Engine performance improvement control method based on improvement of aging loss

Abstract

The application discloses an engine performance improvement control method based on improvement of aging loss, and the method comprises the following steps: obtaining a minimum EGR rate original value, and obtaining a minimum EGR rate filtered value according to the minimum EGR rate original value; determining the minimum EGR rate used for EGR enabling condition judgment according to the minimum EGR rate original value and the minimum EGR rate filtered value; determining whether the EGR closed loop enabling minimum EGR rate condition is met according to the minimum EGR rate; and when the EGR closed loop enabling minimum EGR rate condition is met, judging whether the EGR closed loop is enabled according to the EGR closed loop enabling condition. The application optimizes the minimum EGR rate, optimizes the area range of the EGR rate entering the minimum EGR rate, optimizes the EGR enabling condition judgment method, reduces the oscillation probability of a control actuator, improves the EGR system, and improves the stability of the system.

Description

Technical Field

[0001] This invention relates to the field of engine control, and more particularly to a control method for improving engine performance based on mitigating aging losses. Background Technology

[0002] This invention relates to the field of engine control, and in particular to a method for improving engine performance control based on mitigating aging losses.

[0003] Exhaust gas recirculation (EGR) draws exhaust gas from the exhaust system and introduces it into the intake system. Studies have shown that EGR systems offer advantages in improving emissions, reducing fuel consumption, and enhancing anti-knock capabilities. In low-pressure EGR systems, the control of the mixing valve is particularly important for improving the EGR rate.

[0004] Due to system hysteresis, when the EGR rate enters its minimum EGR rate region, it may cause oscillation of the control actuator, or even instability of the EGR system. Existing technologies utilize methods such as calculating the target EGR rate and performing secondary corrections on it, or correcting the target opening of the mixing valve based on various operating parameters. However, these methods typically do not consider optimizing the minimum EGR rate or optimizing the determination of EGR enabling conditions. Summary of the Invention

[0005] To optimize the minimum EGR rate and the method for determining EGR enabling conditions, this invention proposes an engine performance improvement control method based on improving aging losses.

[0006] Therefore, the technical solution adopted by the present invention is as follows:

[0007] A method for improving engine performance control based on mitigating aging losses, the method comprising:

[0008] Obtain the original value of the minimum EGR rate, and then obtain the minimum EGR rate filter value based on the original value of the minimum EGR rate;

[0009] The minimum EGR rate used for EGR enable condition determination is determined based on the original value of the minimum EGR rate and the filtered value of the minimum EGR rate.

[0010] Determine whether the minimum EGR rate condition for enabling EGR closed-loop is met based on the minimum EGR rate.

[0011] When the minimum EGR rate condition for EGR closed-loop enable is met, determine whether the EGR closed-loop is enabled based on the EGR closed-loop enable condition.

[0012] According to the above scheme, the minimum EGR rate filter value is specifically obtained by multiplying the difference between the original minimum EGR rate value and the minimum EGR rate filter value obtained in the previous sampling period by the sampling period interval, dividing by the minimum EGR rate filter time, and adding the minimum EGR rate filter value obtained in the previous sampling period.

[0013] According to the above scheme, the minimum EGR rate filtering time is obtained in the following way:

[0014] When the preset conditions are met, the minimum EGR rate filtering time is equal to the sum of the minimum EGR rate filtering time self-learning correction coefficient and 1, multiplied by the product of the boost pressure fluctuation correction coefficient, the engine torque fluctuation correction coefficient, and the preset filtering time.

[0015] In other cases, the minimum EGR rate filtering time is equal to the preset filtering time.

[0016] According to the above scheme, the preset conditions are specifically as follows:

[0017] The engine torque fluctuation correction factor or boost pressure fluctuation correction factor is not equal to 1.

[0018] According to the above scheme, the boost pressure fluctuation correction coefficient is determined based on the original value of the boost pressure difference and the filtered value of the boost pressure difference;

[0019] If the absolute value of the difference between the boost pressure difference filter value and the boost pressure difference, divided by the minimum value among the original boost pressure difference value, the boost pressure difference filter value, and the preset value, is greater than a certain value for a continuous period of time, then the boost pressure fluctuation correction coefficient is obtained by calibration; otherwise, the boost pressure fluctuation correction coefficient is equal to 1.

[0020] According to the above scheme, the engine torque fluctuation correction coefficient is determined based on the torque difference and the torque difference filter value; the torque difference is the difference between the engine's requested firing torque and the actual firing torque;

[0021] If the absolute value of the difference between the torque difference filter value and the torque difference, divided by the minimum value among the torque difference, the torque difference filter value, and the preset value, is greater than a certain value for more than a preset time, then the engine torque fluctuation correction coefficient is obtained by calibration; otherwise, the engine torque fluctuation correction coefficient is equal to 1.

