Method for controlling opening degree of mixing valve, electronic equipment and storage medium

Abstract

The invention discloses a method for controlling the opening degree of a mixing valve, electronic equipment and a storage medium, and the method comprises the steps: judging whether the current mixing valve is in a transition working condition from non-full opening to full opening or not according to vehicle information; under the condition that the mixing valve is in the transition working condition from non-full opening to full opening, the current mixing valve opening degree change rate is obtained; according to the mixing valve throttle inlet pressure fluctuation condition and the mixing valve outlet pressure fluctuation condition, a mixing valve opening slowing correction coefficient is determined, and the mixing valve opening slowing correction coefficient is updated in real time according to the learning updating coefficient; and according to the slow opening correction coefficient of the mixing valve and the current opening change rate of the mixing valve, the final opening change rate of the mixing valve is obtained, and the opening of the mixing valve is controlled according to the final opening change rate of the mixing valve and the target opening of the mixing valve. According to the method, the opening change rate of the mixing valve in the full-opening process of the mixing valve can be optimized, and the stability and the dynamic property of the mixing valve in the opening control process are improved.

Description

Technical Field

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

[0002] Exhaust gas recirculation (EGR) is to take exhaust gas from the exhaust gas 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 the efficiency of EGR. Common low-pressure EGR system structures are as follows: Figure 2 shown.

[0003] In the prior art, the target EGR rate calculation method in CN202011247319.6 "A method and system for calculating the target EGR rate" is: determine the basic target EGR rate according to the engine speed and load; obtain the corresponding correction rate according to the special working conditions; determine the initial target EGR rate according to the basic target EGR rate and each correction rate; determine whether EGR is activated according to the EGR activation state conditions; divide the EGR state according to the judgment result, and determine the final target EGR rate. This method calculates the initial target EGR rate from the throttle opening, manifold pressure difference and minimum ignition angle, can accurately calculate the target EGR rate, and introduces the EGR control activation conditions to perform secondary correction on the final target EGR rate, but does not consider the control accuracy of the target opening of the mixing valve. CN202110184826.8 "A method and system for controlling the target opening of an EGR mixing valve" corrects the target opening of the mixing valve according to various working condition parameters, but does not consider the dynamic closed-loop control of the target opening of the mixing valve.

[0004] Therefore, there is an urgent need for a control method for slowing 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 partly full 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 full opening process, so as to further improve the stability and power of the control process and improve the safety protection of the engine.

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

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

[0008] According to the mixing valve slow opening correction coefficient and the current mixing valve opening change rate, the final mixing valve opening change rate is obtained, 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] Wherein, the pressure fluctuation sub-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 according to the mixing valve pressure ratio and the mixing valve outlet pressure change rate;

[0012] The learning update coefficient is updated in real time according to 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 A1 for more than T1 or the mixing valve outlet pressure fluctuation rate is not less than the preset value A2 for more than T2, 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 calibration conditions of the pressure fluctuation sub-correction coefficient include that, during the transition process from the non-fully open to the fully open state of the mixing valve, the EGR rate difference rate does not exceed the preset value A3, the time during which the throttle inlet pressure fluctuation rate is not less than the preset value A4 exceeds the preset time T3, and the time during which the mixing valve outlet pressure fluctuation rate is not less than the preset value A5 exceeds the preset time T4.

[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 A6 and the mixing valve outlet pressure change rate is greater than the preset value A7, 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 calibration condition of the pressure difference correction coefficient is that the EGR rate difference rate does not exceed the preset value A8 during the transition from the mixing valve being partially open to being fully open, and when the engine speed and the engine target boost pressure fluctuate within a preset range, the time for which the supercharger inlet pressure fluctuation range exceeds the preset value A9 does not exceed the preset time T5.

[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 condition is that 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 A 10 ; The absolute value of the engine torque change rate exceeds the preset value A 11 ; 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 A 12 ; When the learning coefficient update activation conditions are met, the learning coefficient is updated.

