CN115680915B - Method, device, equipment and storage medium for designing minimum EGR rate - Google Patents
Method, device, equipment and storage medium for designing minimum EGR rate Download PDFInfo
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Abstract
The invention discloses a design method, a device, equipment and a storage medium for minimum EGR rate, wherein the method comprises the following steps: determining a basic minimum EGR rate according to the engine speed and the load; and determining the original minimum EGR rate and taking the original minimum EGR rate as the minimum EGR rate according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel vapor entering the cylinder from the carbon tank, the engine rotating speed and the basic minimum EGR rate. The beneficial effects are that: the EGR can be closed when the EGR rate is extremely low, so that the influence on the stability of an EGR system is avoided, and meanwhile, the software development cost can be reduced.
Description
Technical Field
The present invention relates to the field of engine technologies, and in particular, to a method, an apparatus, a device, and a storage medium for designing a minimum EGR rate.
Background
Research shows that the EGR system has certain advantages in improving emission, reducing oil consumption and improving anti-knock capability. The EGR exhaust gas reduces the combustion temperature, avoids knocking, and suppresses the ignition advance retardation. The control actuator can oscillate due to the excessively low system hysteresis EGR rate, and even the EGR system is unstable; and if the EGR rate is too low, great requirements are put on the control capability of the EGR system; even an EGR rate that is too low may not exhibit its advantages. Based on the method, a design method of minimum EGR rate is provided, and EGR is closed when the EGR rate is extremely low, so that the influence on the stability of an EGR system is avoided, and meanwhile, the software development cost can be reduced.
Disclosure of Invention
In view of the above-mentioned drawbacks or improvements of the prior art, it is an object of the present invention to provide a method, apparatus, device and storage medium for designing a minimum EGR rate.
To achieve the purpose, the invention adopts the following technical scheme:
In a first aspect, a method for designing a minimum EGR rate includes the steps of:
Determining a basic minimum EGR rate according to the engine speed and the load;
And determining the original minimum EGR rate and taking the original minimum EGR rate as the minimum EGR rate according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel vapor entering the cylinder from the carbon tank, the engine rotating speed and the basic minimum EGR rate.
In one embodiment, the step of determining the original minimum EGR rate and serving as the minimum EGR rate based on the barometric pressure, the water temperature, the number of engine combustions, the barometric temperature, the real-time water temperature of the engine, the engine start water temperature, the engine intake air temperature, the mass and flow of fuel vapor from the canister into the cylinder, the engine speed, and the base minimum EGR rate comprises:
determining a first multiplication factor r 1 according to the atmospheric pressure and the water temperature;
Determining a second multiplication factor r 2 according to the engine combustion times and the atmospheric temperature;
determining a third multiplication factor r 3 according to the real-time water temperature of the engine and the starting water temperature of the engine;
Determining a fourth multiplication factor r 4 according to the real-time water temperature of the engine and the air inlet temperature of the engine;
and determining a fifth multiplication factor r 5 according to the mass and flow of fuel vapor entering the cylinder by the carbon tank and the engine speed.
In one embodiment, the raw minimum EGR rate r EGRVehicleMin is obtained according to the following equation:
rEGRVehicleMin＝rEGRBenchMin·(1+r1)·(1+r2)·(1+r3)·(1+r4)·(1+r5)；
wherein r EGRBenchMin represents the base minimum EGR rate.
In one embodiment, the method for designing the minimum EGR rate further includes performing a self-learning update when the engine operating condition is stable:
After the update stage of self-learning update is determined, according to a target average value rho DsrdAvg of the fresh air intake density of the cylinder, an average value rho ActFilterAvg of the filtering value of the fresh air intake density of the actual cylinder, a target air-fuel ratio r DsrdAFRavg and an average value r AFRFilterAvg of the filtering value of the actual air-fuel ratio, under the current working condition, updating the initial value of the learning value;
Determining a new minimum EGR rate learning value according to the learning value initial value and the last minimum EGR rate learning value under the same working condition;
and determining a final minimum EGR rate according to the current original minimum EGR rate and the new minimum EGR rate learning value.
In one embodiment, after the self-learning update stage is determined, the step of updating the learning value initial value according to the target average rho DsrdAvg of the intake air charge density of the fresh air in the cylinder, the average rho ActFilterAvg of the filtering value of the intake air charge density of the fresh air in the actual intake air in the cylinder, the target air-fuel ratio r DsrdAFRavg and the average r AFRFilterAvg of the filtering value of the actual air-fuel ratio under the current working condition includes:
Determining a first judgment value according to a target average value rho DsrdAvg of the fresh air intake density of the cylinder and an average value rho ActFilterAvg of the actual fresh air intake density filtering value of the cylinder under the current working condition;
Determining a second judgment value according to the target air-fuel ratio r DsrdAFRavg and an average value r AFRFilterAvg of the actual air-fuel ratio filtering values;
And determining the initial value of the learning value according to the first judging value and the second judging value.
