Method, electronic device and storage medium for controlling mixing valve opening

Abstract

The present invention discloses a method, electronic device, and storage medium for controlling the opening of a mixing valve, wherein the method includes the following steps: determining whether the current mixing valve is in a transitional operating state from non-fully open to fully open based on vehicle information; obtaining the current mixing valve opening change rate when the mixing valve is in the transitional operating state from non-fully open to fully open; determining a mixing valve opening slowdown correction coefficient based on the mixing valve throttle inlet pressure fluctuation and the mixing valve outlet pressure fluctuation, and updating the mixing valve opening slowdown correction coefficient in real time based on a learning update coefficient; obtaining a final mixing valve opening change rate based on the mixing valve opening slowdown correction coefficient and the current mixing valve opening change rate, and controlling the mixing valve opening based on the final mixing valve opening change rate and the mixing valve target opening. The present invention can optimize the mixing valve opening change rate during the mixing valve entering the fully open process, and improve the stability and dynamics of the mixing valve opening control process.

Description

Technical Field

[0001] The present invention relates to the field of engine control, and in particular to a method, electronic device and storage medium for controlling the opening of a mixing valve. Background Art

[0002] Exhaust Gas Recirculation (EGR) is the process of taking exhaust gas from the exhaust system and feeding it into the intake system. Studies have shown that the EGR system has certain advantages in improving emissions, reducing fuel consumption, and improving anti-knock capabilities. The control of the mixing valve in the low-pressure EGR system is particularly important for improving EGR efficiency. Common low-pressure EGR system structures include: Figure 2 shown.

[0003] In the prior art, the target EGR rate calculation method described in CN202011247319.6, "A Method and System for Calculating a Target EGR Rate," is as follows: determining a base target EGR rate based on engine speed and load; obtaining corresponding correction rates based on specific operating conditions; determining an initial target EGR rate based on the base target EGR rate and various correction rates; determining whether EGR is activated based on EGR activation conditions; and classifying the EGR state based on the judgment results to determine the final target EGR rate. This method calculates the initial target EGR rate based on throttle opening, manifold pressure difference, and minimum ignition angle, accurately calculating the target EGR rate. Furthermore, it incorporates EGR control activation conditions to perform a secondary correction on the final target EGR rate, but does not consider the control accuracy of the mixing valve target opening. CN202110184826.8, "A Method and System for Controlling an EGR Mixing Valve Target Opening," corrects the mixing valve target opening based on various operating condition parameters, but does not consider dynamic closed-loop control of the mixing valve target opening.

[0004] Therefore, there is an urgent need for a method to slow down the opening of the mixing valve opening request based on intake control stability, which balances the control stability during the process of the mixing valve changing from full opening to partial opening and optimizes the mixing valve opening change rate based on the accuracy of the EGR rate. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method, electronic equipment and storage medium for controlling the opening of a mixing valve, which are used to optimize the rate of change of the mixing valve opening when the mixing valve enters the fully open process, so as to further improve the stability and power performance during the control process and improve the safety protection of the engine.

[0006] The technical solution adopted by the present invention is a method, electronic device and storage medium for controlling the opening of a mixing valve, wherein the method comprises the steps of: judging whether the mixing valve is currently in a transitional operating state from non-fully open to fully open based on vehicle information;

[0007] When the mixing valve is in a transitional operating condition from non-fully open to fully open, the current rate of change of the mixing valve opening is obtained; a correction coefficient for slowing down the opening of the mixing valve is determined according to the pressure fluctuation of the mixing valve throttle inlet and the pressure fluctuation of the mixing valve outlet, and the correction coefficient for slowing down the opening of the mixing valve is updated in real time;

[0008] The final mixing valve opening change rate is obtained according to the mixing valve slow opening correction coefficient and the current mixing valve opening change rate, and the mixing valve opening is controlled according to the final mixing valve opening change rate and the mixing valve target opening.

[0009] Furthermore, the mixing valve slow opening correction coefficient is the product of the pressure fluctuation sub-correction coefficient, the pressure difference sub-correction coefficient and the learning update coefficient;

[0010] The pressure fluctuation correction coefficient is determined according to the throttle inlet pressure fluctuation rate and the mixing valve outlet pressure fluctuation rate;

[0011] Determine the pressure difference correction coefficient based on the mixing valve pressure ratio and the mixing valve outlet pressure change rate;

[0012] The learning update coefficient is updated in real time based on the torque responsiveness and EGR rate responsiveness.

