Control method for improving EGR closed-loop activation condition and computer storage medium

Abstract

The invention discloses a control method for improving an EGR closed-loop activation condition and a computer storage medium, and the method comprises the steps: obtaining a minimum EGR rate, and judging whether a minimum EGR rate condition of EGR closed-loop enabling is met or not according to the minimum EGR rate; and when the minimum EGR rate condition of EGR closed loop enabling is met, whether the EGR closed loop is enabled or not is judged according to the EGR closed loop condition. According to the method, the minimum EGR rate is obtained, the minimum EGR rate condition of EGR closed-loop enabling is judged, and judgment of the closed-loop enabling condition of the EGR system is optimized, so that the pressure stability in the enabling transition process of the EGR system is improved, and the control stability of the whole EGR system is improved.

Description

Technical Field

[0001] The invention relates to the field of engine control, and in particular to a control method for improving EGR closed-loop activation conditions and a computer storage medium. Background Art

[0002] Exhaust Gas Recirculation (EGR) takes exhaust gas from the exhaust and enters 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 as it improves the effect of the EGR rate.

[0003] Due to system hysteresis, when the EGR rate enters its minimum EGR rate region, it may cause controller oscillation, or even EGR system instability. In the prior art, methods for optimizing the minimum EGR rate and optimizing the EGR enabling conditions are generally not considered. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention proposes a control method and a computer storage medium for improving EGR closed-loop activation conditions.

[0005] To this end, the technical solution adopted in the present invention is:

[0006] A control method for improving EGR closed-loop activation conditions, the method comprising:

[0007] Obtain the minimum EGR rate, and determine whether the minimum EGR rate condition for enabling the EGR closed loop is met according to the minimum EGR rate;

[0008] When the minimum EGR rate condition for enabling the EGR closed loop is met, whether the EGR closed loop is enabled is determined based on the EGR closed loop condition.

[0009] According to the above scheme, whether the minimum EGR rate condition for enabling EGR closed loop is met is specifically:

[0010] When the difference between the target EGR rate and the minimum EGR rate is greater than the calculated value of one, the EGR closed loop enabling minimum EGR rate condition is met;

[0011] When the difference between the target EGR rate and the minimum EGR rate is not greater than the calculated value 2, and the absolute value of the difference between the target EGR rate and the actual EGR rate is not greater than the preset value, the minimum pressure condition for enabling the EGR closed loop is not met;

[0012] In other cases, the minimum EGR rate condition for enabling the EGR closed loop maintains the previous state, wherein the vehicle is in a default state when it is powered on, and the default state is that the minimum EGR rate condition for enabling the EGR closed loop is not met.

[0013] According to the above scheme, the calculated value one is obtained by multiplying the sum of the general threshold correction coefficient for enabling the minimum EGR rate, the special threshold correction coefficient for enabling the minimum EGR rate one and 1 by the preset value one.

[0014] According to the above scheme, the calculated value 2 is obtained by multiplying the difference obtained by subtracting the general threshold correction coefficient for enabling the minimum EGR rate and then subtracting the special threshold correction coefficient 2 for enabling the minimum EGR rate from 1 by the preset value 2.

[0015] According to the above scheme, the general threshold correction coefficient for enabling the minimum EGR rate, the special threshold correction coefficient for enabling the minimum EGR rate 1 and the special threshold correction coefficient for enabling the minimum EGR rate 2 are specifically obtained by the following method:

[0016] When the learning activation conditions are met, the average value of the first EGR valve outlet pressure signal and the first EGR valve outlet pressure signal fluctuation rate, the average value of the second EGR valve outlet pressure signal and the second EGR valve outlet pressure signal fluctuation rate, and the average value of the third EGR valve outlet pressure signal and the third EGR valve outlet pressure signal fluctuation rate are read and calculated; and the difference between the first EGR valve outlet pressure signal fluctuation rate, the second EGR valve outlet pressure signal fluctuation rate, and the third EGR valve outlet pressure signal fluctuation rate and the difference between the average value of the first EGR valve outlet pressure signal, the second EGR valve outlet pressure signal, and the third EGR valve outlet pressure signal are determined, and the updated enabling minimum EGR rate general threshold correction coefficient, enabling minimum EGR rate special threshold correction coefficient one, and enabling minimum EGR rate special threshold correction coefficient two are obtained based on the difference value.

[0017] According to the above scheme, the average value of the first EGR valve outlet pressure signal and the fluctuation rate of the first EGR valve outlet pressure signal are the average value of the EGR valve outlet pressure signal and the fluctuation rate of the EGR valve outlet pressure signal in the continuous time of the non-closed-loop enabled state before the EGR system enters the closed-loop enabled state;

[0018] The second EGR valve outlet pressure signal average value and the second EGR valve outlet pressure signal fluctuation rate are the EGR valve outlet pressure signal average value and the EGR valve outlet pressure signal fluctuation rate during the continuous time when the difference between the target EGR rate and the minimum EGR rate does not exceed the preset value after the EGR system enters the closed-loop enabled state;

[0019] The third EGR valve outlet pressure signal average value and the third EGR valve outlet pressure signal fluctuation rate are the EGR valve outlet pressure signal average value and the EGR valve outlet pressure signal fluctuation rate in a continuous time after the EGR system enters a non-closed-loop enabled state from a closed-loop enabled state.