[0022] Further, when the learning coefficient update activation condition is 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 response condition, a high response condition, and other conditions;

[0023] If the response is low, add the preset value A to the learning coefficient after the last update. 14 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 C1, subtract the preset value A from the learning coefficient after the last update. 13 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 state is that the difference between the engine target torque and the actual torque exceeds a preset value A. 14 The continuous time exceeds the preset time T6, and the throttle inlet pressure fluctuation exceeds the preset value A 15 The continuous time exceeds the preset time T7, and the mixing valve outlet pressure fluctuation exceeds the preset value A 16 The continuous time exceeds the preset time T8, and the difference between the engine target torque and the actual torque exceeds the preset value A 17 The continuous time exceeds the preset time T9, and the difference between the target EGR rate and the actual EGR rate exceeds the preset value A 18 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 A. 19 ;

[0028] The judgment basis for the current working condition being in a high response state is that the difference between the engine target torque and the actual torque does not exceed the preset value A. 20 , the difference between the target EGR rate and the actual EGR rate does not exceed the preset value A 21 , the difference between the target opening of the mixing valve and the actual opening of the mixing valve does not exceed the preset value A 22 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 A 23 ;

[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 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 another air flow path of the mixing valve, receiving and cooling the exhaust gas output by the particulate matter collector to increase the exhaust gas flow; an EGR valve connected to the EGR cooler at one end and the mixing valve at the other end, used for throttling and controlling 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 difference 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; 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 non-fully open to fully open to determine the mixing valve slow opening correction coefficient, and updates the mixing valve slow opening correction coefficient by learning the update coefficient, and then determines the final mixing valve opening change rate according to the mixing valve slow opening correction coefficient and the current mixing valve opening change rate, and realizes the control of the mixing valve opening in combination with the mixing valve target opening. The present invention can optimize the stability and power performance in the control process and effectively solve the problems of engine safety protection.

[0034] Furthermore, the present invention sets a pressure fluctuation correction coefficient which is inversely proportional to 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 pressure fluctuation rate at the inlet of the intake throttle valve and the fluctuation of the pressure fluctuation rate at the outlet of the mixing valve.

[0036] Furthermore, the present invention sets a pressure difference correction coefficient which is proportional to the pressure ratio of the mixing valve and inversely proportional to the change rate of the outlet pressure of the mixing valve, which can effectively alleviate the problem of sudden increase in the mixing valve pressure caused by excessive change in the opening of the mixing valve when the mixing valve is fully opened, thereby improving the boost control stability and robustness of the mixing valve;

[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 briefly introduces 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 creative work.

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

[0042] Figure 2 4 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 solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with 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 used to limit the present invention.

[0045] It should be noted that the illustrations provided in the embodiments of the present invention are only used to illustrate the basic concept of the present invention in a schematic manner. Therefore, the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout type may also be more complicated.

[0046] In the present invention, it is also necessary to explain that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, if the terms "first" and "second" appear, they are only used for description and distinction purposes, and cannot be understood 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 pct MGVRaw and the current mixing valve opening change rate dpct MGVRaw ;

[0050] S2. Determine the final mixing valve opening change rate based on the control stability angle, etc., set the mixing valve slow opening correction coefficient r2, and r2 is less than 1.

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

[0052] S2.1. Determine the pressure fluctuation correction factor r 21 .

[0053] Determine whether the current working condition meets any of the following conditions: Throttle inlet pressure fluctuation rate The time not less than the preset value A1 exceeds the preset time T1; the mixing valve outlet pressure fluctuation rate The time not less than the preset value A2 exceeds the preset time T2. In this embodiment, A1 is 0.05, T1 is 0.2s, A2 is 0.05, and T2 is 0.5s.

