CN115585070A - Method, device, equipment and storage medium for adjusting minimum EGR rate - Google Patents

Method, device, equipment and storage medium for adjusting minimum EGR rate Download PDF

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CN115585070A
CN115585070A CN202211212260.6A CN202211212260A CN115585070A CN 115585070 A CN115585070 A CN 115585070A CN 202211212260 A CN202211212260 A CN 202211212260A CN 115585070 A CN115585070 A CN 115585070A
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egr rate
value
determining
minimum egr
minimum
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杨柳春
雷雪
秦龙
郑韩麟
张珍
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Dongfeng Motor Corp
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Dongfeng Motor Corp
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
    • F02D41/0047—Controlling exhaust gas recirculation [EGR]
    • F02D41/0065—Specific aspects of external EGR control
    • F02D41/0072—Estimating, calculating or determining the EGR rate, amount or flow
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/40—Engine management systems

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combined Controls Of Internal Combustion Engines (AREA)

Abstract

The invention discloses a method, a device, equipment and a storage medium for adjusting a minimum EGR rate, wherein the method comprises the following steps: determining a first judgment value according to a target average value of intake density of fresh air entering an air cylinder and an average value of a filtered value of intake density of fresh air actually entering the air cylinder under the current working condition, and determining a second judgment value according to an average value of a filtered value of a target air-fuel ratio and an actual air-fuel ratio; if the first judgment value and the second judgment value are both smaller than the judgment threshold value, determining the minimum EGR rate decrement according to the actual EGR rate average value, the engine rotating speed and the target average value of the intake density of the fresh air entering the cylinder; and determining the final minimum EGR rate according to the existing minimum EGR rate, the minimum EGR rate decrement and the filter coefficient k under the current working condition. Has the advantages that: better protection is provided for drivability and engine.

Description

Method, device, equipment and storage medium for adjusting minimum EGR rate
Technical Field
The invention relates to the technical field of engines, in particular to a method, a device, equipment and a storage medium for adjusting 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. EGR waste gas reduces combustion temperature, avoids knocking and inhibits ignition advance angle delay. The control actuator may oscillate due to the low system hysteresis EGR rate, even the EGR system is unstable; and if the EGR rate is too low, great requirements are made on the control capability of the EGR system; even too low an EGR rate may not exhibit its advantages. Based on the method, the minimum EGR rate is adjusted, the EGR is closed when the EGR rate is extremely low, the influence on the stability of an EGR system is avoided, and meanwhile, the software development cost can be lower.
Disclosure of Invention
In view of the above-mentioned drawbacks and needs of the prior art, it is an object of the present invention to provide a method, apparatus, device and storage medium for adjusting a minimum EGR rate.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, a method of adjusting a minimum EGR rate, includes:
according to the target average value rho of the intake density of the fresh air entering the cylinder under the current working condition DsrdAvg And the average value rho of the intake density filtered value of the fresh air actually entering the cylinder ActFilterAvg Determining a first judgment value C 1 And according to the target air-fuel ratio r DsrdAFRavg And the average value r of the actual air-fuel ratio filtered value AFRFilterAvg Determining a second judgment value C 2 ；
If the first determination value C 1 And a second judgment value C 2 Are all smaller than a judgment threshold value, and the average value r of the actual EGR rate is EGRActAvg Engine speed n Avg And a target average value rho of intake density of fresh air entering the cylinder DsrdAvg Determining a minimum EGR rate decrement Δ r EGRMinDleta ；
According to the existing minimum EGR rate r under the current working condition EGRVehicleMin The minimum EGR rate decrement Δ r EGRMinDleta And a filter coefficient k for determining a final minimum EGR rate r EGRMinFinal 。
In one embodiment, the minimum EGR rate decrement Δ r is determined according to the following equation EGRMinDleta ：
Δr EGRMinDleta ＝r EGRActAvg ×[1-k(n Avg ,rho DsrdAvg )]；
Wherein, k (n) Avg ,rho DsrdAvg ) According to engine speed n Avg And a target average intake air density rho of fresh air entering the cylinder DsrdAvg And (4) determining.
In one embodiment, the minimum EGR rate decrement Δ r is determined EGRMinDleta The method also comprises the following steps:
re-determining the first judgment value C 1 And determining a second determination value C 2 ；
If the first judgment value C 1 And a second judgment value C 2 Are all smaller than the judgment threshold value, and meet the self-learning regulation, and meanwhile, the time interval from the last active minimum EGR rate reduction exceeds the preset interval time, the current minimum EGR rate decrement delta r is continuously reduced EGRMinDleta Wherein the preset interval time is determined according to the engine speed and the intake density original value rho of the fresh air actually entering the cylinder ActRaw And (4) determining.
