Dynamic Control Method of Mixing Valve Opening

Abstract

The present invention relates to a method for dynamically controlling the opening of a mixing valve, comprising: obtaining the opening and change rate of the mixing valve when the mixing valve is in a transitional operating condition from partially open to fully open; determining the rate at which the mixing valve accelerates to fully open based on intake responsiveness requirements, setting the rate as a multiplication correction factor of one; determining the rate at which the mixing valve decelerates to fully open based on a control stability perspective, setting the rate as a multiplication correction factor of two; and determining the final rate of change of the mixing valve opening during the process of the mixing valve entering full open based on the multiplication correction factors of one and two. Based on the objectives of improving emissions and power performance, the present invention simultaneously balances the control accuracy of the EGR system and the improvement of the control accuracy of the intake system, and optimizes the control of the mixing valve opening rate during the process of the mixing valve transitioning from partially open to fully open.

Description

Technical Field

[0001] The present invention relates to the field of engine control, and more particularly to a method for dynamically controlling the opening of a mixing valve. Background Art

[0002] Exhaust Gas Recirculation (EGR) draws exhaust gas from the exhaust system and recirculates it into the intake system. Research has shown that EGR systems offer advantages in improving emissions, reducing fuel consumption, and improving anti-knock performance. Controlling the mixing valve in low-pressure EGR systems is particularly important for improving EGR efficiency.

[0003] Chinese patent CN112459910A discloses a method and system for calculating a target EGR rate, which determines a basic target EGR rate based on engine speed and load, but does not consider the control accuracy of the target opening of the mixing valve.

[0004] Chinese patent CN112901361A discloses an EGR mixing valve target opening control method and system, which corrects the mixing valve target opening according to various operating parameters, but does not consider dynamic closed-loop control of the mixing valve target opening. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a dynamic control method for the opening of a mixing valve, which weighs the dynamics in the process of the mixing valve changing from fully open to partially open, and optimizes the change rate of the mixing valve opening from the perspective of control stability and emission improvement.

[0006] The technical solution adopted by the present invention to solve the technical problem is to construct a dynamic control method for the opening of a mixing valve, comprising:

[0007] Obtain the mixing valve opening and change rate when the mixing valve is in a transitional state from non-fully open to fully open;

[0008] The rate at which the mixing valve is accelerated to full opening is determined based on the intake responsiveness requirement and is set as a multiplication correction factor of one;

[0009] The rate at which the mixing valve is slowed down to full opening is determined based on the control stability angle, and is set as a multiplication correction factor of two;

[0010] The final mixing valve opening change rate during the mixing valve entering the fully open process is determined according to the multiplication correction coefficient one and the multiplication correction coefficient two.

[0011] According to the above scheme, the multiplication correction coefficient is ,in and Both are sub-correction coefficients.

[0012] According to the above scheme, the sub-correction coefficient The method for determining is as follows:

[0013] When one of the following conditions is met,

[0014] (1) Throttle full open time ratio Not less than 0.05, and the difference rate of air intake Not less than 0.05;

[0015] (2) The engine speed is not less than 1000 rpm, and the boost pressure difference rate Not less than 0.1;

[0016]

[0017] Otherwise, if none of the above conditions are met, ;

[0018] In the formula, the throttle valve fully open time ratio The continuous time when the throttle valve enters the fully open state Maximum time with full throttle opening The ratio of intake volume difference The target fresh air intake density entering the cylinder The actual fresh air intake density entering the cylinder difference The fresh air intake density entering the cylinder is the same as the target ratio; characteristic coefficient Full throttle opening time ratio Difference rate with intake volume coefficient of determination; characteristic coefficient is the boost pressure difference rate A coefficient determined by the engine speed n.

[0019] According to the above scheme, the coefficient The calibration method is to adjust the throttle full opening time ratio at different engine speeds and stable boost pressure response accuracy. and intake volume difference rate Perform calibration.

[0020] According to the above scheme, the coefficient The calibration method is to fix the engine speed at each level, the throttle valve is not fully open, and the target fresh air intake density entering the cylinder is The actual fresh air intake density entering the cylinder Under the premise of small, by adjusting the difference rate of different boost pressure Perform calibration.

[0021] According to the above scheme, the sub-correction coefficient The method for determining is as follows:

[0022] When one of the following conditions is met,

[0023] (1) Target EGR rate Not less than 0.15, and the transient rate of intake flow Less than -0.05;

[0024] (2) The engine speed is not less than 1000 rpm, and the EGR rate difference rate Less than ±0.015;

[0025]

[0026] Otherwise, if none of the above conditions are met, ;

[0027] In the formula, the characteristic coefficient is the target EGR rate and the transient rate of intake air flow coefficient of determination; characteristic coefficient EGR rate difference rate Coefficient determined by engine speed n; EGR rate difference is the target EGR rate and actual EGR rate difference.

[0028] According to the above scheme, the multiplication correction coefficient is ,in 、 、 and Both are pressure fluctuation correction coefficients.

[0029] According to the above scheme, the pressure fluctuation correction coefficient The method for determining is as follows:

[0030] When one of the following conditions is met,

[0031] (1) Throttle inlet pressure fluctuation rate The time of not less than 0.05 exceeds 0.2s;

[0032] (2) Mixing valve outlet pressure fluctuation rate The time of not less than 0.05 exceeds 0.5s;

[0033]

[0034] Otherwise, if none of the above conditions are met, ;

[0035]

[0036] Where, is the intake pressure at the throttle inlet, is the throttle outlet intake pressure of the Nth sampling period, is the throttle inlet intake pressure after first-order low-pass filtering, is the filtered throttle inlet intake pressure of the Nth sampling period, is the filtered throttle inlet intake pressure of the N-1th sampling period, N=1,2,3…, Equal to the throttle inlet intake pressure at the 0th sampling cycle ; ,in is the number of engine cylinders, is the engine speed, is the throttle inlet intake pressure filtering coefficient;

[0037]

[0038] Where, is the mixing valve outlet pressure, is the outlet pressure of the mixing valve in the Nth sampling period (the sampling period in this example is 10ms), is the outlet pressure of the mixing valve after first-order low-pass filtering, is the filtered mixing valve outlet pressure of the Nth sampling period, is the filtered mixing valve outlet pressure of the N-1th sampling period, N=1,2,3…, Equal to the mixing valve outlet pressure at the 0th sampling cycle ; ,in is the number of engine cylinders, is the engine speed, is the mixing valve outlet pressure filtering coefficient;

[0039] is the throttle inlet pressure fluctuation rate and mixing valve outlet pressure fluctuation rate Determined coefficient.

