CN112780429A - Engine control device and engine control method - Google Patents
Engine control device and engine control method Download PDFInfo
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- CN112780429A CN112780429A CN202011189544.9A CN202011189544A CN112780429A CN 112780429 A CN112780429 A CN 112780429A CN 202011189544 A CN202011189544 A CN 202011189544A CN 112780429 A CN112780429 A CN 112780429A
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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
- F02D41/30—Controlling fuel injection
- F02D41/3005—Details not otherwise provided for
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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
- F02D41/0002—Controlling intake air
- F02D41/0007—Controlling intake air for control of turbo-charged or super-charged engines
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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
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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
- F02D41/003—Adding fuel vapours, e.g. drawn from engine fuel reservoir
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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
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
Abstract
An engine control device and an engine control method perform a pulsation determination as to whether or not intake pulsation is large, and prohibit updating of each of an air-fuel ratio learning value, an alcohol concentration learning value, a dilution learning value, and a fuel vapor concentration learning value, which are learning values updated based on an air-fuel ratio feedback correction value, when it is determined that intake pulsation is large by the pulsation determination.
Description
Technical Field
The present disclosure relates to an engine control device and method for performing air-fuel ratio feedback control of a fuel injection amount.
Background
In an engine control device that performs air-fuel ratio control, a fuel injection amount required to bring an air-fuel ratio of an air-fuel mixture burned in a combustion chamber to a target value is determined. The fuel injection amount is determined based on a detection value of an intake air flow rate detected by an air flow meter provided in the intake passage. Further, an air-fuel ratio sensor provided in the exhaust passage detects an air-fuel ratio of the air-fuel mixture burned in the combustion chamber. Further, air-fuel ratio feedback control is performed to correct the fuel injection amount in accordance with a deviation of the detected value of the air-fuel ratio of the mixture from the target value, thereby improving the accuracy of air-fuel ratio control. In jp 2010-096031 a, it is found that controllability of air-fuel ratio feedback control is improved by learning a learning value such as an air-fuel ratio learning value or a fuel vapor concentration learning value based on an air-fuel ratio feedback correction value and reflecting the learning value on a fuel injection amount.
In the engine, pressure fluctuations of intake air that occur as the intake valve is opened and closed are traced upstream of the intake passage via the throttle valve. Thereby, pulsation is generated in the flow of intake air at the installation position of the air flow meter in the intake passage. When the intake pulsation becomes large, a detection error of the intake air flow rate of the air flow meter becomes large. In addition, when the detection error is reflected in the air-fuel ratio feedback correction value, the result of learning based on the air-fuel ratio feedback correction value, the learning accuracy of the learning value is lowered.
Disclosure of Invention
In order to solve the above problem, according to a first aspect of the present invention, there is provided an engine control device that corrects a fuel injection amount for bringing an air-fuel ratio to a target value by using an air-fuel ratio feedback correction value set based on a deviation between a detection value of the air-fuel ratio and the target value and a learning value updated based on the air-fuel ratio feedback correction value, when performing control of the fuel injection amount. The engine control device is configured to perform a pulsation determination as to whether or not intake pulsation is large, and prohibit updating of the learned value based on the air-fuel ratio feedback correction value when the pulsation determination determines that the intake pulsation is large.
In order to solve the above problem, according to a second aspect of the present invention, there is provided an engine control method for correcting a fuel injection amount to make an air-fuel ratio a target value by using an air-fuel ratio feedback correction value set based on a deviation between a detected value of the air-fuel ratio and the target value and a learning value updated based on the air-fuel ratio feedback correction value, when controlling the fuel injection amount. The engine control method includes: determining whether the intake pulsation is large; and prohibiting updating of the learning value based on the air-fuel ratio feedback correction value when it is determined that the pulsation of intake air is large by the pulsation determination.
Drawings
Fig. 1 is a diagram schematically showing a configuration of an embodiment of an engine control device.
Fig. 2 is a flowchart of processing performed by the engine control device to cope with intake pulsation.
Fig. 3 is a diagram illustrating an embodiment of a pulsation determination.
Detailed Description
Hereinafter, an embodiment of an engine control device will be described in detail with reference to fig. 1 to 3.
First, the configuration of an engine 10 to which the engine control device of the present embodiment is applied will be described with reference to fig. 1. The Engine 10 is a flex-Fuel Engine (Flexible-Fuel Engine) capable of using alcohol Fuel, gasoline Fuel, and a mixed Fuel thereof as Fuel, respectively.