[0013] Furthermore, the method for determining the pressure fluctuation sub-correction coefficient includes:

[0014] If the throttle inlet pressure fluctuation rate is not less than the preset value More than Or the mixing valve outlet pressure fluctuation rate is not less than the preset value More than , the pressure fluctuation correction coefficient is calibrated according to the throttle inlet pressure fluctuation rate and the mixing valve outlet pressure fluctuation rate, otherwise the throttle inlet pressure fluctuation rate is 1.

[0015] Furthermore, the pressure fluctuation correction coefficient calibration condition includes that the EGR rate difference rate during the transition from the mixing valve being partially open to being fully open does not exceed a preset value. At the same time, the throttle inlet pressure fluctuation rate is not less than the preset value The time exceeds the preset time , and the mixing valve outlet pressure fluctuation rate is not less than the preset value The time exceeds the preset time .

[0016] Furthermore, the method for determining the pressure difference correction coefficient includes:

[0017] If the mixing valve pressure ratio is less than the preset value And the mixing valve outlet pressure change rate is greater than the preset value , the pressure difference correction coefficient is calibrated according to the mixing valve pressure ratio and the mixing valve outlet pressure change rate, otherwise the pressure difference correction coefficient is 1.

[0018] Furthermore, the pressure difference correction coefficient calibration condition is that the EGR rate difference rate does not exceed the preset value during the transition from the mixing valve being partially open to being fully open. When the engine speed and the target engine boost pressure fluctuate within a preset range, the supercharger inlet pressure fluctuation range exceeds the preset value. The time does not exceed the preset time .

[0019] Furthermore, the pressure fluctuation sub-correction coefficient is inversely proportional to the throttle inlet pressure fluctuation rate and the mixing valve outlet pressure fluctuation rate; the pressure difference sub-correction coefficient is proportional to the mixing valve pressure ratio and inversely proportional to the mixing valve outlet pressure change rate.

[0020] Furthermore, the learning update coefficient is the learning coefficient plus 1, the default initial value of the learning coefficient is 0, and the learning coefficient is updated in real time according to the torque responsiveness and the EGR rate responsiveness.

[0021] Furthermore, the learning coefficient update activation conditions are as follows: the mixing valve is in the transition process from fully open to partially open; the supercharger is in the closed-loop control activation state; the absolute value of the engine target intake pressure change rate exceeds the preset value; ;The absolute value of the engine request torque change rate exceeds the preset value ; During the time between the current moment and the last time the learning update coefficient was updated, the mileage of the vehicle involved in the engine operation exceeds the preset value ; When the learning coefficient update activation conditions are met, the learning coefficient is updated.

[0022] Furthermore, when the learning coefficient update activation conditions are met, the current operating condition is determined based on the torque responsiveness and the EGR rate responsiveness, and the learning coefficient is updated based on the current operating condition, which includes a low responsiveness condition, a high responsiveness condition, and other conditions.

[0023] If the response is low, increase the preset value on the learning coefficient after the last update. Get the updated learning coefficient;

[0024] If it is in a high response state, record the number of times CNT that the high response state is met. If CNT is greater than the preset value , subtract the preset value from the learning coefficient after the last update Get the updated learning coefficient;

[0025] In other cases, the learning coefficient is equal to the learning coefficient after the last update;

[0026] The learning coefficient and CNT are updated at most once in one driving cycle, and CNT is cleared after the learning coefficient is updated.

[0027] Furthermore, the judgment basis for the current working condition being in a low response situation is that the difference between the engine target torque and the actual torque exceeds a preset value. The continuous time exceeds the preset time , the throttle inlet pressure fluctuation exceeds the preset value The continuous time exceeds the preset time , the mixing valve outlet pressure fluctuation exceeds the preset value The continuous time exceeds the preset time , the difference between the engine target torque and the actual torque exceeds the preset value The continuous time exceeds the preset time , the difference between the target EGR rate and the actual EGR rate exceeds the preset value The absolute value of the difference between the final mixing valve opening change rate and the current mixing valve opening change rate does not exceed the preset value. ;

[0028] The judgment basis for the current working condition to be in a high response state is that the difference between the engine target torque and the actual torque does not exceed the preset value. , the difference between the target EGR rate and the actual EGR rate does not exceed the preset value , the difference between the target opening of the mixing valve and the actual opening of the mixing valve does not exceed the preset value And the absolute value of the difference between the final mixing valve opening change rate and the current mixing valve opening change rate exceeds the preset value ;

[0029] The situations that do not belong to the low response situation and the high response situation are other situations.