In one embodiment, said determining if said first determination value C 1 And a second judgment value C 2 Are all smaller than the judgment threshold value, and meet the self-learning regulation, and meanwhile, the time interval from the last active minimum EGR rate reduction exceeds the preset interval time, the current minimum EGR rate decrement delta r is continuously reduced EGRMinDleta Comprises the following steps:
determining a reduction scaling factor each time the current minimum EGR rate decrement needs to be reduced;
and determining the minimum EGR rate decrement again according to the reduction scale coefficient and the current minimum EGR rate decrement.
In one embodiment, the reduction scaling factor is determined according to the following formula:
S m ＝1+0.05×m；
wherein S is m M is the reduction scale factor of the current reduction times.
In one embodiment, the final minimumEGR Rate r EGRMinFinal Determined according to the following formula:
r EGRMinFinal ＝r EGRVehicleMin ×(1+k×r EGRMinAdapt )。
in one embodiment, the operating condition is determined based on engine speed, intake air temperature, water temperature, intake VVT angle, ignition efficiency, target intake cylinder fresh air intake density, and target air-fuel ratio.
In a second aspect, a minimum EGR rate adjustment apparatus includes:
a first module for entering a target average value rho of intake density of fresh air entering a cylinder according to a current operating condition when an EGR system is turned off DsrdAvg And the average value rho of the intake density filtered value of the fresh air actually entering the cylinder ActFilterAvg Determining a first judgment value C 1 And according to the target air-fuel ratio r DsrdAFRavg And the average value r of the filtered values of the actual air-fuel ratios AFRFilterAvg Determining a second determination value C 2 ；
A second module for determining if the first determination value C is after the EGR system is turned on 1 And a second judgment value C 2 If the average value is less than the judgment threshold value, according to the average value r of the actual EGR rate EGRActAvg Engine speed n Avg And a target average value rho of intake density of fresh air entering the cylinder DsrdAvg Determining a minimum EGR rate decrement Δ r EGRMinDleta ；
A third module for determining a minimum EGR rate r based on a current minimum EGR rate for a current operating condition EGRVehicleMin The minimum EGR rate decrement Δ r EGRMinDleta And a filter coefficient k for determining a final minimum EGR rate r EGRMinFinal 。
In a third aspect, an electronic device includes 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 perform the method as described above when the computer program is invoked.
In a fourth aspect, a computer-readable storage medium stores a computer program for execution by a processor to implement the method described above.
The invention has the beneficial effects that:
according to the minimum EGR rate adjusting method, a first judgment value is determined according to a target average value of intake density of fresh air entering an air cylinder and an average value of a filtered value of intake density of fresh air actually entering the air cylinder under the current working condition, and a second judgment value is determined according to the average value of a target air-fuel ratio and an actual air-fuel ratio filtered value; if the first determination value C 1 And a second judgment value C 2 When the average value of the EGR rates is smaller than the judgment threshold value, determining the minimum EGR rate decrement according to the actual EGR rate average value, the engine rotating speed and the target average value of the intake density of the fresh air entering the cylinder; and determining the final minimum EGR rate according to the existing minimum EGR rate, the minimum EGR rate decrement and the filter coefficient under the current working condition, thereby providing better protection for the driveability and the engine.
For the adjusting device of the minimum EGR rate, determining a first judgment value according to a target average value of intake density of fresh air entering the cylinder and an average value of a filtered value of intake density of fresh air actually entering the cylinder under the current working condition, and determining a second judgment value according to an average value of a filtered value of a target air-fuel ratio and an actual air-fuel ratio; if the first determination value C 1 And a second judgment value C 2 When the average value of the EGR rates is smaller than the judgment threshold value, determining the minimum EGR rate decrement according to the actual EGR rate average value, the engine rotating speed and the target average value of the intake density of the fresh air entering the cylinder; and determining the final minimum EGR rate according to the existing minimum EGR rate, the minimum EGR rate decrement and the filter coefficient under the current working condition, thereby providing better protection for the driveability and the engine.
For the electronic equipment, determining a first judgment value according to a target average value of intake density of fresh air entering an air cylinder and an average value of a filtered value of intake density of fresh air actually entering the air cylinder under the current working condition, and determining a second judgment value according to an average value of a target air-fuel ratio and an actual air-fuel ratio filtered value; if the first determination value C 1 And a second judgment value C 2 If the average value of the EGR rates is less than the judgment threshold value, the average value of the actual EGR rates, the engine speed and the freshness of the entering cylinder are determined according to the actual EGR rate average valueAn air intake density target average value, determining a minimum EGR rate decrement; and determining the final minimum EGR rate according to the existing minimum EGR rate, the minimum EGR rate decrement and the filter coefficient under the current working condition, thereby providing better protection for the driveability and the engine.
For the computer-readable storage medium, determining a first judgment value according to a target average value of intake density of fresh air entering the cylinder and an average value of a filtered value of intake density of fresh air actually entering the cylinder under the current working condition, and determining a second judgment value according to an average value of a filtered value of a target air-fuel ratio and an actual air-fuel ratio; if the first determination value C 1 And a second judgment value C 2 When the average value of the EGR rates is smaller than the judgment threshold value, determining the minimum EGR rate decrement according to the actual EGR rate average value, the engine speed and the intake density target average value of the fresh air entering the cylinder; and determining the final minimum EGR rate according to the existing minimum EGR rate, the minimum EGR rate decrement and the filter coefficient under the current working condition, thereby providing better protection for the driveability and the engine.