The engine 10 has a crankcase 12 in which a crankshaft 11 is housed. A cylinder 14 is formed in the crankcase 12. The piston 13 is housed in a cylinder 14 so as to be capable of reciprocating. Engine oil is stored in a lower portion of the crankcase 12. A combustion chamber 15 for combusting an air-fuel mixture of fuel and intake air is formed inside the cylinder 14. The combustion chamber 15 is a space defined by the inner wall of the cylinder 14 and the piston 13. The combustion chamber 15 is provided with an ignition device 16 that ignites an air-fuel mixture by spark discharge. The combustion chamber 15 is connected to an intake passage 20 through which intake air flows via an intake valve 17. The combustion chamber 15 is connected to an exhaust passage 30 through which exhaust gas flows via an exhaust valve 18.
An air cleaner 21 for filtering foreign substances such as dust in intake air is provided in the intake passage 20. An air flow meter 22 that detects an intake air flow rate GA is provided on the downstream side of the air cleaner 21 in the intake passage 20. A throttle valve 23 that adjusts the intake air flow rate GA is provided on the downstream side of the airflow meter 22 in the intake passage 20. An intake pressure sensor 25 that detects an intake pressure PM is provided in the intake passage 20 on the downstream side of the throttle valve 23. An injector 24 for injecting fuel into intake air is provided in the intake passage 20 on the downstream side of the intake pressure sensor 25. An air-fuel ratio sensor 31 that detects the air-fuel ratio of the air-fuel mixture burned in the combustion chamber 15 is provided in the exhaust passage 30. An exhaust gas purifying catalyst device 32 is provided in the exhaust passage 30 on the downstream side of the air-fuel ratio sensor 31.
Fig. 1 shows only one of the three cylinders 14 that the engine 10 has. A piston 13, a combustion chamber 15, an ignition device 16, an intake valve 17, an exhaust valve 18, and an injector 24 are provided in each of the three cylinders 14.
The engine 10 includes a crankcase ventilation system for ventilating blow-by gas in the crankcase 12. The crankcase ventilation system includes an outside air introduction passage 41 that communicates a portion between the air cleaner 21 and the throttle valve 23 in the intake passage 20 with the crankcase 12. The Crankcase Ventilation system includes a blow-by gas introduction passage 42 that communicates a portion of the intake passage 20 on the downstream side of the throttle valve 23 with the Crankcase 12, and a PCV (Positive Crankcase Ventilation) valve 43 provided in the blow-by gas introduction passage 42. The PCV valve 43 opens when the intake negative pressure on the downstream side of the throttle valve 23 in the intake passage 20 is greater than a predetermined value. The PCV valve 43 opens to allow blowby gas to be discharged from the crankcase 12 to the intake passage 20.
The engine 10 is further provided with a fuel vapor treatment system for releasing fuel vapor generated in the fuel tank 50 into intake air. The fuel vapor treatment system includes a carbon Canister (charcol Canister)51 that adsorbs and stores fuel vapor in the fuel tank 50. The fuel vapor treatment system further includes a purge passage 52 that communicates the canister 51 with a portion of the intake passage 20 on the downstream side of the throttle valve 23, and a purge valve 53 provided in the purge passage 52. The purge valve 53 is a solenoid valve whose opening degree changes according to the amount of energization. The flow rate of purge gas released from the canister 51 into the intake passage 20 through the purge passage 52 changes according to the opening degree of the purge valve 53.
An engine control device 60 applied to the engine 10 is an electronic control unit including a calculation processing device 61 that executes various programs, and a storage device 62 that stores various programs, numerical values, calculation expressions, and the like used when executing the programs. The engine 10 is provided with a crank angle sensor 63 for detecting a rotation phase of the crankshaft 11, a water temperature sensor 64 for detecting an engine water temperature THW which is a temperature of engine cooling water, and the like. Detection signals of various sensors such as the crank angle sensor 63 and the water temperature sensor 64 are input to the engine control device 60, in addition to the air flow meter 22, the intake pressure sensor 25, and the air-fuel ratio sensor 31. The engine control device 60 operates the ignition device 16, the throttle valve 23, the injector 24, the purge valve 53, and the like based on the input detection signal, thereby controlling the operating state of the engine 10. The operating state of the engine 10 is controlled by the arithmetic processing unit 61 reading and executing a program stored in the storage unit 62. The engine control device 60 obtains the engine speed NE from the detection result of the crank angle sensor 63.
(control of Fuel injection amount)
As a part of the engine control, the engine control device 60 controls the fuel injection amount, which is the amount of fuel injected from the injector 24, so that the air-fuel ratio of the air-fuel mixture combusted in the combustion chamber 15 becomes the target value AFT. In the present embodiment, "14.7" which is the stoichiometric air-fuel ratio of gasoline fuel is set as the target air-fuel ratio AFT.