In one embodiment, the first judgment value C 1 is obtained according to the following formula:
The second judgment value C 2 is determined according to the following formula:
In one embodiment, the method further comprises the following steps before entering the self-learning update stage:
determining that an activation condition is met according to the engine and the EGR system;
And after the activation condition is met, entering a stabilization stage, and when the stabilization stage meets a time length condition and the self-learning times are not updated, entering the updating stage.
In a second aspect, a minimum EGR rate designing apparatus includes:
a first module for determining a base minimum EGR rate based on engine speed and load;
And the second module is used for determining the original minimum EGR rate and taking the original minimum EGR rate as the minimum EGR rate according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel vapor entering the cylinder from the carbon tank, the engine rotating speed and the basic minimum EGR rate.
In a third aspect, an electronic device comprises a processor and a memory, the processor and the memory being interconnected;
The memory is used for storing a computer program;
The processor is configured to execute the design method of the minimum EGR rate as described above when the computer program is invoked.
In a fourth aspect, a computer-readable storage medium stores a computer program that is executed by a processor to implement the method of designing a minimum EGR rate described above.
The invention has the beneficial effects that:
For a design method of the minimum EGR rate, determining a basic minimum EGR rate according to the engine speed and the load; according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel steam entering the cylinder from the carbon tank, the engine speed and the basic minimum EGR rate, the original minimum EGR rate is determined and used as the minimum EGR rate, and the EGR can be closed when the EGR rate is extremely small, so that the influence on the stability of an EGR system is avoided, and meanwhile, the software development cost is lower.
For a design device of the minimum EGR rate, determining a basic minimum EGR rate according to the engine speed and the load; according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel steam entering the cylinder from the carbon tank, the engine speed and the basic minimum EGR rate, the original minimum EGR rate is determined and used as the minimum EGR rate, and the EGR can be closed when the EGR rate is extremely small, so that the influence on the stability of an EGR system is avoided, and meanwhile, the software development cost is lower.
For the electronic equipment, determining a basic minimum EGR rate according to the engine speed and the load; according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel steam entering the cylinder from the carbon tank, the engine speed and the basic minimum EGR rate, the original minimum EGR rate is determined and used as the minimum EGR rate, and the EGR can be closed when the EGR rate is extremely small, so that the influence on the stability of an EGR system is avoided, and meanwhile, the software development cost is lower.
Determining a base minimum EGR rate based on engine speed and load for a computer readable storage medium; according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel steam entering the cylinder from the carbon tank, the engine speed and the basic minimum EGR rate, the original minimum EGR rate is determined and used as the minimum EGR rate, and the EGR can be closed when the EGR rate is extremely small, so that the influence on the stability of an EGR system is avoided, and meanwhile, the software development cost is lower.
Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application.
Drawings
The foregoing and/or additional aspects and advantages of the application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a schematic configuration diagram of a low-pressure EGR system provided in the present embodiment;
fig. 2 is a flow chart of a design method of the minimum EGR rate provided in the present embodiment.
Fig. 3 is a schematic structural view of a design device for a minimum EGR rate provided in the present embodiment;
fig. 4 is a schematic structural diagram of the electronic device of the present embodiment.
Detailed Description
The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.
In the description of the present invention, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless expressly stated otherwise, as understood by those skilled in the art. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood by those skilled in the art that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs unless defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
The invention provides a design method of a minimum EGR rate, which is applied to a low-pressure EGR system.
Fig. 1 is a schematic diagram of a low pressure EGR system provided in this embodiment, and as shown in fig. 1, the system includes an air filter, a booster compressor, a throttle valve, an engine, a booster turbine, a catalyst, a particulate matter trap, an EGR cooler, an EGR valve, an EGR temperature sensor, an EGR differential pressure sensor, a flow meter, and a linear oxygen sensor, and it is noted that the linear oxygen sensor is replaced with an integrated temperature and pressure sensor.
The booster compressor is used for compressing fresh air for boosting.
The turbocharger turbine controls the working efficiency of the turbine by controlling the opening of the wastegate valve of the turbocharger, thereby realizing different supercharging capacities.
The low pressure EGR system has increased parts relative to non-low pressure EGR systems: an EGR cooler, an EGR temperature sensor, an EGR valve, an EGR differential pressure sensor, a mixing valve, a flow meter, and an oxygen sensor.
A flow meter is mounted between the air filter and the mixing valve for detecting the flow of fresh air into the engine.
The mixing valve is used for adjusting the pressure of an outlet of the EGR valve, improving the pressure difference of two ends of the EGR valve and improving the EGR rate.
An oxygen sensor is mounted between the compressor and the throttle valve and is adjacent to the throttle valve, the oxygen sensor being for detecting the flow of the mixture into the cylinder.