[0030] Furthermore, the low-pressure EGR system applicable to the present method includes an air filter; a mixing valve connected to the air filter, used to adjust the pressure at the outlet of the EGR valve, increase the pressure difference at both ends of the EGR valve, and extend two air flow paths from behind the mixing valve; a compressor connected to one of the air flow paths of the mixing valve; a throttle connected to the compressor; an engine connected to the throttle, used to compress fresh air for supercharging; a turbine connected to the engine, used to control the opening of the exhaust gas bypass valve; a catalyst connected to the turbine; a particulate matter collector connected to the catalyst; an EGR cooler installed on the other air flow path of the mixing valve, receiving the exhaust gas output by the particulate matter collector and cooling it to increase the exhaust gas flow rate; an EGR valve with one end connected to the EGR cooler and the other end connected to the mixing valve, used to throttle and control the exhaust gas flow entering the cylinder; a temperature sensor installed between the EGR valve and the EGR cooler, used to detect the exhaust gas temperature entering the EGR valve; a pressure differential sensor connected to the EGR valve, used to detect the pressure at the EGR inlet and outlet.

[0031] Another aspect of the present invention provides an electronic device, comprising: a storage device for storing executable instructions; and a processing device for executing the executable instructions stored in the storage device to implement the above-mentioned method for controlling the opening of a mixing valve.

[0032] A third aspect of the present invention provides a storage medium, wherein the storage medium stores a computer program, and when the computer program is executed, the above-mentioned method for controlling the opening of a mixing valve is implemented.

[0033] The beneficial effects of the present invention are as follows: the present invention obtains the operating parameters of the current mixing valve under the transition condition from partially open to fully open to determine the mixing valve slow-opening correction coefficient, updates the mixing valve slow-opening correction coefficient by learning the update coefficient, and then determines the final mixing valve opening change rate based on the mixing valve slow-opening correction coefficient and the current mixing valve opening change rate. Combined with the mixing valve target opening, the mixing valve opening is controlled. The present invention can optimize stability and power performance during the control process and effectively address issues such as engine safety protection.

[0034] Furthermore, the present invention sets a pressure fluctuation correction coefficient that is inversely proportional to the magnitude of the throttle inlet pressure fluctuation rate and the mixing valve outlet pressure fluctuation rate, which can effectively limit the adverse effects of excessive fluctuations in the throttle inlet pressure and the mixing valve outlet pressure on the control process.

[0035] Furthermore, the present invention maintains the stability of the mixing valve control by limiting the magnitude of the fluctuation of the intake throttle inlet pressure fluctuation rate and the fluctuation of the mixing valve outlet pressure fluctuation rate.

[0036] Furthermore, the present invention provides a pressure differential correction coefficient that is proportional to the mixing valve pressure ratio and inversely proportional to the rate of change of the mixing valve outlet pressure. This can effectively mitigate the sudden increase in the mixing valve pressure caused by excessive changes in the mixing valve opening when the mixing valve is fully opened, thereby improving the mixing valve's boost control stability and robustness.

[0037] Furthermore, the present invention maintains the stability of the mixing valve control by limiting the magnitude of the mixing valve pressure ratio fluctuation and the mixing valve outlet pressure change rate fluctuation;

[0038] Furthermore, when updating the learning coefficient, the present invention gradually restores the original mixing valve change rate if the current operating conditions meet certain conditions, thereby improving the EGR rate and optimizing emissions and fuel economy.

[0039] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 Flowchart of the method for controlling the opening of a mixing valve according to the present invention;

[0042] Figure 2 This is a structural diagram of a low-pressure EGR system in one embodiment of the present invention.

[0043] The reference numerals include: 1. air filter; 2. mixing valve; 3. compressor; 4. throttle; 5. engine; 6. turbine; 7. catalyst; 8. particulate matter collector; 9. EGR cooler; 10. EGR valve; 11. temperature sensor; 12. differential pressure sensor. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present 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 only used to explain the present invention and are not intended to limit the present invention.

