WO2022264482A1 - 内燃機関の制御装置 - Google Patents
内燃機関の制御装置 Download PDFInfo
- Publication number
- WO2022264482A1 WO2022264482A1 PCT/JP2022/003910 JP2022003910W WO2022264482A1 WO 2022264482 A1 WO2022264482 A1 WO 2022264482A1 JP 2022003910 W JP2022003910 W JP 2022003910W WO 2022264482 A1 WO2022264482 A1 WO 2022264482A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- amount
- change
- combustion
- state
- control device
- Prior art date
Links
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 238
- 230000008859 change Effects 0.000 claims abstract description 161
- 238000010790 dilution Methods 0.000 claims abstract description 71
- 239000012895 dilution Substances 0.000 claims abstract description 71
- 239000000446 fuel Substances 0.000 claims description 63
- 239000000203 mixture Substances 0.000 claims description 27
- 230000007423 decrease Effects 0.000 claims description 13
- 230000003247 decreasing effect Effects 0.000 claims description 5
- 230000001133 acceleration Effects 0.000 claims description 4
- 238000012937 correction Methods 0.000 abstract description 15
- 238000004364 calculation method Methods 0.000 abstract description 9
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 238000012545 processing Methods 0.000 description 30
- 238000000034 method Methods 0.000 description 24
- 230000008569 process Effects 0.000 description 24
- 239000007789 gas Substances 0.000 description 22
- 238000001514 detection method Methods 0.000 description 10
- 238000002347 injection Methods 0.000 description 10
- 239000007924 injection Substances 0.000 description 10
- 230000001276 controlling effect Effects 0.000 description 7
- 238000010586 diagram Methods 0.000 description 7
- 239000003054 catalyst Substances 0.000 description 6
- 230000006870 function Effects 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 230000006872 improvement Effects 0.000 description 4
- 230000007246 mechanism Effects 0.000 description 4
- 238000004088 simulation Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 238000013459 approach Methods 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000004044 response Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000009841 combustion method Methods 0.000 description 2
- 239000000498 cooling water Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000001687 destabilization Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Images
Classifications
-
- 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]
- F02D41/005—Controlling exhaust gas recirculation [EGR] according to engine operating conditions
-
- 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]
- F02D41/0077—Control of the EGR valve or actuator, e.g. duty cycle, closed loop control of position
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D35/00—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for
- F02D35/02—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions
- F02D35/028—Controlling engines, dependent on conditions exterior or interior to engines, not otherwise provided for on interior conditions by determining the combustion timing or phasing
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D37/00—Non-electrical conjoint control of two or more functions of engines, not otherwise provided for
- F02D37/02—Non-electrical conjoint control of two or more functions of engines, not otherwise provided for one of the functions being ignition
-
- 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
- F02D41/009—Electrical control of supply of combustible mixture or its constituents using means for generating position or synchronisation signals
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P5/00—Advancing or retarding ignition; Control therefor
- F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
- F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P5/00—Advancing or retarding ignition; Control therefor
- F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
- F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
- F02P5/15—Digital data processing
- F02P5/1502—Digital data processing using one central computing unit
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P9/00—Electric spark ignition control, not otherwise provided for
- F02P9/002—Control of spark intensity, intensifying, lengthening, suppression
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D2200/00—Input parameters for engine control
- F02D2200/02—Input parameters for engine control the parameters being related to the engine
- F02D2200/024—Fluid pressure of lubricating oil or working fluid
-
- 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
Definitions
- the present invention relates to a control device for an internal combustion engine.
- EGR exhaust Gas Recirculation
- the intake pipe pressure can be increased compared to when dilution combustion is not used, so it is possible to reduce the pump loss under low load conditions of the internal combustion engine.
- the heat capacity when burning the same amount of fuel can be increased, so the combustion temperature of the air-fuel mixture can be lowered and the cooling loss can be reduced.
- the occurrence of abnormal combustion can be suppressed by suppressing the reaction progress leading to the self-ignition reaction due to the introduction of the EGR gas.
- the ignition timing can be advanced so as to approach the optimum timing, so that the exhaust loss can be reduced.
- the degree of dilution of the air-fuel mixture is the ratio of the mass sum of the mixed gas consisting of air and EGR gas to the fuel mass (gas-fuel ratio G/F), the air-to-fuel mass ratio (air-fuel ratio A/F), the intake gas EGR ratio (EGR rate) is often evaluated.
- the air-fuel ratio and EGR rate are adapted for each vehicle type in advance, and various actuators are operated so as to achieve the adapted values of the air-fuel ratio and EGR rate so as to satisfy the adapted state.
- Patent Document 1 estimates a combustion phase at which a combustion mass ratio estimated based on the output of a crank angle sensor becomes a set value, and manipulates the degree of dilution and ignition timing so that the estimated combustion phase becomes the set phase. of combustion control is proposed.
- the degree of dilution can be manipulated based on the combustion phase, for example, the degree of dilution that achieves the combustion phase specified in advance as the target value can be realized.
- the target value of the degree of dilution is basically set with a margin and does not become the limit value of the degree of dilution.
- the achieved combustion phase is an average state, and it is not guaranteed that the variation in the combustion state for each cycle is sufficiently small.
- An object of the present invention is to provide a control device for an internal combustion engine that can realize the operation of the internal combustion engine when the degree of dilution is close to the limit.
- an internal combustion engine control apparatus of the present invention calculates an amount of change in a parameter indicating a combustion state of an internal combustion engine, and compares the amount of change in the parameter indicating the combustion state with a target value of the amount of change.
- a processor for correcting the operation amount of an actuator for adjusting the degree of dilution of the air-fuel mixture according to the difference between the two, and bringing the amount of change closer to the target value.
- FIG. 1 is a configuration diagram showing a system configuration of an internal combustion engine
- FIG. 1 is a configuration diagram showing the configuration of a control device for an internal combustion engine to which the present invention is applied
- FIG. It is a control block diagram which becomes an embodiment of the present invention.
- 4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention
- FIG. 4 is a diagram showing the relationship between the EGR valve opening and the flow rate relative value
- 4 is a timing chart showing combustion states and states of various actuators when the embodiment of the present invention is executed.
- 4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention
- 4 is a timing chart showing combustion states and states of various actuators when the embodiment of the present invention is executed.
- 4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention
- 4 is a timing chart showing combustion states and states of various actuators when the embodiment of the present invention is executed.
- It is a control block diagram which becomes an embodiment of the present invention.
- 4 is a control flow chart for explaining control steps executed by a control block according to an embodiment of the present invention;
- It is a control block diagram which becomes the 2nd Embodiment of this invention.
- It is a control block diagram which becomes the 2nd Embodiment of this invention.
- 8 is a control flow chart for explaining control steps executed by a control block according to a second embodiment of the present invention;
- This embodiment relates to a control device for an internal combustion engine, and in particular, in a system that dilutes and burns a fuel-air mixture such as an exhaust gas recirculation system or lean combustion, control of the degree of dilution of the mixture according to the combustion state, ignition It concerns the control of the device.
- the purpose of this embodiment is, for example, to estimate the amount of change in the combustion state while driving, and operate the dilution and ignition device based on the estimated amount of change, so that the dilution is close to the limit that can be set for each aircraft. It is an object of the present invention to provide a control device for an internal combustion engine that can realize the operation of the internal combustion engine under certain conditions.
- Fig. 1 shows the system configuration of a spark ignition type internal combustion engine used in automobiles, which is equipped with an in-cylinder fuel injection valve that directly injects gasoline fuel into the cylinder.
- the internal combustion engine ENG is an in-cylinder injection internal combustion engine for automobiles that performs spark ignition combustion.
