A control method for improving an EGR closed-loop activation condition and a computer storage medium

Abstract

The application discloses a control method for improving EGR closed-loop activation conditions and a computer storage medium, and the method comprises the following steps: obtaining a minimum EGR rate, judging whether a minimum EGR rate condition of EGR closed-loop enabling is met according to the minimum EGR rate; when the minimum EGR rate condition of EGR closed-loop enabling is met, judging whether EGR closed-loop is enabled according to an EGR closed-loop condition. The application optimizes the closed-loop enabling condition judgment of the EGR system by obtaining the minimum EGR rate and judging the minimum EGR rate condition of EGR closed-loop enabling, thereby improving the pressure stability in the EGR system enabling transition process and improving the control stability of the whole EGR system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engine control, and particularly relates to a control method for improving EGR closed loop activation condition and a computer storage medium. BACKGROUND

[0002] Exhaust gas recirculation (EGR) takes exhaust gas from exhaust system into intake system. Research shows that EGR system has certain advantages in improving emissions, reducing fuel consumption and improving anti-knock ability. The control of the mixing valve in the low-pressure EGR system is particularly important for improving the effect of EGR rate.

[0003] Due to system hysteresis, EGR rate may cause controller oscillation when it enters the minimum EGR rate region, and even EGR system instability. In the prior art, the method for optimizing the minimum EGR rate and optimizing the EGR enablement condition is usually not considered. SUMMARY

[0004] To solve the problems in the prior art, the present application provides a control method for improving EGR closed loop activation condition and a computer storage medium.

[0005] To this end, the technical solution adopted by the present application is as follows:

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

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

[0008] when the minimum EGR rate condition for enabling EGR closed loop is met, determining whether EGR closed loop is enabled according to the EGR closed loop condition.

[0009] According to the above solution, the determination of whether the minimum EGR rate condition for enabling EGR closed loop is met is specifically as follows:

[0010] when the difference between the target EGR rate and the minimum EGR rate is greater than the first calculation value, the minimum EGR rate condition for enabling EGR closed loop is met;

[0011] when the difference between the target EGR rate and the minimum EGR rate is not greater than the second calculation value, 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 EGR closed loop is not met;

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

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

[0014] According to the above scheme, the calculated value two is obtained by multiplying the difference between 1 minus the minimum EGR rate enabling general threshold correction coefficient minus the minimum EGR rate enabling special threshold correction coefficient two by the preset value two.

[0015] According to the above scheme, the minimum EGR rate enabling general threshold correction coefficient, the minimum EGR rate enabling special threshold correction coefficient one and the minimum EGR rate enabling special threshold correction coefficient two are obtained by the following way:

[0016] When the learning activation condition is met, the first EGR valve outlet pressure signal average value and the first EGR valve outlet pressure signal fluctuation rate, the second EGR valve outlet pressure signal average value and the second EGR valve outlet pressure signal fluctuation rate, the third EGR valve outlet pressure signal average value and the third EGR valve outlet pressure signal fluctuation rate are read and calculated; and the difference values between the first EGR valve outlet pressure signal fluctuation rate, the second EGR valve outlet pressure signal fluctuation rate, the third EGR valve outlet pressure signal fluctuation rate and the difference values between the first EGR valve outlet pressure signal average value, the second EGR valve outlet pressure signal average value, the third EGR valve outlet pressure signal average value are judged, and the updated minimum EGR rate enabling general threshold correction coefficient, the minimum EGR rate enabling special threshold correction coefficient one and the minimum EGR rate enabling special threshold correction coefficient two are obtained according to the difference values.

[0017] According to the above scheme, 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 before the EGR system enters the closed loop enabling state, in the non-closed loop enabling 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 in the continuous time after the EGR system enters the closed loop enabling state, when the difference between the target EGR rate and the minimum EGR rate does not exceed the preset value;

[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 the continuous time after the EGR system enters the non-closed loop enabling state from the closed loop enabling state.

[0020] According to the above scheme, the learning activation condition is:

[0021] The EGR system experiences a non-closed loop enabled state, a closed loop enabled state, and a non-closed loop enabled state again.

[0022] In the process of the EGR system experiencing a non-closed loop enabled state, a closed loop enabled state, and a non-closed loop enabled state again, the continuous time in the non-closed loop enabled state and the continuous time in the closed loop enabled state both exceed a preset time.