Additional aspects and advantages of the present 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 present application.
Drawings
The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
FIG. 1 is a schematic structural diagram of a low-pressure EGR system provided in the present embodiment;
fig. 2 is a flowchart illustrating a method for adjusting the minimum EGR rate according to the present embodiment.
FIG. 3 is a schematic structural diagram of the minimum EGR rate adjustment apparatus provided in the present embodiment;
fig. 4 is a schematic structural diagram of the electronic device of the present embodiment.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or may be connected through the use of two elements or the interaction of two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. 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 within the art that, unless otherwise defined, 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. 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 method for adjusting a minimum EGR rate, which is applied to a low-pressure EGR system.
Fig. 1 is a schematic diagram of the configuration of the low-pressure EGR system provided in this embodiment, and as shown in fig. 1, the system includes an air filter, a supercharger compressor, a throttle valve, an engine, a supercharger turbine, a catalyst, a particulate 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 should be noted that the linear oxygen sensor is replaced with an integrated temperature and pressure sensor.
The supercharger compressor is used for compressing fresh air for supercharging.
The supercharger turbine controls the operating efficiency of the turbine by controlling the opening of the waste gate valve of the supercharger, thereby achieving different supercharging capacities.
The low-pressure EGR system has the following added parts compared with the non-low-pressure EGR system: EGR cooler, EGR temperature sensor, EGR valve, EGR differential pressure sensor, mixing valve, flow meter and oxygen sensor.
A flow meter is mounted between the air filter and the mixing valve for sensing the flow of fresh air into the engine.
The mixing valve is used for adjusting the pressure at the outlet of the EGR valve, improving the pressure difference at two ends of the EGR valve and improving the EGR rate.
An oxygen sensor is installed between the compressor and the throttle valve and near the throttle valve, and the oxygen sensor is used for detecting the flow of the mixture entering the cylinder.
The EGR cooler is used to cool the exhaust gas, facilitating an increase in the exhaust gas flow and a decrease in the exhaust gas temperature.
The EGR valve acts as a throttle, controlling the flow of exhaust gas into the cylinder.
An EGR temperature sensor is used to detect the temperature of exhaust gas entering the EGR valve.
The EGR differential pressure 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 flowchart illustrating a method for adjusting the minimum EGR rate according to the present embodiment.
As shown in FIG. 2, the adjusting method includes a step S100 of obtaining a target average value rho of intake air density of fresh air entering a cylinder according to the current working condition DsrdAvg And the average value rho of the intake density filtered value of the fresh air actually entering the cylinder ActFilterAvg Determining a first judgment value C 1 And according to the target air-fuel ratioRatio r DsrdAFRavg And the average value r of the filtered values of the actual air-fuel ratios AFRFilterAvg Determining a second determination value C 2 。
It should be noted that the operating condition is determined based on the engine speed, the intake air temperature, the water temperature, the intake VVT angle, the ignition efficiency, the target air-fuel ratio, and the target intake air density of the fresh air into the cylinder.
Before step S100, it is necessary to determine whether or not the conditions for proceeding to step S100 are satisfied, based on the engine and EGR valve states.
First, whether an activation condition is satisfied is determined based on the engine and the EGR valve.
The conditions include that the following conditions are satisfied simultaneously:
and the engine is in an out-of-operation state.
The EGR system is in a closed loop control active state.
The difference between the current actual EGR rate and the minimum EGR rate is not more than a preset range, and the example is +/-0.02%; wherein, if the EGR rate is not self-learned, the EGR rate is the original minimum EGR rate of the whole vehicle; if learned, the learned minimum EGR rate is taken.
The difference between the actual EGR rate and the target EGR rate does not exceed a preset range, and the preset range of the embodiment is +/-1%. The canister was not opened.
The engine speed is within a certain range, 600rpm to 5900rpm is taken in the embodiment, the fluctuation of the engine speed entering the ignition angle self-learning of the EGR rate is small, and +/-15 rpm is taken in the embodiment.
The load (intake density of fresh air into the cylinder) is within a certain range, which is 200mgpl to 3000mgpl in this embodiment, and the load fluctuation of the ignition angle self-learning of the intake EGR rate is small, which is defined as being small within ± 20 mgpl.
The actual EGR rate is in a certain range, and the fluctuation of the actual EGR rate entering the minimum EGR rate self-learning is small, wherein the actual EGR rate is +/-1 percent in the example.
The engine water temperature is in a certain range (0 ℃ to 100 ℃ is taken in the example), and the fluctuation of the actual EGR rate entering the ignition angle self-learning of the EGR rate is smaller, and +/-2 ℃ is taken in the example.