[0045] It should be noted that the illustrations provided in the embodiments of the present invention are only schematic illustrations of the basic concept of the present invention. Therefore, the drawings only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0046] In the present invention, it should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like are used to indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate the description of the present application and to simplify the description. They are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present application. Furthermore, the terms "first" and "second" are used solely for descriptive and distinguishing purposes and should not be construed as indicating or implying relative importance.

[0047] Example 1

[0048] This embodiment provides a method for controlling the opening of a mixing valve for a low-pressure EGR system, such as Figure 1 As shown, the steps include:

[0049] S1. When the current mixing valve is in a transitional state from non-fully open to fully open, obtain various operating parameters of the current mixing valve, including the current mixing valve opening and the current mixing valve opening change rate ;

[0050] S2. Determine the final mixing valve opening change rate based on the control stability angle, etc., and set the mixing valve slow opening correction coefficient ,and Less than 1.

[0051] Specifically, r2=r 21 ×r 22 ×(1+r Adapt2 ).

[0052] S2.1. Determine the pressure fluctuation correction factor .

[0053] Determine whether the current working condition meets any of the following conditions: Throttle inlet pressure fluctuation rate Not less than the preset value The time exceeds the preset time ; Mixing valve outlet pressure fluctuation rate Not less than the preset value The time exceeds the preset time In this embodiment Take 0.05, Take 0.2s, Take 0.05, Take 0.5s.

[0054] Furthermore, the throttle inlet intake pressure after the first-order low-pass filter in the Nth sampling period is .

[0055] in, is the intake pressure at the throttle inlet; is the intake pressure at the throttle outlet of the Nth sampling period; is the intake pressure at the throttle inlet after first-order low-pass filtering; The throttle inlet pressure after first-order low-pass filtering in the N-1th sampling cycle; N = 1, 2, 3...; sampling cycle interval In this example, the value is 10ms; the coefficient ,in is the number of engine cylinders, is the engine speed, is the filter coefficient of the intake pressure at the throttle inlet. In this example, the number of engine cylinders is 4 and the engine speed is 1000 rpm. Take 0.1, The purpose of this setting is to normalize the processing. Under different numbers of cylinders and speeds, there is no need to do special calibration. It is only necessary to calibrate the engine cylinder number to 4 and the engine speed to 1000rpm, thereby reducing the calibration test work.

[0056] The outlet pressure of the mixing valve after first-order low-pass filtering in the Nth sampling period is: .

[0057] Among them, p aftMix is the outlet pressure of the mixing valve; p aftMix (N) is the outlet pressure of the mixing valve in the Nth sampling period; p aftMixFilter is the outlet pressure of the mixing valve after first-order low-pass filtering; p aftMixFilter (N-1) is the mixing valve outlet pressure after first-order low-pass filtering in the N-1th sampling period; N=1,2,3…; sampling period interval In this example, 10ms is used; K aftMix is the coefficient: in is the number of engine cylinders, is the engine speed, K aftMix is the filter coefficient of the intake pressure at the throttle inlet. In this example, the number of engine cylinders is 4, the engine speed is 1000 rpm, and k aftMix Take 0.1, The purpose of this setting is to normalize the processing. Under different numbers of cylinders and speeds, there is no need to do special calibration. It is only necessary to calibrate the engine cylinder number to 4 and the engine speed to 1000rpm, thereby reducing the calibration test work.

[0058] If none of the above conditions are met, then ; If any of the above conditions are met, further methods are used to obtain :

[0059] Specifically, is the throttle inlet pressure fluctuation rate and mixing valve outlet pressure fluctuation rate Determine the characteristic coefficient. The bigger, The smaller the value, the slower the speed at which the mixing valve enters the fully open state, thus avoiding the drastic fluctuation of the throttle inlet pressure due to excessive fluctuation of the mixing valve opening; The bigger, The smaller the value, the slower the speed at which the mixing valve enters the fully open state, thus avoiding drastic fluctuations in the mixing valve outlet pressure due to excessive fluctuations in the mixing valve opening;

[0060] Furthermore, the characteristic coefficient The calibration basis is to ensure that the EGR rate difference rate is Not exceeding the preset value At the same time, the throttle inlet pressure fluctuation rate Not less than the preset value More than And the mixing valve outlet pressure fluctuation rate Not less than More than In this embodiment, Take ±0.015; Take 0.08, Take 0.2s, Take 0.08, Take 0.5s.