[0023] The reason for the EGR system being in the non-closed loop enabled state is that the EGR closed loop enabled minimum EGR rate condition is not met in the non-closed loop enabled state, and the EGR closed loop enabled minimum EGR rate condition is met when entering the closed loop enabled state.

[0024] The continuous time for which the difference between the target EGR rate and the minimum EGR rate of the EGR system in the closed loop state does not exceed a preset range exceeds a preset time.

[0025] The engine speed fluctuation is within a preset range.

[0026] The intake density fluctuation into the cylinder is 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 degree fluctuation range is within a preset range.

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

[0031] According to the above scheme, the EGR valve outlet pressure signal fluctuation rate is determined by an EGR valve outlet pressure original value and an EGR valve outlet pressure filtered value; wherein the EGR valve outlet pressure original value is detected; and the EGR valve outlet pressure filtered value is calculated according to the EGR valve outlet pressure original value and the EGR valve outlet pressure filtered value of the last sampling period.

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

[0033] When the difference values among the first, second, and third EGR valve outlet pressure signal fluctuation rates are all within a preset range one, and the difference value among the first, second, and third EGR valve outlet pressure signal average values is within a preset range two, and the continuous satisfaction times exceed a preset value, the enabling minimum EGR rate general threshold correction coefficient is increased, and the enabling minimum EGR rate special threshold correction coefficient one and the enabling minimum EGR rate special threshold correction coefficient two remain unchanged.

[0034] When the difference values between the first, second, and third EGR valve outlet pressure signal fluctuation rates are all within the preset range one, and the difference value between the first and second EGR valve outlet pressure signal average values is within the preset range two, and the difference value between the second and third EGR valve outlet pressure signal average values is not within the preset range three, and the number of continuous satisfaction is greater than the preset value, the general minimum EGR rate threshold correction coefficient is not changed, the special minimum EGR rate threshold correction coefficient one is increased, and the special minimum EGR rate threshold correction coefficient two is not changed;

[0035] When the difference values between the first, second, and third EGR valve outlet pressure signal fluctuation rates are all within the preset range one, and the difference value between the first and second EGR valve outlet pressure signal average values is within the preset range two, and the difference value between the second and third EGR valve outlet pressure signal average values is not within the preset range three, and the number of continuous satisfaction is greater than the preset value, the general minimum EGR rate threshold correction coefficient is not changed, the special minimum EGR rate threshold correction coefficient one is increased, and the special minimum EGR rate threshold correction coefficient two is not changed;

[0036] When the difference values between the first, second, and third EGR valve outlet pressure signal fluctuation rates are all within the preset range one, and the difference value between the first and second EGR valve outlet pressure signal average values is within the preset range two, and the difference value between the second and third EGR valve outlet pressure signal average values is not within the preset range three, and the number of continuous satisfaction is greater than the preset value, the general minimum EGR rate threshold correction coefficient is not changed, the special minimum EGR rate threshold correction coefficient one is increased, and the special minimum EGR rate threshold correction coefficient two is not changed;

[0037] When the difference values between the first, second, and third EGR valve outlet pressure signal fluctuation rates are all within the preset range one, and the difference value between the first and second EGR valve outlet pressure signal average values is within the preset range two, and the difference value between the second and third EGR valve outlet pressure signal average values is not within the preset range three, and the number of continuous satisfaction is greater than the preset value, the general minimum EGR rate threshold correction coefficient is not changed, the special minimum EGR rate threshold correction coefficient one is increased, and the special minimum EGR rate threshold correction coefficient two is not changed;

[0038] When the difference values between the first, second, and third EGR valve outlet pressure signal fluctuation rates are all within the preset range one, and the difference value between the first and second EGR valve outlet pressure signal average values is within the preset range two, and the difference value between the second and third EGR valve outlet pressure signal average values is not within the preset range three, and the number of continuous satisfaction is greater than the preset value, the general minimum EGR rate threshold correction coefficient is not changed, the special minimum EGR rate threshold correction coefficient one is increased, and the special minimum EGR rate threshold correction coefficient two is not changed;

[0039] When the difference between the first, second, and third EGR valve outlet pressure signal fluctuation rates is not within the preset range one, the difference between the first and second EGR valve outlet pressure signal average values is between the preset range two and the preset range three, the difference between the second and third EGR valve outlet pressure signal average values is not within the preset range three, and the number of consecutive satisfaction is greater than the preset value, the enable minimum EGR rate general threshold correction coefficient and the enable minimum EGR rate special threshold correction coefficient one remain unchanged, and the enable minimum EGR rate special threshold correction coefficient two is decreased.