[0020] According to the above scheme, the learning activation conditions are:

[0021] The EGR system has gone through a non-closed-loop enabled state to a closed-loop enabled state and then to a non-closed-loop enabled state;

[0022] In the process of the EGR system going from a non-closed-loop enabled state to a closed-loop enabled state and then to a non-closed-loop enabled state, the two continuous times in the non-closed-loop enabled state and the continuous time in the closed-loop enabled state both exceed the preset time;

[0023] The reason why the EGR system changes from a non-closed-loop enabled state is that the EGR closed-loop enabled minimum EGR rate condition is not satisfied in the non-closed-loop enabled state, and the EGR closed-loop enabled minimum EGR rate condition is satisfied when entering the closed-loop enabled state;

[0024] The continuous time when the difference between the target EGR rate and the minimum EGR rate does not exceed the preset range when the EGR system enters the closed-loop state exceeds the preset time;

[0025] The engine speed fluctuation is within the preset range;

[0026] The density of the air entering the cylinder fluctuates within a preset range;

[0027] The target boost pressure fluctuation is within a preset range;

[0028] The difference between the target boost pressure and the actual boost pressure is within a preset range;

[0029] The mixing valve opening fluctuation range is within the preset range;

[0030] The EGR valve inlet temperature fluctuation range is within the preset range.

[0031] According to the above scheme, the fluctuation rate of the EGR valve outlet pressure signal is determined by the original value of the EGR valve outlet pressure and the filtered value of the EGR valve outlet pressure; wherein the original value of the EGR valve outlet pressure is obtained by detection; and the filtered value of the EGR valve outlet pressure is calculated based on the original value of the EGR valve outlet pressure and the filtered value of the EGR valve outlet pressure in the previous sampling cycle.

[0032] According to the above scheme, the updated minimum EGR rate general threshold correction coefficient, the minimum EGR rate special threshold correction coefficient 1 and the minimum EGR rate special threshold correction coefficient 2 are obtained according to the difference value:

[0033] When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are all within the preset range one, and the difference values ​​among the average values ​​of the first, second and third EGR valve outlet pressure signals are within the preset range two, and the number of consecutive satisfactions is greater than the preset value, the minimum EGR rate general threshold correction coefficient is increased, and the minimum EGR rate special threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two remain unchanged;

[0034] When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are all within the preset range one, and the difference values ​​among the average values ​​of the first, second and third EGR valve outlet pressure signals are within the preset range three, and the number of consecutive satisfactions is greater than the preset value, the minimum EGR rate general threshold correction coefficient is reduced, and the minimum EGR rate special threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two remain unchanged;

[0035] When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are all within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is within the preset range two, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is not within the preset range three, and the number of consecutive satisfactions is greater than the preset value, the minimum EGR rate general threshold correction coefficient is enabled to remain unchanged, the minimum EGR rate special threshold correction coefficient one is enabled to increase, and the minimum EGR rate special threshold correction coefficient two is enabled to decrease;

[0036] When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is not within the preset range three, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is within the preset range two, and the number of consecutive times of satisfaction is greater than the preset value, the minimum EGR rate general threshold correction coefficient is enabled to remain unchanged, the minimum EGR rate special threshold correction coefficient one is enabled to decrease, and the minimum EGR rate special threshold correction coefficient two is enabled to increase;

[0037] When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is within the preset range two, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is between the preset range two and the preset range three, and the number of consecutive satisfactions is greater than the preset value, then the minimum EGR rate special threshold correction coefficient one is increased, and the minimum EGR rate general threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two remain unchanged;

[0038] When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is not within the preset range three, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is between the preset range two and the preset range three, and the number of consecutive times of satisfaction is greater than the preset value, then the minimum EGR rate special threshold correction coefficient one is reduced, and the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient two remain unchanged;

[0039] When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is between the preset range two and the preset range three, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is within the preset range two, and the number of consecutive times of satisfaction is greater than the preset value, then the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient one are enabled to remain unchanged, and the minimum EGR rate special threshold correction coefficient two is enabled to increase;

[0040] When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are all not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is between the preset range two and the preset range three, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is not within the preset range three, and the number of consecutive times of satisfaction is greater than the preset value, then the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient one are enabled to remain unchanged, and the minimum EGR rate special threshold correction coefficient two is enabled to decrease;

[0041] In other cases, the general threshold correction coefficient for enabling the minimum EGR rate, the special threshold correction coefficient 1 for enabling the minimum EGR rate, and the special threshold correction coefficient 2 for enabling the minimum EGR rate remain unchanged.

[0042] According to the above scheme, the default value of the number of consecutive satisfactions is 0, which is saved after the vehicle is powered off.