- An air flow sensor 1 for measuring the intake air amount and intake air temperature, a supercharger compressor 4a for supercharging the intake air, an intercooler 7 for cooling the intake air, and an electronically controlled throttle 2 for adjusting the intake pipe pressure. are provided at appropriate locations in each of the intake pipes.
- the humidity sensor 3 is a sensor capable of detecting relative humidity and absolute humidity.
- a fuel injection device 13 injector for injecting fuel into the cylinder 14 of each cylinder and an ignition device (hereinafter referred to as ignition coil 16 and spark plug 17) for supplying ignition energy are provided for each cylinder.
- the cylinder head is provided with a variable valve 5 for adjusting the air-fuel mixture flowing into the cylinder or the exhaust gas discharged from the cylinder. By adjusting the variable valve 5, the intake air amount and the internal EGR amount of all cylinders are adjusted.
- a high-pressure fuel pump (not shown) for supplying high-pressure fuel to the fuel injection device 13 is connected to the fuel injection device 13 through a fuel pipe.
- a fuel pressure sensor is provided.
- a crank angle sensor 19 is attached to detect the position of the piston of the internal combustion engine. Output information of the crank angle sensor 19 is sent to the ECU 20 .
- a turbine 4b for applying rotational force to the compressor 4a of the supercharger by exhaust energy
- an electronically controlled wastegate valve 11 for adjusting the flow rate of exhaust gas flowing to the turbine 4b
- a three-way catalyst 10 for purifying the exhaust gas.
- An air-fuel ratio sensor 9 for detecting the air-fuel ratio of the exhaust gas on the upstream side of the three-way catalyst 10 is provided at an appropriate position in each of the exhaust pipes 15 .
- a temperature sensor 18 is provided to measure the temperature of cooling water circulating in the internal combustion engine.
- an EGR pipe is provided for recirculating the exhaust gas from the exhaust pipe downstream of the three-way catalyst 10 to the intake pipe upstream of the compressor 4a.
- EGR valves (EGR mechanism) for controlling the EGR flow rate are attached to the EGR pipes at appropriate positions.
- the output information obtained from the airflow sensor 1, the temperature sensor 18 and the air-fuel ratio sensor 9 is sent to the control unit (ECU 20) that controls the internal combustion engine. Further, output information obtained from the accelerator opening sensor 12 is sent to the ECU 20 .
- the accelerator opening sensor 12 detects the depression amount of the accelerator pedal, that is, the accelerator opening.
- the ECU 20 calculates the required torque based on the output information from the accelerator opening sensor 12 . That is, the accelerator opening sensor 12 is used as a required torque detection sensor that detects the required torque to the internal combustion engine.
- the ECU 20 also calculates the rotation speed of the internal combustion engine based on the output information of the crank angle sensor.
- the ECU 20 optimally calculates main operating variables of the internal combustion engine, such as air flow rate, fuel injection amount, ignition timing, and fuel pressure, based on the operating conditions of the internal combustion engine obtained from the output information of the various sensors.
- the fuel injection amount calculated by the ECU 20 is converted into a valve opening pulse signal and sent to the fuel injection device 13 . Also, an ignition signal is sent to the ignition coil 16 so that the engine is ignited at the ignition timing calculated by the ECU 20 . Further, the throttle opening calculated by the ECU 20 is sent to the electronic control throttle 2 as a throttle driving signal.
- Fuel is injected into the air that has flowed into the cylinder 14 from the intake pipe through the intake valve to form an air-fuel mixture.
- the air-fuel mixture is exploded by a spark generated from the ignition plug 17 at a predetermined ignition timing, and the combustion pressure pushes down the piston to provide driving force for the internal combustion engine.
- the exhaust gas after the explosion passes through the exhaust pipe 15 and is sent to the three-way catalyst 10, and the exhaust components are purified in the three-way catalyst 10 and discharged to the outside.
- FIG. 2 shows a control block showing the configuration of an internal combustion engine control device to which the present invention is applied.
- Input signals such as air amount information from the air flow sensor 1, accelerator depression information from the accelerator opening sensor 12, and angle information from the crank angle sensor 19 are input to an input circuit 21 of an ECU 20, which is control means.
- the input signals are not limited to these, additional description will be given as appropriate.
- the input signal of each sensor is sent to the input port within the input/output port 22 .
- the input information sent to the input port is temporarily stored in the RAM 23c and processed by the CPU 23a according to a predetermined control program.
- a control program describing the contents of arithmetic processing is written in the ROM 23b in advance.
- the output information indicating the amount of operation of the fuel injection valves and ignition coils for controlling the internal combustion engine calculated according to the control program is temporarily stored in the RAM 23c and then sent to the output port in the input/output port 22. It is sent to the fuel injection valve and ignition coil through the drive circuit.
- actuators are also used in internal combustion engines, their description is omitted here.
- an ignition control unit 24 and an EGR rate control unit 25 are shown as drive circuits. controls the opening of the EGR valve.
- the ECU 20 is provided with an ignition control section 24 for controlling the energization time of the ignition coil and the amount of discharge energy.
- the ignition control unit 24 may be mounted in a device other than the ECU 20 without any problem. The same applies to the EGR rate control section 25 as well.
- the ECU 20 calculates the discharge energy of the spark plug according to the detected air amount, crank angle, cooling water temperature, intake air temperature, etc., and energizes the ignition coil at appropriate timing (energization time and ignition timing) to The air-fuel mixture inside is ignited, and the EGR valve opening is controlled by energizing the motor for controlling the opening of the EGR valve.
- FIG. 3 is a control block showing an overview of the discharge energy control performed by the ignition control section 24 and the EGR rate control section 25 in the ECU 20, which is the control device for the internal combustion engine according to the embodiment of the present invention.
- a steady-state determination unit 31 determines whether the engine is operating in a steady state based on the detected air flow rate, throttle opening, EGR valve opening, and other actuator operation amounts and detected values. The determined result is sent to the combustion center change amount calculator 32 .
- the combustion center change amount calculation unit 32 calculates the crank angle sensor signal, particularly around the ignition timing, before the exhaust valve opening timing, indicators related to operating conditions (intake pressure, intake temperature, ignition timing, valve timing of variable valve timing), air-fuel mixture
- the amount of change in the combustion center position is calculated based on the indices related to the degree of dilution (EGR rate, air-fuel ratio, humidity).
- the calculated amount of change in the combustion center position is input to the actuator operation amount correcting section 33 .
- the actuator manipulated variable correction unit 33 sets the manipulated variables of the EGR valve opening, the ignition timing, and the primary coil energization amount based on the estimated change amount of the combustion center position and the combustion center position.
- FIG. 4A shows a control flow of arithmetic processing for dilution control in the first embodiment.
- Step S401 is a process executed by the combustion center change amount calculation unit 32
- step S402 is a process executed by the steady state determination unit 31
- steps S403 to S406 are processes executed by the actuator operation amount correction unit. is.
- step S401 the amount of change in the combustion center position is calculated based on the angular velocity and various parameters. Detailed processing here will be described separately.
- step S402 a steady determination is made based on the actuator operation amount and the air amount detection value. Specifically, the determination is based on whether the amount of change in each of the operation amount of the actuator and the detection value of the air amount within a predetermined period is less than a predetermined value. If the amount of change within the predetermined period is less than the predetermined value, the steady state determination flag is set to 1, and if the same condition is not satisfied, the steady state determination flag is set to 0.
- the predetermined period can be set to 500 ms and the predetermined value to 10%.
- step S403 it is determined whether the engine is in a steady state and a dilution combustion condition from the opening of the EGR valve. Whether or not the steady condition is met is determined by the steady state determination flag set in step S402. Whether or not the engine is in the diluted combustion state is determined by whether or not the EGR valve is fully closed. If it is fully closed, it is determined that the dilution condition is not met. Therefore, if the steady-state determination flag is 1 and the EGR valve opening is not fully closed, the process proceeds to step S404. If the steady-state determination flag is 0 or the EGR valve opening is fully closed, the flow ends.