The intake air temperature is in a certain range (30 ℃ to 80 ℃ in the example), and the fluctuation of the actual EGR rate entering the ignition angle self-learning of the EGR rate is small, and +/-1.5 ℃ is taken in the example.
The deviation of the target intake VVT angle from the actual exhaust VVT angle is within a preset range, in this example, ± 0.5 °.
The deviation of the target exhaust VVT angle from the actual exhaust VVT angle is within a preset range, which is ± 0.5 ° in this example.
The fluctuation in the efficiency of the ignition angle is small, and the fluctuation range of this example is defined as small at ± 0.05.
No knocking or pre-ignition occurred.
The fluctuation of the atmospheric pressure is small, and in the embodiment, the fluctuation is small, namely the fluctuation range is within +/-0.02 kPa.
The oxygen sensor heating is completed.
The fluctuation of the intake air charge density of the target intake cylinder fresh air is small, and the fluctuation range of this embodiment within ± 10mgpl is defined as small.
The difference between the target intake cylinder fresh air charge density and the actual intake cylinder fresh air charge density does not exceed a preset range, which is ± 15mgpl in this example.
The target air-fuel ratio fluctuation was small, and. + -. 0.08 was taken in this example.
The difference between the target air-fuel ratio and the actual air-fuel ratio does not exceed a preset range, and the preset range in the present embodiment is ± 0.1.
No fuel injection system or intake system-related parts or functional faults occur.
The engine in the hybrid vehicle type participates in parallel direct drive. It should be noted that if the series is adopted, the active adjustment of the EGR rate may cause the torque of the engine to fluctuate, so that the series power generation may be unstable.
If either condition is not met, the step of the minimum EGR rate adjustment method will be stopped if the activation condition is deemed not to be met.
After the activation condition is satisfied, the stabilization phase is considered to be entered, the stabilization phase maintaining time exceeds T0 (in the embodiment, T0 is set to 5 s), and meanwhile, the minimum EGR rate is not updated in the T1 time period, and then the activation phase is entered.
In the activation phase, the sum of engine speed, intake air temperature, water temperature, intake VVT angle, ignition efficiency, actual EGR rate, target intake cylinder fresh air intake density, actual intake cylinder fresh air intake density, target air-fuel ratio, and actual air-fuel ratio are added up for a certain time T2 (not 10s in this embodiment).
Wherein the intake air density filtered value rho of the fresh air actually entering the cylinder ActFilter Calculated according to the following formula:
rho ActFilter ＝K Rho ×[rho ActRaw (N)-rho ActFilter (N-1)]+rho ActFilter (N-1)；
wherein rho ActRaw (N) actual intake cylinder fresh air intake density raw value, rho, for the Nth sampling period ActFilter Represents the actual intake air density (i.e., the actual intake air intake density filtered value) rho after the first-order low-pass filtering ActFilter (N-1) is the actual intake cylinder fresh air intake density filter value for the N-1 sample period, N =1,2,3 …. Note that rho ActFilter (0) Represents the actual intake cylinder fresh air intake density raw value just as it entered the activation phase; the sampling period interval is set to 10ms.
K Rho Is a coefficient which is filtered according to the number m of engine cylinders, the engine speed n and the fresh air quantity k Rho Determined according to the following formula:
K Rho ＝m·n·k Rho /4000；
the number of cylinders of the engine is 4 in the example, the rotating speed of the engine is 1000rpm Rho Taking 0.02, the purpose of the setting is to normalize the treatment, under different cylinder numbers and rotating speeds, the special calibration is not needed, only a 4-cylinder machine and k with the rotating speed of 1000rpm need to be calibrated Rho Thereby reducing the calibration test work.
Actual air-fuel ratio filter value r AFRFilter Obtained according to the following formula:
r AFRFilter (N)＝K AFR ·[r AFRRaw (N)-r AFRFilter (N-1)]+r AFRFilter (N-1)；
wherein r is AFRRaw For actual air-fuel ratio original value, r AFRRaw (N) is the actual original value of the air-fuel ratio in 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 filtering 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 filtering value of the N-1 sampling period, N =1,2,3 … …, r AFRFilter (0) Is the actual air-fuel ratio original value, K, just before entering the self-learning activation phase AFR As a coefficient, K in this example AFR ＝m·n·k Afr /4000, wherein k Afr Fresh air intake density filtered value rho depending on actual intake of engine into cylinder ActFilter 。
In this embodiment, when the filter values of the intake density of fresh air actually entering the cylinder of the engine are 300, 500, 700, 1000, 1500, 2000, 2500 and 3000, respectively, k corresponds to k Afr 0.15, 0.17, 0.18, 0.2, 0.21, 0.23, 0.24, 0.25, respectively.
And after T2, entering an updating stage.
The minimum EGR rate for each operating condition is stored in the non-volatile memory EEPROM. There will be an initial default value in EEPROM, which is 1. The stored value in the EEPROM is updated after the minimum EGR rate self-learning is completed.