[0043] According to the above scheme, after obtaining the updated general threshold correction coefficient for enabling the minimum EGR rate, the special threshold correction coefficient one for enabling the minimum EGR rate and the special threshold correction coefficient two for enabling the minimum EGR rate, if the difference between the calculated value one and the calculated value two is less than a certain value, the general threshold correction coefficient for enabling the minimum EGR rate, the special threshold correction coefficient one for enabling the minimum EGR rate and the special threshold correction coefficient two for enabling the minimum EGR rate shall remain the general threshold correction coefficient for enabling the minimum EGR rate, the special threshold correction coefficient one for enabling the minimum EGR rate and the special threshold correction coefficient two for enabling the minimum EGR rate updated last time.

[0044] According to the above scheme, judging whether the EGR closed loop is enabled according to the EGR closed loop conditions is as follows:

[0045] When the following EGR closed-loop conditions are met, the EGR closed-loop is enabled:

[0046] There were no malfunctions related to the EGR system parts;

[0047] No fuel cut request occurs and the fuel cut recovery time exceeds the preset time;

[0048] The engine speed is within the preset speed range;

[0049] The intake air temperature is within the preset range;

[0050] The engine water temperature is within the preset range;

[0051] The atmospheric temperature is within the preset range;

[0052] Atmospheric pressure exceeds the preset pressure value.

[0053] A computer storage medium stores a computer program executable by a processor, wherein the computer program executes any one of the control methods for improving EGR closed-loop activation conditions described above.

[0054] The beneficial effects produced by the present invention are:

[0055] The present invention optimizes the judgment of the closed-loop enabling condition of the EGR system by obtaining the minimum EGR rate and judging the minimum EGR rate condition for EGR closed-loop enabling, thereby improving the pressure stability during the enabling transition process of the EGR system and improving the control stability of the entire EGR system. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 A method flow chart of an embodiment of the present invention;

[0057] Figure 2 This is a schematic diagram of the structure of a system with EGR according to an embodiment of the present invention.

[0058] In the figure, 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

[0059] 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.

[0060] Embodiment 1:

[0061] The present invention proposes a control method to improve the EGR closed-loop activation conditions, such as Figure 1 As shown, the method specifically includes:

[0062] S1. Obtain the minimum EGR rate, and determine whether the minimum EGR rate condition for enabling the EGR closed loop is met based on the minimum EGR rate.

[0063] The method of obtaining the minimum EGR rate can be found in patent CN202211212260.6 "Method, device, equipment and storage medium for adjusting the minimum EGR rate".

[0064] When the difference between the target EGR rate and the minimum EGR rate is greater than the calculated value A, the EGR closed loop enabling minimum EGR rate condition is met;

[0065] When the difference between the target EGR rate and the minimum EGR rate is not greater than the calculated value B, and the absolute value of the difference between the target EGR rate and the actual EGR rate is not greater than the preset value (in this embodiment, the preset value is 0.1), the minimum pressure condition for enabling the EGR closed loop is not met;

[0066] In other cases, the minimum EGR rate condition for enabling the EGR closed loop maintains the previous state, wherein the vehicle is in a default state when it is powered on, and the default state is that the minimum EGR rate condition for enabling the EGR closed loop is not met.

[0067] The calculated values ​​A and B are modified by the universal threshold correction factor r of the minimum EGR rate enabled Adpt , Enable the minimum EGR rate special threshold correction factor -r Lrn1 and enable the minimum EGR rate special threshold correction factor r Lrn2 In a preferred embodiment of the present invention, A=C1×(1+r Adpt +r Lrn1 ); B = C2 × (1-r Adpt -r Lrn2 ), AB is not less than 0.001.

[0068] where r Adpt 、r Lrn1 and r Lrn2 The default value is 0 and is saved when the vehicle is powered off.

[0069] Embodiment 2:

[0070] In a preferred embodiment of the present invention, r Adpt 、r Lrn1 and r Lrn2 According to the last updated r Adpt (z), r L rn1(z) and r L rn2(z) is updated, and it is updated when the learning activation condition is met, where the learning activation condition is specifically:

[0071] The EGR system has gone through a non-closed-loop enabled state to a closed-loop enabled state and then to a non-closed-loop enabled state;

[0072] In the process of the EGR system going from the non-closed-loop enabled state to the closed-loop enabled state and then to the non-closed-loop enabled state, the two continuous times in the non-closed-loop enabled state and the continuous time in the closed-loop enabled state both exceed the preset time t1. In this embodiment, t1 is 0.5s.

[0073] The reason why the EGR system changes from a non-closed-loop enabled state is that the EGR closed-loop enabled minimum EGR rate condition is not satisfied in the non-closed-loop enabled state, and the EGR closed-loop enabled minimum EGR rate condition is satisfied when entering the closed-loop enabled state;

[0074] The continuous time when the difference between the target EGR rate and the minimum EGR rate does not exceed the preset value when the EGR system enters the closed-loop state exceeds the preset time t1. In this embodiment, the preset value is the calculated value A+deviation D, where D is 0.02;

[0075] The engine speed fluctuation is within a preset range, which in this embodiment is ±15 rpm;

[0076] The density of the air entering the cylinder fluctuates within a preset range, which in this embodiment is ±25 mgl;

[0077] The target boost pressure fluctuation is within a preset range, which in this embodiment is ±2 kPa;

[0078] The difference between the target boost pressure and the actual boost pressure is within a preset range, which in this embodiment is ±2 kPa;

[0079] The mixing valve opening fluctuation range is within a preset range, and in this embodiment, the preset range is ±1%;

[0080] The EGR valve inlet temperature fluctuation range is within a preset range, and in this embodiment, the preset range is ±5°C.