- step S404 it is determined whether the absolute value of the difference between the amount of change in the combustion center position and the desired amount of change is less than a predetermined value.
- the fact that the absolute value of the same difference is less than the predetermined value indicates that the operation is being performed under conditions close to the allowable amount of change. If the absolute value of the same difference is greater than or equal to the predetermined value, the process proceeds to step S405. On the other hand, if the absolute value of the same difference is less than the predetermined value, the flow ends.
- step S405 an EGR flow rate increase/decrease target based on the difference between the combustion state change amount target and the combustion state change amount is calculated.
- the amount of change is smaller than the target amount of change (when the difference between the target amount of change and the amount of change is positive)
- the EGR flow rate is increased, and the amount of change is greater than the target amount of change. If the difference between the target amount of change and the amount of change is negative, the EGR flow rate is decreased.
- EGR flow rate increase/decrease target value C x air flow rate x (target change - change)
- C is the fit coefficient
- the parameter should be determined based on experiments.
- Step S406 the EGR valve operation amount is calculated based on the EGR flow rate increase/decrease target value determined in step S405. Examples are shown below.
- FIG. 4B shows the relationship between the EGR valve opening and the flow rate. In FIG. 4B, the value of the flow rate when the valve is fully open is 1, and the value when the valve is fully closed is 0, and the flow rate is normalized to 0-1.
- the EGR valve opening and the normalized amount of change in the flow rate can be measured in advance by engine tests and simulations, and stored in the ECU as a flow rate map centered on the EGR valve opening, which can be used for control.
- ⁇ Regr be the EGR flow rate increase/decrease target value calculated in step S405, and let ⁇ be the current EGR valve opening degree.
- the target value of the EGR flow rate is represented by the following relationship.
- Target value of EGR flow rate F( ⁇ C ) ⁇ (1+ ⁇ Regr)
- black circles in FIG. 4B indicate the relationship between the EGR valve opening degree and the flow rate that can be discretely set.
- the relationship between the settable opening and the flow rate is stored as a map.
- the black circles in FIG. 4B are EGR valve opening conditions that can be set and are values held on the map. If the EGR valve can be operated discretely, it is important to set the opening of the EGR valve within a range that does not exceed this target value when the opening of the EGR valve is changed.
- the target value of the EGR flow rate (F( ⁇ C ) ⁇ (1+ ⁇ Regr)) is larger than the flow rate (F( ⁇ C+1 )) at the valve opening ⁇ C+1 .
- the target value of the EGR valve opening can be ⁇ C+1 .
- the opening degree of the EGR valve can be set more finely.
- the black circles in FIG. 4B mean the values held on the map. Since the target value of the EGR flow rate is between F( ⁇ C+2 ) and F( ⁇ C+1 ) on the map, these values, ⁇ C+2 and ⁇ C+1 are used to obtain the target value ⁇ ′ of the EGR valve opening degree.
- Target value ⁇ ′ A ⁇ (EGR flow rate target value ⁇ F( ⁇ C+1 ))+ ⁇ C+1
- A ( ⁇ C+2 ⁇ C+1 ) ⁇ (F( ⁇ C+2 ) ⁇ F( ⁇ C+1 ))
- the EGR flow rate to be realized can be brought closer to the target value assumed in step S405.
- the EGR flow rate can be increased within a range in which destabilization of combustion can be suppressed, and efficiency can be further improved.
- the EGR flow rate change rate can be changed according to the difference between the combustion state change amount and the change amount target. can reduce the time to reach optimal conditions.
- Fig. 5 shows an example of the results of the above processing. From the top, the throttle opening, the amount of air (detected value), the amount of change in the combustion center, the steady determination flag, the EGR valve opening, and the EGR rate are shown.
- the throttle opening changes at time t1
- the steady state judgment is made at time t2
- the EGR increase operation starts based on the amount of change in the combustion center at time t3
- the steady state judgment after the operation is made at time t4
- the steady state judgment is made at time t5.
- Various operations such as the start of EGR reduction operation based on the amount of change in the combustion center are occurring.
- FIG. 6 shows a control flow of arithmetic processing for controlling the degree of dilution, ignition timing, and ignition energy in the first embodiment.
- Step S601 is a process executed by the combustion center change amount calculation unit 32
- step S602 is a process executed by the steady state determination unit 31
- steps S603 to S612 are executed by the actuator operation amount correction unit 33. processing.
- Step S601 is the same processing as step S401 in FIG. 4A.
- Step S602 is the same processing as step S402 in FIG. 4A.
- Step S603 is the same processing as step S403 in FIG. 4A.
- step S604 it is determined whether the absolute value of the difference between the amount of change in the combustion center position and the desired amount of change is less than a predetermined value.
- the fact that the absolute value of the same difference is less than the predetermined value indicates that the operation is being performed under conditions close to the allowable amount of change. If the absolute value of the same difference is greater than or equal to the predetermined value, the process proceeds to step S605. On the other hand, if the absolute value of the same difference is less than the predetermined value, the flow ends.
- Step S605 it is determined whether the amount of change is greater than the target amount of change.
- Step S605 is a block for determining whether the combustion state has become unstable or stabilized. If the amount of change is greater than the target amount of change, the process advances to step S606 to control the ignition system. If the amount of change is equal to or less than the target amount of change, the process advances to step S611 to control the degree of dilution.
- step S606 it is determined whether or not the ignition timing considered flag is 0.
- the ignition timing considered flag indicates whether or not it is evaluated under current operating conditions whether the amount of change in the combustion state is reduced by advancing the ignition timing when the amount of change in the combustion state is large. is.
- Step S607 It is determined whether the amount of change in the combustion state is reduced by advancing the ignition timing. For example, when the amount of change in the combustion state is greater than a predetermined value before and after the ignition timing is advanced (when the amount of change in the combustion state is significantly decreased), it is determined that there is improvement, and the process proceeds to step S609. When the amount of change in the combustion state before and after the ignition timing advance is smaller than the predetermined value, it is determined that there is no improvement, and the process proceeds to step S608. [Step S608] In step S608, since there is no change in the combustion state before and after advancing the ignition timing, it is determined that there is no effect of advancing the ignition timing, and the ignition timing is returned to the state before advancing (reference ignition timing).
- step S609 it is determined whether the amount of energy that can be generated by the ignition coil reaches the upper limit. This determination is to determine whether it is possible to increase the energy that can be generated by the coil by increasing the energization amount of the coil. For example, if it is a normal coil, it is determined whether the setting of the primary coil energization amount is the upper limit of the primary coil energization amount. The coil energization amount is limited by heat generation of the coil and magnetic saturation of the coil.
- Step S611 is the same processing as step S405 in FIG.
- Step S612 is the same processing as step S406 in FIG.
- step S613 the ignition timing is advanced by a predetermined value, and the ignition timing considered flag is set to "1".
- the predetermined value of the ignition advance amount is mapped in advance for each operating condition. For example, it can be set in the range of about 2deg. to 5deg.
- FIG. 7 shows an example of the results of the above processing. From the top, the throttle opening, the amount of air (detected value), the amount of change in the combustion center, which is one of the combustion states, the steady state determination flag, the EGR valve opening, and the EGR rate are shown.
- the ignition advance operation is started at time t1
- the EGR increasing operation is performed based on the amount of change in the combustion center at time t2.
- the ignition energy primary coil energization period
- the EGR reduction operation is performed based on the amount of change in the combustion center at time t5. .
- FIG. 8 is a control flow of arithmetic processing for controlling the degree of dilution, ignition timing, and ignition energy in the first embodiment, but some judgments are made based on the average value of the combustion state instead of the amount of change in the combustion state.