[0022] According to the above scheme, the specific determination of the minimum EGR rate used for EGR enable condition judgment is as follows:

[0023] When any special operating condition is met, the minimum EGR rate is equal to the original value of the minimum EGR rate.

[0024] In other cases, the minimum EGR rate is equal to the minimum EGR rate filter value.

[0025] According to the above scheme, the specific special operating conditions are as follows:

[0026] Special requirements, condition one:

[0027] The difference between the ignition angle efficiency and the ignition angle efficiency of the previous sampling period is within a preset range or the ignition angle efficiency exceeds a preset value.

[0028] The engine did not request a fuel cut-off.

[0029] The engine did not experience any knocking or pre-ignition.

[0030] The fluctuation of the engine's fresh air intake density does not exceed the preset range;

[0031] When all the above conditions are met simultaneously for a continuous period of time exceeding the preset time, it indicates that special requirement condition one is met;

[0032] Special requirements, condition two:

[0033] The difference between the air-fuel ratio and the air-fuel ratio in the previous sampling period exceeds a preset value;

[0034] The engine did not request a fuel cut-off.

[0035] The engine intake air temperature exceeds the preset value;

[0036] The engine coolant temperature exceeds the preset value;

[0037] When the continuous time during which all the above conditions are met exceeds the preset time, it indicates that special requirement condition two is met.

[0038] According to the above scheme, the specific method for determining whether the minimum EGR rate condition for enabling EGR closed-loop is met is as follows:

[0039] When the difference between the target EGR rate and the minimum EGR rate is greater than a preset value of one, the condition for enabling the minimum EGR rate in the EGR closed loop is met.

[0040] If the difference between the target EGR rate and the minimum EGR rate is not greater than the preset 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 3, then the minimum EGR rate condition for enabling EGR closed loop is not met.

[0041] In other cases, the minimum EGR rate condition for EGR closed-loop enable remains in the previous state, with the default state being when the vehicle is powered on, where the minimum EGR rate condition for EGR closed-loop enable is not met.

[0042] According to the above scheme, the specific steps for determining whether the EGR closed-loop is enabled based on the EGR closed-loop enable condition are as follows:

[0043] No faults were found in any of the components of the EGR system;

[0044] No fuel cut-off request was received and the fuel cut-off recovery time exceeded the preset time;

[0045] The minimum EGR rate condition for EGR closed-loop enable is satisfied;

[0046] The engine speed is within the preset speed range;

[0047] Intake air temperature is within the preset range;

[0048] Engine coolant temperature is within the preset range;

[0049] Atmospheric temperature is within the preset range;

[0050] Atmospheric pressure exceeds the preset pressure value.

[0051] According to the above scheme, the minimum EGR rate filtering time self-learning correction coefficient is obtained in the following way:

[0052] The minimum EGR rate filtering time self-learning correction coefficients are updated when any of the following conditions are met:

[0053] Scenario 1:

[0054] EGR closed-loop enable, and the EGR closed-loop enable time does not exceed the preset time;

[0055] The continuous time during which the boost pressure fluctuation correction coefficient exceeds a certain value exceeds the preset time;

[0056] The engine torque fluctuation correction coefficient is greater than a certain value for more than a preset time.

[0057] The difference between the target EGR rate and the current minimum EGR rate shall not exceed a preset value;

[0058] The cumulative mileage of the engine whose self-learning coefficient has not been updated exceeds the preset value;

[0059] If all of the above conditions are met, it indicates that condition one is satisfied;

[0060] Scenario 2:

[0061] The time for the EGR closed-loop enabled state to transition from the active to the inactive state does not exceed a preset time.

[0062] The activation time of the EGR closed-loop enable state exceeds the preset time.

[0063] Request that the fluctuation of the fire circuit torque be within the preset range;

[0064] The target boost pressure fluctuation is within the preset range;

[0065] The cumulative mileage of the engine whose self-learning coefficient has not been updated exceeds the preset value;

[0066] When the minimum EGR rate condition for EGR closed-loop enable is not met, the EGR closed-loop enable state enters the inactive state.

[0067] If all the above conditions are met, it indicates that condition two is satisfied.

[0068] According to the above scheme, when condition one is met, read the average value of the absolute value of the ratio of the difference between the target EGR rate and the actual EGR rate to the target EGR rate within a certain period of time after the EGR closed-loop enable is activated. If the average value is not greater than the preset value, the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the sum of the previously updated minimum EGR rate filtering time self-learning correction coefficient and the change value.

[0069] If the average value is greater than the preset value, record the number of times the average value is greater than the preset value. If the number of times the average value is greater than the preset value is greater than the preset number, and no condition one is met during the increase of the number, then the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the difference between the previously updated minimum EGR rate filtering time self-learning correction coefficient and the change value.

[0070] In other cases where condition one is satisfied, the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the previously updated minimum EGR rate filtering time self-learning correction coefficient.