[0040] When the difference between the first, second, and third EGR valve outlet pressure signal fluctuation rates is not within the preset range one, the difference between the first and second EGR valve outlet pressure signal average values is between the preset range two and the preset range three, the difference between the second and third EGR valve outlet pressure signal average values is not within the preset range three, and the number of consecutive satisfaction is greater than the preset value, the enable minimum EGR rate general threshold correction coefficient and the enable minimum EGR rate special threshold correction coefficient one remain unchanged, and the enable minimum EGR rate special threshold correction coefficient two is decreased.

[0041] In other cases, the enable minimum EGR rate general threshold correction coefficient, the enable minimum EGR rate special threshold correction coefficient one, and the enable minimum EGR rate special threshold correction coefficient two remain unchanged.

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

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

[0044] According to the above scheme, the EGR closed loop is determined according to the EGR closed loop condition. Specifically, the EGR closed loop is enabled when the following conditions are met:

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

[0046] No related faults of EGR system parts occur;

[0047] No oil interruption request occurs and the oil interruption recovery time exceeds the preset time;

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

[0049] The intake air temperature is in a preset range.

[0050] The engine water temperature is in a preset range.

[0051] The atmospheric temperature is in a preset range.

[0052] The atmospheric pressure exceeds a preset pressure value.

[0053] A computer storage medium has stored therein a computer program executable by a processor, the computer program performing the control method for improving an EGR closed-loop activation condition according to any one of the preceding embodiments.

[0054] The present application has the following beneficial effects:

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

[0056] Figure 1 A method flowchart of an embodiment of the present application;

[0057] Figure 2 A system structure schematic diagram of an embodiment of the present application with EGR.

[0058] In the figure, 1 is an air filter, 2 is a mixing valve, 3 is a compressor, 4 is a throttle valve, 5 is an engine, 6 is a turbine, 7 is a catalyst, 8 is a particulate trap, 9 is an EGR cooler, 10 is an EGR valve, 11 is a temperature sensor, and 12 is a differential pressure sensor. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0060] Embodiment 1:

[0061] The present application proposes a control method for improving an EGR closed-loop activation condition, as shown in Figure 1 The method specifically includes:

[0062] S1, obtaining a minimum EGR rate, and judging whether the minimum EGR rate satisfies a minimum EGR rate condition for EGR closed-loop enablement according to the minimum EGR rate.

[0063] The minimum EGR rate can be obtained by the patent CN202211212260.6 "Minimum EGR rate adjusting method, device, equipment and storage medium".

[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 enables the minimum EGR rate condition to be 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 of the EGR closed loop is not met;

[0066] In other cases, the minimum EGR rate condition of the EGR closed loop maintains the last state, wherein the vehicle is powered on by default, and the default state is that the EGR closed loop enables the minimum EGR rate condition to be met.

[0067] The calculated value A and the calculated value B are obtained by modifying the minimum EGR rate general threshold value correction coefficient r Adpt , the minimum EGR rate special threshold value correction coefficient one r Lrn1 and the minimum EGR rate special threshold value correction coefficient two r Lrn2 . In a preferred embodiment of the present application, A=C1x(1+r Adpt +r Lrn1 ); B=C2x(1-r Adpt -r Lrn2 ), A-B is not less than 0.001.

[0068] Wherein the default values of r Adpt , r Lrn1 and r Lrn2 are 0, and can be saved when the vehicle is powered off.