In the case of a flexible fuel engine, the stoichiometric air-fuel ratio varies according to the alcohol concentration of the fuel in use. The stoichiometric air-fuel ratio refers to the air-fuel ratio of a mixture containing oxygen in an amount such that the fuel is completely combusted without excess/deficiency. For example, the theoretical air-fuel ratio when the alcohol concentration of the fuel in use is "85%" is "10.0". Thus, when the alcohol concentration of the fuel in use is "85%" with the in-cylinder air amount MC being constant, the fuel injection amount required to obtain the stoichiometric air-fuel ratio is "1.47" times as large as that of the case where the alcohol concentration is "0%".
Strictly speaking, the output value of the air-fuel ratio sensor 31 represents the air excess ratio λ of the air-fuel mixture burned in the combustion chamber 15. The air excess ratio λ is a ratio of the mass of actual air in the air-fuel mixture to the mass of air containing oxygen in an amount such that the fuel in the air-fuel mixture is completely combusted without excess/deficiency. In the present embodiment, the product of the air excess ratio λ indicated by the output value of the air-fuel ratio sensor 31 and "14.7" which is the theoretical air-fuel ratio of gasoline fuel is used as the detection value AF of the air-fuel ratio detected by the air-fuel ratio sensor 31 (AF ═ λ × 14.7). Further, in the present embodiment, in the fuel injection amount control, the fuel injection amount is controlled so that the detection value AF of the air-fuel ratio becomes the target value AFT. That is, the fuel injection amount is controlled so that the air excess ratio λ of the air-fuel mixture burned in the combustion chamber 15 becomes "1".
When controlling the fuel injection amount, the engine control device 60 first calculates the in-cylinder air amount MC, which is the mass of air introduced into the combustion chamber 15, and calculates the quotient of the in-cylinder air amount MC divided by the target air-fuel ratio AFT as the basic injection amount QBSE. Then, the engine control device 60 calculates a value obtained by correcting the basic injection amount QBSE based on the air-fuel ratio feedback correction value FAF, the air-fuel ratio learning value KG, the alcohol concentration learning value KALC, the dilution learning value LDIL, and the fuel vapor concentration learning value FGPG as the command injection amount QINJ. Then, engine control device 60 instructs injector 24 to inject fuel in an amount indicated by the command injection amount QINJ.
The command injection amount QINJ is calculated so as to satisfy the relationship of equation (1). "REF" in the equation (1) indicates a blow-by gas release amount, which is a flow rate of blow-by gas released into the intake passage 20 by the blow-by gas ventilation system. The blow-by GAs emission amount REF is determined based on the intake air flow rate GA. In addition, "PGR" in the equation (1) represents a vapor removal rate, which is a ratio of the vapor removal amount to the intake air flow rate GA. The vapor purge amount indicates the flow rate of purge gas released from the canister 51 to the intake passage 20 by the fuel vapor treatment system. The vapor purge rate PGR is determined based on the engine speed NE, the intake air flow rate GA, and the opening degree of the purge valve 53.
QINJ＝QBSE×(1+FAF+KG+LDIL×REF+FGPG×PGR)×(1+KALC)…(1)
When such control of the fuel injection amount is performed, the engine control device 60 performs air-fuel ratio feedback control. The engine control device 60 learns the air-fuel ratio learning value KG, the alcohol concentration learning value KALC, the dilution learning value LDIL, and the fuel vapor concentration learning value FGPG based on the air-fuel ratio feedback correction value FAF, which is a correction value of the fuel injection amount under the air-fuel ratio feedback control.
(air-fuel ratio feedback control)
First, air-fuel ratio feedback control will be described. The engine control device 60 performs air-fuel ratio feedback control by updating the air-fuel ratio feedback correction value FAF based on a deviation Δ AF (AFT-AF) of a detection value AF of the air-fuel ratio detected by the air-fuel ratio sensor 31 from a target value AFT of the air-fuel ratio. Specifically, engine control device 60 calculates the product of deviation Δ AF multiplied by a predetermined proportional gain KP as the value of a proportional term, the product of the time-differentiated value of deviation Δ AF multiplied by a predetermined differential gain KD as the value of a differential term, and the product of the time-integrated value of deviation Δ AF multiplied by a predetermined integral gain KI as the value of an integral term. Engine control device 60 then sets the sum of the calculated values of the proportional term, the derivative term, and the integral term as an air-fuel ratio feedback correction value FAF. The air-fuel ratio feedback control is started when the engine water temperature THW rises to or above a predetermined air-fuel ratio feedback start temperature after the engine 10 is started.
