CN113027617B - Engine scavenging control device, system, method and computer readable medium - Google Patents
Engine scavenging control device, system, method and computer readable medium Download PDFInfo
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- CN113027617B CN113027617B CN201911357730.6A CN201911357730A CN113027617B CN 113027617 B CN113027617 B CN 113027617B CN 201911357730 A CN201911357730 A CN 201911357730A CN 113027617 B CN113027617 B CN 113027617B
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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
- F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
- F02D9/08—Throttle valves specially adapted therefor; Arrangements of such valves in conduits
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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
- F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
- F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
- F02D13/0203—Variable control of intake and exhaust valves
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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
- F02D13/00—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing
- F02D13/02—Controlling the engine output power by varying inlet or exhaust valve operating characteristics, e.g. timing during engine operation
- F02D13/0261—Controlling the valve overlap
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- 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
- Y02T10/12—Improving ICE efficiencies
Abstract
The invention provides an engine scavenging control device, system, method and computer readable medium capable of reducing the influence of turbo lag, reducing emission, avoiding pollution and reducing the cost of an engine. The engine scavenging control apparatus is for a turbocharged engine using an in-cylinder direct injection technique and a variable valve timing system, and includes: an intake valve opening degree calculating section that calculates an intake valve opening degree by dividing a difference between an actual intake valve angle and an advanced intake valve opening angle by a valve overlap angle; a calculation parameter acquisition unit that acquires atmospheric pressure, a pre-vortex temperature, a post-vortex temperature, and a target intake pipe pressure as calculation parameters; an air flow rate ratio calculation unit that calculates an air flow rate ratio corresponding to an intake valve opening degree in real time on the basis of the calculation parameter; and an actual air amount calculation unit that calculates an actual air amount in the cylinder by multiplying the detected air amount by the air flow rate ratio.
Description
Technical Field
The present invention relates to an engine scavenging control device, an engine scavenging control system, an engine scavenging control method, and a computer-readable medium storing a program that causes the engine scavenging control method to be executed.
Background
Conventionally, when a vehicle with a turbocharged engine is driven to accelerate rapidly at a low rotational speed, it has been found that the speed is suddenly increased after a delay of several seconds, causing the driver to feel an uncomfortable feeling that the vehicle has been kicked once. This problem is mainly caused by the fact that, at a low engine speed, the amount of exhaust gas generated is low and insufficient to drive the turbine, and therefore, a large amount of exhaust gas reaches the turbine through the air pipe after the engine speed increases, which causes a time lag, i.e., turbo lag.
As a method for eliminating the turbo lag, a Variable Valve Timing (VVT) technology has been proposed, which compensates for the poor experience caused by turbo lag and the drawback of insufficient intake and unclean exhaust by opening and closing the Valve early and late. The timing at which the intake valve and the exhaust valve are simultaneously opened in the valve timing is referred to as "valve overlap angle". Because of the valve overlap angle, the air in the cylinder is in a flowing state before the exhaust valve is completely closed, the air flow passing through the cylinder has a certain error with the flow measured by the flow sensor before the throttle valve, and an ECU (Electronic Control Unit) controls the oil injection according to the measured flow, so that the predicted optimal air-fuel ratio cannot be achieved, and the emission is increased due to the enrichment.
In order to solve the above problems, the following solutions are proposed: first, an intake/exhaust pressure of an engine is acquired by a sensor, an intake/exhaust pressure difference is calculated, a valve overlap angle is detected, when the intake/exhaust pressure difference is equal to or greater than a pressure difference window value and the valve overlap angle is equal to or greater than an angle window value, an engine scavenging calculation mode is entered, an engine scavenging coefficient is searched for from a calibrated coefficient value table, an actual air volume in an engine cylinder is calculated from the searched engine scavenging coefficient, and finally, a fuel injection amount is calculated from the calculated actual air volume and fuel injection is performed (see patent document 1).
Documents of the prior art
Patent document
Patent document 1: chinese patent No. 108798917
Disclosure of Invention
Technical problem to be solved by the invention
However, in patent document 1, in order to detect the intake and exhaust pressures of the engine, an additional pressure sensor needs to be added, which leads to an increase in the cost of the engine. In addition, since the engine scavenging coefficient is obtained by looking up a table from the intake/exhaust pressure difference and the valve overlap angle by a calibration means, there is a large error. In addition, since the last total gas amount is multiplied by a coefficient to perform correction and iterative calculation is performed according to the last result, an error between the last obtained gas amount and the actual gas amount becomes larger.