[0069] Embodiment 2:

[0070] In a preferred embodiment of the present application, r Adpt , r Lrn1 and r Lrn2 are updated according to the last updated r Adpt (z), r L rn1(z) and r L rn2(z), which are updated when the learning activation condition is met, wherein the learning activation condition is specifically:

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

[0072] In the course of the EGR system experiencing a non-closed loop enabling state to a closed loop enabling state and then to a non-closed loop enabling state again, both the continuous time in the non-closed loop enabling state and the continuous time in the closed loop enabling state exceed a preset time t1, in this embodiment, t1 is 0.5 s;

[0073] The reason for the EGR system to be in the non-closed loop enabling state is that the EGR closed loop enabling minimum EGR rate condition is not met when the EGR system is in the non-closed loop enabling state, and the EGR closed loop enabling minimum EGR rate condition is met when the EGR system enters the closed loop enabling state;

[0074] The continuous time, in which the difference between the target EGR rate and the minimum EGR rate of the EGR system in the closed loop state does not exceed a preset value, exceeds a preset time t1, in this embodiment, the preset value is a calculated value A+D, wherein D is 0.02;

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

[0076] The intake density fluctuation into the cylinder is within a preset range, in this embodiment, the preset range is ±25 mgl;

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

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

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

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

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

[0082] wherein r EGROut Pre1 r EGROutPre2 and r EGROutPre3 is determined according to an EGR valve outlet pressure original value p EGROut and an EGR valve outlet pressure filtered value p EGROutFilter , wherein the EGR valve outlet pressure original value p EGROut is detected by a sensor; the EGR valve outlet pressure filtered value p EGROutFilter is calculated according to the EGR valve outlet pressure original value and the EGR valve outlet pressure filtered value of the last sampling period:

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

[0084] wherein p EGROut (N) is the EGR valve outlet pressure original value of the Nth sampling period, p EGROutFilter (N) is the EGR valve outlet pressure filtered value of the Nth sampling period, p EGROutFilter (N-1) is the EGR valve outlet pressure filtered value of the (N-1)th sampling period, N = 1, 2, 3,..., and p EGROutFilter (0) is equal to the EGR valve outlet pressure original value p EGROut (0) at the 0th sampling period, which occurs at the initial time of t1; K EGROutPre is a coefficient, wherein m is the number of engine cylinders, n is the engine speed, the number of engine cylinders in the embodiment is 4, and the calibration speed of k EGROutPre is 1000 rpm. This setting is to normalize, without special calibration at different cylinder numbers and speeds, only the k EGROutPre of 4-cylinder engine and 1000 rpm speed needs to be calibrated, thereby reducing calibration test work, and k EGROutPre is an EGR valve outlet pressure difference filtered coefficient, which is taken as 0.1 in the embodiment.

[0085] In the embodiment, the sampling period interval Δt is taken as 10 ms.

[0086] wherein r EGROut Pre1 is equal to the EGR valve outlet pressure difference during the continuous time t1 in the non-closed loop enabled state before the EGR system enters the closed loop enabled state

[0087] r EGROutPre2Equal to the difference between the target EGR rate and the minimum EGR rate in the closed loop state of the EGR system entering the closed loop state within the continuous time t1 not exceeding the preset value A+D

[0088] r EGROutPre3 Equal to the difference between the target EGR rate and the minimum EGR rate in the closed loop state of the EGR system entering the closed loop state within the continuous time t1 not exceeding the preset value A+D

[0089] r EGROutAvg1 , p EGROutAvg2 , p EGROutAvg3 , r EGROutPre1 , r EGROutPre2 and r EGROutPre3 After that, the difference values between p EGROutAvg1 , p EGROutAvg2 and p EGROutAvg3 and the difference values between r EGROutPre1 , r EGROutPre2 and r EGROutPre3 are judged:

[0090] When the difference values between p EGROutAvg1 , p EGROutAvg2 and p EGROutAvg3 are all within the preset range D (in this embodiment, the preset range D is ±2kPa), and the difference values between r EGROutPre1 , r EGROutPre2 and r EGROutPre3 are all within the preset range E1 (in this embodiment, the preset range E1 is ±0.005), and the continuous satisfaction times exceed the threshold F1 (in this embodiment, the threshold F1 is 10), wherein the continuous satisfaction times are added at most once each time the learning condition is satisfied, until the next learning condition is not satisfied again and enters the satisfaction state, and then it is judged whether to add, then r Adpt =r Adpt (z)+0.02, r Lrn1 =r Lrn1 (z), r Lrn2 =r Lrn2 (z), wherein 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 the difference values between p EGROutAvg1 , p EGROutAvg2 and p EGROutAvg3 are all within the preset range D, and the difference values between r EGROutPre1 , r EGROutPre2 and r EGROutPre3the difference between r Adpt = r Adpt (z) - 0.015, r Lrn1 = r Lrn1 (z), r Lrn2 = r Lrn2 (z) + 0.015;