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

[0055] Among them, p pre is the intake pressure at the throttle inlet; p pre (N) is the throttle outlet intake pressure at the Nth sampling cycle; p preFilter is the throttle inlet intake pressure after first-order low-pass filtering; p preFilter (N-1) is the throttle inlet intake pressure after the first-order low-pass filter in the N-1th sampling period; N = 1, 2, 3...; the sampling period interval Δt in this example is 10ms; the coefficient Where m is the number of engine cylinders, n is the engine speed, k pre 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 pre Take 0.1, The purpose of this setting is to normalize the processing. Under different numbers of cylinders and speeds, there is no need for special calibration. You only need 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 the first-order low-pass filter 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 cycle; p aftMixFilter is the outlet pressure of the mixing valve after first-order low-pass filtering; p aftMixFilter (N-1) is the outlet pressure of the mixing valve after the first-order low-pass filter in the N-1th sampling period; N = 1, 2, 3...; the sampling period interval Δt is 10ms in this example; K aftMix is the coefficient: Where m is the number of engine cylinders, n 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 for special calibration. You only need to calibrate the engine cylinder number to 4 and the engine speed to 1000rpm, thereby reducing the calibration test work.

[0058] If the above conditions are not met, then r 21 =1; if any of the above conditions is met, a further method is used to obtain r 21 :

[0059] Specifically, is the throttle inlet pressure fluctuation rate The 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 drastic fluctuations in the throttle inlet pressure due to excessive fluctuations in 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 outlet pressure of the mixing valve due to excessive fluctuations in the opening of the mixing valve;

[0060] Furthermore, the characteristic coefficient The calibration basis is to ensure that the EGR rate difference rate is The throttle inlet pressure fluctuation rate does not exceed the preset value A3. The time not less than the preset value A4 exceeds T3 and the mixing valve outlet pressure fluctuation rate The time not less than A5 exceeds T4. In this embodiment, A3 is ±0.015; A4 is 0.08, T3 is 0.2s, A5 is 0.08, and T4 is 0.5s.

[0061] Furthermore, the throttle inlet pressure fluctuation rate and mixing valve outlet pressure fluctuation rate Too frequent fluctuations will lead to The adjustment change is too large, which further leads to r 21 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 Fluctuation does not exceed the preset value A 24 , and the mixing valve outlet pressure fluctuation rate Fluctuation does not exceed the preset value A 25 When Not updated. Among them, the intake throttle inlet pressure fluctuation rate The 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. The mixing valve outlet pressure fluctuation rate The 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. 24 Take ±0.02, A 25 Take ±0.02.

[0063] S2.2. Determine the pressure difference correction factor r 22 .

[0064] Determine whether the current working condition meets the following conditions at the same time: Mixing valve pressure ratio Less than the preset value A6; mixing valve outlet pressure change rate dp aftMix Greater than the preset value A7, in this example, A6 is 0.2, A7 is 15kPa / 10ms. is the mixing valve outlet pressure p aftMix and mixing valve inlet pressure p bfMix Ratio.

[0065] If the current working condition cannot meet the above conditions at the same time, then r 22 =1; if the current working condition meets the above conditions at the same time, then And take a further approach to obtain r 22 :

[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 The speed at which the mixing valve enters the fully open state can be slowed down to avoid excessive changes in the mixing valve outlet pressure due to excessive changes in the closed-loop mixing valve opening, which further leads to a sudden increase in the mixing valve pressure, thereby 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 A8. When the engine speed and the engine target boost pressure fluctuate within a preset range, the time for which the supercharger inlet pressure fluctuation range exceeds the preset value A9 does not exceed the preset time T5. In this embodiment, A8 is ±0.015, A9 is ±2 kPa, and T5 is 0.1 s.