The EGR cooler is used to cool the exhaust gases in order to increase the flow of exhaust gases and to reduce the temperature of the exhaust gases.
The EGR valve acts as a throttle to control the flow of exhaust gas into the cylinder.
The EGR temperature sensor is used to detect the temperature of exhaust gas entering the EGR valve.
The EGR pressure difference sensor is used to detect a difference in exhaust gas pressure between both sides of EGR.
When the engine enters an EGR rate closed-loop control activation state, the EGR rate control adopts PID control.
Fig. 2 is a flow chart of a design method of the minimum EGR rate provided in the present embodiment.
As shown in FIG. 2, the method includes determining a base minimum EGR rate based on engine speed and load S100.
It should be noted that, the basic minimum EGR rate is obtained by calibrating the engine on the bench, the calibration is based on infinitely decreasing the EGR rate under the condition that the EGR system is turned on (until the fluctuation of the engine speed is not less than ±30rpm under the steady-state condition, or the fluctuation of the actual opening degree of the EGR valve exceeds ±1.5%, the EGR rate is stopped to be continuously decreased, the current EGR rate is recorded), by comparing the EGR rate-free condition under the same condition with the EGR rate recorded before, if the EGR rate on-state fuel consumption is not more than 0.2%, the minimum EGR rate is increased until the EGR rate on-state fuel consumption is more than 0.2%, and the EGR rate at this time is taken as the minimum EGR rate.
The determination based on the engine speed and load (intake air density of fresh air into the cylinder) was obtained together according to the above test method, as shown in table 1.
TABLE 1
It should be noted that, in table 1, the basic minimum EGR rate equal to 0 represents that the EGR system itself is not activated under the condition, which is determined in part by the engine combustion stability, knocking, and the like, and the basic minimum EGR rate equal to 0 represents the minimum EGR rate of the EGR system under the condition.
Step S100 is followed by step S200 of determining an original minimum EGR rate and using the original minimum EGR rate as the minimum EGR rate according to the atmospheric pressure, the water temperature, the number of times of engine combustion, the atmospheric temperature, the real-time water temperature of the engine, the starting water temperature of the engine, the air inlet temperature of the engine, the mass flow of fuel vapor entering the cylinder from the carbon tank, the engine speed and the basic minimum EGR rate.
Specifically, step S200 includes:
A first multiplication factor r 1 is determined from the barometric pressure and the water temperature. It will be appreciated that the lower the atmospheric pressure or lower the water temperature, i.e. the leaner the air or lower the mixture temperature/poorer the atomization results in poorer engine combustion stability, and that an increase in the minimum EGR rate is required to reduce the impact on engine combustion stability and avoid abnormal engine shake.
And determining a second multiplication factor r 2 according to the engine combustion times and the atmospheric temperature. The number of engine combustions is the sum of the number of cylinder ignitions from the start of engine start.
It will be appreciated that the lower the number of combustions or the lower the atmospheric temperature, the poorer the engine combustion stability and the need to increase the minimum EGR rate to reduce the impact on the engine combustion stability and avoid abnormal engine shake.
And determining a third multiplication factor r 3 according to the real-time water temperature of the engine and the starting water temperature of the engine. It will be appreciated that the lower the real-time water temperature or the lower the engine start water temperature, the poorer the engine combustion stability, and the minimum EGR rate needs to be increased to reduce the impact on the engine combustion stability, avoiding abnormal engine shake.
And determining a fourth multiplication factor r 4 according to the real-time water temperature of the engine and the air inlet temperature of the engine. It will be appreciated that the lower the real-time water temperature or the lower the engine intake temperature, the poorer the engine combustion stability, and the minimum EGR rate needs to be increased to reduce the impact on the engine combustion stability, avoiding abnormal engine shake.
And determining a fifth multiplication factor r 5 according to the mass and flow of fuel vapor entering the cylinder by the carbon tank and the engine speed. It will be appreciated that the lower the engine speed, the worse the engine combustion stability, the higher the mass flow of fuel vapor into the cylinder from the canister, and the lower the impact on the engine combustion stability, requiring an increase in the minimum EGR rate, avoiding abnormal engine shake.
The first, second, third, fourth and fifth multiplication factors are identified according to the current working condition of the engine to improve combustion stability in the EGR control process; the first to fifth multiplication factors are determined by using a prior art scheme based on the above concept under severe engine working conditions (such as too small temperature and pressure signals, poor engine combustion, carbon tank flow interference and the like, and the minimum EGR rate needs to be improved to improve combustion stability, and the engine combustion condition is better after the temperature is increased, and the minimum EGR rate is reduced to improve the EGR benefit).
All five multiplication factors (all are values greater than or equal to 1) are determined by ensuring that the combustion stability evaluation index COV of the engine is within + -3%.