[0040] According to the above scheme, the pressure fluctuation correction coefficient The method for determining is as follows:

[0041] To meet the mixing valve pressure ratio Less than 0.2, and the mixing valve outlet pressure change rate When it is greater than the preset value, ,otherwise ;

[0042] Characteristic coefficient The calibration basis is to ensure that the EGR rate difference rate is While not exceeding the preset value (±0.015), when the engine speed is stable and the engine target boost pressure is stable, the time for the supercharger inlet pressure fluctuation range to exceed ±2kPa shall not exceed 0.1s.

[0043] According to the above scheme, the pressure fluctuation correction coefficient The method for determining is as follows:

[0044] When one of the following conditions is met,

[0045] (1) Throttle fully closed time ratio Not less than 0.05, and the difference rate of air intake Less than -0.05;

[0046] (2) The engine speed is not less than 1000 rpm, and the boost pressure difference rate Less than -0.1;

[0047]

[0048] Otherwise, if none of the above conditions are met, ;

[0049] Where, the throttle fully closed time ratio is The continuous time when the throttle valve enters the fully closed state Maximum time with throttle fully closed The ratio of intake volume difference The target fresh air intake density entering the cylinder The actual fresh air intake density entering the cylinder difference The fresh air intake density entering the cylinder is the same as the target ratio; characteristic coefficient The throttle valve fully closed time ratio Difference rate with intake volume coefficient of determination; characteristic coefficient is the boost pressure difference rate A coefficient determined by the engine speed n.

[0050] According to the above scheme, the pressure fluctuation correction coefficient The method for determining is as follows:

[0051] In order to meet the gas volume entering the cylinder The fluctuation exceeds 20mgpl / 10ms continuously for a period exceeding the preset value, and the air-fuel ratio difference rate The time of continuous less than -0.2 exceeds the preset value, and the cylinder intake temperature When the temperature is greater than 50°C and the target EGR rate does not exceed the preset value,

[0052]

[0053] otherwise, ;

[0054] Where, the cylinder flow fluctuation rate is The fresh air intake flow rate entering the cylinder during the current sampling period Compared with the fresh air intake flow into the cylinder in the previous sampling period difference The fresh air intake flow rate entering the cylinder during the current sampling period ratio; air-fuel ratio difference rate Target air-fuel ratio and actual air-fuel ratio difference and target air-fuel ratio The ratio of is the cylinder flow fluctuation rate Air-fuel ratio difference coefficient of determination; characteristic coefficient Air-fuel ratio difference rate Cylinder intake temperature Determined coefficient.

[0055] According to the above scheme, in the method of determining the final mixing valve opening change rate during the mixing valve entering the fully open process according to the multiplication correction coefficient 1 and the multiplication correction coefficient 2,

[0056] If the multiplication correction coefficient is greater than 1, it indicates that the preliminary mixing valve enters the fully open state in advance;

[0057] If the multiplication correction coefficient 1 is not greater than 1 and the multiplication correction coefficient 2 is less than 1, it indicates that the preliminary mixing valve is delayed in entering the fully open state;

[0058] If neither of the above two conditions is satisfied, it indicates that the preliminary mixing valve enters the normal control state.

[0059] According to the above scheme, in the method of determining the final mixing valve opening change rate during the mixing valve entering the fully open process according to the multiplication correction coefficient 1 and the multiplication correction coefficient 2,

[0060] When the final mixing valve state is the fully open state under normal control, ;

[0061] The final mixing valve state is when the mixing valve enters the fully open state in advance. ;

[0062] The final mixing valve state is when the mixing valve is delayed to enter the fully open state. ;

[0063] Where, is the final mixing valve opening change rate, is the rate of change of the mixing valve opening when the mixing valve is in the transition condition from non-fully open to fully open, is the multiplication correction factor of one, is the multiplication correction factor of two.

[0064] The present invention also provides an electronic device comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the program is executed by the processor, the processor executes the steps of the mixing valve opening dynamic control method.

[0065] The implementation of the mixing valve opening dynamic control method of the present invention has the following beneficial effects:

[0066] The present invention aims to improve emissions and power, while balancing the control accuracy of the EGR system and improving the control accuracy of the intake system, and optimizes the control rate of the mixing valve opening when the mixing valve changes from partially open to fully open. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0068] Figure 1 It is a schematic diagram of the low-pressure EGR system architecture;

[0069] Figure 2 is a flow chart of the method for dynamic control of mixing valve opening of the present invention;

[0070] Figure 3 It is a logic block diagram of the dynamic control method of the mixing valve opening of the present invention;

[0071] In the figure, 1-air filter, 2-mixing valve, 3-compressor, 4-throttle, 5-engine, 6-turbine, 7-catalyst, 8-particulate matter trap, 9-EGR cooler, 10-EGR valve, 11-temperature sensor, 12-differential pressure sensor. DETAILED DESCRIPTION

[0072] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0073] Example 1

[0074] like Figure 1As shown, the low-pressure EGR system includes an air filter, a mixing valve, a supercharger compressor, a throttle, an engine, a supercharger turbine, a catalyst, a particulate matter trap, an EGR cooler, an EGR valve, an EGR temperature sensor, and an EGR differential pressure sensor.

[0075] The supercharger compressor compresses fresh air for supercharging; the supercharger turbine controls the working efficiency of the turbine by controlling the opening of the supercharger's exhaust bypass valve, thereby achieving different supercharging capabilities; the low-pressure EGR system has the following additional components compared to the non-low-pressure EGR system: EGR cooler, EGR temperature sensor, EGR valve, EGR pressure difference sensor, and mixing valve; the mixing valve is used to adjust the pressure at the EGR valve outlet, increase the pressure difference at both ends of the EGR valve, and increase the EGR rate; the EGR cooler is used to cool the exhaust gas to increase the exhaust gas flow rate and reduce the exhaust gas temperature; the EGR valve has a throttling effect to control the exhaust gas flow entering the cylinder; the EGR temperature sensor is used to detect the exhaust gas temperature entering the EGR valve; the EGR pressure difference sensor is used to detect the pressure at the EGR inlet and outlet.