[0068] Furthermore, the mixing valve pressure ratio and the mixing valve outlet pressure change rate dp aftMix Too frequent fluctuations will lead to The adjustment change is too large, which leads to r 22 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] Pressure ratio at mixing valve Fluctuation does not exceed the preset value A 26 , this embodiment A 26 Take ±0.05, and the mixing valve outlet pressure change rate dp aftMix Fluctuation does not exceed the preset value A 27 When, this embodiment A 27 Take ±3kPa / 10ms, correction factor 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 cycle The difference between the mixing valve outlet pressure change rate dp aftMix Fluctuation is the rate of change of the outlet pressure of the mixing valve during this sampling period dp aftMix The mixing valve outlet pressure change rate dp compared to the previous sampling cycle aftMix The sampling period in this example is 10ms.

[0070] S2.3. Determine the learning update coefficient r radpt2 .

[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 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 A 10 , this example A 10 Take 25kPa / 10ms; the absolute value of the engine request torque change rate exceeds the preset value A 11 , this example A 11 Take 30Nm / 10ms; 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 A 12 , this example A 12 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 operating condition meets the following conditions, it is judged as the first case, including: the difference between the engine target torque and the actual torque exceeds the preset value A 14 The continuous time exceeds the preset time T6. In this embodiment, A 14 Take ±5Nm, T6 take 0.7s; Throttle inlet pressure fluctuation exceeds the preset value A 15 The continuous time exceeds the preset time T7, wherein the throttle inlet pressure fluctuation is the difference between the current inlet pressure and the inlet pressure of the previous sampling cycle. In this embodiment, A 15 Take ±2kPa, T7 take 0.3s; the mixing valve outlet pressure fluctuation exceeds the preset value A 16 The continuous time of the mixing valve outlet pressure fluctuation exceeds the preset time T8, wherein the mixing valve outlet pressure fluctuation is the difference between the current inlet pressure and the inlet pressure of the previous sampling cycle. In this embodiment, A 16 Take ±2kPa, T8 take 0.3s; the difference between the engine target torque and the actual torque exceeds the preset value A 17 The continuous time exceeds the preset time T9. In this embodiment, A 17 Take ±5Nm, T9 take 0.7s; the difference between the target EGR rate and the actual EGR rate exceeds the preset value A 18 In this example, A 18 Take ±0.15; |dpct MGVNew -dpct MGVRaw The value of | does not exceed the preset value A 19 In this example, A 19 Take -15% / 10ms, where dpct MGVNew is the final mixing valve opening change rate, dpct MGVRaw 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. Adapt2 =r Adapt2 (z)+A 14 , where r Adapt2 (z) is the learning update coefficient obtained in the previous learning. In this embodiment, A 14 Take 0.005.

[0075] Furthermore, if the current operating condition meets the following conditions, it is judged as the second case, including: the difference between the engine target torque and the actual torque does not exceed the preset value A 20 In this embodiment, A 20 Take ±5Nm; the difference between the target EGR rate and the actual EGR rate does not exceed the preset value A 21 In this example, A 21 Take ±0.1; the difference between the target opening of the mixing valve and the actual opening of the mixing valve shall not exceed the preset value A 22 In this example, A 22 Take ±1%; |dpct MGVNew -dpct MGVRaw The value of | exceeds the preset value A 23 , this example A 23 Take -25% / 10ms.

[0076] Record the number of times CNT that the above four conditions are met at the same time. If CNT exceeds the preset value C1, in this example C1 is 50, and gradually restore the original mixing valve change rate. The purpose of gradual recovery 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, update r Adapt2 =r Adapt2 (z)-0.02, A 13 Take 0.02.

[0077] Furthermore, CNT is updated only once in each driving cycle, r Adapt2 After the update, CNT is cleared. Adapt2 It is also only updated once per drive cycle.

[0078] In other cases, r Adapt2 =r Adapt (z), that is, r Adapt2 No updates are performed.