[0061] Furthermore, the throttle inlet pressure fluctuation rate and mixing valve outlet pressure fluctuation rate Too frequent fluctuations will lead to Adjustment changes are too large, further leading to The change is too large, resulting in excessive fluctuations in the mixing valve opening control, which makes the mixing valve control have poor stability. To avoid this situation, the following processing is performed in this embodiment:

[0062] Throttle inlet pressure fluctuation rate at intake volume Fluctuation does not exceed the preset value , and the mixing valve outlet pressure fluctuation rate Fluctuation does not exceed the preset value When the correction factor Not updated. Among them, the intake throttle inlet pressure fluctuation rate Fluctuation is the difference between the throttle inlet pressure fluctuation rate in this sampling period and the throttle inlet pressure fluctuation rate in the previous sampling period, and the mixing valve outlet pressure fluctuation rate Fluctuation is the difference between the mixing valve outlet pressure fluctuation rate in this sampling period and the mixing valve outlet pressure fluctuation rate in the previous sampling period. In this embodiment, the sampling period is 10ms. Take ±0.02, Take ±0.02.

[0063] S2.2. Determine the pressure difference correction coefficient .

[0064] Determine whether the current working conditions meet the following conditions at the same time: mixing valve pressure ratio Less than the preset value ; Mixing valve outlet pressure change rate dp aftMix Greater than the preset value In this example, Take 0.2, Take 15kPa / 10ms. The mixing valve pressure ratio is the mixing valve outlet pressure p aftMix and mixing valve inlet pressure p bfMix The ratio.

[0065] If the current working condition cannot meet the above conditions at the same time, then ; If the current working condition meets the above conditions at the same time, then And take further steps to obtain :

[0066] Specifically, the mixing valve pressure ratio The smaller the characteristic coefficient The smaller the mixing valve outlet pressure change rate dp aftMix The larger the characteristic coefficient The smaller the characteristic coefficient It can slow down the speed at which the mixing valve enters the fully open state, avoiding excessive changes in the mixing valve outlet pressure due to excessive changes in the closed-loop mixing valve opening, further causing a sudden increase in the mixing valve pressure, and thus causing a sudden increase in the boost pressure inlet, resulting in poor stability and robustness of the boost control.

[0067] Furthermore, the characteristic coefficient The calibration basis is to ensure that the EGR rate difference rate is Not exceeding the preset value When the engine speed and the target engine boost pressure fluctuate within the preset range, the supercharger inlet pressure fluctuation range exceeds the preset value. The time does not exceed the preset time In this embodiment, Take ±0.015, Take ±2kPa, Take 0.1s.

[0068] Furthermore, the mixing valve pressure ratio and the mixing valve outlet pressure change rate dp aftMix Too frequent fluctuations will lead to Adjustment changes are too large, which leads to The change is too large, which causes the mixing valve opening control to fluctuate too much, resulting in poor control stability of the mixing valve. To avoid this situation, the following processing is performed in this embodiment:

[0069] Mixing valve pressure ratio Fluctuation does not exceed the preset value , this embodiment Take ±0.05, and the mixing valve outlet pressure change rate dp aftMix Fluctuation does not exceed the preset value When, this embodiment Take ±3kPa / 10ms, correction coefficient Not updated. Among them, the mixing valve pressure ratio Fluctuation is the mixing valve pressure ratio during this sampling period Mixing valve pressure ratio compared to the previous sampling period The difference between the mixing valve outlet pressure change rate dp aftMix Fluctuation is the rate of change of the mixing valve outlet pressure dp during this sampling period aftMix The mixing valve outlet pressure change rate dp compared to the previous sampling period aftMix The sampling period in this example is 10ms.

[0070] S2.3. Determine the learning update coefficient .

[0071] S2.3.1. Determine whether the current operating conditions meet the learning update activation conditions, where the learning update activation conditions include: the mixing valve is in the transition from fully open to partially open; the supercharger is in the closed-loop control activation state; the absolute value of the engine target intake pressure change rate exceeds the preset value , this example Take 25kPa / 10ms; the absolute value of the engine request torque change rate exceeds the preset value , this example Take 30Nm / 10ms; during the time interval between the current moment and the last time the learning update coefficient was updated, the mileage of the vehicle involved in the engine operation exceeds the preset value , this example Take 20,000 kilometers.