[0076] The present invention proposes a method for dynamic control of the mixing valve opening to solve problems such as control stability, power performance, and engine safety protection in this process. Patent CN202110184826.8 "Method for determining the target opening of an EGR system mixing valve" and patent CN202110184815.X "Method for determining the activation state of a mixing valve in a low-pressure EGR system" both mention transition control in the process of the mixing valve changing from non-fully open (activated state) to fully open (activated), and determine the transition change of the target opening of the mixing valve. This patent optimizes the change rate of the target opening of the mixing valve when the mixing valve requests to enter the full opening process, so as to further improve problems such as control stability, power performance, and engine safety protection during the control process.

[0077] like Figure 2-3 As shown, the method for dynamically controlling the opening degree of a mixing valve of the present invention comprises the following steps:

[0078] S1. Based on the current public technology, the current mixing valve is in a transitional state from non-fully open to fully open, and the current mixing valve opening is , and the rate of change is .

[0079] S2, based on the intake responsiveness requirement, determine the rate at which the mixing valve accelerates to full opening, and set it as the multiplication correction coefficient of one. , where the coefficient is Not less than 1. Multiplication correction factor 1 It consists of two parts, namely The intake responsiveness requirement directly affects the dynamic responsiveness.

[0080] S201, Sub-correction coefficient The method for determining is as follows:

[0081] When one of the following conditions is met,

[0082] (A) Throttle full open time ratio Not less than 0.05, and the difference rate of air intake Not less than 0.05;

[0083] (B) The engine speed is not less than 1000 rpm, and the boost pressure difference rate Not less than 0.1;

[0084]

[0085] Otherwise, if none of the above conditions are met, .

[0086] If the above conditions are met, the next step is described Detailed method of obtaining:

[0087] i) Full throttle time ratio The continuous time when the throttle valve enters the fully open state Maximum time with full throttle opening (calibrated as 0.8s in this example), that is, when the throttle valve enters the fully open state for a continuous time exceeding the maximum fully open time, the mixing valve opening change rate remains unchanged; the intake volume difference rate The target fresh air intake density entering the cylinder The actual fresh air intake density entering the cylinder difference The fresh air intake density entering the cylinder is the same as the target The ratio.

[0088] Characteristic coefficient Full throttle opening time ratio Difference rate with intake volume Determine the coefficient. The larger the value, the longer the throttle valve needs to be fully open, indicating that the power torque demand is large, and the characteristic coefficient The larger the value, the faster the mixing valve opens, the better the throttling loss of the mixing valve, and the more responsive the power torque demand. When the larger the value, the difference in gas volume response will affect the dynamic response, and the characteristic coefficient The larger the value, the faster the mixing valve enters full opening, improves the mixing valve throttling loss, and responds to power torque requirements.

[0089] That The calibration method is to adjust the throttle full opening time ratio at different engine speeds n under the premise of stable boost pressure response accuracy (the difference between the target boost pressure and the actual boost pressure is within ±2kPa). and intake volume difference rate Calibration is performed based on ensuring that the difference between the engine target torque and the actual torque is controlled within ±5Nm for no more than 0.5s during the transition from the mixing valve being partially open to being fully open.

[0090] The minimum adjustment coefficient is 1 and the maximum is 1.3. Avoid excessive adjustment that causes the difference between the target EGR rate and the actual EGR rate to exceed the preset value (±0.12 in this example).

[0091] In order to avoid the difference in intake volume Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r11 changes too much, resulting in excessive fluctuations in the mixing valve opening control and poor mixing valve control stability, the following treatment should be performed:

[0092] Intake volume difference rate Fluctuation (difference rate of intake volume during this sampling period) Compared with the previous sampling period When the sampling period (10ms in this example) does not exceed the preset value (±0.1 in this example), the correction coefficient No update.

[0093] ii) Characteristic coefficient is the boost pressure difference rate (Boost pressure difference and target pressure The ratio of the boost pressure difference is the target boost pressure and actual boost pressure The difference between the boost pressure and the engine speed n determines the coefficient. The larger the value, the worse the boost pressure response. In order to improve the boost pressure response capability, the characteristic coefficient The larger the speed, the faster the mixing valve opens, the better the mixing valve throttling loss, the higher the boost inlet pressure, and the faster the response to the boost pressure response demand; at a lower speed n, the same boost pressure difference rate , then the boost response capability is poor at low speed. Based on this, the characteristic coefficient Also bigger.

[0094] That The calibration method is to fix the engine speed n at each level, with the throttle valve not fully open and the target fresh air intake density entering the cylinder The actual fresh air intake density entering the cylinder Under the premise of small (difference between target gas volume and actual gas volume is within ±20mgpl), by adjusting the difference rate of different boost pressures Calibration is carried out based on ensuring that the difference between the target boost pressure and the actual boost pressure exceeds ±2kPa for no more than 0.3s.

[0095] The minimum adjustment coefficient is 1, and the maximum value is greater than the characteristic coefficient The maximum value is small, and in this example it is 1.15. The purpose is to give priority to the intake air volume responsiveness control over the boost pressure control. The poor boost pressure responsiveness can be adjusted by the boost actuator, and the boost pressure does not directly affect the intake air volume entering the cylinder like the intake air volume, so it does not directly affect the power performance. And if Excessive control will affect the EGR rate response accuracy, so the setting is made based on this.

[0096] To avoid engine speed n and Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r11 changes too much, the mixing valve opening control fluctuates too much, resulting in poor mixing valve control stability, thereby affecting the response accuracy of the EGR rate, the following treatment is performed:

[0097] The engine speed fluctuation n (the difference between the engine speed in this sampling period and the engine speed in the previous sampling period, the sampling period in this example is 10ms) does not exceed the preset value (in this example, ±40rpm) and Fluctuation (during this sampling period Compared with the previous sampling period When the sampling period (10ms in this example) does not exceed the preset value (±0.12 in this example), the correction coefficient No update.

[0098] S202, Sub-correction coefficient The method for determining is as follows:

[0099] When one of the following conditions is met,

[0100] (A) Target EGR rate Not less than 0.15, and the transient rate of intake flow Less than -0.05;

[0101] (B) The engine speed is not less than 1000rpm, and the EGR rate difference Less than ±0.015;

[0102]

[0103] Otherwise, if none of the above conditions are met, .