(air-fuel ratio learning)
Next, air-fuel ratio learning will be described. Engine control device 60 learns the steady deviation amount of detected value AF of the air-fuel ratio from target value AFT as air-fuel ratio learned value KG by air-fuel ratio learning. The air-fuel ratio learning is performed on the condition that the operating state of engine 10 is stable and alcohol concentration learning, dilution learning, and fuel vapor concentration learning, which will be described later, are not performed during execution of the air-fuel ratio feedback control.
In the air-fuel ratio learning, it is checked at every predetermined control cycle whether or not the absolute value of the moving average value FAFSM of the air-fuel ratio feedback correction value FAF is equal to or greater than a predetermined value "F0". When the moving average value FAFSM is equal to or greater than "F0", the air-fuel ratio learning value KG is updated so that the sum obtained by adding the predetermined value "K0" to the value before update is the value after update. On the other hand, when the moving average value FAFSM is equal to or less than "-F0", the air-fuel ratio learning value KG is updated so that the difference obtained by subtracting "K0" from the value before update is set as the value after update. A value exceeding "0" and less than "F0" is set as a prescribed value "K0". When the state in which the absolute value of the moving average value FAFSM of the air-fuel ratio feedback correction value FAF is smaller than "F0" continues for a predetermined time or longer, air-fuel ratio learning is completed. After the air-fuel ratio learning is completed, when the absolute value of the moving average value FAFSM becomes "F0" or more, the air-fuel ratio learning is started again.
(alcohol concentration learning)
Next, the alcohol concentration learning will be explained. Engine control device 60 learns, as alcohol concentration learned value KALC, a correction value of the fuel injection amount for compensating for a deviation of a detected value AF of the air-fuel ratio from a target value AFT due to a difference in alcohol concentration in the fuel by alcohol concentration learning. When it is confirmed that the fuel supply to the fuel tank 50 is performed during the stop period of the engine 10 at the time of starting the engine 10, the alcohol concentration learning is performed in accordance with the start of the air-fuel ratio feedback control. The presence or absence of refueling is confirmed based on the opening and closing of the refueling cap and the change in the remaining fuel amount in the fuel tank 50.
In the alcohol concentration learning, it is checked at every predetermined control cycle whether or not the absolute value of the moving average value FAFSM of the air-fuel ratio feedback correction value FAF is equal to or greater than a predetermined value "F1". When the moving average value FAFSM is equal to or greater than "F1", the alcohol concentration learning value KALC is updated so that the sum of the value before update and the predetermined value "K1" is the value after update. On the other hand, when the moving average value FAFSM is equal to or less than "-F1", the alcohol concentration learning value KALC is updated so that the difference obtained by subtracting "K1" from the value before update is set as the value after update. A value exceeding "0" and less than "F1" is set as a prescribed value "K1". When the state in which the absolute value of the moving average value FAFSM of the air-fuel ratio feedback correction value FAF is smaller than "F1" continues for a predetermined time or longer, the alcohol concentration learning is completed. When the alcohol concentration learning is accurately performed without an error, the alcohol concentration learning value KALC at the time of completion of learning becomes "0" when the alcohol concentration of the fuel in use is "0%" and becomes "0.47" when the alcohol concentration of the fuel in use is "85%".
(dilution learning)
Next, dilution learning will be explained. The engine control device 60 learns the dilution learning value LDIL used for correction for compensating for a deviation of the detected value AF of the air-fuel ratio from the target value AFT due to the influence of the blowby gas released into the intake passage 20 by the crankcase ventilation system by dilution learning. The dilution learning is performed when the air-fuel ratio feedback control is being performed, the alcohol concentration learning is not being performed, and it is determined by the dilution determination that the influence of the blowby gas release on the air-fuel ratio is large. In the dilution determination, it is determined whether or not the influence of blow-by gas release on the air-fuel ratio is large based on the estimated dilution amount DIL, the air-fuel ratio feedback correction value FAF, the engine water temperature THW, and the like. Specifically, in the dilution determination, when the estimated dilution amount DIL is equal to or greater than a predetermined dilution determination value, the air-fuel ratio feedback correction value FAF is equal to or less than a predetermined negative value, and the engine water temperature THW is equal to or less than a predetermined low water temperature determination value, it is determined that the influence of blow-by gas release on the air-fuel ratio is large.