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

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

[0094] When the difference between p EGROutAvg1 , p EGROutAvg2 and p EGROutAvg3 is not within the preset range D, and the difference between r EGROutPre1 and r EGROutPre2 is within the preset range E1, and the difference between r EGROutPre2 and r EGROutPre3the difference value between r Adpt = r Adpt (z), r Lrn1 = r Lrn1 (z) + 0.005, r Lrn2 = r Lrn2 (z) - 0.005;

[0095] When the difference value between p EGROutAvg1 , p EGROutAvg2 and p EGROutAvg3 is not within the preset range D, and the difference value between r EGROutPre1 and r EGROutPre2 is not within the preset range E2, and the difference value between r EGROutPre2 and r EGROutPre3 is within the preset range E1-E2, and the number of continuous satisfaction exceeds the threshold F6 (the threshold F6 is 20 in this embodiment), then r Adpt = r Adpt (z), r Lrn1 = r Lrn1 (z) - 0.005, r Lrn2 = r Lrn2 (z) + 0.005;

[0096] When the difference value between p EGROutAvg1 , p EGROutAvg2 and p EGROutAvg3 is not within the preset range D, and the difference value between r EGROutPre1 and r EGROutPre2 is within the preset range E1-E2, and the difference value between r EGROutPre2 and r EGROutPre3 is within the preset range E1, and the number of continuous satisfaction exceeds the threshold F7 (the threshold F7 is 20 in this embodiment), then r Adpt = r Adpt (z), r Lrn1 = r Lrn1 (z), r Lrn2 = r Lrn2 (z) + 0.005;

[0097] When the difference value between p EGROutAvg1 , p EGROutAvg2 and p EGROutAvg3 is not within the preset range D, and the difference value between r EGROutPre1 and r EGROutPre2 is within the preset range E1-E2, and the difference value between r EGROutPre2 and r EGROutPre3 is not within the preset range E2, and the number of continuous satisfaction exceeds the threshold F8 (the threshold F8 is 20 in this embodiment), 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 calculation value A minus the calculation value B is less than 0.001, the current update is still maintained, 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 the number of continuous satisfaction is cleared at the same time.

[0100] The default value of the number of continuous satisfaction is 0, and can be saved after the vehicle is powered off, r Adpt , r Lrn1 , r Lrn2 After being updated, the number of continuous satisfaction is cleared.

[0101] S2, when the minimum EGR rate condition of EGR closed loop enablement is met, it is judged 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 application, the EGR closed loop condition for judging EGR closed loop enablement is specifically:

[0104] No related faults of each part of the EGR system occur;

[0105] No oil interruption request occurs and the oil interruption recovery time exceeds the preset time, and the preset time is 0.3s in the present embodiment;

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

[0107] The engine speed is in the preset speed interval, and the preset speed interval is 750rpm-5500rpm in the present embodiment;

[0108] The intake air temperature is in a preset range. In the embodiment, if the current state is EGR closed loop not enabled, the EGR closed loop state is entered, and it is required to ensure that the minimum intake air temperature is not lower than 10℃. If the current state is EGR closed loop enabled, the EGR system closed loop enabled state is exited, and it is required to ensure that the minimum intake air temperature is lower than 7℃. If the current state is EGR closed loop not enabled, the EGR closed loop state is entered, and it is required to ensure that the maximum intake air temperature is not higher than 60℃. If the current state is EGR closed loop enabled, the EGR system closed loop enabled state is exited, and it is required to ensure that the maximum intake air temperature is higher than 65℃.

[0109] The engine water temperature is in a preset range. In the embodiment, if the current state is EGR closed loop not enabled, the EGR closed loop state is entered, and it is required to ensure that the minimum water temperature is not lower than 60℃. If the current state is EGR closed loop enabled, the EGR system closed loop enabled state is exited, and it is required to ensure that the minimum water temperature is lower than 55℃. If the current state is EGR closed loop not enabled, the EGR closed loop state is entered, and it is required to ensure that the maximum water temperature is not higher than 115℃. If the current state is EGR closed loop enabled, the EGR system closed loop enabled state is exited, and it is required to ensure that the maximum water temperature is higher than 120℃.