[0071] When condition two is met, read the average value of the boost pressure fluctuation correction coefficient and the average value of the engine torque fluctuation correction coefficient during the activation period before the EGR closed-loop enable state enters the inactive state, and read the average value of the boost pressure fluctuation correction coefficient and the average value of the engine torque fluctuation correction coefficient during the inactive period after the EGR closed-loop enable state enters the inactive state. If the preset value one is greater than the average value of the boost pressure fluctuation correction coefficient two and less than the average value of the boost pressure fluctuation correction coefficient one, and the preset value two is greater than the average value of the engine torque fluctuation correction coefficient two and less than the average value of the engine torque fluctuation correction coefficient one, then the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the previously updated minimum EGR rate filtering time self-learning correction coefficient minus 0.1.

[0072] If the preset value 1 is less than the average value 2 of the boost pressure fluctuation correction coefficient and greater than the average value 1 of the boost pressure fluctuation correction coefficient, and the preset value 2 is less than the average value 2 of the engine torque fluctuation correction coefficient and greater than the average value 1 of the engine torque fluctuation correction coefficient, then the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the previously updated minimum EGR rate filtering time self-learning correction coefficient plus 0.12.

[0073] In other cases that satisfy condition two, the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the previously updated minimum EGR rate filtering time self-learning correction coefficient.

[0074] A computer-readable storage medium having a computer program stored thereon, the computer program including executable instructions that, when executed by a processor, implement the engine performance improvement control method described above based on improving aging losses.

[0075] The beneficial effects of this invention are:

[0076] This invention optimizes the minimum EGR rate, the range of regions where the EGR rate enters the minimum EGR rate, and the method for determining the EGR enable condition, thereby reducing the oscillation probability of the control actuator, improving the EGR system, and enhancing the system's stability. Attached Figure Description

[0077] Figure 1 This is a flowchart of a method according to an embodiment of the present invention;

[0078] Figure 2 This is a schematic diagram of a system structure with EGR according to another embodiment of the present invention.

[0079] In the diagram, 1-air filter; 2-mixing valve; 3-compressor; 4-throttle body; 5-engine; 6-turbine; 7-catalyst; 8-particulate matter trap; 9-EGR cooler; 10-EGR valve; 11-temperature sensor; 12-differential pressure sensor. Detailed Implementation

[0080] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0081] This invention proposes a control method for improving engine performance based on mitigating aging losses, such as... Figure 1 As shown, the method specifically includes:

[0082] S1. Obtain the original value of the minimum EGR rate, and obtain the minimum EGR rate filter value based on the original value of the minimum EGR rate.

[0083] Minimum EGR rate original value r EGRRateMinRaw Specifically, the minimum EGR rate obtained in patent CN202211212260.6, "Method, Apparatus, Equipment and Storage Medium for Adjusting Minimum EGR Rate", can be used as the original value of the minimum EGR rate.

[0084] Minimum EGR rate filter value rEGRRateMinFilt The calculation method is as follows:

[0085]

[0086] Where, r EGRRateMinFilt (z) is the minimum EGR rate filter value obtained in the previous sampling period, and its default value is equal to the original minimum EGR rate value r at the same time. EGRRateMinRaw ;T EGRRateMinFilter Δt is the minimum EGR rate filtering time; Δt is the sampling period interval.

[0087] Among them, the minimum EGR rate filtering time T EGRRateMinFilter The calculation method is as follows:

[0088] When the following preset conditions are met: r TrqErr or r BoostErr When T is not equal to 1, EGRRateMinFilter =T0×r Tr q E rr×r B oost E rr×(1+r A dapt)

[0089] In other cases, T EGRRateMinFilter =T0

[0090] Where T0 is the preset period, which is 0.04s in this example; r BoostErr r is the boost pressure fluctuation correction factor; TrqErr r is the engine torque ripple correction factor. Adapt This is the self-learning correction coefficient for the minimum EGR rate filter time. Its default value is 0, and it can be saved after the vehicle is powered off.

[0091] The boost pressure fluctuation correction coefficient is determined based on the difference between the boost pressure difference and the boost pressure difference filter value.

[0092] p BoostErrFilter (N)=K BoostErr ×[p BoostErr (N)-p BoostErrFilter [(N-1)]+p BoostErrFilter (N-1)

[0093] Where, p BoostErr The boost pressure difference (i.e., the difference between the target boost pressure and the actual boost pressure, which is 0 by default when the boost closed-loop control is not enabled), p BoostErr (N) represents the boost pressure difference during the Nth sampling period, p BoostErrFilter p represents the boost pressure difference after first-order low-pass filtering. B oost E rrF ilter(N) is the filtered boost pressure difference after the Nth sampling period, p BoostErrFilter (N-1) represents the pressure difference during the (N-1)th sampling period, where N = 1, 2, 3…, and p BoostErrFilter (0) equals the pressure difference p during the 0th sampling period. BoostErr (0), which occurs when the vehicle is powered on; the sampling period interval is 10ms in this example; K BoostErr For coefficients, Where m is the number of engine cylinders, n is the engine speed, and k BoostErr The boost pressure difference filter coefficient is 0.03 in this example, and the engine has 4 cylinders. BoostErr The calibration speed is 1000 rpm. The purpose of this setting is normalization. No special calibration is needed for different numbers of cylinders and engine speeds; only the 4-cylinder engine and the k-type engine at 1000 rpm require calibration. BoostErr This reduces calibration testing work.