- Step S801 is a process executed by the combustion center change amount calculation unit 32
- step S802 is a process executed by the steady state determination unit 31
- steps S803 to S810 are executed by the actuator operation amount correction unit 33. processing.
- Step S801 is the same processing as step S401 in FIG. 4A.
- Step S802 is the same processing as step S402 in FIG. 4A.
- Step S603 is the same processing as step S403 in FIG. 4A.
- step S804 the same determination as in step S604 of FIG. 6 is performed. If the absolute value of the difference between the amount of change in the combustion center position and the desired amount of change is greater than or equal to the predetermined value, the process proceeds to step S805. On the other hand, if the absolute value of the same difference is less than the predetermined value, the condition is determined to be optimal and the flow ends.
- step S805 it is determined whether the average value of the combustion center position, which is the average value of the combustion state, is within a predetermined range. It is considered necessary to position the combustion center position within a range of approximately 10 deg.ATDC after the top dead center in order to increase the thermal efficiency.
- the predetermined range is 10 deg. can be set as
- the setting range is not limited to this numerical value, and can be appropriately set depending on the engine and degree of dilution. If the average value of the combustion center position is within the predetermined range, it is determined that the ignition timing is set to an appropriate state, and the process proceeds to step S806. , the process advances to step S811 to correct the ignition timing.
- step S806 the same determination as in step S605 of FIG. 6 is performed. If the amount of change is greater than the target amount of change, the process advances to step S807 to control the ignition system. If the amount of change is equal to or less than the target amount of change, the process advances to step S809 to control the degree of dilution.
- step S807 the same determination as in step S609 of FIG. 6 is performed. If the ignition energy setting has not reached the upper limit, the process proceeds to step S807 to increase the ignition energy. If it reaches the upper limit, the flow advances to step S809 to control the degree of dilution.
- Step S808 is the same processing as step S610 in FIG.
- Step S809 is the same processing as step S405 in FIG.
- Step S810 is the same processing as step S406 in FIG.
- step S811 is processing for controlling the combustion center position based on the ignition timing. For example, if the combustion center position is before top dead center, retard the ignition timing, and if the combustion center position is later than 10deg.ATDC after top dead center, advance the ignition timing. do.
- the ignition timing correction amount may be determined by the following formula.
- Ignition timing correction amount Average value of combustion center position ⁇ Target combustion center position
- a positive value of the ignition timing correction amount means to retard the ignition timing, and a negative value means to advance the ignition timing.
- the target combustion center position may be, for example, 5 degrees.
- the target combustion center position is not a fixed value, but may be changed for each engine, or may be changed for each operating condition. By setting in this way, appropriate ignition timing operation can be easily performed based on the combustion state.
- the ignition timing can be set quantitatively by operating the ignition timing based on the average value of the combustion center position.
- the ignition energy can be manipulated, it is possible to use an actuator with a quick response.
- FIG. 9 shows an example of the results of the above processing. From the top, the throttle opening, the amount of air (detected value), the combustion center position, which is one of the combustion states, the amount of change in the combustion center, which is one of the combustion states, the steady state judgment flag, the EGR valve opening, and the EGR rate indicates
- the ignition advance operation is started at time t1
- the EGR increasing operation is performed based on the amount of change in the combustion center at time t2.
- the combustion center position is within the predetermined range surrounded by the dashed line, the amount of change in the combustion center is larger than the target value. do.
- an EGR reduction operation is performed based on the amount of change in the combustion center.
- the combustion center position By manipulating the ignition timing starting from time t1, the combustion center position enters a predetermined value. Furthermore, the amount of change in the combustion center position has decreased, and the difference between the amount of change in the combustion center position and the target value indicated by the dashed line has increased. In this way, by performing an operation based on the amount of change in the combustion state, even after the ignition timing has been set to an appropriate state and has reached a stable state, the state of dilution is set to a high state, improving efficiency. It may be possible.
- the combustion center position is within the predetermined range, but since the amount of change in the combustion state is greater than the predetermined value, the ignition energy is increased, so the primary coil energization period begins to increase. Although the amount of change in the combustion state due to the energization of the ignition coil due to the increase in the energization period decreases, it does not reach the target value indicated by the dashed line, so the dilution degree operation starts at time t5. In this case, the ignition energy is maintained without changing the setting of the primary coil energization time.
- the ignition timing can be set to an appropriate state based on a more quantitative index, and the ignition energy and the degree of dilution can be operated based on the amount of change in the combustion state, and the appropriate means can be quickly selected. Furthermore, it is possible to quickly transition to a state with high efficiency.
- FIG. 10 shows blocks for executing processing in the combustion center change amount calculation unit 32 in FIG.
- An air-fuel mixture state estimator 1001 estimates the air-fuel mixture state based on various inputs of intake pressure, EGR rate, air-fuel ratio, humidity, intake air temperature, and valve timing (variable valve timing mechanism (variable valve 5)).
- In-cylinder pressure history estimating section 1002 estimates the in-cylinder pressure history or the in-cylinder pressure at a plurality of crank angles based on the result estimated by the air-fuel mixture state estimating section and the information on the angular velocity of the crank angle.
- the combustion center estimation unit 1003 estimates the combustion center position based on the information of the cylinder pressure estimated by the cylinder pressure history estimation unit and the combustion model formula. Further, the combustion center position variation calculation unit 1004 calculates the amount of change in the combustion center position based on the estimated values of the combustion center position for a plurality of cycles.
- the amount of change in the combustion state described above means the amount of change in the combustion center position.
- FIG. 11 is a flow chart showing the processing executed by each block in FIG. Step S1101 is performed by the air-fuel mixture state estimation unit, steps S1102 and S1103 are performed by the in-cylinder pressure history estimation unit 1002, step S1104 is performed by the combustion center estimation unit 1003, and step S1105 is performed by the combustion center position fluctuation calculation unit 1004.
- step S1101 the fuel amount (input energy amount) as the state of the air-fuel mixture is estimated from information such as the intake pressure using the following equation.
- step S1103 a crank angle ((ii) described later) and a maximum value of in-cylinder pressure ((iii) described later) are calculated from the relational expression between the angular velocity and the in-cylinder pressure.
- ⁇ ( ⁇ k ) is angular velocity [rad/s]
- t( ⁇ k ) is time [s] at crank angle ⁇ k
- p( ⁇ k ) is cylinder pressure at crank angle ⁇ k [Pa]
- p atm is the atmospheric pressure [Pa]
- ⁇ is the specific heat ratio of unburned gas [-]
- ⁇ b is the specific heat ratio of burned gas [-].
- the specific heat ratio of unburned gas and the specific heat ratio of burned gas vary depending on the state of the gas, but can be set to a value of approximately 1.2 to 1.4.
- the value of p( ⁇ k ) can be estimated using an estimation formula. For example, there is the following estimation formula.
- Cint is a model constant and ⁇ E is the ratio of exhaust heat to input energy [-]. These values can be predetermined by engine tests or simulations.
- ⁇ pmax is calculated by substituting the in-cylinder volume V( ⁇ pmax ) that maximizes the in-cylinder pressure in (i) for V( ⁇ ) and solving the nonlinear equation.
- pmax is calculated by substituting the in-cylinder volume V( ⁇ pmax ) at which the in-cylinder pressure of (i) is maximum into V( ⁇ ).
- Step S1104 Using (i) to (iii) calculated in step S1103, the combustion center position is calculated.
- ⁇ IE is the ratio of output and exhaust heat to input energy [-]
- Cpmax is the model constant [-].
- the combustion ratio at the maximum pressure is calculated by substituting (i) to (iii) calculated in step S1103.
- a and m are model constants. These values can be predetermined by engine tests or simulations.