[0072] S2.3.2. If the current working condition meets the learning update activation conditions, further determine the current working condition.

[0073] Specifically, if the current working condition meets the following conditions, it is determined to be the first case, including: the difference between the engine target torque and the actual torque exceeds the preset value The continuous time exceeds the preset time In this embodiment Take ±5Nm, Take 0.7s; the throttle inlet pressure fluctuation exceeds the preset value The continuous time exceeds the preset time , where the throttle inlet pressure fluctuation is the difference between the current inlet pressure and the inlet pressure of the previous sampling period. In this embodiment Take ±2kPa, Take 0.3s; the mixing valve outlet pressure fluctuation exceeds the preset value The continuous time exceeds the preset time , where the mixing valve outlet pressure fluctuation is the difference between the current inlet pressure and the inlet pressure of the previous sampling period. In this embodiment, Take ±2kPa, Take 0.3s; the difference between the engine target torque and the actual torque exceeds the preset value The continuous time exceeds the preset time In this embodiment Take ±5Nm, Take 0.7s; the difference between the target EGR rate and the actual EGR rate exceeds the preset value In this example, Take ±0.15; |dpct MGVNew -dpct MGVRaw The value of | does not exceed the preset value In this example, Take -15% / 10ms, where is the final mixing valve opening change rate, is the current mixing valve opening change rate.

[0074] In this case, the torque responsiveness and EGR rate responsiveness are poor, and a small adjustment is made to the learning update coefficient. ,in is the learning update coefficient obtained in the last learning. In this embodiment Take 0.005.

[0075] Furthermore, if the current working condition meets the following conditions, it is determined to be the second case, including: the difference between the engine target torque and the actual torque does not exceed the preset value In this embodiment Take ±5Nm; the difference between the target EGR rate and the actual EGR rate does not exceed the preset value In this example, Take ±0.1; the difference between the target opening of the mixing valve and the actual opening of the mixing valve does not exceed the preset value In this example, Take ±1%; |dpct MGVNew -dpct MGVRaw The value of | exceeds the preset value , this example Take -25% / 10ms.

[0076] Record the number of times the above four conditions are met at the same time CNT. If CNT exceeds the preset value , this example Take 50 and gradually restore the original mixing valve change rate. The purpose of gradual restoration is to improve the EGR rate, achieve the EGR rate advantage, and improve emissions and fuel economy. In this case, the torque responsiveness and EGR rate responsiveness are good, and the learning update coefficient is slightly adjusted. In this embodiment, the update , Take 0.02.

[0077] Furthermore, the CNT is updated only once per driving cycle. After updating, CNT is cleared. It is also only updated once per drive cycle.

[0078] In other cases, ,Right now No updates are performed.

[0079] S2.4, according to the obtained Calculate the correction factor for mixing valve slow opening.

[0080] S3. Multiply the obtained mixing valve slow opening correction coefficient by the current mixing valve opening change rate to obtain a final mixing valve opening change rate, and control the mixing valve opening according to the final mixing valve opening change rate.

[0081] Example 2

[0082] This embodiment provides a low-pressure EGR system for controlling the opening of a mixing valve, the structure of which is as follows: Figure 2As shown, this system is adapted to the method for controlling the opening of the mixing valve described in Example 1. It includes: an air filter 1; a mixing valve 2 connected to the air filter, used to adjust the pressure at the outlet of the EGR valve 10, increase the pressure difference between the two ends of the EGR valve 10, and extend two air flow paths from the mixing valve 2; a compressor 3 connected to one of the air flow paths of the mixing valve 2; a throttle 4 connected to the compressor 3; an engine 5 connected to the throttle 4, used to compress fresh air for supercharging; a turbine 6 connected to the engine 5, used to control the opening of the exhaust bypass valve; a catalyst 7 connected to the turbine 6; a particulate matter trap 8 connected to the catalyst 7; and a device installed on the exhaust pipe. The EGR cooler 9 on the other air flow path of the mixing valve 2 is used to receive the exhaust gas output by the particulate matter collector 8 and cool it to increase the exhaust gas flow rate; one end is connected to the EGR cooler 9, and the other end is connected to the EGR valve 10 of the mixing valve 2, which is used to control the exhaust gas flow entering the cylinder; the temperature sensor 11 installed between the EGR valve 10 and the EGR cooler 9 is used to detect the exhaust gas temperature entering the EGR valve 10; the pressure difference sensor 12 connected to the EGR valve 10 is used to detect the pressure at the inlet and outlet of the EGR valve 10.