Specifically, the average value n of the engine speed after the time T2 of the update phase (80 s in the present embodiment) is entered Avg Average value of intake air temperature T ManAvg Average value of water temperature T coolantAvg Intake VVT angle average phi IntakeVVTAvg Average value of ignition efficiency r SparkEffAg Average intake density rho of fresh air of target intake cylinder DsrdAvg Target air-fuel ratio r DsrdAFRAvg Average value rho of intake density filtered value of fresh air actually entering cylinder ActFilterAvg Actual air-fuel ratio filtered value average value r AFRFilterAvg Actual EGR Rate average value r ActEGRAvg And stored in the EEPROM.
Continuing with step S100, C 1 Is determined according to the following formula:
Figure BDA0003875530660000111
C 2 is determined according to the following formula:
Figure BDA0003875530660000112
after the step S100, the step S200 is performed, if the first judgment value C is 1 And a second judgment value C 2 Are all smaller than a judgment threshold value, and the average value r of the actual EGR rate is EGRActAvg Engine speed n Avg And a target average value rho of intake density of fresh air entering the cylinder DsrdAvg Determining a minimum EGR rate decrement Δ r EGRMinDleta 。
In this embodiment, the determination threshold is set to 0.02. If the first determination value C is determined according to the calculation result of step S100 1 And a second judgment value C 2 Are all less than 0.02, then the average value r is obtained according to the actual EGR rate EGRActAvg Engine speed n Avg And a target average value rho of intake density of fresh air entering the cylinder DsrdAvg Determining a minimum EGR rate decrement Δ r EGRMinDleta 。
In the present embodiment, the minimum EGR rate reduction Δ r EGRMinDleta Determined according to the following formula:
Δr EGRMinDleta ＝r EGRActAvg ×[1-k(n Avg ,rho DsrdAvg )]；
wherein, k (n) Avg ,rho DsrdAvg ) From the engine speed n Avg And a target average value rho of intake density of fresh air entering the cylinder DsrdAvg And (5) reading the table for determination.
In this embodiment, k (n) Avg ,rho DsrdAvg ) As determined from table 1:
Figure BDA0003875530660000121
TABLE 1
Subtracting the minimum EGR rate decrement Δ r from the current minimum EGR rate EGRMinDleta After a period of time (set to 3s in this example) and its limit to its minimum value, 0 in this example.
Then, continuously observing whether a first judgment value C appears 1 And a second judgment value C 2z If one of the EGR flow rates is not smaller than the judgment threshold value, the current minimum EGR rate is continuously reduced.
In this embodiment, it is also necessary to determine whether the activation condition is satisfied and whether the interval duration from the last active minimum EGR rate reduction is longer than the expected duration T5 while continuing the observation. The predicted period T5 depends on the engine speed and the original value r of the intake density of the fresh air actually entering the cylinder hoActRaw 。
In the present embodiment, the predicted time period T5 is determined according to table 2.
Figure BDA0003875530660000122
Figure BDA0003875530660000131
TABLE 2
Specifically, the current minimum EGR rate decrement Δ r continues to be decreased EGRMinDleta Comprises the following steps:
determining a reduction scaling factor each time the current minimum EGR rate decrement needs to be reduced;
and determining the minimum EGR rate decrement again according to the reduction scale coefficient and the current minimum EGR rate decrement.
Specifically, the reduction scale factor is determined according to the following formula:
S m ＝1+0.05×m；
wherein S is m For reduction of current reduction timesSmall scale factor, m is the number of downscaling.
Note that, every time a new minimum EGR rate reduction amount Δ r is determined, it is determined EGRMinDleta And gradually increasing the waiting time, namely gradually increasing the value of T5, and increasing the interval time of the active control to avoid causing fluctuation to the torque of the control system and the rotating speed of the engine.
After the step S200, the step S300 is carried out, according to the existing minimum EGR rate r under the current working condition EGRVehicleMin The minimum EGR rate decrement Δ r EGRMinDleta And a filter coefficient k for determining a final minimum EGR rate r EGRMinFinal 。
Final minimum EGR rate r EGRMinFinal Determined according to the following formula:
r EGRMinFinal ＝r EGRVehicleMin ×(1+k×r EGRMinAdapt )。
in this example, k is 0.02.
The above completes the entire description of the adjustment method of the minimum EGR rate.
According to the method for adjusting the minimum EGR rate, a first judgment value is determined according to a target average value of intake density of fresh air entering an air cylinder and an average value of a filtered value of intake density of fresh air actually entering the air cylinder under the current working condition, and a second judgment value is determined according to an average value of a filtered value of a target air-fuel ratio and an actual air-fuel ratio; if the first determination value C 1 And a second judgment value C 2 When the average value of the EGR rates is smaller than the judgment threshold value, determining the minimum EGR rate decrement according to the actual EGR rate average value, the engine rotating speed and the target average value of the intake density of the fresh air entering the cylinder; and determining the final minimum EGR rate according to the existing minimum EGR rate, the minimum EGR rate decrement and the filter coefficient under the current working condition, thereby providing better protection for the driveability and the engine protection.