[0094] Obtain the filter value p of the boost pressure difference BoostErrFilter Then, make a judgment Does the continuous satisfaction time exceed the preset value t1? If the continuous satisfaction time does not exceed t1, then r BoostErr The value is 1; if the continuous satisfaction time exceeds t1, then... In this embodiment, k1 is taken as 0.02, and t1 is taken as 0.08s. The results obtained from the calibration are shown in the table below:

[0095]

[0096] In other words, the filter time is not adjusted when the pressure difference of the boost pressure does not change much. Increasing the filter time is to avoid further aggravation of the boost pressure fluctuation caused by the fluctuation of the minimum EGR rate.

[0097] Engine torque fluctuation correction coefficient r TrqErr Determined based on the torque difference and the difference in torque difference filter value:

[0098]

[0099] Among them, M TrqErr M is the difference between the requested firing torque and the actual firing torque of the engine (referred to as torque difference). TrqErr (N) represents the torque difference during the Nth sampling period, M TrqErrFilter M represents the torque difference after first-order low-pass filtering. TrqErrFilter (N) represents the filtered torque difference in the Nth sampling period, M TrqErrFilter(N-1) represents the filtered torque difference in the (N-1)th sampling period, where N = 1, 2, 3…, and M… TrqErrFilter (0) equals the torque difference M at the 0th sampling period. TrqErr (0), which occurs when the vehicle is powered on, and the default value is 0; the sampling period interval is 10ms in this example; K TrqErr For coefficients, Where m is the number of engine cylinders, n is the engine speed, and in this example, the engine has 4 cylinders. TrqErr The calibration speed is 1000 rpm, k TrqErr This is the torque difference filtering coefficient; in this example, it is set to 0.08.

[0100] Obtain the torque difference filter value M TrqErrFilter Then, make a judgment Does the continuous satisfaction time exceed the preset value t2? If the continuous satisfaction time does not exceed t2, then r TrqErr The value is 1; if the continuous satisfaction time exceeds t1, then... In this embodiment, k2 is taken as 0.03, and t2 is taken as 0.05s. The results obtained from the calibration are shown in the table below:

[0101]

[0102] Finally, the minimum EGR rate filter value r is... EGRRateMinFilt The setting is forced to be between 0.03s and 0.3s to avoid excessive adjustment.

[0103] Minimum EGR rate filtering time self-learning correction coefficient r Adapt Update when the following preset conditions are met:

[0104] Default scenario 1:

[0105] When the following conditions are met:

[0106] EGR closed-loop enable is enabled, and the EGR closed-loop enable time does not exceed the preset time, which is 0.1s in this example;

[0107] r BoostErr >k1 continuously satisfies the preset value t1 for a period of time.

[0108] r TrqErr >k2 continuously satisfies the preset value t2 for a longer period of time;

[0109] The difference between the target EGR rate and the current minimum EGR rate shall not exceed a preset value, which is 0.01 in this embodiment;

[0110] The cumulative mileage of the engine whose self-learning coefficient has not been updated exceeds the preset value, which is 20,000 kilometers in this example.

[0111] After all the above conditions are met, read the average absolute value r of the ratio of the difference between the target EGR rate and the actual EGR rate to the target EGR rate within a certain period of time after the EGR closed-loop enable is activated. EGRRatioErrAvg If the following occurs:

[0112] (1)r EGRRatioErrAvg Not greater than the preset value; in this example, it is set to 0.015. f1(r BoostErr ) is r BoostErr Correction coefficient 1, f1(r) TrqErr ) is r TrqErr Correction coefficient 1, f1(r) EGRRatioErrAvg ) is r EGRRatioErrAvg Correction coefficients, where f1(r) BoostErr f1(r) TrqErr ) and f1(r EGRRatioErrAvg The result obtained from calibration is:

[0113] <![CDATA[r BoostErr ]]> 0.02 0.05 0.08 0.12 0.15 0.23 <![CDATA[f1(r BoostErr )]]> 1 1.02 1.05 1.06 1.08 1.1

[0114] <![CDATA[r TrqErr ]]> 0.03 0.05 0.08 0.12 0.14 0.16 <![CDATA[f1(r TrqErr )]]> 0.01 0.01 0.015 0.018 0.02 0.025

[0115] <![CDATA[r EGRRatioErrAvg ]]> 0 0.01 0.015 <![CDATA[f1(r EGRRatioErrAvg )]]> 0.02 0.01 0

[0116] The purpose of the above adjustments is that if the EGR rate is near the minimum EGR rate and the EGR rate fluctuation is not significant, but the boost pressure fluctuation is too large or the torque difference is too large, then it is necessary to further reduce the fluctuation of the EGR rate, that is, the EGR rate filtering time needs to be extended.