[0083] Specifically, compared with the non-low-pressure EGR system, the low-pressure EGR system adds an EGR cooler 9, a temperature sensor 11, an EGR valve 10, a pressure difference sensor 12 and a mixing valve 2, wherein the control of the mixing valve 2 plays an important role in improving the EGR rate.

[0084] Example 3

[0085] This embodiment provides an electronic device, comprising: a storage device for storing executable instructions; and a processing device for executing the executable instructions stored in the storage device to implement the above-mentioned method for controlling the opening of a mixing valve.

[0086] Example 4

[0087] This embodiment provides a storage medium, in which a computer program is stored. When the computer program is executed, the above-mentioned method for controlling the opening of a mixing valve is implemented.

[0088] In summary, the present invention provides a method, electronic device, and storage medium for controlling the opening of a mixing valve. For a mixing valve in a transitional operating state from partially open to fully open, the present parameters are obtained to determine the current operating conditions. The method further calculates and obtains a pressure fluctuation sub-correction coefficient, a pressure difference sub-correction coefficient, and a learning update coefficient. These coefficients are used to determine the final rate of change of the mixing valve opening, and the mixing valve is then controlled in conjunction with the target opening of the mixing valve. The present invention can optimize the control of the rate of change of the mixing valve opening when the mixing valve is in a transitional operating state from partially open to fully open, improve the stability and power of the control process, ensure engine safety, and, at the same time, play an important role in improving the EGR rate during the control process.

[0089] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0090] The size of the serial numbers of the steps in the above embodiments does not mean 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 the present application.

[0091] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all such improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A method for controlling the opening of a mixing valve for a low-pressure EGR system, characterized in that: include: According to the vehicle information, determine whether the current mixing valve is in a transitional operating state from non-fully open to fully open; When the mixing valve is in a transitional operating condition from non-fully open to fully open, the current rate of change of the mixing valve opening is obtained; a correction coefficient for slowing down the opening of the mixing valve is determined according to the pressure fluctuation of the mixing valve throttle inlet and the pressure fluctuation of the mixing valve outlet, and the correction coefficient for slowing down the opening of the mixing valve is updated in real time; The final mixing valve opening change rate is obtained according to the mixing valve slow opening correction coefficient and the current mixing valve opening change rate, and the mixing valve opening is controlled according to the final mixing valve opening change rate and the mixing valve target opening.

2. The method for controlling the opening of a mixing valve according to claim 1, wherein: The mixing valve slow opening correction coefficient is the product of the pressure fluctuation correction coefficient, the pressure difference correction coefficient and the learning update coefficient; The pressure fluctuation correction coefficient is determined according to the throttle inlet pressure fluctuation rate and the mixing valve outlet pressure fluctuation rate; Determine the pressure difference correction coefficient based on the mixing valve pressure ratio and the mixing valve outlet pressure change rate; The learning update coefficient is updated in real time based on the torque responsiveness and EGR rate responsiveness.

3. The method for controlling the opening of a mixing valve according to claim 2, characterized in that: The method for determining the pressure fluctuation sub-correction coefficient includes: If the throttle inlet pressure fluctuation rate is not less than the preset value More than Or the mixing valve outlet pressure fluctuation rate is not less than the preset value More than , the pressure fluctuation correction coefficient is calibrated according to the throttle inlet pressure fluctuation rate and the mixing valve outlet pressure fluctuation rate, otherwise the throttle inlet pressure fluctuation rate is 1.

4. The method for controlling the opening of a mixing valve according to claim 3, wherein: The pressure fluctuation correction coefficient calibration conditions include that the EGR rate difference rate does not exceed the preset value during the transition from the mixing valve being partially open to being fully open. At the same time, the throttle inlet pressure fluctuation rate is not less than the preset value The time exceeds the preset time , and the mixing valve outlet pressure fluctuation rate is not less than the preset value The time exceeds the preset time .