[0081] When the above learning activation conditions are met at the same time, read and calculate the average value of the EGR valve outlet pressure signal p in the non-closed-loop enabled state before the EGR system enters the closed-loop enabled state EGROutAvg1 and EGR valve outlet pressure signal fluctuation rate r EGROut Pre1 , the average value p of the EGR valve outlet pressure signal during the continuous time t1 when the difference between the target EGR rate and the minimum EGR rate does not exceed the preset value A+D in the EGR system entering the closed loop state EGROutAvg2 and EGR valve outlet pressure signal fluctuation rate r EGROutPre2 , the average value of the EGR valve outlet pressure signal p during the continuous time t1 when the EGR system enters the non-closed loop enabled state from the closed loop enabled state EGROutAvg3 and EGR valve outlet pressure signal fluctuation rate r EGROutPre3 In this embodiment, the above continuous time is equal to the preset time t1.

[0082] Among them, r EGROut Pre1 、r EGROutPre2 and r EGROutPre3 According to the original value of EGR valve outlet pressure p EGROut and EGR valve outlet pressure filter value p EGROutFilter Determine, where the original value of the EGR valve outlet pressure p EGROut Detected by the sensor; EGR valve outlet pressure filter value p EGROutFilter The calculation is based on the original value of the EGR valve outlet pressure and the filtered value of the EGR valve outlet pressure in the previous sampling cycle:

[0083] p EGROutFilter (N) = K EGROutPre ×[p EGROut (N)-p EGROutFilter (N-1)]+p EGROutFilter (N-1)

[0084] Among them, p EGROut (N) is the original value of the EGR valve outlet pressure in the Nth sampling cycle, p EGROutFilter (N) is the EGR valve outlet pressure filter value of the Nth sampling cycle, p EGROutFilter (N-1) is the EGR valve outlet pressure filter value of the N-1th sampling period, N = 1, 2, 3..., p EGROutFilter (0) is equal to the original value of the EGR valve outlet pressure p at the 0th sampling cycle EGROut (0), all of which occur at the initial time t1; K EGROutPre is the coefficient, Where m is the number of engine cylinders, n is the engine speed, in this embodiment the number of engine cylinders is 4, k EGROutPre The calibrated speed is 1000rpm. This setting is for normalization. No special calibration is required for different cylinder numbers and speeds. Only the 4-cylinder engine and the speed of 1000rpm need to be calibrated. EGROutPre , thereby reducing the calibration test work, k EGROutPre is the EGR valve outlet pressure difference filtering coefficient, which is 0.1 in this embodiment.

[0085] In this embodiment, the sampling period interval Δt Take 10ms.

[0086] Among them, r EGROut Pre1 It is equal to the continuous time t1 of the non-closed-loop enabled state before the EGR system enters the closed-loop enabled state.

[0087] r EGROutPre2It is equal to the continuous time t1 during which the difference between the target EGR rate and the minimum EGR rate does not exceed the preset value A+D when the EGR system enters the closed loop state

[0088] r EGROutPre3 It is equal to the continuous time t1 from the closed-loop enabled state to the non-closed-loop enabled state

[0089] Get p EGROutAvg1 、p EGROutAvg2 、p EGROutAvg3 、r EGROutPre1 、r EGROutPre2 and r EGROutPre3 After that, judge p EGROutAvg1 、p EGROutAvg2 and p EGROutAvg3 The difference between the values ​​and r EGROutPre1 , r EGROutPre2 and r EGROutPre3 The difference between:

[0090] When p EGROutAvg1 、p EGROutAvg2 and p EGROutAvg3 The difference between them is within the preset range D (in this embodiment, the preset range D is ±2 kPa), and r EGROutPre1 , r EGROutPre2 and r EGROutPre3 When the differences between them are within the preset range E1 (in this embodiment, the preset range E1 is ±0.005), and the number of consecutive satisfactions exceeds the threshold F1 (in this embodiment, the threshold F1 is 10), the number of consecutive satisfactions is accumulated at most once each time the learning condition is met, until the next time the learning condition is no longer met and enters the state of being met, then it is determined whether to accumulate, then r Adpt =r Adpt (z)+0.02, r Lrn1 =r Lrn1 (z), r Lrn2 =r Lrn2 (z), where r Adpt (z) is the last updated r Adpt ; r Lrn1 (z) is the last updated r Lrn1 ; r Lrn2 (z) is the last updated r Lrn2 ;