[0110] The atmospheric temperature is in a preset range. In the embodiment, if the current state is EGR closed loop not enabled, the EGR closed loop state is entered, and it is required to ensure that the minimum atmospheric temperature is not lower than 5℃. If the current state is EGR closed loop enabled, the EGR system closed loop enabled state is exited, and it is required to ensure that the minimum atmospheric temperature is lower than 3℃. If the current state is EGR closed loop not enabled, the EGR closed loop state is entered, and it is required to ensure that the maximum atmospheric temperature is not higher than 55℃. If the current state is EGR closed loop enabled, the EGR system closed loop enabled state is exited, and it is required to ensure that the maximum atmospheric temperature is higher than 60℃.

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

[0112] After the EGR closed loop is enabled, the EGR closed loop control is performed, the hybrid valve and the EGR valve are controlled to act based on the target EGR rate and the actual EGR rate, so that the actual EGR rate follows the target EGR rate.

[0113] Embodiment 4:

[0114] As Figure 2As shown, the application also provides a system structure with EGR, comprising 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 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 circuit comprising a differential pressure sensor 12 connected to the EGR valve 10; the two ends of the branch circuit are connected to the outlet of the particulate trap 8 and the outlet of the mixing valve 2, respectively; wherein the mixing valve 2 is used to adjust the pressure at the outlet of the EGR valve 10, to increase the pressure difference at the two ends of the EGR valve 10, the engine 5 is used to compress fresh air to increase the pressure, the turbine 6 is used to control the opening degree of the exhaust gas bypass valve, the EGR cooler 9 is used to receive and cool the exhaust gas output by the particulate trap 8, to increase the exhaust gas flow, the EGR valve 10 is used to control the exhaust gas flow entering the cylinder, the temperature sensor 11 is used to detect the temperature of the exhaust gas entering the EGR valve 10, and the differential pressure sensor 12 is used to detect the pressure at the inlet and outlet of the EGR valve 10. The system structure is used to execute the control method for improving the EGR closed loop activation condition described in the embodiment.

[0115] The application optimizes the closed loop enablement condition judgment of the EGR system by acquiring the minimum EGR rate and judging the minimum EGR rate condition of the EGR closed loop enablement, improves the pressure stability during the enablement transition process of the EGR system, and improves the control stability of the entire EGR system.

[0116] Embodiment 5:

[0117] The application 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 complete mutual communication through the communication bus.

[0118] The memory stores a computer program, and when the program is executed by the processor, the processor executes the steps of the method.

[0119] Embodiment 6:

[0120] The application also provides a computer readable storage medium, which stores executable instructions, and the instructions are executed by the processor to realize the method.

[0121] Those skilled in the art should understand that the embodiments of the application can be provided as a method, a system or a computer program product. Therefore, the application can be in the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0122] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0123] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

[0124] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.

Claims

1. A control method for improving an EGR closed loop activation condition, characterized by, The method comprises: obtaining a minimum EGR rate, and determining whether a minimum EGR rate condition for enabling EGR closed loop is met according to the minimum EGR rate; when the minimum EGR rate condition for enabling EGR closed loop is met, determining whether EGR closed loop is enabled according to an EGR closed loop condition; wherein the determination of whether the minimum EGR rate condition for enabling EGR closed loop is met comprises: when the difference between the target EGR rate and the minimum EGR rate is greater than a first calculation value, the minimum EGR rate condition for enabling EGR closed loop is met; when the difference between the target EGR rate and the minimum EGR rate is not greater than a second calculation value, and the absolute value of the difference between the target EGR rate and the actual EGR rate is not greater than a preset value, the minimum EGR rate condition for enabling EGR closed loop is not met; in other cases, the minimum EGR rate condition for enabling EGR closed loop maintains the previous state, wherein the default state when the vehicle is powered on is that the minimum EGR rate condition for enabling EGR closed loop is not met; wherein the first calculation value is obtained by multiplying the sum of the enabling minimum EGR rate general threshold correction coefficient, the enabling minimum EGR rate special threshold correction coefficient one and 1 by the preset value one; wherein the second calculation value is obtained by multiplying the difference between 1 minus the enabling minimum EGR rate general threshold correction coefficient minus the enabling minimum EGR rate special threshold correction coefficient two by the preset value two; when the learning activation condition is met, the enabling minimum EGR rate general threshold correction coefficient, the enabling minimum EGR rate special threshold correction coefficient one and the enabling minimum EGR rate special threshold correction coefficient two are updated.