[0104] If the above conditions are met, the next step is described Detailed method of obtaining:

[0105] i) Characteristic coefficient is the target EGR rate and the transient rate of intake air flow Determine the coefficient at the target EGR rate The smaller it is, the faster the mixing valve opens, and the characteristic coefficient The larger the value, the faster the mixing valve opens, and the throttling loss of the mixing valve is improved; in the transient rate of intake flow The smaller the value, the greater the transient response of gas flow. In order to respond to the power acceleration demand in time, the characteristic coefficient The larger it is, the faster it will enter the full opening of the mixing valve, improve the throttling loss of the mixing valve, and respond to the power torque demand;

[0106] That The calibration method is to adjust the target EGR rate to different values ​​under the premise that the EGR rate response accuracy is good (the difference between the target EGR rate and the actual EGR rate is within ±0.1) at each engine speed n. and intake flow transient rate Calibration is performed based on ensuring that the difference between the engine target torque and the actual torque is controlled within ±5Nm for no more than 0.5s during the transition from the mixing valve being partially open to being fully open.

[0107] The minimum adjustment coefficient is 1 and the maximum is 1.35. Avoid excessive adjustment, which may cause the difference between the target opening of the mixing valve and the actual opening of the mixing valve to exceed the preset value (±1% in this example).

[0108] To avoid the target EGR rate Fluctuation or transient rate of intake air flow Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r12 changes too much, resulting in excessive fluctuations in the mixing valve opening control and poor mixing valve control stability, the following treatment should be performed:

[0109] At target EGR rate Fluctuation (target EGR rate in this sampling period Compared with the target EGR rate in the previous sampling cycle The sampling period is 10ms in this example) does not exceed the preset value (±0.1 in this example), and the intake flow transient rate Fluctuation (intake flow transient rate during this sampling period) Compared with the transient rate of intake flow in the previous sampling period , when the sampling period (10ms in this example) does not exceed the preset value (±0.1 in this example), No update.

[0110] ii) Characteristic coefficient EGR rate difference rate (EGR rate difference and target pressure The ratio of EGR rate difference is the target EGR rate and actual EGR rate The coefficient determined by the difference between the EGR rate and the engine speed n. The smaller it is, the better the EGR rate responsiveness is. The larger the value, the faster the mixing valve opens, the better the throttling loss of the mixing valve, the higher the engine charging capacity, and the better the engine charging efficiency. According to different engine speeds n, the same EGR rate difference rate is set. , from the perspective of improving the throttling loss of the mixing valve and the engine charging efficiency, to achieve the best charging efficiency, the characteristic coefficient is determined .

[0111] That The calibration method is to fix the target EGR rate at each engine speed n. Stable (target EGR rate fluctuation within ±0.05) and intake air flow transient rate Under the premise of stability (its fluctuation range is ±0.03), different EGR rate differences can be achieved by adjusting the EGR valve Calibration is performed based on ensuring that the engine fuel consumption point is at the lowest level.

[0112] In order to avoid the difference between engine speed n and EGR rate Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r11 changes too much, the mixing valve opening control fluctuates too much, resulting in poor mixing valve control stability, thereby affecting the response accuracy of the EGR rate, the following treatment is performed:

[0113] The engine speed fluctuation n (the difference between the engine speed in this sampling period and the engine speed in the previous sampling period, the sampling period in this example is 10ms) does not exceed the preset value (in this example, ±40rpm) and the EGR rate difference rate Fluctuation (during this sampling period Compared with the previous sampling period When the sampling period (10ms in this example) does not exceed the preset value (±0.015 in this example), the correction coefficient No update.

[0114] S3, based on the control stability angle, determine the rate at which the mixing valve slows down to full opening, set as the multiplication correction coefficient of two , where the coefficient is two Not greater than 1. ,in 、 、 and Both are pressure fluctuation correction coefficients.

[0115] S301, pressure fluctuation correction coefficient The method for determining is as follows:

[0116] When one of the following conditions is met,

[0117] (A) Throttle inlet pressure fluctuation rate The time of not less than 0.05 exceeds 0.2s;

[0118] (B) Mixing valve outlet pressure fluctuation rate The time of not less than 0.05 exceeds 0.5s;

[0119]

[0120] It should be noted that

[0121]

[0122] in, is the intake pressure at the throttle inlet, is the intake pressure at the throttle outlet during the Nth sampling period (the sampling period in this example is 10ms), is the throttle inlet intake pressure after first-order low-pass filtering, is the filtered throttle inlet intake pressure of the Nth sampling period, is the filtered throttle inlet intake pressure of the N-1th sampling period, N=1,2,3…, Equal to the throttle inlet intake pressure at the 0th sampling cycle ; Sampling period interval In this example, it is 10ms. is the coefficient: ; The number of engine cylinders in this example is 4, The calibration speed is 1000rpm. The purpose of this setting is to normalize the process. Under different cylinder numbers and speeds, no special calibration is required. Only the 4-cylinder engine and the speed of 1000rpm need to be calibrated. , thus reducing the calibration test work. is the number of engine cylinders, is the engine speed, is the throttle inlet intake pressure filter coefficient, which is 0.1 in this example.

[0123]

[0124] in, is the mixing valve outlet pressure, is the outlet pressure of the mixing valve in the Nth sampling period (the sampling period in this example is 10ms), is the outlet pressure of the mixing valve after first-order low-pass filtering, is the filtered mixing valve outlet pressure of the Nth sampling period, is the filtered mixing valve outlet pressure of the N-1th sampling period, N=1,2,3…, Equal to the mixing valve outlet pressure at the 0th sampling cycle ; Sampling period interval In this example, it is 10ms. is the coefficient: (The number of engine cylinders in this example is 4, The calibration speed is 1000rpm. The purpose of this setting is to normalize the process. Under different cylinder numbers and speeds, no special calibration is required. Only the 4-cylinder engine and the speed of 1000rpm need to be calibrated. , thereby reducing calibration testing work), where is the number of engine cylinders, is the engine speed, is the filtering coefficient of the mixing valve outlet pressure, which is 0.1 in this example.

[0125] Otherwise, if none of the above conditions are met, .

[0126] If the above conditions are met, the next step is described Detailed method of obtaining:

[0127] is the throttle inlet pressure fluctuation rate and mixing valve outlet pressure fluctuation rate Determine the coefficient of pressure fluctuation rate at the throttle inlet The larger the characteristic coefficient is, the The smaller the pressure, the slower the mixing valve opens, avoiding excessive fluctuations in the mixing valve opening and further worsening the throttle inlet pressure fluctuations. The larger the characteristic coefficient is, the The smaller the pressure, the slower the mixing valve from fully opening, thus avoiding excessive fluctuations in the mixing valve opening and further worsening the mixing valve outlet pressure fluctuations.