- the combustion period is calculated by substituting the combustion ratio calculated in (iv) and the crank angle calculated in (ii).
- Step S1105 Calculate the amount of change in the combustion state from the accumulated information on the combustion center position.
- the standard deviation of the combustion center position can be used as the amount of change in the combustion state.
- the standard deviation has a strong correlation with the standard deviation or the amount of change in engine torque, and is suitable as an indicator of the amount of change in the combustion state.
- the combustion center position and its variation can be calculated with high accuracy without using an in-cylinder pressure sensor or similar detection device.
- the point above is to detect the angular velocity based on the crank angle sensor at two points before and after the ignition timing and after the top dead center. It is appropriate to use the crank angular velocity under the same two conditions because the crank angular velocity changes greatly when combustion occurs under the same two conditions, and changes due to combustion are included as information.
- the processor (CPU 23a, FIG. 2) of the control device for the internal combustion engine calculates the amount of change in a parameter (for example, combustion center position) indicating the combustion state of the internal combustion engine (combustion center change amount calculator 32, FIG. 3).
- a processor (CPU 23a) corrects the operation amount of an actuator (for example, an EGR valve) that adjusts the dilution of the air-fuel mixture according to the difference between the amount of change in the parameter indicating the combustion state and the target value of the amount of change. Bring the amount closer to the target value (actuator operation amount correction unit 33, FIG.
- the degree of dilution is adjusted, and the amount of change (variation in combustion state) of the parameter indicating the combustion state (for example, the combustion center position) approaches the target value (upper limit value of variation in combustion state). Therefore, the internal combustion engine can be operated in a state where the degree of dilution is close to the limit. As a result, the fuel consumption of the internal combustion engine can be reduced.
- the actuator is, for example, an EGR valve.
- the processor CPU 23a
- increases the opening of the EGR valve time t3, FIG. 5.
- the opening degree of the EGR valve is decreased as the difference between the amount of change and the target value increases (time t5, FIG. 5).
- the EGR in this embodiment is external EGR, it may be internal EGR in which the timing of closing the exhaust valve is delayed by a variable valve timing mechanism (variable valve 5) to return the exhaust gas to the combustion chamber.
- the actuator that adjusts the degree of dilution of the air-fuel mixture is the variable valve timing mechanism, but it can be said that the exhaust valve also functions as the EGR valve.
- the processor advances the ignition timing when the amount of change in the parameter indicating the combustion state is greater than the target value (time t1, FIG. 7). As a result, the amount of change in the parameter indicating the combustion state can be reduced more quickly and brought closer to the target value.
- the processor increases the discharge energy generated in the ignition device if the amount of change does not decrease (time t4, FIG. 7). As a result, the combustion state is stabilized, and the amount of change in the parameter indicating the combustion state can be reduced. Moreover, since the discharge energy is increased only when there is no effect of advance, it is possible to suppress wear of the electrode of the spark plug.
- a parameter that indicates the combustion state is, for example, the average value of the combustion center position.
- the processor CPU 23a advances the ignition timing when the average value of the combustion center position is outside the predetermined range (time t1, FIG. 9). Thereby, the ignition timing can be advanced according to the average value of the combustion center position.
- the processor increases the discharge energy generated in the ignition device when the average value of the combustion center position is within a predetermined range and the amount of change in the parameter indicating the combustion state is greater than the target value (time t4, FIG. 9).
- the ignition timing can be advanced in accordance with the average value of the combustion center position and the amount of change in the parameter indicating the combustion state.
- the parameter indicating the combustion state is the crank angle (combustion center position) at which the combustion ratio of the air-fuel mixture is a predetermined value (0.5). or the crank angle at which the in-cylinder pressure is maximized.
- the parameter that indicates the combustion state is the combustion center position.
- the processor (CPU 23a) estimates the in-cylinder pressure of the internal combustion engine based on the crank angular velocity ( ⁇ 1) at the first timing after the ignition timing and the crank angular velocity ( ⁇ 2) at the second timing before the exhaust valve opens.
- the combustion center position is estimated using the in-cylinder pressure (Fig. 11).
- the combustion center position can be estimated without using an in-cylinder sensor (pressure sensor).
- an in-cylinder sensor since an in-cylinder sensor is not used, the manufacturing cost can be reduced.
- the combustion center position may be estimated using the in-cylinder pressure detected by the sensor (Fig. 13). This can reduce the load on the processor, for example.
- the processor (CPU 23a) corrects the operation amount of the actuator when the intake system is in a steady state (FIG. 4A), but the running state is a constant speed state or the running state is a constant acceleration state. It may be corrected when it is in the state.
- the manipulated variable of the actuator can be corrected while the manipulated variable (correction target) of the actuator does not fluctuate as much as possible.
- the amount of change may be any deviation that indicates the difference from the reference value.
- the reference value may be the value of a parameter (for example, combustion center position) indicating the combustion state in the previous combustion cycle instead of the average value. That is, the amount of change may be a cycle amount of change that indicates the amount of change for each combustion cycle.
- FIG. 12 is a control block showing an outline of the discharge energy control performed by the ignition control unit 24 and the EGR rate control unit 25 in the ECU 20, which is the control device for the internal combustion engine according to the embodiment of the present invention.
- Embodiment. The difference from the embodiment of FIG. 3 is that the detected value of the in-cylinder pressure is used to calculate the amount of change in the combustion center. 3 and 12, the steady-state determination section and the actuator operation amount correction section are the same. The difference is that part of the input to the combustion center change amount calculation unit changes from the value of the crank angle sensor to the in-cylinder pressure.
- FIG. 13 shows the block configuration of the combustion center change amount calculator 1202 of the second embodiment of the present invention.
- the mixture state estimator 1301 is the same as the mixture state estimator 1001 in FIG.
- the combustion center position fluctuation calculating section 1303 is the same as the combustion center position fluctuation calculating section 1004 in FIG.
- the difference from Fig. 3 is that there is no in-cylinder pressure history estimating unit because the detected value of the in-cylinder pressure can be input, and the processing of the combustion center estimating unit is different due to the input of the detected value of the in-cylinder pressure. is.
- the combustion ratio at the in-cylinder pressure detection timing calculated in (vii) is substituted to calculate the combustion period.
- the combustion center position is calculated by substituting the combustion period calculated in (viii).
- the point above is to detect the cylinder pressure at two points before and after the ignition timing and after the top dead center.
- the points after the top dead center have the state of progress of combustion at a predetermined timing, and it is appropriate to select the state in the middle of combustion as much as possible.
- the in-cylinder pressure may be detected using an in-cylinder pressure sensor, or may be detected indirectly from the information of an index correlated with the in-cylinder pressure (for example, the secondary voltage of the ignition coil, etc.). .
- the present invention is not limited to the above-described embodiments, and includes various modifications.
- the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations.
- part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment.
- each of the above configurations, functions, etc. may be realized by hardware, for example, by designing a part or all of them with an integrated circuit.
- each of the above configurations, functions, and the like may be realized by software by a processor (microcomputer) interpreting and executing a program for realizing each function.
- Information such as programs, tables, and files that implement each function can be stored in memory, hard disks, SSD (Solid State Drives), and other recording devices, or IC cards, SD cards, DVDs, and other recording media.
- a control device for an internal combustion engine comprising: a combustion state estimator for estimating a combustion state in the internal combustion engine;
- the combustion state estimator is a combustion state estimator that estimates the combustion state based on the crank angle sensor signal, and based on the crank angular velocity at a predetermined timing after the ignition timing and the crank angular velocity at a predetermined timing before the exhaust valve opens, from (1), comprising: an in-cylinder pressure history estimating unit for estimating in-cylinder history of the internal combustion engine; and a combustion center estimating unit for estimating a combustion state based on the estimated in-cylinder pressure history. (4) any control device.