[0079] S2.4, according to the obtained r 21 、r 22 、r Adapt2Calculate 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 2 As 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 collector 8 connected to the catalyst 7; and a 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 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, which includes: a storage device for storing executable instructions; 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 condition from non-fully open to fully open, the current parameters are obtained to judge the current operating condition, and the pressure fluctuation sub-correction coefficient, the pressure difference sub-correction coefficient and the learning update coefficient are further calculated to obtain the final mixing valve opening change rate through these coefficients, and then the mixing valve is controlled in combination with the mixing valve target opening. The present invention can optimize the opening change rate control when the mixing valve is in a transitional operating condition from non-fully open to fully open, improve the stability and power during the control process, ensure the safety of the engine, and at the same time, it also plays 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, and 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 order of execution of each step in the above embodiment does not mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment 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 these 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, it is determined whether the current mixing valve is in a transitional working condition 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 mixing valve opening change rate is obtained; a mixing valve slow-down opening correction coefficient is determined according to the mixing valve throttle inlet pressure fluctuation and the mixing valve outlet pressure fluctuation, and the mixing valve slow-down opening correction coefficient is updated in real time; According to the mixing valve slow opening correction coefficient and the current mixing valve opening change rate, the final mixing valve opening change rate is obtained, 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, characterized in that: 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; Wherein, the pressure fluctuation sub-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 according to the mixing valve pressure ratio and the mixing valve outlet pressure change rate; The learning update coefficient is updated in real time according to 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 correction coefficient includes: If the throttle inlet pressure fluctuation rate is not less than the preset value A1 for more than T1 or the mixing valve outlet pressure fluctuation rate is not less than the preset value A2 for more than T2, 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, characterized in that: The pressure fluctuation correction coefficient calibration conditions include that the EGR rate difference rate does not exceed the preset value A3 during the transition from the mixing valve being partially open to being fully open, the time when the throttle inlet pressure fluctuation rate is not less than the preset value A4 exceeds the preset time T3, and the time when the mixing valve outlet pressure fluctuation rate is not less than the preset value A5 exceeds the preset time T4.

5. The method for controlling the opening of a mixing valve according to claim 2, characterized in that: The method for determining the pressure difference correction coefficient includes: If the mixing valve pressure ratio is less than the preset value A6 and the mixing valve outlet pressure change rate is greater than the preset value A7, 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 A8 during the transition from the mixing valve being partially open to being fully open, and when the engine speed and the engine target boost pressure fluctuate within a preset range, the time for which the supercharger inlet pressure fluctuation range exceeds the preset value A9 does not exceed the preset time T5.

7. The method for controlling the opening of a mixing valve according to claim 2, characterized in that: 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, characterized in that: 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.

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 A 10 ; The absolute value of the engine torque change rate exceeds the preset value A 11 ; 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 A 12 ; 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, characterized in that: 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 response condition, a high response condition, and other conditions; If the response is low, add the preset value A to the learning coefficient after the last update. 14 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 C1, subtract the preset value A from the learning coefficient after the last update. 13 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, characterized in that: The judgment basis for the current working condition being in a low response state is that the difference between the engine target torque and the actual torque exceeds the preset value A at the same time. 14 The continuous time exceeds the preset time T6, and the throttle inlet pressure fluctuation exceeds the preset value A 15 The continuous time exceeds the preset time T7, and the mixing valve outlet pressure fluctuation exceeds the preset value A 16 The continuous time exceeds the preset time T8, and the difference between the engine target torque and the actual torque exceeds the preset value A 17 The continuous time exceeds the preset time T9, and the difference between the target EGR rate and the actual EGR rate exceeds the preset value A 18 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 A. 19 ; The judgment basis for the current working condition being in a high response state is that the difference between the engine target torque and the actual torque does not exceed the preset value A. 20 , the difference between the target EGR rate and the actual EGR rate does not exceed the preset value A 21 , the difference between the target opening of the mixing valve and the actual opening of the mixing valve does not exceed the preset value A 22 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 A 23 ; 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 comprises: 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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