[0128] That 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 (±0.015) The time of not less than 0.08 exceeds 0.2s and the mixing valve outlet pressure fluctuation rate The time of not less than 0.08 exceeds 0.5s;

[0129] In order to avoid throttle inlet pressure fluctuation rate and mixing valve outlet pressure fluctuation rate Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r21 changes too much, resulting in excessive fluctuations in the mixing valve opening control and poor mixing valve control stability, the following treatment should be performed:

[0130] Throttle inlet pressure fluctuation rate at intake volume Fluctuation (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 sampling period in this example is 10ms) does not exceed the preset value (in this example it is ±0.02), and the mixing valve outlet pressure fluctuation rate When the fluctuation (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, the sampling period in this example is 10ms) does not exceed the preset value (in this example, ±0.02), the correction coefficient No update.

[0131] S302, pressure difference correction coefficient The method for determining is as follows:

[0132] When the following conditions are met, the mixing valve pressure ratio (mixing valve outlet pressure and mixing valve inlet pressure The ratio of the mixing valve outlet pressure is less than 0.2, and the mixing valve outlet pressure change rate is Greater than the preset value, in this example 15kPa / 10ms;

[0133]

[0134] Otherwise, if none of the above conditions are met, .

[0135] If the above conditions are met, the next step is described Detailed method of obtaining:

[0136] Mixing valve pressure ratio The smaller the pressure is (indicating that the difference between the mixing valve inlet and outlet pressures is too large), and the mixing valve outlet pressure change rate is The larger the characteristic coefficient is, the The smaller it is, the slower the mixing valve is fully opened. The closed-loop mixing valve opening changes too much, resulting in a large change in the mixing valve outlet pressure, which causes a sudden increase in the mixing valve pressure and a sudden increase in the boost pressure inlet, resulting in poor boost control stability and robustness.

[0137] That The calibration basis is to ensure that the EGR rate difference rate is While not exceeding the preset value (±0.015), when the engine speed is stable and the engine target boost pressure is stable, the time for the supercharger inlet pressure fluctuation range to exceed ±2kPa shall not exceed 0.1s;

[0138] To avoid mixing valve pressure ratio and the mixing valve outlet pressure change rate Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r22 changes too much, resulting in excessive fluctuations in the mixing valve opening control and poor mixing valve control stability, the following treatment should be performed:

[0139] Mixing valve pressure ratio Fluctuation (mixing valve pressure ratio during this sampling period Mixing valve pressure ratio compared to the previous sampling period The difference between the sampling period and the sampling period in this example is 10ms) does not exceed the preset value (in this example, ±0.05), and the mixing valve outlet pressure change rate Fluctuation (the rate of change of the mixing valve outlet pressure during this sampling period) The rate of change of the mixing valve outlet pressure compared with the previous sampling period When the difference between the sampling period and the sampling period does not exceed the preset value (±3kPa / 10ms in this example), the correction coefficient No update.

[0140] S303, power reduction sub-correction coefficient The method for determining is as follows:

[0141] When one of the following conditions is met,

[0142] (A) Throttle fully closed (i.e. the throttle opening is minimum here to quickly reduce the air volume) time ratio Not less than 0.05, and the difference rate of air intake Less than -0.05;

[0143] (B) The engine speed is not less than 1000 rpm, and the boost pressure difference rate Less than -0.1.

[0144]

[0145] Otherwise, if none of the above conditions are met, .

[0146] If the above conditions are met, the next step is described Detailed method of obtaining:

[0147] i) Throttle fully closed time ratio The continuous time when the throttle valve enters the fully closed state Maximum time with throttle fully closed (calibrated as 0.8s in this example), that is, when the throttle valve enters the fully closed state for a continuous time exceeding the maximum fully closed time, the mixing valve opening change rate remains unchanged; the intake volume difference rate The target fresh air intake density entering the cylinder The actual fresh air intake density entering the cylinder difference The fresh air intake density entering the cylinder is the same as the target The ratio.

[0148] Characteristic coefficient The throttle valve fully closed time ratio Difference rate with intake volume Determine the coefficient. The larger the value, the longer the throttle valve needs to be fully closed, indicating that the power torque demand is small, and the characteristic coefficient The smaller the value, the slower the mixing valve from opening fully, thus preventing the mixing valve from opening too large and increasing the air intake capacity and failing to reduce the air volume quickly; The smaller the value, the greater the overshoot capability of the gas volume response. The smaller it is, the slower the air enters the mixing valve and fully opens, so as to avoid the mixing valve opening being too large, thereby increasing the air intake and charging capacity and failing to reduce the air volume quickly;

[0149] That The calibration method is to adjust the throttle full closing time ratio at different engine speeds n under the premise of stable boost pressure response accuracy (the difference between the target boost pressure and the actual boost pressure is within ±2kPa). and intake volume difference rate Calibration is performed based on ensuring that the difference between the engine target torque and the actual torque is controlled within ±5Nm for no more than 0.5s during the transition from the mixing valve being partially open to being fully open.

[0150] The maximum value of the adjustment coefficient is 1, and the minimum value is 0.85. Avoid excessive adjustment that causes the difference between the target EGR rate and the actual EGR rate to exceed the preset value (±0.12 in this example).

[0151] In order to avoid the difference in intake volume Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r23 changes too much, resulting in excessive fluctuations in the mixing valve opening control and poor mixing valve control stability, the following treatment should be performed:

[0152] Intake volume difference rate Fluctuation (difference rate of intake volume during this sampling period) Compared with the previous sampling period When the sampling period (10ms in this example) does not exceed the preset value (±0.1 in this example), the correction coefficient No update.

[0153] ii) Characteristic coefficient is the boost pressure difference rate (Boost pressure difference and target pressure The ratio of the boost pressure difference is the target boost pressure and actual boost pressure The difference between the boost pressure and the engine speed n determines the coefficient. The smaller the value, the greater the boost pressure response overshoot. In order to reduce the boost pressure overshoot, the characteristic coefficient The smaller the speed, the slower the mixing valve is fully opened, avoiding the mixing valve opening being too large and increasing the supercharger inlet pressure without improving the supercharger pressure overshoot phenomenon; the larger the speed n, the same boost pressure difference rate , the higher the boost response capability at high speed, based on this, the characteristic coefficient Also smaller.

[0154] That The calibration method is to fix the engine speed n at each level, with the throttle valve not fully open and the target fresh air intake density entering the cylinder The actual fresh air intake density entering the cylinder Under the premise of small (difference between target gas volume and actual gas volume is within ±20mgpl), by adjusting the difference rate of different boost pressures Calibration is carried out based on the principle of ensuring that the difference between the target boost pressure and the actual boost pressure exceeds ±2kPa for no more than 0.3s.