The embodiment also provides a minimum EGR rate adjustment device.
Fig. 3 is a schematic structural diagram of the minimum EGR rate adjustment apparatus provided in the present embodiment, and referring to fig. 3, the minimum EGR rate adjustment apparatus includes a first module, a second module, and a third module.
The first module is used forAccording to the target average value rho of the intake density of the fresh air entering the cylinder under the current working condition DsrdAvg And the average value rho of the intake density filtered value of the fresh air actually entering the cylinder ActFilterAvg Determining a first judgment value C 1 And according to the target air-fuel ratio r DsrdAFRavg And the average value r of the filtered values of the actual air-fuel ratios AFRFilterAvg Determining a second determination value C 2 。
The second module is used for judging if the first judgment value C 1 And a second judgment value C 2 If the average value is less than the judgment threshold value, according to the average value r of the actual EGR rates EGRActAvg Engine speed n Avg And a target average value rho of intake density of fresh air entering the cylinder DsrdAvg Determining a minimum EGR rate decrement Δ r EGRMinDleta ；
The third module is used for determining the minimum EGR rate r according to the current working condition EGRVehicleMin The minimum EGR rate decrement Δ r EGRMinDleta And a filter coefficient k for determining a final minimum EGR rate r EGRMinFinal 。
It should be noted that the adjusting device of the minimum EGR rate provided by the present embodiment may be a computer program (including program code) running in a computer device, for example, the adjusting device of the minimum EGR rate is an application software; the minimum EGR rate adjustment device may be used to perform the corresponding steps in the above method provided by the embodiments of the present application.
In some possible embodiments, the adjusting Device for providing the minimum EGR rate according to the present embodiment may be implemented by combining hardware and software, and by way of example, the adjusting Device for providing the minimum EGR rate according to the present embodiment may be a processor in the form of a hardware decoding processor, which is programmed to perform the closed-loop control method for the EGR rate according to the present embodiment, for example, the processor in the form of the hardware decoding processor may be implemented by one or more Application Specific Integrated Circuits (ASICs), digital Signal Processors (DSPs), programmable Logic Devices (PLDs), complex Programmable Logic Devices (CPLDs), field Programmable Gate Arrays (FPGAs), or other electronic components.
In some possible embodiments, the adjusting device for providing the minimum EGR rate according to this embodiment may be implemented in software, which may be software in the form of programs, plug-ins, and the like, and includes a series of modules, such as a first module, a second module, and a third module, to implement the adjusting method for providing the minimum EGR rate according to this embodiment.
The minimum EGR rate adjusting device provided by the embodiment determines a first judgment value according to a target average value of intake density of fresh air entering an air cylinder and an average value of a filtered value of intake density of fresh air actually entering the air cylinder under the current working condition, and determines a second judgment value according to an average value of a filtered value of a target air-fuel ratio and an actual air-fuel ratio; if the first determination value C 1 And a second judgment value C 2 When the average value of the EGR rates is smaller than the judgment threshold value, determining the minimum EGR rate decrement according to the actual EGR rate average value, the engine speed and the intake density target average value of the fresh air entering the cylinder; and determining the final minimum EGR rate according to the existing minimum EGR rate, the minimum EGR rate decrement and the filter coefficient under the current working condition, thereby providing better protection for the drivability and the engine protection.
An embodiment of the present application further provides an electronic device, fig. 4 is a schematic structural diagram of the electronic device of the present embodiment, and as shown in fig. 4, the electronic device 1000 in the present embodiment may include: the processor 1001, the network interface 1004, and the memory 1005, and the electronic device 1000 may further include: a user interface 1003, and at least one communication bus 1002. Wherein a communication bus 1002 is used to enable connective communication between these components. The user interface 1003 may include a Display screen (Display) and a Keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface and a standard wireless interface. 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, such as at least one disk memory. The memory 1005 may optionally be at least one memory device located remotely from the processor 1001. As shown in fig. 4, a memory 1005, which is a kind of computer-readable storage medium, may include therein an operating system, a network communication module, a user interface module, and a device control application program.
In the electronic sub-device 1000 shown in fig. 4, the network interface 1004 may provide network communication functions; the user interface 1003 is an interface for providing a user with input; and the processor 1001 may be used to invoke a device control application stored in the memory 1005 to implement:
according to the target average value rho of intake density of fresh air entering the cylinder under the current working condition DsrdAvg And the average value rho of the intake density filtered value of the fresh air actually entering the cylinder ActFilterAvg Determining a first judgment value C 1 And according to the target air-fuel ratio r DsrdAFRavg And the average value r of the filtered values of the actual air-fuel ratios AFRFilterAvg Determining a second determination value C 2 ；
If the first determination value C 1 And a second judgment value C 2 Are all smaller than a judgment threshold value, and the average value r of the actual EGR rate is EGRActAvg Engine speed n Avg And a target average value rho of intake density of fresh air entering the cylinder DsrdAvg Determining a minimum EGR rate decrement Δ r EGRMinDleta ；
According to the existing minimum EGR rate r under the current working condition EGRVehicleMin The minimum EGR rate decrement Δ r EGRMinDleta And a filter coefficient k, determining a final minimum EGR rate r EGRMinFinal 。
It should be understood that in some possible embodiments, the processor 1001 may be a Central Processing Unit (CPU), and the processor may be other general-purpose processors, DSPs, ASICs, FPGAs, 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 both read-only memory and random access memory, and provides instructions and data to the processor. The portion of memory may also include non-volatile random access memory. For example, the memory may also store device type information.