The estimated dilution amount DIL is an estimated value of the amount of fuel mixed into the engine oil in the crankcase 12. The engine control device 60 calculates the estimated dilution amount DIL in the following manner. That is, the engine control device 60 calculates, at every predetermined calculation cycle, a fuel mixture amount, which is an amount of fuel newly mixed into the engine oil in the same calculation cycle, and a fuel volatilization amount, which is an amount of fuel volatilized from the engine oil in the same calculation cycle. At the same time, the engine control device 60 obtains the estimated dilution amount DIL as a value obtained by integrating the calculated values of the fuel mixture amount and the fuel evaporation amount for each calculation cycle. The fuel mixture amount is calculated based on the engine water temperature THW and the command injection amount QINJ. Specifically, the calculated fuel mixture amount is increased as the engine water temperature THW is lower or the command injection amount QINJ is larger. This reflects the following: as the engine water temperature THW is lower and the wall surface temperature of the cylinder 14 is lower, the higher the ratio of the fuel adhering to the wall surface of the cylinder 14 among the injected fuel, the greater the amount of fuel that drips along the wall surface to the crankcase 12 and is mixed into the engine oil. The fuel evaporation amount is calculated based on the estimated dilution amount DIL and the temperature of the engine oil estimated from the engine water temperature THW. Specifically, the calculated fuel volatilization amount is increased as the temperature of the engine oil is increased or the estimated dilution amount DIL is increased. This reflects the following: the higher the temperature of the oil, the more the proportion of volatilized fuel among the fuel present in the engine oil.
In the dilution learning, it is checked at predetermined control cycles whether or not the absolute value of the moving average value FAFSM of the air-fuel ratio feedback correction value FAF is equal to or greater than a predetermined value "F2". When the absolute value of the moving average value FAFSM is "F2" or more, the update amount Δ L is obtained as a quotient obtained by dividing the predetermined value "L1" by the blowby gas emission amount REF. When the moving average value FAFSM is equal to or greater than "F2", the dilution learning value LDIL is updated so that the sum of the update amount Δ L and the value before update is set as the value after update. On the other hand, when the moving average value FAFSM is equal to or smaller than "-F2", the dilution learning value LDIL is updated so that the difference obtained by subtracting the update amount Δ L from the value before update is the value after update. A value exceeding "0" and less than "F2" is set as a prescribed value "L1".
(learning of fuel vapor concentration)
Next, the fuel vapor concentration learning will be explained. The engine control device 60 learns the fuel vapor concentration learning value FGPG used for correction of the fuel injection amount for compensating for a deviation of the detection value AF of the air-fuel ratio from the target value AFT due to the purge gas release by the fuel vapor treatment system, by the fuel vapor concentration learning. Engine control device 60 performs fuel vapor concentration learning when learning of air-fuel ratio learning value KG is completed, alcohol concentration learning and dilution learning are not performed, and vapor purge rate PGR is equal to or greater than a predetermined value.
When performing the fuel vapor concentration learning, the engine control device 60 checks at every predetermined control cycle whether or not the absolute value of the moving average value FAFSM of the air-fuel ratio feedback correction value FAF is equal to or greater than a predetermined value "F3". When the absolute value of the moving average value FAFSM is "F3" or more, the update amount Δ P is obtained as a quotient obtained by dividing the predetermined value "P1" by the vapor purge rate PGR. When the moving average value FAFSM is equal to or greater than "F3", the fuel vapor concentration learning value FGPG is updated so that the sum of the value before update and the update amount Δ P is set as the value after update. On the other hand, when the moving average value FAFSM is equal to or less than "-F3", the fuel vapor concentration learning value FGPG is updated so that the difference obtained by subtracting the update amount Δ P from the value before update is the value after update. A value exceeding "0" and less than "F3" is set as a prescribed value "P1".
(response to intake air pulsation)
As described above, in the present embodiment, the basic injection amount QBSE is obtained from the in-cylinder air amount MC, and the basic injection amount QBSE is corrected by the air-fuel ratio feedback correction value FAF and the respective learning values, so that the command injection amount QINJ is obtained. As calculation methods of the in-cylinder air amount MC for calculating the basic injection amount QBSE, the following three methods are known. That is, a Mass Flow (Mass Flow) method of calculating the in-cylinder air amount MC based on a detection value of the intake air Flow rate GA detected by the air Flow meter 22, a Speed density (Speed density) method of calculating the in-cylinder air amount MC based on a detection value of the intake air pressure PM detected by the intake air pressure sensor 25, and a Throttle Speed (Throttle Speed) method of calculating the in-cylinder air amount MC based on an opening degree of the Throttle valve 23 are used.
In most operating conditions of the engine 10, the mass flow rate method of the three calculation methods described above can calculate the in-cylinder air amount MC with the highest accuracy. Therefore, basically, the in-cylinder air amount MC is calculated by a mass flow method. However, in the engine 10, the pressure variation of the intake air caused by opening and closing of the intake valve 17 is traced upstream of the intake passage via the throttle valve 23. Thereby, pulsation is generated in the flow of intake air at the position where the airflow meter 22 is disposed in the intake passage. In particular, in a three-cylinder engine having three cylinders 14, the opening periods of the intake valves 17 of the cylinders 14 do not overlap, and therefore such intake pulsation tends to increase. Further, although the throttle valve 23 functions as a stopper that hinders the up-tracking of the pressure variation of the intake air, the up-tracking of the pressure variation of the intake air is not sufficiently blocked by the throttle valve 23 when the opening degree of the throttle valve 23 is large. Therefore, the intake pulsation is likely to become large.