[0117] (2)r EGRRatioErrAvg If the value is greater than the preset value, in this example it is 0.05, and the value of r is recorded at this time. EGRRatioErrAvg The number of times CNT exceeds the preset value (CNT is saved after the vehicle is powered off, and its default value is 0). If CNT exceeds the preset value, in this example, it is set to 10. Furthermore, if the first condition is not met during the increase of CNT, then... Where, f2(r) BoostErr f2(r) TrqErr f2(r) and f2(r) EGRRatioErrAvg The result obtained from calibration is:

[0118] <![CDATA[r BoostErr ]]> 0.02 0.05 0.08 0.12 0.15 0.23 <![CDATA[f2(r BoostErr )]]> 1 1.02 1.05 1.06 1.08 1.1

[0119] <![CDATA[r TrqErr ]]> 0.03 0.05 0.08 0.12 0.14 0.16 <![CDATA[f2(r TrqErr )]]> 0.01 0.015 0.02 0.022 0.025 0.03

[0120]

[0121]

[0122] The purpose of the above adjustments is to mitigate the fluctuations in EGR rate when it is near the minimum EGR rate, and to reduce the fluctuations in boost pressure or torque when it is too large, thus preventing excessive fluctuations in EGR rate from affecting the stability of engine combustion.

[0123] (3) In other cases, r Adapt =r Adapt (z).

[0124] Scenario 2:

[0125] When the following conditions are met:

[0126] The time for the EGR closed-loop enable state to transition from active to inactive does not exceed a preset time. In this embodiment, the preset time is 0.05s. The condition for the EGR closed-loop enable condition to transition to inactive is that the minimum EGR rate condition for EGR closed-loop enable is not met.

[0127] The activation time of the EGR closed-loop enable state exceeds a preset time, which is 0.5s in this embodiment;

[0128] The torque fluctuation in the fire circuit is required to be within a preset range, which in this embodiment is ±2Nm;

[0129] The target boost pressure fluctuation is within a preset range, which in this embodiment is ±2kPa;

[0130] The cumulative mileage of the engine whose self-learning coefficient has not been updated exceeds the preset value, which is 20,000 kilometers in this embodiment.

[0131] After all the above conditions are met, read r during the active state time (0.2s in this example) before the EGR closed-loop enable state enters the inactive state. BoostErr Average value r BoostErrAvg1 and r TrqErr Average value r TrqErrAvg1 And r during the inactive state time (0.2s in this example) after the EGR closed-loop enable state enters the inactive state. Boost E rr Average value r BoostErrAvg2 and r Trq E rr Average value r TrqErrAvg2 If the following occurs:

[0132] (1)r BoostErrAvg1 >k1>r BoostErrAvg2 , and r TrqErrAvg1 >k2>r TrqErrAvg2 Then r A d apt =r Adapt (z)-0.1

[0133] (2)r BoostErrAvg1 <k1<r BoostErrAvg2 , and r TrqErrAvg1 <k2<r TrqErrAvg2 ,but

[0134] r Adapt =r Adapt (z)+0.12

[0135] (3) In other cases, r Adapt =r Adapt (z)

[0136] Where, r Adapt (z) is the self-learning correction coefficient r of the minimum EGR rate filter time obtained from the previous self-learning update. Adapt .

[0137] The self-learning correction coefficient r for the minimum EGR rate filtering time in this case. Adapt After the update, the new coefficients will only be used to update the minimum EGR rate filter time in the next driving cycle of the vehicle.

[0138] S2. Determine the minimum EGR rate used for EGR enable condition judgment based on the original value of the minimum EGR rate and the filtered value of the minimum EGR rate.

[0139] When meeting any special operating condition, it is necessary to achieve the EGR rate request as soon as possible, then the minimum EGR rate is equal to the original value of the minimum EGR rate;

[0140] In other cases, to further ensure the stability of EGR control, the minimum EGR rate is equal to the minimum EGR rate filter value.

[0141] The specific special operating conditions are as follows:

[0142] Special requirements, condition one:

[0143] The difference between the ignition angle efficiency and the ignition angle efficiency of the previous sampling period is within a preset range or the ignition angle efficiency exceeds a preset value. In this embodiment, the preset range is more than 0.2 but not more than 0.3, and the preset value is 0.95.

[0144] The engine did not request a fuel cut-off.

[0145] The engine did not experience any knocking or pre-ignition.