The raw minimum EGR rate r EGRVehicleMin is obtained according to the following formula:
rEGRVehicleMin＝rEGRBenchMin·(1+r1)·(1+r2)·(1+r3)·(1+r4)·(1+r5)；
Where r EGRBenchMin denotes the base minimum EGR rate.
After step S200, when the engine working condition is stable, self-learning updating of the minimum EGR rate is performed to ensure the accuracy of self-learning.
In this embodiment, the activation condition of self-learning needs to be satisfied:
1. the engine is in an operating state;
2, the EGR system is in a closed-loop control activation state;
3. The difference between the current actual EGR rate and the minimum EGR rate (the original minimum EGR rate of the whole vehicle if the current EGR rate is not learned, and the learned minimum EGR rate is taken if the current EGR rate is learned) is not more than a preset range, and the difference is taken to be +/-0.02% in the embodiment;
4. the difference between the actual EGR rate and the target EGR rate does not exceed the preset range, which is + -1% in this example
5. The carbon canister is unopened;
6. the engine speed is within a certain range, 600rpm to 5900rpm is taken in the example, the fluctuation of the engine speed which enters the ignition angle self-learning of the EGR rate is small, and + -15 rpm is taken in the example;
7. The load (fresh air intake density of the entering cylinder) is in a certain range, the example takes 200mgpl to 3000mgpl, the load fluctuation of the self-learning ignition angle of the entering EGR rate is small, and the example takes + -20 mgpl;
8. the actual EGR rate is in a certain range, and the fluctuation of the actual EGR rate entering the self-learning of the minimum EGR rate is smaller, and the actual EGR rate is + -1% in the embodiment;
9. The engine water temperature is in a certain range (0 ℃ to 100 ℃ in this example), and the actual EGR rate fluctuation of the ignition angle self-learning of the entering EGR rate is small, and + -2 ℃ in this example. ;
10. the intake air temperature is in a certain range (30 to 80 ℃ in this example), and the actual EGR rate fluctuation of the ignition angle self-learning of the intake EGR rate is small, and 1.5 ℃ in this example. ;
11. the deviation of the target intake VVT angle from the actual exhaust VVT angle is within a preset range, which takes + -0.5 DEG in this example;
12. The deviation of the target exhaust VVT angle from the actual exhaust VVT angle is within a preset range, which takes + -0.5 DEG in this example;
13. The fluctuation of the firing angle efficiency is small, and the sample is + -0.05.
14. Knocking and pre-ignition did not occur.
15. The fluctuation of the atmospheric pressure is small, and the sample is + -0.02 kPa.
16. Heating the oxygen sensor is completed;
17. The density fluctuation of fresh air intake of a target entering cylinder is small, and 10mgpl is taken in the example
18. The difference between the fresh air inlet density of the target inlet cylinder and the fresh air inlet density of the actual inlet cylinder is not more than a preset range, and 15+/-mgpl is taken in the embodiment;
19. the fluctuation of the target air-fuel ratio is small, this example takes + -0.08;
20. the difference between the target air-fuel ratio and the actual air-fuel ratio does not exceed a preset range, which is + -0.1 in this example;
21. no malfunction of the fuel injection system or of the related components or functions of the air intake system occurs.
If either condition is not met, the step of the design method of the minimum EGR rate will be stopped, assuming that the activation condition is not met.
After the activation condition is satisfied, the method is regarded as entering a stabilization stage, and the purpose of the stabilization stage is to ensure the stability and reliability of the subsequent self-learning. The stabilization phase is maintained for a time period exceeding T0 (in this embodiment, T0 is set to 5 s), and at the same time, the minimum EGR rate is not updated for the period of T1, and the activation phase is entered.
In the activation phase, the total engine speed, the total intake air temperature, the total water temperature, the total intake VVT angle, the total ignition efficiency, the total actual EGR rate, the total target intake cylinder fresh air intake density, the total actual intake cylinder fresh air intake density filter value, the total target air-fuel ratio, and the total actual air-fuel ratio filter value are accumulated for a certain period T2 (3 s in the present embodiment).
Wherein the actual in-cylinder fresh air intake density filter value rho ActFilter is calculated according to the following formula:
rhoActFilter＝KRho×[rhoActRaw(N)-rhoActFilter(N-1)]+rhoActFilter(N-1)；
Wherein rho ActRaw (N) represents the actual in-cylinder fresh air intake density raw value of the nth sampling period, rho ActFilter represents the actual in-cylinder fresh air intake density after the first-order low-pass filtering (i.e., the actual in-cylinder fresh air intake density filtered value), and rho ActFilter (N-1) is the actual in-cylinder fresh air intake density filtered value of the nth-1 sampling period, n=1, 2,3 …. Note that rho ActFilter (0) represents the actual in-cylinder fresh air intake density original value immediately after the activation phase; the sampling period interval is set to 10ms.