In a specific implementation, the electronic device 1000 may execute, through each built-in functional module thereof, the implementation manner provided in each step in fig. 2, which may be specifically referred to as the implementation manner provided in each step, and is not described herein again.
An embodiment of the present application further provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and is executed by a processor to implement the method provided in each step in fig. 2, which may specifically refer to the implementation manner provided in each step, and is not described herein again.
The computer readable storage medium may be an internal storage unit, such as a hard disk or a memory of an electronic device, which provides the method for adjusting the minimum EGR rate according to any of the foregoing embodiments. 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 (SMC), a Secure Digital (SD) card, a flash card (flash card), and the like, which are provided on the electronic device. The computer readable storage medium may further include a magnetic disk, an optical disk, a read-only memory (ROM), a Random Access Memory (RAM), and 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 for storing 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 processor of the electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions to 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, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and may be performed in other orders unless explicitly stated herein. Moreover, at least a portion of the steps in the flow chart of the figure may include multiple sub-steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, which are not necessarily performed in sequence, but may be performed alternately or alternately with other steps or at least a portion of the sub-steps or stages of other steps.
The foregoing is only a partial embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and decorations can be made without departing from the principle of the present application, and these modifications and decorations should also be regarded as the protection scope of the present application.

Claims (10)

1. A method of adjusting a minimum EGR rate, comprising:
according to the target average value rho of the intake density of the fresh air entering the cylinder under the current working condition DsrdAvg And the average value rho of the intake density filtered value of the fresh air actually entering the cylinder ActFilterAvg Determining a first judgment value C 1 And according to the target air-fuel ratio r DsrdAFRavg And the average value r of the filtered values of the actual air-fuel ratios AFRFilterAvg Determining a second judgment value C 2 ；
If the first determination value C 1 And a second judgment value C 2 Are all smaller than a judgment threshold value, and the average value r of the actual EGR rate is EGRActAvg Engine speed n Avg And a target average value rho of intake density of fresh air entering the cylinder DsrdAvg Determining a minimum EGR rate decrement Δ r EGRMinDleta ；
According to the existing minimum EGR rate r under the current working condition EGRVehicleMin The minimum EGR rate decrement Δ r EGRMinDleta And a filter coefficient k for determining a final minimum EGR rate r EGRMinFinal 。
2. The adjustment method of the minimum EGR rate according to claim 1, characterized in that the minimum EGR rate decrement Δ r is determined according to the following formula EGRMinDleta ：
Δr EGRMinDleta ＝r EGRActAvg ×[1-k(n Avg ,rho DsrdAvg )]；
Wherein, k (n) Avg ,rho DsrdAvg ) According to engine speed n Avg And a target average intake air density rho of fresh air entering the cylinder DsrdAvg And (5) determining.
3. The adjustment method of the minimum EGR rate of claim 2, characterized in that the minimum EGR rate decrement Δ r is determined EGRMinDleta The method also comprises the following steps:
re-determining the first judgment value C 1 And determining a second determination value C 2 ；
If the first judgment value C 1 And a second judgment value C 2 Are all smaller than the judgment threshold value, and meet the self-learning regulation, and meanwhile, the time interval from the last active minimum EGR rate reduction exceeds the preset interval time, the current minimum EGR rate decrement delta r is continuously reduced EGRMinDleta Wherein the preset interval time is determined according to the engine speed and the intake density original value rho of the fresh air actually entering the cylinder ActRaw And (4) determining.
4. The method for adjusting a minimum EGR rate according to claim 3, wherein the first determination value C is set 1 And a second judgment value C 2 Are all smaller than the judgment threshold value, and satisfy self-learning regulation, and meanwhile, if the time interval from the last active minimum EGR rate reduction exceeds the preset interval time, the current minimum EGR rate reduction delta r is continuously reduced EGRMinDleta Comprises the following steps:
determining a reduction scaling factor each time the current minimum EGR rate decrement needs to be reduced;
and determining the minimum EGR rate decrement again according to the reduction scale coefficient and the current minimum EGR rate decrement.
5. The adjustment method of the minimum EGR rate according to claim 4, wherein the reduction scaling factor is determined according to the following formula:
S m ＝1+0.05×m；
wherein S is m M is the reduction scale factor of the current reduction times.