The present invention has been made to solve the above problems, and an object of the present invention is to provide an engine scavenging control apparatus, system, method, and computer-readable medium storing a program that causes the engine scavenging control method to be executed, which can solve the problems of inaccurate air flow and insufficient power due to an inaccurate air flow and an insufficient air-fuel ratio at the time of acceleration due to the presence of a valve overlap angle, and which can correct the actual air flow in a cylinder and thus the fuel injection amount in real time by using only a sensor that is necessary for an engine, thereby reducing the influence of turbo lag, reducing emissions, avoiding pollution, and reducing the overall cost of the engine.
Technical scheme for solving technical problem
An engine scavenging control device according to the present invention is an engine scavenging control device for a turbocharged engine using an in-cylinder direct injection technique and a variable valve timing system, the engine scavenging control device including: an intake valve opening degree calculation unit that calculates an intake valve opening degree by acquiring an intake valve actual angle, an intake valve advanced opening angle, and an exhaust valve retarded closing angle of the engine and dividing a difference between the intake valve actual angle and the intake valve advanced opening angle by a valve overlap angle that is a difference between the exhaust valve retarded closing angle and the intake valve advanced opening angle; a calculation parameter acquisition unit that acquires atmospheric pressure, a pre-vortex temperature, a post-vortex temperature, and an intake pipe target pressure as calculation parameters; an air flow rate ratio calculation unit that calculates an air flow rate ratio corresponding to the intake valve opening degree in real time based on the calculation parameter; and an actual gas amount calculation unit that acquires a detected gas amount in the cylinder, and calculates the actual gas amount in the cylinder by multiplying the detected gas amount by the air flow rate ratio.
Further, an engine scavenging control system according to the present invention includes: the engine scavenging control apparatus as described above; the engine; and the sensors are arranged on the engine and at least comprise a crankshaft angle sensor, a camshaft position sensor, an engine water temperature sensor, an engine rotating speed sensor, an air flow meter, an atmospheric pressure sensor and a temperature sensor.
Further, an engine scavenging control method according to the present invention is an engine scavenging control method for a turbocharged engine using an in-cylinder direct injection technique and a variable valve timing system, the engine scavenging control method including: an intake valve opening degree calculation step of obtaining an intake valve actual angle, an intake valve advanced opening angle, and an exhaust valve retarded closing angle of the engine, and calculating the intake valve opening degree by dividing a difference between the intake valve actual angle and the intake valve advanced opening angle by a valve overlap angle that is a difference between the exhaust valve retarded closing angle and the intake valve advanced opening angle; a calculation parameter acquisition step of acquiring atmospheric pressure, a pre-vortex temperature, a post-vortex temperature, and a target pressure of an intake pipe as calculation parameters; an air flow rate ratio calculation step of calculating an air flow rate ratio corresponding to the intake valve opening degree in real time based on the calculation parameter; and an actual gas amount calculation step of acquiring a detected gas amount in the cylinder, and multiplying the detected gas amount by the air flow rate to calculate the actual gas amount in the cylinder.
Further, the computer-readable medium according to the present invention stores a program for executing the engine scavenging control method as described above.
Effects of the invention
According to the engine scavenging control apparatus, system, method, and computer-readable medium of the present invention, since the air flow rate corresponding to the degree of opening of the intake valve is calculated in real time based on the calculation parameter, and the actual air quantity in the cylinder is calculated by multiplying the detected air quantity by the air flow rate, the air quantity in the cylinder is corrected by the mathematical model in the air flow rate calculation unit, and the calculation accuracy of the actual air quantity in the cylinder can be improved. In addition, since the gas amount in the cylinder is corrected in real time, the calculation accuracy of the actual gas amount in the cylinder can be further improved. In addition, only sensors such as an air flow meter and a crank angle sensor which are necessary for the engine are used in the process of calculating the actual air quantity, and extra sensors such as a pressure sensor are not needed, so that the cost of the whole engine can be reduced.
Drawings
Fig. 1 is a block diagram showing the overall configuration of an engine scavenging control system according to the present invention.
Fig. 2 is a schematic diagram for explaining the concept of the valve overlap angle of the engine.