[0091] When p EGROutAvg1 、p EGROutAvg2 and p EGROutAvg3 The difference between them is within the preset range D, and r EGROutPre1 , r EGROutPre2 and r EGROutPre3When the differences between them are not within the preset range E2 (in this embodiment, the preset range E2 is ±0.001), and the number of consecutive satisfactions exceeds the threshold F2 (in this embodiment, the threshold F2 is 10), then r Adpt =r Adpt (z)-0.015, r Lrn1 =r Lrn1 (z), r Lrn2 =r Lrn2 (z);

[0092] When p EGROutAvg1 、p EGROutAvg2 and p EGROutAvg3 The difference between them is within the preset range D, and r EGROutPre1 and r EGROutPre2 The difference between them is within the preset range E1, and r EGROutPre2 and r EGROutPre3 When the difference between them is not within the preset range E2, and the number of times it is continuously satisfied exceeds the threshold F3 (the threshold F3 in this embodiment is 10), then r Adpt =r Adpt (z), r Lrn1 =r Lrn1 (z)+0.01, r Lrn2 =r Lrn2 (z) -0.01;

[0093] When p EGROutAvg1 、p EGROutAvg2 and p EGROutAvg3 The difference between them is not within the preset range D, and r EGROutPre1 and r EGROutPre2 The difference between them is not within the preset range E2, and r EGROutPre2 and r EGROutPre3 When the difference between the two is within the preset range E1, and the number of times it is continuously satisfied exceeds the threshold F4 (the threshold F4 in this embodiment is 10), then r Adpt =r Adpt (z), r Lrn1 =r Lrn1 (z)-0.01, r Lrn2 =r Lrn2 (z)+0.01;

[0094] When p EGROutAvg1 、p EGROutAvg2 and p EGROutAvg3 The difference between them is not within the preset range D, and r EGROutPre1 and r EGROutPre2 The difference between them is within the preset range E1, and r EGROutPre2 and r EGROutPre3When the difference between the two is within the preset range E1-E2, and the number of times it is continuously satisfied exceeds the threshold F5 (the threshold F5 in this embodiment is 20), then r Adpt =r Adpt (z), r Lrn1 =r Lrn1 (z)+0.005, r Lrn2 =r Lrn2 (z);

[0095] When p EGROutAvg1 、p EGROutAvg2 and p EGROutAvg3 The difference between them is not within the preset range D, and r EGROutPre1 and r EGROutPre2 The difference between them is not within the preset range E2, and r EGROutPre2 and r EGROutPre3 When the difference between the two is within the preset range E1-E2, and the number of times it is continuously satisfied exceeds the threshold F6 (the threshold F6 in this embodiment is 20), then r Adpt =r Adpt (z), r Lrn1 =r Lrn1 (z)-0.005, r Lrn2 =r Lrn2 (z);

[0096] When p EGROutAvg1 、p EGROutAvg2 and p EGROutAvg3 The difference between them is not within the preset range D, and r EGROutPre1 and r EGROutPre2 The difference between them is within the preset range E1 to E2, and r EGROutPre2 and r EGROutPre3 When the difference between the two is within the preset range E1, and the number of times it is continuously satisfied exceeds the threshold F7 (the threshold F7 in this embodiment is 20), then r Adpt =r Adpt (z), r Lrn1 =r Lrn1 (z), r Lrn2 =r Lrn2 (z) + 0.005;

[0097] When p EGROutAvg1 、p EGROutAvg2 and p EGROutAvg3 The difference between them is not within the preset range D, and r EGROutPre1 and r EGROutPre2 The difference between them is within the preset range E1 to E2, and r EGROutPre2 and r EGROutPre3 When the difference between them is not within the preset range E2, and the number of times it is continuously satisfied exceeds the threshold F8 (the threshold F8 in this embodiment is 20), then rAdpt =r Adpt (z), r Lrn1 =r Lrn1 (z), r Lrn2 =r Lrn2 (z) -0.005;

[0098] In other cases, r Adpt =r Adpt (z), r Lrn1 =r Lrn1 (z), r Lrn2 =r Lrn2 (z).

[0099] In r Adpt 、r Lrn1 、r Lrn2 After the above learning value is updated, if the calculated value A minus the calculated value B is less than 0.001, the update will not be continued, that is, the above learning value remains unchanged, r Adpt =r Adpt (z), r L rn1=r L rn1(z),r L rn2=r L rn2(z), and at the same time, all consecutive satisfaction times are cleared to zero.

[0100] The default value of the number of consecutive satisfactions is 0, and it can be saved after the vehicle is powered off. Adpt 、r Lrn1 、r Lrn2 After the update, the number of consecutive satisfactions is reset to zero.

[0101] S2. When the minimum EGR rate condition for enabling the EGR closed loop is met, determine whether the EGR closed loop is enabled according to the EGR closed loop condition.