K Rho is a coefficient that is determined from the number of engine cylinders m, the engine speed n, and the fresh air amount filter coefficient K Rho according to the following formula:
KRho＝m·n·kRho/4000；
The number of engine cylinders is 4, the engine speed is 1000rpm, k Rho is 0.02, and the purpose of the arrangement is to perform normalization processing, and only the 4-cylinder engine and the k Rho with the speed of 1000rpm are required to be calibrated without special calibration under different cylinder numbers and speeds, so that calibration test work is reduced.
The actual air-fuel ratio filter value r AFRFilter is obtained according to the following formula:
rAFRFilter(N)＝KAFR·[rAFRRaw(N)-rAFRFilter(N-1)]+rAFRFilter(N-1)；
Where r AFRRaw is the actual air-fuel ratio raw value, r AFRRaw (N) is the actual air-fuel ratio raw value of the nth sampling period, r AFRFilter is the actual air-fuel ratio after the first-order low-pass filtering (i.e., the actual air-fuel ratio filtered value), r AFRFilter (N) is the actual air-fuel ratio filtered value of the nth sampling period, r AFRFilter (N-1) is the actual air-fuel ratio degree filtered value of the nth-1 sampling period, n=1, 2, 3 … …, r AFRFilter (0) is the actual air-fuel ratio raw value immediately after entering the self-learning activation phase, and K AFR is the coefficient, in this embodiment, K AFR＝m·n·kAfr/4000, where K Afr depends on the engine actual entering cylinder fresh air intake density filtered value rho ActFilter.
In this embodiment, when the actual intake air density filtering values of the fresh air of the engine entering the cylinders are 300, 500, 700, 1000, 1500, 2000, 2500 and 3000, respectively, the corresponding k Afr is 0.15, 0.17, 0.18, 0.2, 0.21, 0.23, 0.24 and 0.25, respectively. In this embodiment kAfr is set to 0.023.
After T2, the update phase is entered. After the update phase, the design method further comprises the steps of:
updating the initial value of the learning value according to the target average value rho DsrdAvg of the fresh air intake density of the cylinder, the average value rho ActFilterAvg of the filtering value of the fresh air intake density of the actual cylinder, the target air-fuel ratio r DsrdAFRavg and the average value r AFRFilterAvg of the filtering value of the actual air-fuel ratio under the current working condition;
Determining a new minimum EGR rate learning value according to the learning value initial value and the last minimum EGR rate learning value under the same working condition;
and determining a final minimum EGR rate according to the current original minimum EGR rate and the new minimum EGR rate learning value.
The minimum EGR rate for each condition is stored in the non-volatile memory EEPROM. There will be an initial default value in EEPROM that is 1. The stored value in the EEPROM is updated after the minimum EGR rate self-learning is completed.
The number of times of the self-learning stabilization stage (1 is added after each satisfaction) under the corresponding working condition does not exceed the preset number of times, and when the example takes 30 times, the minimum EGR rate learning value maintains the last learning value. Otherwise, updating is carried out.
The engine speed average n Avg, the intake air temperature average T ManAvg, the water temperature average T coolantAvg, the intake VVT angle average phi IntakeVVTAvg, the ignition efficiency average r SparkEffAg, the target intake cylinder fresh air intake air density average rho DsrdAvg, the target air-fuel ratio r DsrdAFRAvg, the actual intake cylinder fresh air intake air density filter value average rho ActFilterAvg, the actual air-fuel ratio filter value average r AFRFilterAvg, the actual EGR rate average r ActEGRAvg after the update period T2 (80 s in this embodiment) is entered, and are stored in the EEPROM.
C 1 is determined according to the following formula:
C 2 is determined according to the following formula:
if neither C 1 nor C 2 is less than 0.05, the learning value initial value r EGRMinAdaptRaw is 1.02.
If C 1 is not less than 0.05 and C 2 is between 0.02 and 0.05, the learning value initial value r EGRMinAdaptRaw is 1.01.
If C 1 is between 0.02 and 0.05, and C 2 is not less than 0.05, the learning value initial value r EGRMinAdaptRaw is 1.05.
If both C 1 and C 2 are between 0.02 and 0.05, the learned value initial value r EGRMinAdaptRaw is 1.02.
If neither C 1 nor C 2 is greater than 0.02, the learning value initial value r EGRMinAdaptRaw is 1.02.
