaining time is the time from the current moment until the EGR valve target opening exits the state of constant maintenance. Wherein, the pressure ratio coefficient is composed of The calculation yielded, where Indicates the pressure ratio coefficient. This indicates the actual outlet pressure of the mixing valve. This indicates the actual pressure at the inlet of the mixing valve. The pressure ratio correction factor represents the ratio of the actual pressure at the throttle outlet to the actual pressure at the throttle inlet; the pressure ratio correction factor is obtained through calibration. Among them, the updated remaining time Depend on The calculation yielded that, This indicates the remaining time during which the target opening of the EGR valve will remain unchanged. Indicates based on pressure ratio Change in boost pressure difference Determined calibration value, Indicates the change in outlet pressure of the mixing valve Change in boost pressure difference Determined calibration value, This represents the self-learning coefficient for the remaining time.

2. The EGR closed-loop exit control method based on boost control according to claim 1, characterized in that, The initial value of the duration for which the target opening of the EGR valve remains unchanged is obtained by calibration based on the pressure ratio coefficient and the real-time engine speed. The calibration basis is as follows: within several sampling periods from the start of the EGR closed-loop condition not being met to the end of the initial duration, the fluctuation of the difference between the target boost pressure and the actual boost pressure is within a preset range.

3. The EGR closed-loop exit control method based on boost control according to claim 2, characterized in that, The specific number of the sampling periods is determined by the turbocharger response time; the turbocharger response time is obtained by multiplying the turbocharger response initial time by the sum of the turbocharger response initial time self-learning coefficient and 1.

4. The EGR closed-loop exit control method based on boost control according to claim 3, characterized in that, The turbocharger response initial time is specifically the time it takes for the air-fuel mixture to flow from the turbocharger compressor to the throttle outlet. It is obtained by setting different EGR rates and measuring the time under different engine speeds and different actual intake air densities entering the cylinder, and taking the average of multiple data.

5. The EGR closed-loop exit control method based on boost control according to claim 1, characterized in that, The specific change in the boost pressure difference is: the difference between the maximum and minimum boost pressure difference within the most recent sampling periods.

6. The EGR closed-loop exit control method based on boost control according to claim 1, characterized in that, The calibration basis for the calibration values ​​of the pressure ratio and the change in boost pressure difference, and the calibration values ​​of the change in the outlet pressure of the mixing valve and the change in the boost pressure difference, is: to ensure that the fluctuation of the difference between the target boost pressure and the actual boost pressure is within a preset range within a preset time after the remaining time after the update.

7. The EGR closed-loop exit control method based on boost control according to claim 2 or 6, characterized in that, The fluctuation of the difference between the target boost pressure and the actual boost pressure is within a preset range, specifically determined by ensuring that the preset conditions are met within several sampling periods from the first sampling period when the EGR closed-loop conditions are not met until the end of the initial duration value.

8. The EGR closed-loop exit control method based on boost control according to claim 3, characterized in that, The self-learning coefficients for the initial response time and the remaining response time of the turbocharger are obtained in the following ways: If the difference between the updated remaining time and the previous remaining time is greater than the preset value and the change in the mixing valve outlet pressure exceeds the preset value by one, and the number of consecutive occurrences exceeds the preset value, then the self-learning coefficient of the remaining time will be increased based on the self-learning coefficient of the previously stored remaining time, and the self-learning coefficient of the booster response initial time will be increased based on the self-learning coefficient of the previously stored booster response initial time. If the difference between the remaining time after the update and the remaining time before the update is greater than a preset value of one, and the number of consecutive occurrences exceeds a preset value, then the self-learning coefficient of the remaining time will be increased based on the self-learning coefficient of the remaining time stored in the previous update. If the difference between the updated remaining time and the previous remaining time is not greater than the preset value of 2, and the change in the outlet pressure of the mixing valve exceeds the preset value and the number of consecutive occurrences exceeds the preset value, then the self-learning coefficient of the remaining time is reduced based on the self-learning coefficient of the previously stored remaining time, and the self-learning coefficient of the booster response initial time is equal to the self-learning coefficient of the previously stored booster response initial time reduced. If the difference between the remaining time after the update and the remaining time before the update is not greater than the preset value of 2, and the number of consecutive occurrences exceeds the preset value, then the self-learning coefficient of the remaining time is equal to the self-learning coefficient of the previously stored remaining time, reduced by the same factor. If the difference between the remaining time after the update and the remaining time before the update is greater than the preset value one, and the difference between the remaining time after the last update and the remaining time before the update is not greater than the preset value two, then the self-learning coefficient of the remaining time is equal to the self-learning coefficient of the remaining time stored last time, plus the original value. If the difference between the remaining time after the update and the remaining time before the update is not greater than the preset value two, and the difference between the remaining time after the update and the remaining time before the update is greater than the preset value one, then the self-learning coefficient of the remaining time is equal to the self-learning coefficient of the remaining time stored last time, reduced from the value of the previous self-learning coefficient. In other cases, the self-learning coefficient for the remaining time and the self-learning coefficient for the initial time of the turbocharger response remain unchanged.

9. The EGR closed-loop exit control method based on boost control according to claim 8, characterized in that, The initial value for the number of consecutive occurrences is 0. This value can be saved after the vehicle is powered off and can be updated at most once during each driving cycle.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that... The computer program includes executable instructions that, when executed by a processor, implement the EGR closed-loop exit control method based on boost control as described in claims 1-9.

11. A vehicle, characterized in that, The vehicle includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement an EGR closed-loop exit control method based on boost control as described in claims 1-9.

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