2. The control method of claim 1, wherein, The enabling minimum EGR rate general threshold correction coefficient, the enabling minimum EGR rate special threshold correction coefficient one and the enabling minimum EGR rate special threshold correction coefficient two are obtained by the following method: when the learning activation condition is met, the first EGR valve outlet pressure signal average value and the first EGR valve outlet pressure signal fluctuation rate, the second EGR valve outlet pressure signal average value and the second EGR valve outlet pressure signal fluctuation rate, and the third EGR valve outlet pressure signal average value 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 first EGR valve outlet pressure signal average value, the second EGR valve outlet pressure signal average value and the third EGR valve outlet pressure signal average value are determined, and the updated enabling minimum EGR rate general threshold correction coefficient, the enabling minimum EGR rate special threshold correction coefficient one and the enabling minimum EGR rate special threshold correction coefficient two are obtained according to the difference values.

3. The control method of claim 2, wherein, 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 in the non-closed loop enabling state before the EGR system enters the closed loop enabling 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 in 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 enabling 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 the continuous time after the EGR system enters the non-closed loop enabling state from the closed loop enabling state.

4. The control method of claim 2, wherein the EGR close loop activation condition is improved by, The learning activation condition is: The EGR system has experienced the non-closed loop enabling state to the closed loop enabling state and then to the non-closed loop enabling state again; In the process of the EGR system experiencing the non-closed loop enabling state to the closed loop enabling state and then to the non-closed loop enabling state again, the continuous time in the non-closed loop enabling state and the continuous time in the closed loop enabling state both exceed the preset time; The reason why the EGR system enters the non-closed loop enabling state is that the EGR closed loop enabling minimum EGR rate condition is not met in the non-closed loop enabling state, and the EGR closed loop enabling minimum EGR rate condition is met when entering the closed loop enabling state; The continuous time when the difference between the target EGR rate and the minimum EGR rate does not exceed the preset range in the closed loop state of the EGR system exceeds the preset time; The engine speed fluctuation is within the preset range; The intake density fluctuation into the cylinder is within the preset range; The target boost pressure fluctuation is within the preset range; The difference between the target boost pressure and the actual boost pressure is within the preset range; The mixing valve opening degree fluctuation range is within the preset range; The EGR valve inlet temperature fluctuation range is within the preset range.

5. The control method of claim 2, wherein the EGR close loop activation condition is improved by, The EGR valve outlet pressure signal fluctuation rate is determined by the EGR valve outlet pressure original value and the EGR valve outlet pressure filtered value; wherein the EGR valve outlet pressure original value is detected; and the EGR valve outlet pressure filtered value is calculated according to the EGR valve outlet pressure original value and the EGR valve outlet pressure filtered value in the last sampling period.