[0155] The maximum value of the adjustment coefficient is 1, and the minimum value is greater than the characteristic coefficient The minimum value is large, and in this example it is 0.92. The purpose is to give priority to the intake air volume responsiveness control over the boost pressure control. The poor boost pressure responsiveness can be adjusted by the boost actuator, and the boost pressure does not directly affect the intake air volume entering the cylinder like the intake air volume, so it does not directly affect the power performance. And if Excessive control will affect the EGR rate response accuracy, so the setting is made based on this.

[0156] To avoid engine speed n and Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r23 changes too much, the mixing valve opening control fluctuates too much, resulting in poor mixing valve control stability, thereby affecting the response accuracy of the EGR rate, the following treatment is performed:

[0157] The engine speed fluctuation n (the difference between the engine speed in this sampling period and the engine speed in the previous sampling period, the sampling period in this example is 10ms) does not exceed the preset value (in this example, ±40rpm) and Fluctuation (during this sampling period Compared with the previous sampling period When the sampling period (10ms in this example) does not exceed the preset value (±0.12 in this example), the correction coefficient No update.

[0158] S304, emission correction factor The method for determining is as follows:

[0159] When the following conditions are met,

[0160] Air volume entering the cylinder Fluctuation (the amount of gas entering the cylinder during this sampling period) Compared with the gas volume entering the cylinder during the previous sampling period The difference between the two, the sampling period in this example is 10ms) exceeds 20mgpl / 10ms for a time that exceeds the preset value (0.5s in this example), and the air-fuel ratio difference rate The time that the temperature is continuously less than -0.2 exceeds the preset value (0.5s in this example), and the cylinder inlet temperature Greater than 50°C, and the target EGR rate does not exceed the preset value (0.1 in this example);

[0161]

[0162] Otherwise, if none of the above conditions are met, .

[0163] If the above conditions are met, the next step is described Detailed method of obtaining:

[0164] i) Cylinder flow rate fluctuation rate The fresh air intake flow rate entering the cylinder during the current sampling period Compared with the fresh air intake flow into the cylinder in the previous sampling period difference The fresh air intake flow rate entering the cylinder during the current sampling period Air-fuel ratio difference rate Target air-fuel ratio and actual air-fuel ratio difference and target air-fuel ratio ratio.

[0165] Characteristic coefficient is the cylinder flow fluctuation rate Air-fuel ratio difference Determine the coefficient of fluctuation of flow rate in cylinder The larger the air-fuel ratio difference The smaller it is, the greater the increase in intake flow and the leaner the air-fuel ratio, and the characteristic coefficient The smaller it is, the slower the mixing valve opens, preventing EGR exhaust gas from entering the cylinder, which can easily lead to an increase in NOx emissions.

[0166] That The calibration method is to use the cylinder inlet temperature Under the premise of not exceeding the preset value (55℃ in this example), the flow fluctuation rate of different cylinders is adjusted Air-fuel ratio difference Calibration is performed based on ensuring the lowest NOx emissions during the transition from partially open to fully open mixing valve.

[0167] The maximum value of the adjustment coefficient is 1, and the minimum value is 0.92. Avoid excessive adjustment that causes the difference between the target EGR rate and the actual EGR rate to exceed the preset value (±0.12 in this example).

[0168] To avoid cylinder flow fluctuations and air-fuel ratio difference Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r24 changes too much, resulting in excessive fluctuations in the mixing valve opening control and poor mixing valve control stability, the following treatment should be performed:

[0169] Fluctuation rate of flow in cylinder Fluctuation (difference rate of intake volume and cylinder flow fluctuation rate during this sampling period) Cylinder flow fluctuation rate compared with the previous sampling period The difference between the two, the sampling period in this example is 10ms) does not exceed the preset value (in this example ±0.05), and the air-fuel ratio difference rate Fluctuation (difference rate of air-fuel ratio in this sampling period) The difference between the air-fuel ratio in the previous sampling period When the difference (the sampling period in this example is 10ms) does not exceed the preset value (in this example ±0.1), the correction coefficient No update.

[0170] ii) Characteristic coefficient Air-fuel ratio difference rate Cylinder intake temperature Determine the coefficient of the difference in air-fuel ratio The smaller the cylinder intake temperature The higher the value, the leaner the air-fuel ratio and the higher the intake temperature. The smaller it is, the slower the flow of EGR exhaust gas into the cylinder will be, which will easily cause an increase in NOx emissions.

[0171] That The calibration method is to measure the amount of gas entering the cylinder Fluctuation (the amount of gas entering the cylinder during this sampling period) Compared with the gas volume entering the cylinder during the previous sampling period The difference between the two (the sampling period in this example is 10ms) does not exceed 20mgpl / 10ms, and the air-fuel ratio difference rate is fixed. Under the premise, by adjusting the cylinder intake temperature Calibration is performed based on ensuring the lowest NOx emissions during the transition from partially open to fully open mixing valve.

[0172] The maximum value of the adjustment coefficient is 1, and the minimum value is 0.5. Avoid excessive adjustment that causes the difference between the target EGR rate and the actual EGR rate to exceed the preset value (±0.12 in this example).

[0173] To avoid the cylinder intake temperature and air-fuel ratio difference Too frequent fluctuations lead to If the adjustment change is too large and the correction coefficient r24 changes too much, resulting in excessive fluctuations in the mixing valve opening control and poor mixing valve control stability, the following treatment should be performed:

[0174] Cylinder intake temperature Fluctuation (cylinder intake temperature during this sampling period Compared with the cylinder intake temperature in the previous sampling period The difference between the two, the sampling period in this example is 10ms) does not exceed the preset value (in this example ±5℃), and the air-fuel ratio difference rate Fluctuation (difference rate of air-fuel ratio in this sampling period) The difference between the air-fuel ratio in the previous sampling period When the difference (the sampling period in this example is 10ms) does not exceed the preset value (in this example ±0.1), the correction coefficient No update.

[0175] S4. Determine the final mixing valve opening change rate when the mixing valve enters the fully open process according to the multiplication correction coefficient 1 and the multiplication correction coefficient 2.

[0176] First, judge.

[0177] 1) If If it is greater than 1, it indicates that the preliminary mixing valve enters the fully open state in advance;

[0178] 2) If the first case is not satisfied, if If it is less than 1, it indicates that the preliminary mixing valve is delayed in entering the fully open state;

[0179] 3) If neither of the above two conditions is met, it indicates that the preliminary mixing valve enters the normal control state.