6. The adjustment method of minimum EGR rate according to claim 1, characterized in that the final minimum EGR rate r EGRMinFinal Determined according to the following formula:
r EGRMinFinal ＝r EGRVehicleMin ×(1+k×r EGRMinAdapt )。
7. the adjustment method of the minimum EGR rate according to claim 1, wherein the operating condition is determined according to engine speed, intake air temperature, water temperature, intake VVT angle, ignition efficiency, target intake cylinder fresh air intake density, target air-fuel ratio.
8. An adjustment device of a minimum EGR rate, characterized by comprising:
a first module for entering a target average value rho of intake density of fresh air entering a cylinder according to a current operating condition when an EGR system is turned off DsrdAvg And the average value rho of the intake density filtered value of the fresh air actually entering the cylinder ActFilterAvg Determining a first judgment value C 1 And according to the target air-fuel ratio r DsrdAFRavg And the average value r of the filtered values of the actual air-fuel ratios AFRFilterAvg Determining a second judgment value C 2 ；
A second module for determining if the first determination value C is after the EGR system is turned on 1 And a second judgment value C 2 If the average value is less than the judgment threshold value, according to the average value r of the actual EGR rates EGRActAvg Engine speed n Avg And intake density target of fresh air entering cylinderMean rho DsrdAvg Determining a minimum EGR rate decrement Δ r EGRMinDleta ；
A third module to determine a current minimum EGR rate r based on a current operating condition EGRVehicleMin The minimum EGR rate decrement Δ r EGRMinDleta And a filter coefficient k for determining a final minimum EGR rate r EGRMinFinal 。
9. 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 perform the method of any of claims 1 to 7 when the computer program is invoked.
10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which is executed by a processor to implement the method of any one of claims 1 to 7.
CN202211212260.6A 2022-09-30 2022-09-30 Method, device, equipment and storage medium for adjusting minimum EGR rate Pending CN115585070A (en)

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Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07293352A (en) * 1994-04-27 1995-11-07 Toyota Motor Corp Air-fuel ratio control device for engine having egr device
JP2001280202A (en) * 2000-03-31 2001-10-10 Mitsubishi Motors Corp Exhaust gas recirculation system
JP2003222043A (en) * 2002-01-30 2003-08-08 Mazda Motor Corp Engine control unit
CN101278112A (en) * 2005-10-06 2008-10-01 卡特彼勒公司 Gaseous fuel engine charge density control system
JP2008274874A (en) * 2007-05-01 2008-11-13 Nissan Motor Co Ltd Fuel injection control device for internal combustion engine
US20090249783A1 (en) * 2008-04-04 2009-10-08 General Electric Company Locomotive Engine Exhaust Gas Recirculation System and Method
JP2012255405A (en) * 2011-06-09 2012-12-27 Toyota Motor Corp Egr device of internal combustion engine
CN103180586A (en) * 2010-10-26 2013-06-26 丰田自动车株式会社 Control device for internal combustion engine
US20150040862A1 (en) * 2013-08-09 2015-02-12 Hyundai Motor Company Method of monitoring egr system
CN106481465A (en) * 2015-08-27 2017-03-08 长城汽车股份有限公司 The computational methods of EGR rate, system and vehicle
CN109209659A (en) * 2018-09-12 2019-01-15 深圳环境能源研究院有限公司 A kind of EGR rate update the system and method based on internal combustion engine charge factor
CN117120711A (en) * 2021-04-15 2023-11-24 日产自动车株式会社 Control method and control device for internal combustion engine

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07293352A (en) * 1994-04-27 1995-11-07 Toyota Motor Corp Air-fuel ratio control device for engine having egr device
JP2001280202A (en) * 2000-03-31 2001-10-10 Mitsubishi Motors Corp Exhaust gas recirculation system
JP2003222043A (en) * 2002-01-30 2003-08-08 Mazda Motor Corp Engine control unit
CN101278112A (en) * 2005-10-06 2008-10-01 卡特彼勒公司 Gaseous fuel engine charge density control system
JP2008274874A (en) * 2007-05-01 2008-11-13 Nissan Motor Co Ltd Fuel injection control device for internal combustion engine
US20090249783A1 (en) * 2008-04-04 2009-10-08 General Electric Company Locomotive Engine Exhaust Gas Recirculation System and Method
CN103180586A (en) * 2010-10-26 2013-06-26 丰田自动车株式会社 Control device for internal combustion engine
JP2012255405A (en) * 2011-06-09 2012-12-27 Toyota Motor Corp Egr device of internal combustion engine
US20150040862A1 (en) * 2013-08-09 2015-02-12 Hyundai Motor Company Method of monitoring egr system
CN106481465A (en) * 2015-08-27 2017-03-08 长城汽车股份有限公司 The computational methods of EGR rate, system and vehicle
CN109209659A (en) * 2018-09-12 2019-01-15 深圳环境能源研究院有限公司 A kind of EGR rate update the system and method based on internal combustion engine charge factor
CN117120711A (en) * 2021-04-15 2023-11-24 日产自动车株式会社 Control method and control device for internal combustion engine

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