In such a state where the intake pulsation is large, the detection error of the intake air flow rate GA of the air flow meter 22 becomes large, and as a result, the calculation accuracy of the in-cylinder air amount MC by the mass flow system is lowered. If the basic injection amount QBSE is calculated from the calculated value of the in-cylinder air amount MC according to the mass flow method at this time, the calculated error amount of the in-cylinder air amount MC is superimposed on the deviation between the fuel injection amount required to bring the air-fuel ratio to the target value AFT and the basic injection amount QBSE. Therefore, controllability of air-fuel ratio feedback is degraded. Further, the detection error of the intake air flow rate GA is reflected in the air-fuel ratio feedback correction value FAF and the result of learning based on the air-fuel ratio feedback correction value FAF. Therefore, the learning accuracy of each learning value is lowered. The engine control device 60 of the present embodiment performs processing for suppressing deterioration in controllability of air-fuel ratio feedback and learning accuracy of each learning value due to such intake pulsation.
Fig. 2 shows a process of engine control device 60 for coping with a decrease in controllability of air-fuel ratio feedback due to intake air pulsation and learning accuracy of each learning value. Engine control device 60 repeatedly executes the processing of fig. 2 at predetermined control cycles during the operation of engine 10.
When this process is started, first, in step S100, a pulsation determination is made as to whether or not intake pulsation is large. In the present embodiment, when the pulse rate RTE is equal to or greater than the predetermined pulsation determination value R0, it is determined that the intake pulsation is large. The pulse rate RTE is calculated based on the output value VA of the airflow meter 22 in the predetermined determination period T. Specifically, as shown in fig. 3, the pulse rate RTE is calculated as a quotient ((VMAX-VMIN)/VAVE) obtained by dividing a difference obtained by subtracting the minimum value VMIN from the maximum value VMAX of the output value VA in the determination period T by the average value VAVE of the output value VA in the determination period T. A period longer than the period of the intake pulsation is set as the determination period T.
If it is determined by the pulsation determination that the intake pulsation is not large (no in step S100), the process proceeds to step S110. In step S110, the in-cylinder air amount MC is calculated by the mass flow method, and then the present routine is ended.
If it is determined that the intake pulsation is large by the pulsation determination (yes at step S100), the process proceeds to step S120. After the in-cylinder air amount MC is calculated by the throttle speed method in step S120, the process proceeds to step S130. After the above-described updating of the air-fuel ratio learning value KG, alcohol concentration learning value KALC, dilution learning value LDIL, and fuel vapor concentration learning value FGPG is prohibited in step S130, the present routine ends the process. That is, even in a situation where air-fuel ratio learning, alcohol concentration learning, dilution learning, and fuel vapor concentration learning are originally intended, updating of the air-fuel ratio learning value KG, the alcohol concentration learning value KALC, the dilution learning value LDIL, and the fuel vapor concentration learning value FGPG is not performed.
The operation of the present embodiment configured as described above will be described.
As described above, when the intake pulsation increases, the accuracy of detection of the intake air flow rate GA by the airflow meter 22 decreases, and the accuracy of calculation of the in-cylinder air amount MC by the mass flow method decreases. In contrast, in the present embodiment, when it is determined by the pulsation determination that the intake pulsation is large, the calculation method of the in-cylinder air amount MC is switched to the throttle speed method that is not affected by the intake pulsation. This can suppress a decrease in the calculation accuracy of the in-cylinder air amount MC due to intake pulsation.
The calculation accuracy of the in-cylinder air amount MC by the throttle speed system is not affected by the intake pulsation, but is not higher than that by the mass flow system when the intake pulsation is not large. Therefore, it is difficult to sufficiently ensure the calculation accuracy of the in-cylinder air amount MC while the in-cylinder air amount MC is calculated by the throttle speed method. That is, the calculated value of the in-cylinder air amount MC based on the throttle speed system at this time may include a certain degree of error. In contrast, in the present embodiment, when it is determined by the pulsation determination that the intake pulsation is large, the updating of the air-fuel ratio learning value KG, the alcohol concentration learning value KALC, the dilution learning value LDIL, and the fuel vapor concentration learning value FGPG is prohibited. That is, the air-fuel ratio learning value KG, the alcohol concentration learning value KALC, the dilution learning value LDIL, and the fuel vapor concentration learning value FGPG based on the air-fuel ratio feedback correction value FAF reflecting the calculation error of the in-cylinder air amount MC by the velocity density method are not updated.