[0180] The check period for each status in this example is 10ms.

[0181] If the preliminary mixing valve is in full open state in advance, and , the preliminary mixing valve enters the fully open state in advance; otherwise, the preliminary mixing valve enters the fully open state in advance;

[0182] If the preliminary mixing valve is currently delayed from entering the fully open state, and , the preliminary mixing valve is delayed to enter the fully open state; otherwise, judge again, if The preliminary mixing valve enters the fully open state in advance; otherwise, judge again, if The preliminary mixing valve enters the fully open state 2 in advance; otherwise, the preliminary mixing valve enters the fully open state 1 in advance.

[0183] If the previous state is that the preliminary mixing valve enters the normal control state, and the current state is that the preliminary mixing valve enters the fully open state in advance, the final mixing valve state is that the mixing valve enters the fully open state in advance;

[0184] Similarly, if the previous state is that the preliminary mixing valve enters the normal control state, and the current state is that the preliminary mixing valve delays entering the fully open state, then the final mixing valve state is that the mixing valve delays entering the fully open state;

[0185] If the previous state is that the preliminary mixing valve enters the fully open state in advance, and the current state is that the preliminary mixing valve delays entering the fully open state, then the final mixing valve state first enters the normal control state of the mixing valve and maintains it for a period of time t0, and the following situations are divided:

[0186] A) If the state of the preliminary mixing valve delayed entering fully open changes before the end of time t0 (for example, the state of the preliminary mixing valve delayed entering fully open 1 is adjusted to the state of the preliminary mixing valve delayed entering fully open 2), the final mixing valve state is immediately changed to the state of the mixing valve delayed entering fully open.

[0187] B) If the delay in the initial mixing valve entering the fully open state does not change within the end of time t0, or the initial mixing valve enters the fully open state in advance again, the final mixing valve state will still be the normal control state of the mixing valve.

[0188] C) If time t0 expires, the final mixing valve state is immediately updated to the delayed fully open state. For t0, the primary priorities are emissions, dynamics, and control stability, ranked from high to low, and the mixing valve outlet pressure fluctuation is guaranteed to not exceed ±20 kPa / 10 ms. If the initial delayed fully open state X (X can be 1, 2, 3, or 4, as described above) is in progress, then t0 = t0 - X. t0 - 4 < t0 - 3 < t0 - 2 < t0 - 1, with t0 - 4 = 0.03 s, t0 - 3 = 0.08 s, t0 - 2 = 0.1 s, and t0 - 4 = 0.12 s.

[0189] If the previous state is that the preliminary mixing valve is delayed in entering the fully open state, and the current state is that the preliminary mixing valve is advanced in entering the fully open state, then the final mixing valve state will first enter the normal control state of the mixing valve and maintain it for a period of time t1, and then the following situations will occur:

[0190] A) If the preliminary mixing valve enters the fully open state early before the end of time t1 (for example, the preliminary mixing valve enters the fully open state early 1 is adjusted to the preliminary mixing valve enters the fully open state early 2), the final mixing valve state is immediately changed to the mixing valve enters the fully open state early.

[0191] B) If the preliminary mixing valve enters the fully open state ahead of time and no change occurs before the end of time t1, or if the preliminary mixing valve enters the fully open state later than before, the final mixing valve state will still be the normal control state of the mixing valve.

[0192] C) If time t1 expires, the final mixing valve state is immediately updated to fully open in advance. For t0, the primary priorities are dynamics and control stability, prioritized from high to low, and the mixing valve outlet pressure fluctuation is guaranteed to not exceed ±20 kPa / 10 ms. If the initial mixing valve is in state Y (Y is 1 or 2 as described above), then t1 = t1 - Y. t1 - 1 < t1 - 2, with t1 - 1 = 0.03 s and t1 - 2 = 0.05 s. Note that t0 - 4 is the minimum, prioritizing emissions improvement.

[0193] In the transition process from non-fully open to fully open, the final mixing valve opening rate is :

[0194] (1) When the final mixing valve state is the fully open state under normal control, ;

[0195] (2) The final mixing valve state is when the mixing valve enters the fully open state in advance. ;

[0196] (3) The final mixing valve state is when the mixing valve is delayed to enter the fully open state. .

[0197] Example 2

[0198] The present invention also provides an electronic device comprising: a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; a computer program is stored in the memory, and when the program is executed by the processor, the processor executes the steps of the mixing valve opening dynamic control method.

[0199] Example 3

[0200] The present invention also provides a computer-readable storage medium having executable instructions stored thereon. When the instructions are executed by a processor, the processor implements the method for dynamically controlling the opening degree of a mixing valve.

[0201] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0202] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0203] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0204] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0205] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are protected by the present invention.

Claims

1. A method for dynamic control of mixing valve opening, characterized in that: include: Obtain the mixing valve opening and change rate when the mixing valve is in a transitional state from non-fully open to fully open; The rate at which the mixing valve is accelerated to full opening is determined based on the intake responsiveness requirement and is set as a multiplication correction factor of one; The rate at which the mixing valve is slowed down to full opening is determined based on the control stability angle, and is set as a multiplication correction factor of two; Determine the final mixing valve opening change rate when the mixing valve enters the fully open process according to the multiplication correction coefficient 1 and the multiplication correction coefficient 2; In the method of determining the final mixing valve opening change rate during the mixing valve entering the fully open process according to the multiplication correction coefficient 1 and the multiplication correction coefficient 2, When the final mixing valve state is the fully open state under normal control, ; The final mixing valve state is when the mixing valve enters the fully open state in advance. ; The final mixing valve state is when the mixing valve is delayed to enter the fully open state. ; Where, is the final mixing valve opening change rate, is the rate of change of the mixing valve opening when the mixing valve is in the transition condition from non-fully open to fully open, is the multiplication correction factor of one, is the multiplication correction factor of two.

2. The method for dynamic control of mixing valve opening according to claim 1, characterized in that: The multiplication correction factor is ,in and Both are sub-correction coefficients.

3. The method for dynamic control of mixing valve opening according to claim 2, characterized in that: The sub-correction factor The method for determining is as follows: When one of the following conditions is met, (1) Throttle full open time ratio Not less than 0.05, and the difference rate of air intake Not less than 0.05; (2) The engine speed is not less than 1000 rpm, and the boost pressure difference rate Not less than 0.1; Otherwise, if none of the above conditions are met, ; In the formula, the throttle valve fully open time ratio The continuous time when the throttle valve enters the fully open state Maximum time with full throttle opening The ratio of intake volume difference The target fresh air intake density entering the cylinder Compared with the actual fresh air intake density entering the cylinder difference The fresh air intake density entering the cylinder is the same as the target ratio; characteristic coefficient Full throttle opening time ratio Difference rate with intake volume coefficient of determination; characteristic coefficient is the boost pressure difference rate A coefficient determined by the engine speed n.