[0102] Embodiment 3:

[0103] In a preferred embodiment of the present invention, the EGR closed-loop conditions for determining whether the EGR closed-loop is enabled are specifically:

[0104] There were no malfunctions related to the EGR system parts;

[0105] No fuel cut-off request occurs and the fuel cut-off recovery time exceeds the preset time. In this embodiment, the preset time is 0.3s;

[0106] The minimum EGR rate condition for EGR closed loop is met;

[0107] The engine speed is within a preset speed range, and in this embodiment, the preset speed range is 750 rpm to 5500 rpm;

[0108] The intake air temperature is within the preset range. In this embodiment, if the current state is that the EGR closed loop is not enabled, then the EGR closed loop state is entered, and it is necessary to ensure that the minimum intake air temperature is not less than 10°C. If the current state is the EGR closed loop enabled state, then the EGR system closed loop enabled state needs to be exited to ensure that the minimum intake air temperature is 7°C lower; if the current state is that the EGR closed loop is not enabled, then the EGR closed loop state is entered, and it is necessary to ensure that the maximum intake air temperature does not exceed 60°C; if the current state is the EGR closed loop enabled state, then the EGR system closed loop enabled state needs to be exited to ensure that the maximum intake air temperature exceeds 65°C;

[0109] The engine water temperature is within the preset range. In this embodiment, if the current state is that the EGR closed loop is not enabled, then the EGR closed loop state is entered, and it is necessary to ensure that the minimum water temperature is not lower than 60°C. If the current state is the EGR closed loop enabled state, then the EGR system closed loop enabled state needs to be exited to ensure that the minimum water temperature is lower than 55°C; if the current state is that the EGR closed loop is not enabled, then the EGR closed loop state is entered, and it is necessary to ensure that the maximum water temperature does not exceed 115°C; if the current state is the EGR closed loop enabled state, then the EGR system closed loop enabled state needs to be exited to ensure that the maximum water temperature exceeds 120°C;

[0110] The atmospheric temperature is within the preset range. In this embodiment, if the current state is that the EGR closed loop is not enabled, then the EGR closed loop state is entered, and it is necessary to ensure that the minimum atmospheric temperature is not lower than 5°C. If the current state is the EGR closed loop enabled state, then the EGR system closed loop enabled state needs to be exited to ensure that the minimum atmospheric temperature is 3°C lower than the minimum atmospheric temperature; if the current state is that the EGR closed loop is not enabled, then the EGR closed loop state is entered, and it is necessary to ensure that the maximum atmospheric temperature does not exceed 55°C; if the current state is the EGR closed loop enabled state, then the EGR system closed loop enabled state needs to be exited to ensure that the maximum atmospheric temperature exceeds 60°C;

[0111] The atmospheric pressure exceeds the preset pressure value. In this embodiment, when the atmospheric pressure exceeds 66 kPa, the EGR closed-loop enabling condition is allowed to be entered, and when the atmospheric temperature is lower than 64 kPa, the EGR closed-loop enabling condition needs to be exited.

[0112] After the EGR closed loop is enabled, the EGR closed loop control is performed. Based on the target EGR rate and the actual EGR rate, the mixing valve and the EGR valve are controlled to make the actual EGR rate follow the target EGR rate.

[0113] Embodiment 4:

[0114] like Figure 2As shown, the present invention also provides a system structure with EGR, including an air filter 1, a mixing valve 2, a compressor 3, a throttle 4, an engine 5, a turbine 6, a catalyst 7, a particulate matter trap 8, and an EGR cooler 9, an EGR valve 10, a temperature sensor 11 installed between the EGR valve 10 and the EGR cooler 9, and a branch composed of a pressure difference sensor 12 connected to the EGR valve 10; the two ends of the branch are respectively connected to the outlet of the particulate matter trap 8 and the outlet of the mixing valve 2; wherein the mixing valve 2 is used to adjust the pressure at the outlet of the EGR valve 10 and increase the pressure difference at both ends of the EGR valve 10, the engine 5 is used to compress fresh air for supercharging, the turbine 6 is used to control the opening of the exhaust bypass valve, the EGR cooler 9 is used to receive the exhaust gas output by the particulate matter trap 8 and cool it to increase the exhaust gas flow rate, the EGR valve 10 is used to control the exhaust gas flow entering the cylinder, the temperature sensor 11 is used to detect the exhaust gas temperature entering the EGR valve 10, and the pressure difference sensor 12 is used to detect the pressure at the inlet and outlet of the EGR valve 10. The system structure is used to execute a control method for improving EGR closed-loop activation conditions described in this embodiment.

[0115] The present invention optimizes the judgment of the closed-loop enabling condition of the EGR system by obtaining the minimum EGR rate and judging the minimum EGR rate condition for EGR closed-loop enabling, improves the pressure stability during the enabling transition of the EGR system, and improves the control stability of the entire EGR system.

[0116] Embodiment 5:

[0117] 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;

[0118] A computer program is stored in the memory, and when the program is executed by the processor, the processor is caused to perform the steps of the method.

[0119] Embodiment 6:

[0120] The present invention also provides a computer-readable storage medium on which executable instructions are stored. When the instructions are executed by a processor, the processor implements the method described above.

[0121] 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 adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0122] 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 box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes 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 generate 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.

[0123] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate 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 A function specified in one or more boxes.

[0124] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

Claims

1. A control method for improving EGR closed-loop activation conditions, characterized in that: The method comprises: Obtain the minimum EGR rate, and determine whether the minimum EGR rate condition for enabling the EGR closed loop is met according to the minimum EGR rate; When the minimum EGR rate condition for enabling the EGR closed loop is met, whether the EGR closed loop is enabled is determined based on the EGR closed loop condition.