- the combustion state estimator is a combustion state estimator that estimates the combustion state based on an estimated value or a detected value of an in-cylinder pressure. Composed of an in-cylinder pressure history estimating unit that estimates the in-cylinder history of the internal combustion engine based on the estimated or detected value of the in-cylinder pressure at the previous predetermined timing, and a combustion center estimating unit that estimates the combustion state based on the estimated in-cylinder pressure history.
- the control device according to any one of (1) to (4), characterized by comprising the estimating unit.
- the manipulated variable correction unit operates to increase discharge energy generated by an ignition device provided in the internal combustion engine when the amount of change in the combustion state is greater than an allowable upper limit value of the amount of change in the combustion state.
- the control device according to any one of (1) to (7), characterized by comprising means for
- the manipulated variable correction unit advances the timing for generating discharge energy by an ignition device provided in the internal combustion engine when the amount of change in the combustion state is greater than an allowable upper limit value of the amount of change in the combustion state.
- the control device according to any one of (1) to (8) characterized by
- manipulated variable correction unit manipulates the timing of generating discharge energy by an ignition device provided in the internal combustion engine when the average value of the combustion state does not fall within a predetermined range. Any control device from (8).
- control device according to any one of (1) to (9), further comprising a steady state determination section for determining that the state of the intake system is in a steady state, and when the steady state determination section determines that the intake system is in a steady state, various actuators
- a steady state determination section for determining that the state of the intake system is in a steady state, and when the steady state determination section determines that the intake system is in a steady state, various actuators
- control device comprising a running state determination unit that determines that the running state is in a constant speed state, and when determining that the running state is in a constant speed state,
- a control device for an internal combustion engine characterized in that it operates various actuators.
- control device comprising a running state determination unit that determines that the running state is in a constant acceleration state, and when determining that the state is in a constant acceleration state,
- a control device for an internal combustion engine characterized in that it operates various actuators.
- the degree of dilution can be controlled based on the amount of change in the combustion state in the internal combustion engine. You can set the upper limit of the dilution in the range. By setting the upper limit of the dilution rate within the range of allowable changes in the combustion state, it is possible to set the dilution rate differently for each aircraft based on the variation of each aircraft, and improve the efficiency during actual driving for each aircraft. .
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Signal Processing (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
Description
以下、図面を参照しながら、本発明の実施形態について説明するが、以下に示す実施形態に共通の構成を図1乃至図3を用いて説明する。
また、気筒内に流入する混合気、または気筒内から排出する排気ガスを調整する可変バルブ5が、シリンダヘッドに備えられている。可変バルブ5を調整することにより、全気筒の吸気量および内部EGR量を調整する。
ステップS401では、角速度、各種パラメータに基づき燃焼中心位置の変化量を算出する。ここでの詳細の処理は、別途、説明する。
ステップS402では、アクチュエータ操作量、空気量検出値に基づき定常判定する。具体的には、アクチュエータの操作量、空気量の検出値のそれぞれの所定期間内の変化量が所定値未満であることに基づき判定する。所定期間内の変化量が所定値未満である場合は、定常判定フラグを1、同条件を満たさない場合は定常判定フラグを0と設定する。例えば、所定期間を500ms、所定値を10%と設定できる。
ステップS403では、定常条件であり、かつ、EGRバルブの開度から希釈燃焼条件にあるかを判断する。定常条件か否かは、ステップS402で設定した定常判定フラグにより判断する。希釈燃焼状態にあるかは、EGRバルブが全閉か否かで判断する。全閉であれば、希釈条件では無いと判断する。したがって、定常判定フラグが1かつ、EGRバルブ開度が全閉では無い、場合は、ステップS404に進む。定常判定フラグが0またはEGRバルブ開度が全閉の場合は、フローを終了する。
ステップS404では、燃焼中心位置の変化量と変化量目標値の差の絶対値が所定値未満であるかを判断する。同差の絶対値が所定値未満であるということは、許容される変化量に近い条件にて運転ができていることを示す。同差の絶対値が所定値以上である場合は、ステップS405に進む。一方、同差の絶対値が所定値より未満である場合は、フローを終了する。
ステップS405では、燃焼状態の変化量目標と燃焼状態の変化量の差に基づくEGR流量増減目標を算出する。これは、変化量目標に比べて変化量が小さい場合(変化量目標と変化量の差が正の場合)は、EGR流量を増加する方向に操作し、変化量目標に比べて変化量が大きい場合(変化量目標と変化量の差が負の場合)は、EGR流量を減少させる方向に操作する。例えば、以下の式で算出すればよい。
EGR流量増減率目標値=C×空気流量×(変化量目標-変化量)
ステップS406では、ステップS405で決めたEGR流量増減率目標値に基づき、EGRバルブ操作量を算出する。以下に事例を示す。図4Bは、EGRバルブ開度と流量の関係を示している。図4Bにおいては、バルブ開度全開の流量における値を1、全閉における値を0として、流量を0~1に正規化して表している。EGRバルブ開度と正規化した流量の変化量は、エンジン試験やシミュレーションにより予め計測し、EGRバルブ開度を軸とする流量のマップとしてECUに保持することで、制御に用いることができる。以下の説明では、バルブ開度と正規化した流量の関係を次のように表現する。
相対流量値=F(EGRバルブ開度)