Fig. 3 is a block diagram showing the configuration of an engine scavenging control device according to the present invention.
Fig. 4 is a schematic diagram for explaining a calculation method of the intake valve opening degree.
Fig. 5 is a graph schematically showing the function of the air flow ratio.
Fig. 6 is a pressure characteristic graph for explaining the operation and effect of the engine scavenging control apparatus according to the present invention.
Fig. 7 is a flowchart showing an operation of the engine scavenging control device according to the present invention.
Detailed Description
The following describes a mode for carrying out the present invention with reference to the drawings.
Fig. 1 is a block diagram showing the overall configuration of an engine scavenging control system according to the present invention. As shown in fig. 1, the engine scavenging control system includes an ECU100, a fuel injector 200, an engine 300, and a plurality of sensors that monitor various parameters of the engine 300.
ECU100 monitors various data (e.g., braking, gear shifting, etc.) and various states of vehicle operation (acceleration, slip, fuel consumption, etc.) while engine 300 is running, calculates information transmitted from various sensors according to a pre-designed program, and transmits each parameter to each relevant actuator after processing to perform various predetermined control functions. Although not shown, the ECU100 includes an engine scavenging control device 10 described later, and the engine scavenging control device 10 is connected to a plurality of sensors described later, for example, calculates a fuel injection amount of fuel to be injected into the cylinder based on monitoring signals from the plurality of sensors, and performs fuel injection control of the fuel injector 200 based on the calculated fuel injection amount.
Examples of the plurality of sensors that monitor various parameters of engine 300 include a crank angle sensor 20, a camshaft position sensor 30, an engine water temperature sensor 40, an engine rotational speed sensor 50, and an air flow meter 60 mounted on engine 300, and an atmospheric pressure sensor and a temperature sensor, not shown, mounted on engine 300. The function of these sensors will be explained later. In addition to these sensors, sensors necessary for the engine, such as the intake pipe pressure sensor 70, the throttle position sensor 80, the front oxygen sensor 90, and the rear oxygen sensor 91, are mounted to the engine 300, and the structures and functions of these sensors are known in the art, and therefore, the description thereof is omitted.
The concept of the valve overlap angle is explained below.
Fig. 2 is a schematic diagram for explaining the concept of the valve overlap angle of the engine. As shown in FIG. 2, the piston is defined as the zero position of the crankshaft at bottom dead center, where one revolution of the circumference is two strokes and one cycle is two revolutions. Define # OVERLAPA as the valve overlap angle, # IN _ VVTDMX as the intake valve early opening angle, # EX _ VVTTDMX as the exhaust valve late closing angle. As shown, # OVERLAPA = # EX _ VVTRTDMX- # IN _ VVTADVMX. Where # IN _ VVTADVMX and # EX _ VVTRTDMX are target values obtained by the engine scavenging control apparatus 10 by looking up the MAP IN accordance with the operating conditions of the engine, for example, based on signals from the camshaft position sensor 30, the engine water temperature sensor 40, the engine speed sensor 50, the air flow meter 60, and the like IN fig. 1, respectively. Since current degree monitoring can only achieve 10 ° accuracy, all angles are measured in 10 °. In addition, in order to compensate for the response delay and the delay between the signal and the mechanical structure, the magnitude of the valve overlap angle may be calculated by means of delay correction so that the value is more accurate.
The structure of the engine scavenging control apparatus 10 will be described below.
Fig. 3 is a block diagram showing the configuration of the engine scavenging control device 10 according to the present invention. As shown in fig. 3, the engine scavenging control device 10 includes an intake valve opening degree calculation unit 1, a calculation parameter acquisition unit 2, an air flow ratio calculation unit 3, and an actual air amount calculation unit 4.
The intake valve opening degree calculation portion 1 acquires, for example, an intake valve actual angle from the crank angle sensor 20 IN fig. 1, calculates a valve overlap angle # ovalap IN conjunction with the intake valve advanced opening angle # IN _ VVTADVMX and the exhaust valve retarded closing angle # EX _ VVTRTDMX obtained as described above, and calculates the intake valve opening degree IN the following manner.