2. A control method for improving EGR closed-loop activation conditions according to claim 1, characterized in that: The specific conditions for judging whether the minimum EGR rate for enabling EGR closed loop is met are: When the difference between the target EGR rate and the minimum EGR rate is greater than the calculated value of one, the EGR closed loop enabling minimum EGR rate condition is met; When the difference between the target EGR rate and the minimum EGR rate is not greater than the calculated value 2, and the absolute value of the difference between the target EGR rate and the actual EGR rate is not greater than the preset value, the minimum pressure condition for enabling the EGR closed loop is not met; In other cases, the minimum EGR rate condition for enabling the EGR closed loop maintains the previous state, wherein the vehicle is in a default state when it is powered on, and the default state is that the minimum EGR rate condition for enabling the EGR closed loop is not met.

3. A control method for improving EGR closed-loop activation conditions according to claim 2, characterized in that: The calculated value one is obtained by multiplying the sum of the general threshold correction coefficient for enabling the minimum EGR rate, the special threshold correction coefficient for enabling the minimum EGR rate one and 1 by the preset value one.

4. A control method for improving EGR closed-loop activation conditions according to claim 2, characterized in that: The calculated value 2 is obtained by multiplying the difference obtained by subtracting the general threshold correction coefficient of the minimum EGR rate enabled and then subtracting the special threshold correction coefficient 2 of the minimum EGR rate enabled by 1 by the preset value 2.

5. A control method for improving EGR closed-loop activation conditions according to claim 3 or 4, characterized in that: The general threshold correction coefficient for enabling the minimum EGR rate, the special threshold correction coefficient 1 for enabling the minimum EGR rate, and the special threshold correction coefficient 2 for enabling the minimum EGR rate are specifically obtained by the following method: When the learning activation conditions are met, the average value of the first EGR valve outlet pressure signal and the first EGR valve outlet pressure signal fluctuation rate, the average value of the second EGR valve outlet pressure signal and the second EGR valve outlet pressure signal fluctuation rate, and the average value of the third EGR valve outlet pressure signal and the third EGR valve outlet pressure signal fluctuation rate are read and calculated; and the difference between the first EGR valve outlet pressure signal fluctuation rate, the second EGR valve outlet pressure signal fluctuation rate, and the third EGR valve outlet pressure signal fluctuation rate and the difference between the average value of the first EGR valve outlet pressure signal, the second EGR valve outlet pressure signal, and the third EGR valve outlet pressure signal are determined, and the updated enabling minimum EGR rate general threshold correction coefficient, enabling minimum EGR rate special threshold correction coefficient one, and enabling minimum EGR rate special threshold correction coefficient two are obtained based on the difference value.

6. A control method for improving EGR closed-loop activation conditions according to claim 5, characterized in that: The first EGR valve outlet pressure signal average value and the first EGR valve outlet pressure signal fluctuation rate are: the EGR valve outlet pressure signal average value and the EGR valve outlet pressure signal fluctuation rate in the continuous time of the non-closed-loop enabled state before the EGR system enters the closed-loop enabled state; The second EGR valve outlet pressure signal average value and the second EGR valve outlet pressure signal fluctuation rate are: the EGR valve outlet pressure signal average value and the EGR valve outlet pressure signal fluctuation rate during the continuous time when the difference between the target EGR rate and the minimum EGR rate does not exceed the preset value after the EGR system enters the closed-loop enabled state; The third EGR valve outlet pressure signal average value and the third EGR valve outlet pressure signal fluctuation rate are: the EGR valve outlet pressure signal average value and the EGR valve outlet pressure signal fluctuation rate in a continuous time after the EGR system enters a non-closed-loop enabled state from a closed-loop enabled state.

7. A control method for improving EGR closed-loop activation conditions according to claim 5, characterized in that: The learning activation conditions are: The EGR system has gone through a non-closed-loop enabled state to a closed-loop enabled state and then to a non-closed-loop enabled state; In the process of the EGR system going from a non-closed-loop enabled state to a closed-loop enabled state and then to a non-closed-loop enabled state, the two continuous times in the non-closed-loop enabled state and the continuous time in the closed-loop enabled state both exceed the preset time; The reason why the EGR system changes from a non-closed-loop enabled state is that the EGR closed-loop enabled minimum EGR rate condition is not satisfied in the non-closed-loop enabled state, and the EGR closed-loop enabled minimum EGR rate condition is satisfied when entering the closed-loop enabled state; The continuous time when the difference between the target EGR rate and the minimum EGR rate does not exceed the preset range when the EGR system enters the closed-loop state exceeds the preset time; The engine speed fluctuation is within the preset range; The density of the air entering the cylinder fluctuates within a preset range; The target boost pressure fluctuation is within a preset range; The difference between the target boost pressure and the actual boost pressure is within a preset range; The mixing valve opening fluctuation range is within the preset range; The EGR valve inlet temperature fluctuation range is within the preset range.