[0146] The fluctuation of the fresh air intake density of the engine does not exceed a preset range, which in this embodiment is ±35 mgpl;

[0147] When all the above conditions are met simultaneously for a continuous period of time exceeding a preset time, it indicates that special requirement condition one is met. In this embodiment, the preset time is 0.03s.

[0148] Special requirements, condition two:

[0149] If the difference between the air-fuel ratio and the air-fuel ratio of the previous sampling period exceeds a preset value, the preset value in this embodiment is 1;

[0150] The engine did not request a fuel cut-off.

[0151] The engine intake air temperature exceeds a preset value, which is 50°C in this embodiment;

[0152] The engine coolant temperature exceeds the preset value, which is 110°C in this embodiment;

[0153] When the continuous time during which all the above conditions are met exceeds the preset time, it indicates that special requirement condition two is met. In this embodiment, the preset time is 0.1s.

[0154] S3. Determine whether the minimum EGR rate condition for enabling EGR closed-loop is met based on the minimum EGR rate.

[0155] The specific EGR closed-loop enabling minimum EGR condition is as follows:

[0156] (1) When the difference between the target EGR rate and the minimum EGR rate is greater than the preset value A, the minimum EGR rate condition for EGR closed-loop is met. In this example, the preset value A is 0.02.

[0157] (2) When the difference between the target EGR rate and the minimum EGR rate is not greater than the preset 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 C, the minimum EGR rate condition for enabling EGR closed loop is not met. In this example, the preset value B is 0.01 and the preset value C is 0.1.

[0158] (3) In other cases, the minimum EGR rate condition for EGR closed-loop enable remains the same as the previous state. When the vehicle is powered on, it is in the default state, which is that the minimum EGR rate condition for EGR closed-loop enable is not met.

[0159] S4. When the minimum EGR rate condition for EGR closed-loop enable is met, determine whether EGR closed-loop is enabled based on the EGR closed-loop enable condition.

[0160] The specific EGR closed-loop enabling condition is as follows:

[0161] No faults were found in any of the components of the EGR system;

[0162] No fuel cut-off request occurred and the fuel cut-off recovery time exceeded the preset time, which is 0.3s in this embodiment;

[0163] The minimum EGR rate condition for EGR closed-loop enable is satisfied;

[0164] The engine speed is within a preset speed range, which in this embodiment is 750rpm to 5500rpm;

[0165] If the intake air temperature is within the preset range, and the current state is EGR closed-loop not enabled, then enter EGR closed-loop state, ensuring that the intake air temperature is not lower than the minimum intake air temperature by 10°C. If the current state is EGR closed-loop enabled, then exit EGR system closed-loop enabled state, ensuring that the intake air temperature is not lower than the minimum intake air temperature by 7°C. If the current state is EGR closed-loop not enabled, then enter EGR closed-loop state, ensuring that the intake air temperature does not exceed the maximum intake air temperature by 60°C. If the current state is EGR closed-loop enabled, then exit EGR system closed-loop enabled state, ensuring that the intake air temperature exceeds the maximum intake air temperature by 65°C.

[0166] If the engine coolant temperature is within the preset range, and the current state is EGR closed-loop not enabled, then enter EGR closed-loop state, ensuring that the coolant temperature is not lower than the minimum coolant temperature of 60℃. If the current state is EGR closed-loop enabled, then exit EGR system closed-loop enabled state, ensuring that the coolant temperature is lower than the minimum coolant temperature of 55℃. If the current state is EGR closed-loop not enabled, then enter EGR closed-loop state, ensuring that the coolant temperature does not exceed the maximum coolant temperature of 115℃. If the current state is EGR closed-loop enabled, then exit EGR system closed-loop enabled state, ensuring that the coolant temperature exceeds the maximum coolant temperature of 120℃.

[0167] If the atmospheric temperature is within a preset range, and the current state is EGR closed-loop not enabled, then enter EGR closed-loop state, ensuring that the temperature is not lower than the minimum atmospheric temperature by 5°C. If the current state is EGR closed-loop enabled, then exit EGR system closed-loop enabled state, ensuring that the temperature is not lower than the minimum atmospheric temperature by 3°C. If the current state is EGR closed-loop not enabled, then enter EGR closed-loop state, ensuring that the temperature does not exceed the maximum atmospheric temperature by 55°C. If the current state is EGR closed-loop enabled, then exit EGR system closed-loop enabled state, ensuring that the temperature exceeds the maximum atmospheric temperature by 60°C.

[0168] When the atmospheric pressure exceeds the preset pressure value, which is 66 kPa in this embodiment; in addition, when the atmospheric pressure is lower than 64 kPa, the EGR closed-loop enable condition is not met.

[0169] EGR closed-loop is enabled only when all of the above conditions are met; otherwise, EGR closed-loop is disabled.