5. The method for controlling the opening of a mixing valve according to claim 2, wherein: The method for determining the pressure difference correction coefficient includes: If the mixing valve pressure ratio is less than the preset value And the mixing valve outlet pressure change rate is greater than the preset value , the pressure difference correction coefficient is calibrated according to the mixing valve pressure ratio and the mixing valve outlet pressure change rate, otherwise the pressure difference correction coefficient is 1.

6. The method for controlling the opening of a mixing valve according to claim 5, characterized in that: The calibration condition of the pressure difference correction coefficient is that the EGR rate difference rate does not exceed the preset value during the transition from the mixing valve being partially open to being fully open When the engine speed and the target engine boost pressure fluctuate within a preset range, the supercharger inlet pressure fluctuation range exceeds the preset value. The time does not exceed the preset time .

7. The method for controlling the opening of a mixing valve according to claim 2, wherein: The pressure fluctuation sub-correction coefficient is inversely proportional to the throttle inlet pressure fluctuation rate and the mixing valve outlet pressure fluctuation rate; the pressure difference sub-correction coefficient is proportional to the mixing valve pressure ratio and inversely proportional to the mixing valve outlet pressure change rate.

8. The method for controlling the opening of a mixing valve according to claim 2, wherein: The learning update coefficient is the learning coefficient plus 1. The default initial value of the learning coefficient is 0. The learning coefficient is updated in real time according to the torque responsiveness and the EGR rate responsiveness.

9. The method for controlling the opening of a mixing valve according to claim 8, characterized in that: The learning coefficient update activation conditions are: the mixing valve is in the transition process from fully open to partially open; the supercharger is in the closed-loop control activation state; the absolute value of the engine target intake pressure change rate exceeds the preset value; ; The absolute value of the engine torque change rate exceeds the preset value ; During the time between the current moment and the last time the learning update coefficient was updated, the mileage of the vehicle involved in the engine operation exceeds the preset value ; When the learning coefficient update activation conditions are met, the learning coefficient is updated.

10. The method for controlling the opening of a mixing valve according to claim 9, wherein: When the learning coefficient update activation conditions are met, the current operating condition is determined based on the torque responsiveness and EGR rate responsiveness, and the learning coefficient is updated based on the current operating condition, which includes low response, high response, and other conditions. If the response is low, increase the preset value on the learning coefficient after the last update. Get the updated learning coefficient; If it is in a high response state, record the number of times CNT that the high response state is met. If CNT is greater than the preset value , subtract the preset value from the learning coefficient after the last update Get the updated learning coefficient; In other cases, the learning coefficient is equal to the learning coefficient after the last update; The learning coefficient and CNT are updated at most once in one driving cycle, and CNT is cleared after the learning coefficient is updated.

11. The method for controlling the opening of a mixing valve according to claim 10, wherein: The judgment basis for the current working condition being in a low response situation is that the difference between the engine target torque and the actual torque exceeds the preset value. The continuous time exceeds the preset time , the throttle inlet pressure fluctuation exceeds the preset value The continuous time exceeds the preset time , the mixing valve outlet pressure fluctuation exceeds the preset value The continuous time exceeds the preset time , the difference between the engine target torque and the actual torque exceeds the preset value The continuous time exceeds the preset time , the difference between the target EGR rate and the actual EGR rate exceeds the preset value The absolute value of the difference between the final mixing valve opening change rate and the current mixing valve opening change rate does not exceed the preset value. ; The judgment basis for the current working condition to be in a high response state is that the difference between the engine target torque and the actual torque does not exceed the preset value. , the difference between the target EGR rate and the actual EGR rate does not exceed the preset value , the difference between the target opening of the mixing valve and the actual opening of the mixing valve does not exceed the preset value And the absolute value of the difference between the final mixing valve opening change rate and the current mixing valve opening change rate exceeds the preset value ; The situations that do not belong to the low response situation and the high response situation are other situations.

12. An electronic device, characterized in that: The electronic device includes: a storage device for storing executable instructions; and a processing device for executing the executable instructions stored in the storage device to implement the method for controlling the opening of a mixing valve according to any one of claims 1 to 11.

13. A storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed, the method for controlling the opening of a mixing valve according to any one of claims 1 to 11 is implemented.

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