8. The control method for improving EGR closed-loop activation conditions according to claim 5, characterized in that: The fluctuation rate of the EGR valve outlet pressure signal is determined by the original value of the EGR valve outlet pressure and the filtered value of the EGR valve outlet pressure; wherein the original value of the EGR valve outlet pressure is obtained by detection; and the filtered value of the EGR valve outlet pressure is calculated based on the original value of the EGR valve outlet pressure and the filtered value of the EGR valve outlet pressure in the previous sampling period.

9. The control method for improving EGR closed-loop activation conditions according to claim 5, characterized in that: According to the difference value, the updated minimum EGR rate general threshold correction coefficient, the minimum EGR rate special threshold correction coefficient 1 and the minimum EGR rate special threshold correction coefficient 2 are obtained as follows: When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are all within the preset range one, and the difference values ​​among the average values ​​of the first, second and third EGR valve outlet pressure signals are within the preset range two, and the number of consecutive satisfactions is greater than the preset value, the minimum EGR rate general threshold correction coefficient is increased, and the minimum EGR rate special threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two remain unchanged; When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are all within the preset range one, and the difference values ​​among the average values ​​of the first, second and third EGR valve outlet pressure signals are within the preset range three, and the number of consecutive satisfactions is greater than the preset value, the minimum EGR rate general threshold correction coefficient is reduced, and the minimum EGR rate special threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two remain unchanged; When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are all within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is within the preset range two, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is not within the preset range three, and the number of consecutive satisfactions is greater than the preset value, the minimum EGR rate general threshold correction coefficient is enabled to remain unchanged, the minimum EGR rate special threshold correction coefficient one is enabled to increase, and the minimum EGR rate special threshold correction coefficient two is enabled to decrease; When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is not within the preset range three, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is within the preset range two, and the number of consecutive times of satisfaction is greater than the preset value, the minimum EGR rate general threshold correction coefficient is enabled to remain unchanged, the minimum EGR rate special threshold correction coefficient one is enabled to decrease, and the minimum EGR rate special threshold correction coefficient two is enabled to increase; When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is within the preset range two, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is between the preset range two and the preset range three, and the number of consecutive satisfactions is greater than the preset value, then the minimum EGR rate special threshold correction coefficient one is increased, and the minimum EGR rate general threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two remain unchanged; When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is not within the preset range three, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is between the preset range two and the preset range three, and the number of consecutive times of satisfaction is greater than the preset value, then the minimum EGR rate special threshold correction coefficient one is reduced, and the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient two remain unchanged; When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is between the preset range two and the preset range three, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is within the preset range two, and the number of consecutive times of satisfaction is greater than the preset value, then the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient one are enabled to remain unchanged, and the minimum EGR rate special threshold correction coefficient two is enabled to increase; When the difference values ​​among the fluctuation rates of the first, second and third EGR valve outlet pressure signals are all not within the preset range one, and the difference value between the average values ​​of the first and second EGR valve outlet pressure signals is between the preset range two and the preset range three, and the difference value between the average values ​​of the second and third EGR valve outlet pressure signals is not within the preset range three, and the number of consecutive times of satisfaction is greater than the preset value, then the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient one are enabled to remain unchanged, and the minimum EGR rate special threshold correction coefficient two is enabled to decrease; In other cases, the general threshold correction coefficient for enabling the minimum EGR rate, the special threshold correction coefficient 1 for enabling the minimum EGR rate, and the special threshold correction coefficient 2 for enabling the minimum EGR rate remain unchanged.

10. A control method for improving EGR closed-loop activation conditions according to claim 9, characterized in that: The default value of the number of consecutive satisfactions is 0, which is saved after the vehicle is powered off.

11. A control method for improving EGR closed-loop activation conditions according to claim 2 or 9, characterized in that: After obtaining the updated general threshold correction coefficient for enabling minimum EGR rate, special threshold correction coefficient one for enabling minimum EGR rate and special threshold correction coefficient two for enabling minimum EGR rate, if the difference between calculated value one and calculated value two is less than a certain value, the general threshold correction coefficient for enabling minimum EGR rate, special threshold correction coefficient one for enabling minimum EGR rate and special threshold correction coefficient two for enabling minimum EGR rate shall remain the general threshold correction coefficient for enabling minimum EGR rate, special threshold correction coefficient one for enabling minimum EGR rate and special threshold correction coefficient two for enabling minimum EGR rate updated last time.

12. The control method for improving EGR closed-loop activation conditions according to claim 1, characterized in that: The specific method for judging whether the EGR closed loop is enabled is as follows: When the following EGR closed-loop conditions are met, the EGR closed-loop is enabled: There were no malfunctions related to the EGR system parts; No fuel cut request occurs and the fuel cut recovery time exceeds the preset time; The engine speed is within the preset speed range; The intake air temperature is within the preset range; The engine water temperature is within the preset range; The atmospheric temperature is within the preset range; Atmospheric pressure exceeds the preset pressure value.

13. A computer storage medium, characterized in that: A computer program executable by a processor is stored therein, and the computer program executes a control method for improving EGR closed-loop activation conditions according to any one of claims 1 to 12.

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