EGR流量の目標値=F(θC)×(1+ΔRegr)
目標値θ’=A×(EGR流量の目標値-F(θC+1))+θC+1
A=(θC+2-θC+1)÷(F(θC+2)-F(θC+1))
ステップS601は、図4AのステップS401と同一の処理である。
ステップS602は、図4AのステップS402と同一の処理である。
ステップS603は、図4AのステップS403と同一の処理である。
ステップS604では、燃焼中心位置の変化量と変化量目標値の差の絶対値が所定値未満であるかを判断する。同差の絶対値が所定値未満であるということは、許容される変化量に近い条件にて運転ができていることを示す。同差の絶対値が所定値以上である場合は、ステップS605に進む。一方、同差の絶対値が所定値未満である場合は、フローを終了する。
ステップS605では、変化量が変化量目標よりも大きいかを判断する。ステップS605は、燃焼状態の不安定化、安定化を判断するブロックである。変化量が変化量目標よりも大きい場合は、ステップS606に進み、点火系の制御をおこなう。変化量が変化量目標以下である場合は、ステップS611に進み、希釈度への制御に進む。
ステップS606では、点火時期検討済フラグが0であるかを判断する。点火時期検討済フラグは、燃焼状態の変化量が大きい状態にある際に、点火時期を進角化することで、同変化量が小さくなるかを現運転条件で評価したか否かを示すフラグである。点火時期検討済フラグ=0は、点火時期を進角設定し運転を行っていないこと、同フラグが1は、点火時期を進角し燃焼状態の変化量が変化するかを評価済みであること、を示す。点火時期検討済フラグ=1の場合は、ステップS607に進み、点火時期検討済フラグ=0の場合は、ステップS613に進む。
点火時期を進角制御したことで燃焼状態の変化量が減少したかを判断する。例えば、点火時期の進角前後で、燃焼状態の変化量が所定値よりも大きい場合(燃焼状態の変化量が有意に減少した場合)は、改善有と判断し、ステップS609に進む。点火時期の進角前後で、燃焼状態の変化量が所定値よりも小さい場合は、改善無しと判断し、ステップS608に進む。
[ステップS608]
ステップS608では、点火時期の進角前後で燃焼状態の変化が無いということで、点火時期進角の効果は無いと判断し、点火時期を進角前の状態(基準点火時期)に戻す。続いて、ステップS609に進む。
[ステップS609]
ステップS609では、点火コイルで発生できるエネルギ量の上限に達しているかを判断する。この判定は、コイルの通電量の増加により、コイルで発生できるエネルギの増加が可能かを判断することである。例えば、通常のコイルであれば、1次コイル通電量の設定が1次コイル通電量の上限になっているかを判定する。コイル通電量は、コイルの発熱、コイルの磁気飽和といったことで制限される。
ステップS611は、図4のステップS405と同一の処理である。
[ステップS612]
ステップS612は、図4のステップS406と同一の処理である。
[ステップS613]
ステップS613では、点火時期を予め決めた所定値だけ進角に補正し、点火時期検討済フラグ=1とする。点火進角量の所定値は、運転条件毎に予めマップ化しておく。例えば、2deg.から5deg.程度の範囲で設定できる。
ステップS801は、図4AのステップS401と同一の処理である。
ステップS802は、図4AのステップS402と同一の処理である。
ステップS603は、図4AのステップS403と同一の処理である。
ステップS804では、図6のステップS604と同一の判定を行う。燃焼中心位置の変化量と変化量目標値の差の絶対値が所定値以上である場合は、ステップS805に進む。一方、同差の絶対値が所定値より未満である場合は、状態が最適にあると判断し、フローを終了する。
ステップS805では、燃焼状態の平均値である燃焼中心位置の平均値が所定範囲にあるかを判断する。燃焼中心位置は、上死点後から概ね10deg.ATDCの範囲に位置することが熱効率を高める上で必要と考えられている。例えば、所定範囲として上死点後から10deg.と設定できる。ほかにも、設定範囲(所定範囲)はこの数値に限らず、エンジンや希釈度程度により適切に設定できる。燃焼中心位置の平均値が所定範囲にある場合は、点火時期が適切な状態に設定されていると判断し、ステップS806に進み、燃焼中心位置の平均値が所定の範囲から外れている場合は、ステップS811に進み点火時期の補正を行う。
ステップS806では、図6のステップS605と同一の判定を行う。変化量が変化量目標よりも大きい場合は、ステップS807に進み、点火系の制御をおこなう。変化量が変化量目標以下である場合は、ステップS809に進み、希釈度への制御に進む。
ステップS807では、図6のステップS609と同一の判定を行う。点火エネルギの設定が、上限になっていない場合は、点火エネルギ増加を行うため、ステップS807に進む。上限に至っている場合は、希釈度の制御をおこなうため、ステップS809に進む。
ステップS808は、図6のステップS610と同一の処理である。
ステップS809は、図4のステップS405と同一の処理である。
ステップS810は、図4のステップS406と同一の処理である。
ステップS811は、燃焼中心位置が不適切な状態にあるので、点火時期により燃焼中心位置の制御をおこなう処理である。例えば、燃焼中心位置が上死点より前に来ているのであれば、点火時期を遅角化し、燃焼中心位置が上死点後10deg.ATDCよりも遅いのであれば、点火時期を進角化する。例えば、以下の式で点火時期の補正量を決めても良い。
点火時期補正量の正の値は点火時期を遅角することを意味し、負の値は点火時期を進角することを示す。目標燃焼中心位置は例えば5deg.とすればよい。目標燃焼中心位置は、一定の値ではなく、エンジンごとに変えても良いし、運転条件毎に変えても良い。このように設定することで、燃焼状態を踏まえて適切な点火時期の操作が簡単にできる。
ステップS1101では、次式を用いて混合気の状態として投入した燃料量(投入エネルギ量)を吸気圧等の情報から推定する。
ステップS1103では、角速度と筒内圧力の関係式から、クランク角度(後述の(ii))、筒内圧最大値(後述の(iii))を算出する。
ステップS1103で算出した(i)~(iii)を用いて、燃焼中心位置を算出する。
燃焼中心位置の蓄積情報から、燃焼状態の変化量を算出。燃焼状態の変化量としては、例えば燃焼中心位置の標準偏差を用いることができる。同標準偏差は、エンジントルクの標準偏差または変化量と相関が強く、燃焼状態の変化量の指標として適している。
これにより、希釈度が調整され、燃焼状態を示すパラメータ(例えば、燃焼中心位置)の変化量(燃焼状態のばらつき)が目標値(燃焼状態のばらつきの上限値)に近づく。そのため、希釈度が限界に近い状態で内燃機関の運転を実現することができる。その結果、内燃機関の燃料消費量を低減することができる。
図12は、本発明の実施形態になる内燃機関の制御装置であるECU20内の点火制御部24、EGR率制御部25で実施される放電エネルギ制御の概要を示す制御ブロックであり、第2の実施形態である。図3の実施形態との違いは、燃焼中心変化量の算出に筒内圧の検出値を用いる点である。図3と図12における、定常判定部、アクチュエータ操作量補正部は同一である。燃焼中心変化量算出部の入力の一部が、クランク角度センサの値から、筒内圧力に変化している部分が異なる点である。
(vii).筒内圧検出時期θMにける燃焼割合の式
(viii).筒内圧検出時期の燃焼割合に基づく燃焼期間の式
(ix).燃焼中心位置の式
前記燃焼状態推定部はクランク角センサ信号に基づき前記燃焼状態を推定する燃焼状態推定部であり、点火時期後の所定時期におけるクランク角速度と、排気弁が開く前の所定タイミングにおけるクランク角速度に基づき、内燃機関の筒内履歴を推定する筒内圧履歴推定部、推定した筒内圧履歴に基づき燃焼状態を推定する燃焼中心推定部、で構成される前記推定部を備えることを特徴とする(1)から(4)のいずれかの制御装置。
前記燃焼状態推定部は筒内圧の推定値または検出値に基づき前記燃焼状態を推定する燃焼状態推定部であり、点火時期後の所定時期における筒内圧の推定値または検出値と、排気弁が開く前の所定タイミングにおける筒内圧の推定値または検出値に基づき、内燃機関の筒内履歴を推定する筒内圧履歴推定部、推定した筒内圧履歴に基づき燃焼状態を推定する燃焼中心推定部、で構成される前記推定部を備えることを特徴とする(1)から(4)のいずれかの制御装置。
前記操作量補正部は、前記燃焼状態の変化量と前記燃焼状態の変化量の目標値の差と希釈度の操作量に正の相関を持つことを特徴とする(1)から(6)のいずれかの制御装置。
前記操作量補正部は、前記燃焼状態の変化量が前記燃焼状態の変化量の許容上限値よりも大きい場合に、前記内燃機関に備えられた点火装置により発生する放電エネルギを増加させるように操作する手段を備えることを特徴とする(1)から(7)のいずれかの制御装置。
Claims (10)
- 内燃機関の燃焼状態を示すパラメータの変化量を算出し、
前記燃焼状態を示すパラメータの変化量と前記変化量の目標値との差に応じて、混合気の希釈度を調整するアクチュエータの操作量を補正し、前記変化量を前記目標値に近づけるプロセッサを備えることを特徴とする内燃機関の制御装置。 - 請求項1に記載の内燃機関の制御装置であって、
前記アクチュエータは、EGR弁であり、
前記プロセッサは、
前記燃焼状態を示すパラメータの変化量が前記目標値より小さい場合、前記差が大きくなるにつれて、前記EGR弁の開度を大きくし、
前記燃焼状態を示すパラメータの変化量が前記目標値より大きい場合、前記差が大きくなるにつれて、前記EGR弁の開度を小さくする
ことを特徴とする内燃機関の制御装置。 - 請求項2に記載の内燃機関の制御装置であって、
前記プロセッサは、
前記燃焼状態を示すパラメータの変化量が前記目標値より大きい場合、点火時期を進角させる
ことを特徴とする内燃機関の制御装置。 - 請求項3に記載の内燃機関の制御装置であって、
前記プロセッサは、
点火時期が進角された後、前記変化量が減少しない場合、点火装置に発生する放電エネルギを増加させる
ことを特徴とする内燃機関の制御装置。 - 請求項2に記載の内燃機関の制御装置であって、
前記燃焼状態を示すパラメータは、燃焼中心位置の平均値であり、
前記プロセッサは、
前記燃焼中心位置の平均値が所定範囲の外にある場合、点火時期を進角させる
ことを特徴とする内燃機関の制御装置。 - 請求項5に記載の内燃機関の制御装置であって、
前記プロセッサは、
前記燃焼中心位置の平均値が所定範囲内にあり、かつ前記燃焼状態を示すパラメータの変化量が前記目標値より大きい場合、点火装置に発生する放電エネルギを増加させる
ことを特徴とする内燃機関の制御装置。 - 請求項1に記載の内燃機関の制御装置であって、
前記燃焼状態を示すパラメータは、
混合気の燃焼割合に相関を持つ指標、
前記混合気の燃焼割合が所定の値となるクランク角度、
筒内圧の最大値、又は
筒内圧が最大となるクランク角度である