As described above, according to the engine control device 60 described above, the following effects can be achieved.
(1) When the calculation accuracy of the in-cylinder air amount MC is lowered due to the influence of the intake air pulsation, the updating of the air-fuel ratio learning value KG, the alcohol concentration learning value KALC, the dilution learning value LDIL, and the fuel vapor concentration learning value FGPG based on the air-fuel ratio feedback correction value FAF reflecting the calculation error of the in-cylinder air amount MC is prohibited. That is, when the intake pulsation is large and the detection error of the intake air flow rate is large, the learning value based on the air-fuel ratio feedback correction value is not updated. Therefore, the learning accuracy of the learned value is easily ensured.
(2) When it is determined by the pulsation determination that the intake pulsation is large, the operation mode of the in-cylinder air amount MC is switched from the mass flow rate mode to the throttle speed mode that is not affected by the intake pulsation. Therefore, it is possible to suppress a decrease in the calculation accuracy of the in-cylinder air amount MC due to the intake air pulsation, and to suppress a decrease in the controllability of the air-fuel ratio feedback.
This embodiment can be modified and implemented as follows. The present embodiment and the following modifications can be implemented in combination with each other within a range not technically contradictory.
The pulsation determination may be performed in a manner different from the above-described embodiment.
The contents of the specific processing relating to the update of the learning value in each of the air-fuel ratio learning, the alcohol concentration learning, the dilution learning, and the fuel vapor concentration learning may be changed as appropriate.
In the above embodiment, when it is determined by the pulsation determination that the intake air pulsation is large, the operation mode of the in-cylinder air amount MC is switched from the mass flow rate mode to the throttle speed mode, but even if the operation mode is switched to the speed density mode, the decrease in the operation accuracy of the in-cylinder air amount MC due to the intake air pulsation can be suppressed.
The switching of the calculation method of the in-cylinder air amount MC according to the pulsation determination may not be performed. If the updating of each learning value based on the air-fuel ratio feedback correction value FAF is prohibited when it is determined by the pulsation determination that the intake pulsation is large, the deterioration of the learning accuracy of the learning value can be suppressed.
In the above embodiment, as the learning based on the air-fuel ratio feedback correction value FAF, four learning of air-fuel ratio learning, alcohol concentration learning, dilution learning, and fuel vapor concentration learning are performed. One to three of the above-described four learning may not be performed. For example, when the alcohol concentration learning method is applied to an engine other than a flex fuel engine, the alcohol concentration learning is not required. In the case of application to an engine without a crankcase ventilation system, dilution learning is not required. In the case of application to an engine that does not have a fuel vapor treatment system, fuel vapor concentration learning is not required.
The engine control device 60 of the above embodiment may be applied to an engine having a different configuration from that of the engine shown in fig. 1. For example, the engine control device 60 may be applied to an engine in which the number of cylinders 14 is other than three, an engine with a supercharger, or the like.
Claims (6)
1. A control device for an engine, which is provided with a control device,
the engine control device corrects the fuel injection amount by an air-fuel ratio feedback correction value set based on a deviation between a detected value of the air-fuel ratio and a target value, and a learning value updated based on the air-fuel ratio feedback correction value, when performing control of the fuel injection amount for bringing the air-fuel ratio to the target value,
the engine control device is configured to perform a pulsation determination as to whether intake pulsation is large, and prohibit updating of the learned value based on the air-fuel ratio feedback correction value when the pulsation determination determines that intake pulsation is large.
2. The engine control apparatus according to claim 1,
the learning value is an air-fuel ratio learning value used in correction of a fuel injection amount for compensating for a steady deviation of a detected value of the air-fuel ratio from a target value.
3. The engine control apparatus according to claim 1 or 2,
the engine control device is suitable for a flexible fuel engine capable of using alcohol fuel, gasoline fuel, and a mixed fuel thereof as fuel,
the learning value is an alcohol concentration learning value used in correction of a fuel injection amount for compensating for a deviation of a detection value of the air-fuel ratio from a target value due to a difference in alcohol concentration of fuel in use.
4. The engine control device according to any one of claims 1 to 3,
the engine control device is suitable for an engine having a crankcase ventilation system for discharging blow-by gas in a crankcase into intake air,
the learning value is a dilution learning value used for correction of a fuel injection amount for compensating for a deviation of a detected value of the air-fuel ratio from a target value due to blow-by gas release.