The purpose of such design is that after the EGR rate is introduced, the air quantity and the air-fuel ratio fluctuate greatly, and the minimum EGR rate needs to be further improved when the dynamic property and the emission influence are large; if only the fluctuation of the air quantity is increased, but the increase of the air-fuel ratio is smaller, the influence on the air quantity is large after the introduction of the EGR rate, the influence on the dynamic property is poor, and the minimum EGR rate is required to be moderately improved; if only the fluctuation of the air-fuel ratio is increased, but the fluctuation of the air quantity is smaller, the condition that the interference on the air quantity is smaller after the introduction of the EGR rate is shown, the influence on the dynamic property is weaker, at the moment, the minimum EGR rate needs to be properly improved, the influence on the emission is avoided, and the emission can be further protected through an exhaust system, so that the improvement of the minimum EGR rate is not larger than the improvement of the minimum EGR rate with the large fluctuation of the air quantity at the moment; if the introduced EGR has less effect on both the amount of air and the air-fuel ratio fluctuation, there is no need to increase the minimum EGR rate.
In addition to the above, the learning value initial value r EGRMinAdaptRaw is 1.
The final minimum EGR rate learned value rEGRMinAdapt and limiting it to within the learned values minimum value 1 and maximum value 1.08 (avoiding exceeding the target EGR rate) results in:
r EGRMinAdapt＝rEGRMinAdapt(z)×(1+rEGRMinAdaptRaw), wherein r EGRMinAdapt (z) is the minimum EGR rate learning value learned under the same condition last time, and the first default value is 1.
And finally, the learned minimum EGR rate learning value r EGRMinFinal is stored in the corresponding working condition of the EEPROM after being calculated according to the following formula:
rEGRMinFinal＝rEGRVehicleMin×(1+rEGRMinAdapt)。
The above completes the entire description of the design method of the minimum EGR rate.
According to the design method of the minimum EGR rate, the basic minimum EGR rate is determined according to the rotation speed and the load of the engine; according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the engine starting water temperature, the engine air inlet temperature, the fuel steam mass flow of the carbon tank entering the cylinder, the engine rotating speed and the basic minimum EGR rate, the original minimum EGR rate is determined and used as the minimum EGR rate, and the EGR can be closed when the EGR rate is extremely small, so that the influence on the stability of an EGR system is avoided, and meanwhile, the software development cost is lower.
The embodiment also provides a design device for the minimum EGR rate.
Fig. 3 is a schematic structural diagram of a design device for a minimum EGR rate according to this embodiment, and referring to fig. 3, the design device for a minimum EGR rate includes a first module and a second module.
The first module is configured to determine a base minimum EGR rate based on engine speed and load.
The second module is used for determining the original minimum EGR rate and taking the original minimum EGR rate as the minimum EGR rate according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the fuel steam mass flow of the carbon tank entering the cylinder, the engine rotating speed and the basic minimum EGR rate.
It should be noted that, the design device of the minimum EGR rate provided in this embodiment may be a computer program (including program code) running in a computer device, for example, the design device of the minimum EGR rate is an application software; the design means of the minimum EGR rate may be used to perform the corresponding steps in the above-described method provided by the embodiments of the present application.
In some possible implementations, the design apparatus for providing the minimum EGR rate according to this embodiment of the present application may be implemented by combining software and hardware, and by way of example, the design apparatus for providing the minimum EGR rate according to this embodiment of the present application may be a processor in the form of a hardware decoding processor that is programmed to perform the design method for providing the minimum EGR rate according to this embodiment of the present application, for example, the processor in the form of a hardware decoding processor may employ one or more application specific integrated circuits (ASIC, applicationSpecific INTEGRATED CIRCUIT), digital signal processors (DIGITAL SIGNAL processors, DSPs), programmable Logic devices (PLDs, programmable Logic Device), complex programmable Logic devices (CPLD, complexProgrammable Logic devices), field programmable gate arrays (FPGAs, field-Programmable GateArray), or other electronic components.
In some possible implementations, the design apparatus for providing the minimum EGR rate according to the present embodiment may be implemented in software, which may be software in the form of a program, a plug-in, or the like, and includes a series of modules, for example, a first module and a second module, to implement the design method for providing the minimum EGR rate according to the present embodiment.
The design device of the minimum EGR rate provided by the embodiment determines a basic minimum EGR rate according to the rotation speed and the load of the engine; according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel steam entering the cylinder from the carbon tank, the engine speed and the basic minimum EGR rate, the original minimum EGR rate is determined and used as the minimum EGR rate, and the EGR can be closed when the EGR rate is extremely small, so that the influence on the stability of an EGR system is avoided, and meanwhile, the software development cost is lower.
An embodiment of the present application further provides an electronic device, and fig. 4 is a schematic structural diagram of the electronic device of the present embodiment, as shown in fig. 4, an electronic device 1000 in the present embodiment may include: processor 1001, network interface 1004, and memory 1005, and in addition, the electronic device 1000 may further include: a user interface 1003, and at least one communication bus 1002. Wherein the communication bus 1002 is used to enable connected communication between these components. The user interface 1003 may include a Display (Display), a Keyboard (Keyboard), and the optional user interface 1003 may further include a standard wired interface, a wireless interface, among others. The network interface 1004 may optionally include a standard wired interface, a wireless interface (e.g., WI-FI interface). The memory 1004 may be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory. The memory 1005 may also optionally be at least one storage device located remotely from the processor 1001. As shown in fig. 4, an operating system, a network communication module, a user interface module, and a device control application may be included in the memory 1005, which is a type of computer-readable storage medium.