[0170] 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 valve 4, an engine 5, a turbine 6, a catalytic converter 7, a particulate filter 8 connected in sequence, 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 differential pressure sensor 12 connected to the EGR valve 10 forming a branch; the two ends of the branch are respectively connected to the outlet of the particulate filter 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 to increase the differential pressure across the EGR valve 10, the engine 5 is used to compress fresh air for boosting, the turbine 6 is used to control the opening of the exhaust bypass valve, the EGR cooler 9 is used to receive and cool the exhaust gas output from the particulate filter 8 to increase the exhaust gas flow rate, the EGR valve 10 is used to control the exhaust gas flow rate 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 architecture is used to execute an EGR closed-loop exit control method based on boost control responsiveness as described in this embodiment.

[0171] This invention optimizes the minimum EGR rate, the range of regions where the EGR rate enters the minimum EGR rate, and the EGR enable condition judgment method, thereby reducing the oscillation probability of the control actuator, improving the EGR system, and enhancing the system stability.

[0172] In addition, the present invention provides a computer-readable storage medium having a computer program stored thereon, the computer program including executable instructions, which, when executed by a processor, implement the engine performance improvement control method based on improving aging losses described above.

[0173] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0174] The order of the steps in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0175] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for improving engine performance control based on mitigating aging losses, characterized in that, The method includes: Obtain the original value of the minimum EGR rate, and then obtain the minimum EGR rate filter value based on the original value of the minimum EGR rate; The minimum EGR rate used for EGR enable condition determination is determined based on the original value of the minimum EGR rate and the filtered value of the minimum EGR rate. Determine whether the minimum EGR rate condition for enabling EGR closed-loop is met based on the minimum EGR rate. When the minimum EGR rate condition for EGR closed-loop enable is met, determine whether EGR closed-loop is enabled based on the EGR closed-loop enable condition. Specifically, the minimum EGR rate filter value is obtained by multiplying the difference between the original minimum EGR rate value and the minimum EGR rate filter value obtained in the previous sampling period by the sampling period interval, dividing by the minimum EGR rate filter time, and adding the minimum EGR rate filter value obtained in the previous sampling period. The minimum EGR rate filtering time is obtained in the following way: When the preset conditions are met, the minimum EGR rate filtering time is equal to the sum of the minimum EGR rate filtering time self-learning correction coefficient and 1, multiplied by the product of the boost pressure fluctuation correction coefficient, the engine torque fluctuation correction coefficient, and the preset filtering time. In other cases, the minimum EGR rate filtering time is equal to the preset filtering time; The boost pressure fluctuation correction coefficient is determined based on the original value of the boost pressure difference and the filtered value of the boost pressure difference. If the absolute value of the difference between the boost pressure difference filter value and the boost pressure difference, divided by the minimum value among the original boost pressure difference value, the boost pressure difference filter value, and the preset value, is greater than a certain value for a continuous period of time, then the boost pressure fluctuation correction coefficient is obtained by calibration; otherwise, the boost pressure fluctuation correction coefficient is equal to 1.

2. The engine performance improvement control method based on improving aging losses according to claim 1, characterized in that, The preset conditions are specifically as follows: The engine torque fluctuation correction factor or boost pressure fluctuation correction factor is not equal to 1.

3. The engine performance improvement control method based on improving aging losses according to claim 1, characterized in that, The engine torque fluctuation correction coefficient is determined based on the torque difference and the torque difference filter value; the torque difference is the difference between the engine's requested firing torque and the actual firing torque. If the absolute value of the difference between the torque difference filter value and the torque difference, divided by the minimum value among the torque difference, the torque difference filter value, and the preset value, is greater than a certain value for more than a preset time, then the engine torque fluctuation correction coefficient is obtained by calibration; otherwise, the engine torque fluctuation correction coefficient is equal to 1.

4. The engine performance improvement control method based on improving aging losses according to claim 1, characterized in that, The specific determination of the minimum EGR rate used for EGR enable condition judgment is as follows: When any special operating condition is met, the minimum EGR rate is equal to the original value of the minimum EGR rate. In other cases, the minimum EGR rate is equal to the minimum EGR rate filter value; The specific special operating conditions are as follows: Special requirements, condition one: The difference between the ignition angle efficiency and the ignition angle efficiency of the previous sampling period is within a preset range or the ignition angle efficiency exceeds a preset value. The engine did not request a fuel cut-off. The engine did not experience any knocking or pre-ignition. The fluctuation of the engine's fresh air intake density does not exceed the preset range; When all the above conditions are met simultaneously for a continuous period of time exceeding the preset time, it indicates that special requirement condition one is met; Special requirements, condition two: The difference between the air-fuel ratio and the air-fuel ratio in the previous sampling period exceeds a preset value; The engine did not request a fuel cut-off. The engine intake air temperature exceeds the preset value; The engine coolant temperature exceeds the preset value; When the continuous time during which all the above conditions are met exceeds the preset time, it indicates that special requirement condition two is met.