4. The method for dynamic control of mixing valve opening according to claim 3, characterized in that: The coefficient The calibration method is to fix the engine speed and the boost pressure response accuracy at each station, that is, the difference between the target boost pressure and the actual boost pressure is within ±2kPa, and adjust the throttle full opening time ratio at different and intake volume difference rate Perform calibration.

5. The method for dynamic control of mixing valve opening according to claim 2, characterized in that: The sub-correction factor The method for determining is as follows: When one of the following conditions is met, (1) Target EGR rate Not less than 0.15, and the transient rate of intake flow Less than -0.05; (2) The engine speed is not less than 1000 rpm, and the EGR rate difference Less than ±0.015; Otherwise, if none of the above conditions are met, ; In the formula, the characteristic coefficient is the target EGR rate and the transient rate of intake air flow coefficient of determination; characteristic coefficient EGR rate difference rate Coefficient determined by engine speed n; EGR rate difference is the target EGR rate and actual EGR rate difference.

6. The method for dynamic control of mixing valve opening according to claim 1, characterized in that: The multiplication correction factor is two ,in 、 、 and Both are pressure fluctuation correction coefficients.

7. The method for dynamic control of mixing valve opening according to claim 6, characterized in that: The pressure fluctuation correction coefficient The method for determining is as follows: When one of the following conditions is met, (1) Throttle inlet pressure fluctuation rate The time of not less than 0.05 exceeds 0.2s; (2) Mixing valve outlet pressure fluctuation rate The time of not less than 0.05 exceeds 0.5s; Otherwise, if none of the above conditions are met, ; Where, is the intake pressure at the throttle inlet, is the throttle outlet intake pressure of the Nth sampling period, is the throttle inlet intake pressure after first-order low-pass filtering, is the filtered throttle inlet intake pressure of the Nth sampling period, is the filtered throttle inlet intake pressure of the N-1th sampling period, N=1,2,3…, Equal to the throttle inlet intake pressure at the 0th sampling cycle ; ,in is the number of engine cylinders, is the engine speed, is the throttle inlet intake pressure filter coefficient; Where, is the mixing valve outlet pressure, is the outlet pressure of the mixing valve in the Nth sampling period, is the outlet pressure of the mixing valve after first-order low-pass filtering, is the filtered mixing valve outlet pressure of the Nth sampling period, is the filtered mixing valve outlet pressure of the N-1th sampling period, N=1,2,3…, Equal to the mixing valve outlet pressure at the 0th sampling cycle ; ,in is the number of engine cylinders, is the engine speed, is the mixing valve outlet pressure filtering coefficient; is the throttle inlet pressure fluctuation rate and mixing valve outlet pressure fluctuation rate Determined coefficient.

8. The method for dynamic control of mixing valve opening according to claim 6, characterized in that: The pressure fluctuation correction coefficient The method for determining is as follows: To meet the mixing valve pressure ratio Less than 0.2, and the mixing valve outlet pressure change rate When it is greater than the preset value, ,otherwise ; Characteristic coefficient The calibration basis is to ensure that the EGR rate difference rate is While not exceeding the preset value (±0.015), when the engine speed is stable and the engine target boost pressure is stable, the time for the supercharger inlet pressure fluctuation range to exceed ±2kPa shall not exceed 0.1s.

9. The method for dynamic control of mixing valve opening according to claim 6, characterized in that: The pressure fluctuation correction coefficient The method for determining is as follows: When one of the following conditions is met, (1) Throttle fully closed time ratio Not less than 0.05, and the difference rate of air intake Less than -0.05; (2) The engine speed is not less than 1000 rpm, and the boost pressure difference rate Less than -0.1; Otherwise, if none of the above conditions are met, ; Where, the throttle fully closed time ratio is The continuous time when the throttle valve enters the fully closed state Maximum time with throttle fully closed The ratio of intake volume difference The target fresh air intake density entering the cylinder Compared with the actual fresh air intake density entering the cylinder difference The fresh air intake density entering the cylinder is the same as the target ratio; characteristic coefficient The throttle valve fully closed time ratio Difference rate with intake volume coefficient of determination; characteristic coefficient is the boost pressure difference rate A coefficient determined by the engine speed n.

10. The method for dynamic control of mixing valve opening according to claim 6, characterized in that: The pressure fluctuation correction coefficient The method for determining is as follows: In order to meet the gas volume entering the cylinder The fluctuation exceeds 20mgpl / 10ms continuously for a period exceeding the preset value, and the air-fuel ratio difference rate The time of continuous less than -0.2 exceeds the preset value, and the cylinder intake temperature When the temperature is greater than 50°C and the target EGR rate does not exceed the preset value, otherwise, ; Where, the cylinder flow fluctuation rate is The fresh air intake flow rate entering the cylinder during the current sampling period Compared with the fresh air intake flow into the cylinder in the previous sampling period difference The fresh air intake flow rate entering the cylinder during the current sampling period ratio; air-fuel ratio difference rate Target air-fuel ratio and actual air-fuel ratio difference and target air-fuel ratio The ratio of is the cylinder flow fluctuation rate Air-fuel ratio difference coefficient of determination; characteristic coefficient Air-fuel ratio difference rate Cylinder intake temperature Determined coefficient.

11. The method for dynamic control of mixing valve opening according to claim 1, characterized in that: In the method of determining the final mixing valve opening change rate during the mixing valve entering the fully open process according to the multiplication correction coefficient 1 and the multiplication correction coefficient 2, If the multiplication correction coefficient is greater than 1, it indicates that the preliminary mixing valve enters the fully open state in advance; If the multiplication correction coefficient 1 is not greater than 1 and the multiplication correction coefficient 2 is less than 1, it indicates that the preliminary mixing valve is delayed in entering the fully open state; If neither of the above two conditions is satisfied, it indicates that the preliminary mixing valve enters the normal control state.

12. An electronic device comprising: A processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; characterized in that a computer program is stored in the memory, and when the program is executed by the processor, the processor executes the steps of the method for dynamic control of the mixing valve opening according to any one of claims 1 to 11.

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