In the electronic device 1000 shown in fig. 4, the network interface 1004 may provide a network communication function; while user interface 1003 is primarily used as an interface for providing input to a user; and the processor 1001 may be used to invoke a device control application stored in the memory 1005 to implement:
Determining a basic minimum EGR rate according to the engine speed and the load;
And determining the original minimum EGR rate and taking the original minimum EGR rate as the minimum EGR rate according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel vapor entering the cylinder from the carbon tank, the engine rotating speed and the basic minimum EGR rate.
It should be appreciated that in some possible embodiments, the processor 1001 described above may be a central processing unit (central processing unit, CPU), which may also be other general purpose processors, DSP, ASIC, FPGA or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The memory may include read only memory and random access memory and provide instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store information of the device type.
In a specific implementation, the electronic device 1000 may execute, through each functional module built in the electronic device, an implementation manner provided by each step in fig. 2, and specifically, the implementation manner provided by each step may be referred to, which is not described herein again.
The embodiment of the present application further provides a computer readable storage medium, where a computer program is stored and executed by a processor to implement the method provided by each step in fig. 2, and specifically, the implementation manner provided by each step may be referred to, which is not described herein.
The computer readable storage medium may be an internal storage unit, such as a hard disk or a memory of an electronic device, of the design method of any of the foregoing embodiments that provides a minimum EGR rate. The computer readable storage medium may also be an external storage device of the electronic device, such as a plug-in hard disk, a smart memory card (SMART MEDIA CARD, SMC), a Secure Digital (SD) card, a flash memory card (FLASH CARD), or the like, which are provided on the electronic device. The computer readable storage medium may also include a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (randomaccess memory, RAM), or the like. Further, the computer-readable storage medium may also include both an internal storage unit and an external storage device of the electronic device. The computer-readable storage medium is used to store the computer program and other programs and data required by the electronic device. The computer-readable storage medium may also be used to temporarily store data that has been output or is to be output.
Embodiments of the present application provide a computer program product or computer program comprising computer instructions stored in a computer readable storage medium. The computer instructions are read from the computer-readable storage medium by a processor of the electronic device, and executed by the processor, cause the computer device to perform the method provided by the steps of fig. 2.
It should be understood that, although the steps in the flowcharts of the figures are shown in order as indicated by the arrows, these steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited in order and may be performed in other orders, unless explicitly stated herein. Moreover, at least some of the steps in the flowcharts of the figures may include a plurality of sub-steps or stages that are not necessarily performed at the same time, but may be performed at different times, the order of their execution not necessarily being sequential, but may be performed in turn or alternately with other steps or at least a portion of the other steps or stages.
The foregoing is only a partial embodiment of the present application, and it should be noted that it will be apparent to those skilled in the art that modifications and adaptations can be made without departing from the principles of the present application, and such modifications and adaptations are intended to be comprehended within the scope of the present application.
Claims (9)
1. A method of designing a minimum EGR rate, comprising the steps of:
Determining a basic minimum EGR rate according to the engine speed and the load;
Determining an original minimum EGR rate and taking the original minimum EGR rate as the minimum EGR rate according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel steam entering a cylinder from a carbon tank, the engine rotating speed and the basic minimum EGR rate;
And when the working condition of the engine is stable, performing self-learning update:
After the update stage of self-learning update is determined, according to a target average value rho DsrdAvg of the fresh air intake density of the cylinder, an average value rho ActFilterAvg of the filtering value of the fresh air intake density of the actual cylinder, a target air-fuel ratio r DsrdAFRavg and an average value r AFRFilterAvg of the filtering value of the actual air-fuel ratio, under the current working condition, updating the initial value of the learning value;
Determining a new minimum EGR rate learning value according to the learning value initial value and the last minimum EGR rate learning value under the same working condition;
and determining a final minimum EGR rate according to the current original minimum EGR rate and the new minimum EGR rate learning value.
2. The method of designing a minimum EGR rate according to claim 1, wherein the step of determining the original minimum EGR rate as the minimum EGR rate based on the atmospheric pressure, the water temperature, the number of engine combustions, the atmospheric temperature, the engine real-time water temperature, the engine start-up water temperature, the engine intake air temperature, the mass and flow of fuel vapor from the canister into the cylinder, the engine rotational speed, and the base minimum EGR rate includes:
determining a first multiplication factor r 1 according to the atmospheric pressure and the water temperature;
Determining a second multiplication factor r 2 according to the engine combustion times and the atmospheric temperature;
determining a third multiplication factor r 3 according to the real-time water temperature of the engine and the starting water temperature of the engine;
Determining a fourth multiplication factor r 4 according to the real-time water temperature of the engine and the air inlet temperature of the engine;
and determining a fifth multiplication factor r 5 according to the mass and flow of fuel vapor entering the cylinder by the carbon tank and the engine speed.