5. The engine control device according to any one of claims 1 to 4,
the engine control device is suitable for an engine having a fuel vapor treatment system for releasing fuel vapor generated in a fuel tank into intake air,
the learning value is a fuel vapor concentration learning value used for correction of a fuel injection amount for compensating for a deviation between a detection value of the air-fuel ratio and a target value caused by emission of purge gas.
6. A method for controlling an engine of a vehicle,
in controlling a fuel injection amount for bringing an air-fuel ratio to a target value, the fuel injection amount is corrected by an air-fuel ratio feedback correction value set based on a deviation between a detection value of the air-fuel ratio and the target value and a learning value updated based on the air-fuel ratio feedback correction value,
the engine control method includes:
determining whether the intake pulsation is large; and
when it is determined that the pulsation of the intake air is large by the pulsation determination, updating of the learned value based on the air-fuel ratio feedback correction value is prohibited.
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| JP2019202990A JP2021076059A (en) | 2019-11-08 | 2019-11-08 | Engine control device |
| JP2019-202990 | 2019-11-08 |
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| CN112780429A true CN112780429A (en) | 2021-05-11 |
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| CN202011189544.9A Withdrawn CN112780429A (en) | 2019-11-08 | 2020-10-30 | Engine control device and engine control method |
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| CN (1) | CN112780429A (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06272595A (en) * | 1993-03-16 | 1994-09-27 | Nissan Motor Co Ltd | Air-fuel ratio learning control device for internal combustion engine |
| US6338336B1 (en) * | 1998-09-04 | 2002-01-15 | Denso Corporation | Engine air-fuel ratio control with fuel vapor pressure-based feedback control feature |
| EP1384877A2 (en) * | 2002-07-25 | 2004-01-28 | Toyota Jidosha Kabushiki Kaisha | Apparatus and method for controlling internal combustion engine |
| JP2008115803A (en) * | 2006-11-06 | 2008-05-22 | Honda Motor Co Ltd | Control device for internal combustion engine |
| US20100031941A1 (en) * | 2006-12-13 | 2010-02-11 | Toyota Jidosha Kabushiki Kaisha | Control device and control method for internal combustion engine |
| JP2013221418A (en) * | 2012-04-13 | 2013-10-28 | Mitsubishi Electric Corp | Control device of internal combustion engine and control method of internal combustion engine |
| CN108425758A (en) * | 2017-02-14 | 2018-08-21 | 丰田自动车株式会社 | Fuel injection controller |
| CN109595086A (en) * | 2017-10-03 | 2019-04-09 | 丰田自动车株式会社 | The control device and method of internal combustion engine |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6017240A (en) * | 1983-07-08 | 1985-01-29 | Toyota Motor Corp | Study control method of air-fuel ratio in electronically controlled engine |
| JP2010096031A (en) * | 2008-10-14 | 2010-04-30 | Toyota Motor Corp | Control device for internal combustion engine |
| JP2011012593A (en) * | 2009-07-01 | 2011-01-20 | Hitachi Automotive Systems Ltd | Control device of internal combustion engine |
| JP5471394B2 (en) * | 2009-12-11 | 2014-04-16 | トヨタ自動車株式会社 | Oil dilution determination device for internal combustion engine and control device for internal combustion engine |
-
2019
- 2019-11-08 JP JP2019202990A patent/JP2021076059A/en active Pending
-
2020
- 2020-10-30 CN CN202011189544.9A patent/CN112780429A/en not_active Withdrawn
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06272595A (en) * | 1993-03-16 | 1994-09-27 | Nissan Motor Co Ltd | Air-fuel ratio learning control device for internal combustion engine |
| US6338336B1 (en) * | 1998-09-04 | 2002-01-15 | Denso Corporation | Engine air-fuel ratio control with fuel vapor pressure-based feedback control feature |
| EP1384877A2 (en) * | 2002-07-25 | 2004-01-28 | Toyota Jidosha Kabushiki Kaisha | Apparatus and method for controlling internal combustion engine |
| JP2008115803A (en) * | 2006-11-06 | 2008-05-22 | Honda Motor Co Ltd | Control device for internal combustion engine |
| US20100031941A1 (en) * | 2006-12-13 | 2010-02-11 | Toyota Jidosha Kabushiki Kaisha | Control device and control method for internal combustion engine |
| JP2013221418A (en) * | 2012-04-13 | 2013-10-28 | Mitsubishi Electric Corp | Control device of internal combustion engine and control method of internal combustion engine |
| CN108425758A (en) * | 2017-02-14 | 2018-08-21 | 丰田自动车株式会社 | Fuel injection controller |
| CN109595086A (en) * | 2017-10-03 | 2019-04-09 | 丰田自动车株式会社 | The control device and method of internal combustion engine |
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