6. The control method of claim 2, wherein the EGR close loop activation condition is improved by, The updated enabling minimum EGR rate general threshold correction coefficient, the enabling minimum EGR rate special threshold correction coefficient one and the enabling minimum EGR rate special threshold correction coefficient two obtained according to the difference value are: When the difference values among the first, second and third EGR valve outlet pressure signal fluctuation rates are all within the preset range one, and the difference value among the first, second and third EGR valve outlet pressure signal average values is within the preset range two, and the continuous satisfaction times are greater than the preset value, the enabling minimum EGR rate general threshold correction coefficient is increased, and the enabling minimum EGR rate special threshold correction coefficient one and the enabling minimum EGR rate special threshold correction coefficient two remain unchanged; When the difference values among the first, second and third EGR valve outlet pressure signal fluctuation rates are all within the preset range one, and the difference value among the first, second and third EGR valve outlet pressure signal average values is within the preset range three, and the continuous satisfaction times are greater than the preset value, the enabling minimum EGR rate general threshold correction coefficient is reduced, and the enabling minimum EGR rate special threshold correction coefficient one and the enabling minimum EGR rate special threshold correction coefficient two remain unchanged; When the difference between the first, second, and third EGR valve outlet pressure signal fluctuation rates is not within the preset range one, the difference between the first and second EGR valve outlet pressure signal average values is within the preset range two, and the difference between the second and third EGR valve outlet pressure signal average values is within the preset range two and the preset range three, and the number of consecutive satisfaction is greater than the preset value, the minimum EGR rate special threshold correction coefficient one is decreased, and the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient two are unchanged. When the difference between the first, second, and third EGR valve outlet pressure signal fluctuation rates is not within the preset range one, the difference between the first and second EGR valve outlet pressure signal average values is not within the preset range three, and the difference between the second and third EGR valve outlet pressure signal average values is within the preset range two, and the number of consecutive satisfaction is greater than the preset value, the minimum EGR rate general threshold correction coefficient is unchanged, the minimum EGR rate special threshold correction coefficient one is decreased, and the minimum EGR rate special threshold correction coefficient two is increased. When the difference between the first, second, and third EGR valve outlet pressure signal fluctuation rates is not within the preset range one, the difference between the first and second EGR valve outlet pressure signal average values is within the preset range two, and the difference between the second and third EGR valve outlet pressure signal average values is within the preset range two and the preset range three, and the number of consecutive satisfaction is greater than the preset value, the minimum EGR rate special threshold correction coefficient one is increased, and the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient two are unchanged. When the difference between the first, second, and third EGR valve outlet pressure signal fluctuation rates is not within the preset range one, the difference between the first and second EGR valve outlet pressure signal average values is not within the preset range three, and the difference between the second and third EGR valve outlet pressure signal average values is within the preset range two and the preset range three, and the number of consecutive satisfaction is greater than the preset value, the minimum EGR rate special threshold correction coefficient one is decreased, and the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient two are unchanged. When the difference between the first, second, and third EGR valve outlet pressure signal fluctuation rates is not within the preset range one, the difference between the first and second EGR valve outlet pressure signal average values is within the preset range two and the preset range three, and the difference between the second and third EGR valve outlet pressure signal average values is within the preset range two, and the number of consecutive satisfaction is greater than the preset value, the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient one are unchanged, and the minimum EGR rate special threshold correction coefficient two is increased. When the difference between the first, second and third EGR valve outlet pressure signal fluctuation rates are all not within the preset range one, and the difference between the first and second EGR valve outlet pressure signal average values is between the preset range two and the preset range three, and the difference between the second and third EGR valve outlet pressure signal average values is not within the preset range three, and the continuous satisfaction number is greater than the preset value, the minimum EGR rate general threshold correction coefficient and the minimum EGR rate special threshold correction coefficient one remain unchanged, and the minimum EGR rate special threshold correction coefficient two is reduced. In other cases, the minimum EGR rate general threshold correction coefficient, the minimum EGR rate special threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two remain unchanged.

7. The control method of claim 6, wherein the EGR close-loop activation condition is improved by, The default value of the continuous satisfaction number is 0, which is saved after the vehicle is powered off.

8. The control method of claim 6, wherein the EGR close loop activation condition is improved by, After obtaining the updated minimum EGR rate general threshold correction coefficient, the minimum EGR rate special threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two, if the difference between the calculation value one and the calculation value two is less than a certain value, the minimum EGR rate general threshold correction coefficient, the minimum EGR rate special threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two remain the last updated minimum EGR rate general threshold correction coefficient, the minimum EGR rate special threshold correction coefficient one and the minimum EGR rate special threshold correction coefficient two.

9. The control method of claim 1, wherein the EGR close loop activation condition is improved by, The EGR closed loop is enabled according to the EGR closed loop condition, specifically: When the following EGR closed loop conditions are met, the EGR closed loop is enabled: No related faults of the EGR system parts occur; No oil interruption request occurs and the oil interruption 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; The atmospheric pressure exceeds the preset pressure value.

10. A computer storage medium, characterized in that, The memory stores a computer program executable by the processor, and the computer program executes the control method for improving the EGR closed loop activation condition according to any one of claims 1-9.

Images