ことを特徴とする内燃機関の制御装置。 - 請求項1に記載の内燃機関の制御装置であって、
前記燃焼状態を示すパラメータは、燃焼中心位置であり、
前記プロセッサは、
点火時期後の第1タイミングにおけるクランク角速度と、排気弁が開く前の第2タイミングにおけるクランク角速度に基づき、前記内燃機関の筒内圧を推定し、推定した前記筒内圧を用いて前記燃焼中心位置を推定する、又は
センサによって検出された筒内圧を用いて前記燃焼中心位置を推定する
ことを特徴とする内燃機関の制御装置。 - 請求項1に記載の内燃機関の制御装置であって、
前記プロセッサは、
吸気系状態が定常状態である、走行状態が一定速状態である、又は走行状態が一定加速状態であるときに、前記アクチュエータの操作量を補正する
ことを特徴とする内燃機関の制御装置。 - 請求項1に記載の内燃機関の制御装置であって、
前記変化量は、
基準値との差を示す偏差であり、
前記基準値は、
前の燃焼サイクルにおける前記燃焼状態を示すパラメータの値である
ことを特徴とする内燃機関の制御装置。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US18/562,060 US20240229731A1 (en) | 2021-06-17 | 2022-02-02 | Control Device for Internal Combustion Engine |
DE112022001219.6T DE112022001219T5 (de) | 2021-06-17 | 2022-02-02 | Steuervorrichtung für Brennkraftmaschine |
CN202280031519.9A CN117222803A (zh) | 2021-06-17 | 2022-02-02 | 内燃机的控制装置 |
JP2023529468A JP7539578B2 (ja) | 2021-06-17 | 2022-02-02 | 内燃機関の制御装置 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2021100667 | 2021-06-17 | ||
JP2021-100667 | 2021-06-17 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2022264482A1 true WO2022264482A1 (ja) | 2022-12-22 |
Family
ID=84526945
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2022/003910 WO2022264482A1 (ja) | 2021-06-17 | 2022-02-02 | 内燃機関の制御装置 |
Country Status (5)
Country | Link |
---|---|
US (1) | US20240229731A1 (ja) |
JP (1) | JP7539578B2 (ja) |
CN (1) | CN117222803A (ja) |
DE (1) | DE112022001219T5 (ja) |
WO (1) | WO2022264482A1 (ja) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001271665A (ja) * | 2000-03-24 | 2001-10-05 | Nissan Motor Co Ltd | 可変動弁エンジンの制御装置 |
JP2018168699A (ja) * | 2017-03-29 | 2018-11-01 | 日立オートモティブシステムズ株式会社 | 内燃機関の制御装置 |
JP2019120204A (ja) * | 2018-01-09 | 2019-07-22 | 株式会社Subaru | エンジン制御装置 |
JP2019143579A (ja) * | 2018-02-23 | 2019-08-29 | 三菱電機株式会社 | 内燃機関の制御装置及び制御方法 |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7431512B2 (ja) | 2019-05-23 | 2024-02-15 | 日立Astemo株式会社 | 内燃機関制御装置 |
-
2022
- 2022-02-02 JP JP2023529468A patent/JP7539578B2/ja active Active
- 2022-02-02 DE DE112022001219.6T patent/DE112022001219T5/de active Pending
- 2022-02-02 US US18/562,060 patent/US20240229731A1/en active Pending
- 2022-02-02 CN CN202280031519.9A patent/CN117222803A/zh active Pending
- 2022-02-02 WO PCT/JP2022/003910 patent/WO2022264482A1/ja active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001271665A (ja) * | 2000-03-24 | 2001-10-05 | Nissan Motor Co Ltd | 可変動弁エンジンの制御装置 |
JP2018168699A (ja) * | 2017-03-29 | 2018-11-01 | 日立オートモティブシステムズ株式会社 | 内燃機関の制御装置 |
JP2019120204A (ja) * | 2018-01-09 | 2019-07-22 | 株式会社Subaru | エンジン制御装置 |
JP2019143579A (ja) * | 2018-02-23 | 2019-08-29 | 三菱電機株式会社 | 内燃機関の制御装置及び制御方法 |
Also Published As
Publication number | Publication date |
---|---|
JPWO2022264482A1 (ja) | 2022-12-22 |
US20240229731A1 (en) | 2024-07-11 |
DE112022001219T5 (de) | 2024-01-11 |
JP7539578B2 (ja) | 2024-08-23 |
CN117222803A (zh) | 2023-12-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7489998B2 (en) | Method and device for controlling an internal combustion engine | |
US7788019B2 (en) | Control device of internal combustion engine | |
US10436154B2 (en) | Control device of internal-combustion engine | |
US9010302B2 (en) | Control apparatus of a direct injection gasoline engine | |
US9938912B2 (en) | Control device for internal combustion engine | |
EP3521600B1 (en) | Internal combustion engine control device | |
WO2019230406A1 (ja) | 内燃機関の制御装置および内燃機関の制御方法 | |
JPWO2002081888A1 (ja) | 内燃機関の制御装置 | |
CN113015848B (zh) | 控制装置 | |
US10837418B2 (en) | Internal combustion engine control device | |
WO2018096986A1 (ja) | 内燃機関の制御装置 | |
JP5273310B2 (ja) | 内燃機関の制御装置 | |
WO2022264482A1 (ja) | 内燃機関の制御装置 | |
US11754004B2 (en) | Control method and control device for internal combustion engine | |
JP2008248811A (ja) | 内燃機関の制御装置 | |
JP5695878B2 (ja) | 内燃機関の燃焼制御装置及び方法 | |
EP3075991B1 (en) | Control device for internal combustion engine | |
JP4211700B2 (ja) | 内燃機関の燃料噴射制御装置 | |
JP2006017053A (ja) | 過給機付き内燃機関の燃料噴射時期制御装置 | |
WO2022269976A1 (ja) | 内燃機関の制御装置 | |
JP6311363B2 (ja) | 内燃機関の制御装置 | |
JP2005171765A (ja) | 内燃機関の制御装置及び制御方法 | |
JP6330749B2 (ja) | エンジンの制御装置 | |
JP2014231742A (ja) | 内燃機関の制御装置および制御方法 | |
JP6003808B2 (ja) | 内燃機関の制御装置 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 22824483 Country of ref document: EP Kind code of ref document: A1 |
|
WWE | Wipo information: entry into national phase |
Ref document number: 112022001219 Country of ref document: DE Ref document number: 2023529468 Country of ref document: JP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 202280031519.9 Country of ref document: CN |
|
WWE | Wipo information: entry into national phase |
Ref document number: 18562060 Country of ref document: US |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 22824483 Country of ref document: EP Kind code of ref document: A1 |