3. The method of designing a minimum EGR rate according to claim 2, characterized in that the original minimum EGR rate r EGRVehicleMin is obtained according to the following formula:
rEGRVehicleMin=rEGRBenchMin·(1+ r1)·(1+ r2)·(1+ r3)·(1+ r4)·(1+ r5);
wherein r EGRBenchMin represents the base minimum EGR rate.
4. The method according to claim 1, wherein after the self-learning update stage is determined, the step of updating the learning value initial value according to the target average rho DsrdAvg of the intake air density of the fresh air in the cylinder, the average rho ActFilterAvg of the filtering value of the intake air density of the fresh air in the actual intake air in the cylinder, the target air-fuel ratio r DsrdAFRavg and the average r AFRFilterAvg of the filtering value of the actual air-fuel ratio under the current working condition comprises:
Determining a first judgment value according to a target average value rho DsrdAvg of the fresh air intake density of the cylinder and an average value rho ActFilterAvg of the actual fresh air intake density filtering value of the cylinder under the current working condition;
Determining a second judgment value according to the target air-fuel ratio r DsrdAFRavg and an average value r AFRFilterAvg of the actual air-fuel ratio filtering values;
And determining the initial value of the learning value according to the first judging value and the second judging value.
5. The method of designing a minimum EGR rate according to claim 4, wherein the first determination value C 1 is obtained according to the following formula:
；
The second judgment value C 2 is determined according to the following formula:
。
6. The method of designing a minimum EGR rate according to claim 1, further comprising the step of, before entering the self-learning update phase:
determining that an activation condition is met according to the engine and the EGR system;
And after the activation condition is met, entering a stabilization stage, and when the stabilization stage meets a time length condition and the self-learning times are not updated, entering the updating stage.
7. A minimum EGR rate designing apparatus, comprising:
a first module for determining a base minimum EGR rate based on engine speed and load;
The second module is used for determining an original minimum EGR rate and taking the original minimum EGR rate as the minimum EGR rate according to the atmospheric pressure, the water temperature, the engine combustion times, the atmospheric temperature, the real-time water temperature of the engine, the engine starting water temperature, the engine air inlet temperature, the mass flow of fuel steam entering the cylinder through the carbon tank, the engine rotating speed and the basic minimum EGR rate;
The self-learning updating module is used for carrying out self-learning updating when the working condition of the engine is stable:
After the update stage of self-learning update is determined, according to a target average value rho DsrdAvg of the fresh air intake density of the cylinder, an average value rho ActFilterAvg of the filtering value of the fresh air intake density of the actual cylinder, a target air-fuel ratio r DsrdAFRavg and an average value r AFRFilterAvg of the filtering value of the actual air-fuel ratio, under the current working condition, updating the initial value of the learning value;
Determining a new minimum EGR rate learning value according to the learning value initial value and the last minimum EGR rate learning value under the same working condition;
and determining a final minimum EGR rate according to the current original minimum EGR rate and the new minimum EGR rate learning value.
8. An electronic device comprising a processor and a memory, the processor and the memory being interconnected;
The memory is used for storing a computer program;
the processor is configured to execute the design method of the minimum EGR rate according to any one of claims 1 to 6 when the computer program is called.
9. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program that is executed by a processor to realize the design method of the minimum EGR rate according to any one of claims 1 to 6.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19736522A1 (en) * | 1997-08-22 | 1999-02-25 | Deutz Ag | Control system for IC engine |
| CN111622853A (en) * | 2020-05-29 | 2020-09-04 | 一汽解放汽车有限公司 | Self-adaptive EGR control method based on engine nitrogen and oxygen emission |
Family Cites Families (3)
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| JPS57165656A (en) * | 1981-04-07 | 1982-10-12 | Nissan Motor Co Ltd | Egr device of diesel engine |
| KR102518657B1 (en) * | 2018-07-12 | 2023-04-06 | 현대자동차주식회사 | Method for Exhaust Gas Recirculation Control using Differentiated Valve Duty and EGR System thereof |
| KR20200065359A (en) * | 2018-11-30 | 2020-06-09 | 현대자동차주식회사 | Control method for exhaust gas recirculation system |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19736522A1 (en) * | 1997-08-22 | 1999-02-25 | Deutz Ag | Control system for IC engine |
| CN111622853A (en) * | 2020-05-29 | 2020-09-04 | 一汽解放汽车有限公司 | Self-adaptive EGR control method based on engine nitrogen and oxygen emission |
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