5. The engine performance improvement control method based on improving aging losses according to claim 1, characterized in that, The determination of whether the minimum EGR rate enables the EGR closed-loop condition is met is specifically as follows: When the difference between the target EGR rate and the minimum EGR rate is greater than a preset value of one, the condition for enabling the minimum EGR rate in the EGR closed loop is met. If the difference between the target EGR rate and the minimum EGR rate is not greater than the preset 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 3, then the minimum EGR rate condition for enabling EGR closed loop is not met. In other cases, the minimum EGR rate condition for EGR closed-loop enable remains in the previous state, with the default state being when the vehicle is powered on, where the minimum EGR rate condition for EGR closed-loop enable is not met.

6. The engine performance improvement control method based on improving aging losses according to claim 1, characterized in that, The specific steps for determining whether EGR closed-loop is enabled, based on the EGR closed-loop enable condition, are as follows: No faults were found in any of the components of the EGR system; No fuel cut-off request was received and the fuel cut-off recovery time exceeded the preset time; The minimum EGR rate condition for EGR closed-loop enable is satisfied; The engine speed is within the preset speed range; Intake air temperature is within the preset range; Engine coolant temperature is within the preset range; Atmospheric temperature is within the preset range; Atmospheric pressure exceeds the preset pressure value.

7. The engine performance improvement control method based on improving aging losses according to claim 1, characterized in that, The minimum EGR rate filtering time self-learning correction coefficient is obtained in the following way: The minimum EGR rate filtering time self-learning correction coefficients are updated when any of the following conditions are met: Scenario 1: EGR closed-loop enable, and the EGR closed-loop enable time does not exceed the preset time; The continuous time during which the boost pressure fluctuation correction coefficient exceeds a certain value exceeds the preset time; The engine torque fluctuation correction coefficient is greater than a certain value for more than a preset time. The difference between the target EGR rate and the current minimum EGR rate shall not exceed a preset value; The cumulative mileage of the engine whose self-learning coefficient has not been updated exceeds the preset value; If all of the above conditions are met, it indicates that condition one is satisfied; Scenario 2: The time for the EGR closed-loop enabled state to transition from the active to the inactive state does not exceed a preset time. The activation time of the EGR closed-loop enable state exceeds the preset time. Request that the fluctuation of the fire circuit torque be within the preset range; The target boost pressure fluctuation is within the preset range; The cumulative mileage of the engine whose self-learning coefficient has not been updated exceeds the preset value; When the minimum EGR rate condition for EGR closed-loop enable is not met, the EGR closed-loop enable state enters the inactive state. If all the above conditions are met, it indicates that condition two is satisfied.

8. The engine performance improvement control method based on improving aging losses according to claim 7, characterized in that, When condition one is met, read the average value of the absolute value of the ratio of the difference between the target EGR rate and the actual EGR rate to the target EGR rate within a certain period of time after the EGR closed-loop enable is activated. If the average value is not greater than the preset value, the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the sum of the previously updated minimum EGR rate filtering time self-learning correction coefficient and the change value. If the average value is greater than the preset value, record the number of times the average value is greater than the preset value. If the number of times the average value is greater than the preset value is greater than the preset number, and no condition one is met during the increase of the number, then the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the difference between the previously updated minimum EGR rate filtering time self-learning correction coefficient and the change value. In other cases where condition one is satisfied, the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the previously updated minimum EGR rate filtering time self-learning correction coefficient. When condition two is met, read the average value of the boost pressure fluctuation correction coefficient and the average value of the engine torque fluctuation correction coefficient during the activation period before the EGR closed-loop enable state enters the inactive state, and read the average value of the boost pressure fluctuation correction coefficient and the average value of the engine torque fluctuation correction coefficient during the inactive period after the EGR closed-loop enable state enters the inactive state. If the preset value one is greater than the average value of the boost pressure fluctuation correction coefficient two and less than the average value of the boost pressure fluctuation correction coefficient one, and the preset value two is greater than the average value of the engine torque fluctuation correction coefficient two and less than the average value of the engine torque fluctuation correction coefficient one, then the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the previously updated minimum EGR rate filtering time self-learning correction coefficient minus 0.

1. If the preset value 1 is less than the average value 2 of the boost pressure fluctuation correction coefficient and greater than the average value 1 of the boost pressure fluctuation correction coefficient, and the preset value 2 is less than the average value 2 of the engine torque fluctuation correction coefficient and greater than the average value 1 of the engine torque fluctuation correction coefficient, then the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the previously updated minimum EGR rate filtering time self-learning correction coefficient plus 0.

12. In other cases that satisfy condition two, the updated minimum EGR rate filtering time self-learning correction coefficient is equal to the previously updated minimum EGR rate filtering time self-learning correction coefficient.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program includes executable instructions that, when executed by a processor, implement the engine performance improvement control method based on improving aging losses as described in any one of claims 1-8.

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