A method of calculating the intake valve opening degree will be described with reference to fig. 4. Because the variable valve timing system can adjust the advanced opening angle of the intake valve and the retarded closing angle of the exhaust valve according to different conditions, the valve overlap angle in each period is different. As shown IN fig. 4, # IN _ RLVVT is defined as the intake valve actual angle whose zero point is still when the piston is at the cylinder bottom dead center, # IN _ RLVVT varies with the stroke progression angle, again IN units of 10 °. If the ratio of the angle at which the intake valve is opened to the valve overlap angle, that is, the degree of opening of the intake valve, is defined as x, the calculation is performed based on the following expression (1).
[ mathematical formula 1]
The intake valve opening degree calculation unit 1 outputs the calculated intake valve opening degree x to the air flow ratio calculation unit 3 of the subsequent stage.
Returning to fig. 3, calculation parameter acquisition unit 2 acquires atmospheric pressure from, for example, an atmospheric pressure sensor that detects atmospheric pressure at a location where engine 300 is located, acquires a pre-turbo temperature and a post-turbo temperature from temperature sensors that detect temperatures before and after a turbine of engine 300, and obtains an intake pipe target pressure by looking up a table according to the operating condition of engine 300. Here, # PATM is defined as the obtained atmospheric pressure, # THA is defined as the pre-turbo temperature, # THA2ND is defined as the post-turbo temperature, # TAGTPM1 is defined as the intake pipe target pressure, all of which are factors that affect the intake efficiency, and the calculation parameter acquisition unit 2 outputs them as calculation parameters to the air flow ratio calculation unit 3 of the subsequent stage.
The air flow rate calculation unit 3 calculates the air flow rate corresponding to the intake valve opening degree x in real time based on the acquired calculation parameters # PATM, # THA2ND, and # TAGTPM 1.
Specifically, if # KSCAVEN is defined as the air flow rate ratio, # KSCAVEN is a value that changes from 0 to 1. In addition, since the intake valve opening degree x is the ratio of the opening angle of the intake valve in the valve overlap angle, x is also a value that changes from 0 to 1. Thus, the mathematical model y = ax can be constructed by using the most basic quadratic function formula in mathematics with the value of # KSCAVEN as y 2 + bx + c. If a is defined as a pressure proportionality coefficient, b is defined as a temperature proportionality coefficient, and c is defined as a proportionality constant, a = # PATM/# tagtmp 1, b = # THA/# THA2ND. When x =1, y = a + b + c, c does not take the value, i.e. c =0, because the maximum value that a and b can take is infinitely close to 1. This makes it possible to calculate the air flow rate ratio by using the following equations (2) to (4).
[ mathematical formula 2]
(1) When # IN _ RLVVT ≦ # IN _ VVTVMX (i.e., x ≦ 0)
y＝0 (2)
[ mathematical formula 3]
(2) When # IN _ VVTDMVX < # IN _ RLVVT < # EX _ VVTTMX (i.e., 0 < x < 1)
[ mathematical formula 4]
(3) When # IN _ RLVVT ≧ # EX _ VVTTMMX (i.e., x ≧ 1)
y＝1 (4)
Fig. 5 is a graph schematically showing the function of the air flow rate ratio. As shown in fig. 5, the calculation of the air flow rate ratio is divided into three cases: when the opening angle of the intake valve is equal to or less than an advanced opening angle obtained by looking up a table, that is, when the intake valve is in an exhaust stroke from 0 ° to a start position of a valve overlap angle in the figure, the air flow rate y =0; when the opening angle is between the early intake valve opening angle and the late exhaust valve closing angle, i.e., within the valve overlap angle range in the figure, the air flow rate y is found by the above equation (3); when the opening angle is larger than the exhaust valve retard closing angle obtained by the table lookup, that is, when the intake stroke is 360 ° from the end position of the valve overlap angle in the figure, the air flow rate ratio y =1.
In addition, since the present control logic is active during acceleration, intake pipe target pressure # TAGTPM1 is greater than atmospheric pressure # PATM during supercharging, and therefore, the pressure scaling factor a is a number less than 1. In addition, during normal traveling, the pre-vortex temperature # THA is smaller than the post-vortex temperature # THA2ND, and therefore, the temperature proportionality coefficient b is also a number smaller than 1.
Returning again to fig. 3, the air flow ratio calculation unit 3 calculates the air flow ratio # KSCAVEN based on the above-described manner, and then outputs it to the actual air amount calculation unit 4. When entering the scavenging mode, since the intake valve is opened early and the exhaust valve is closed late, the presence of the valve overlap angle causes a small amount of air to flow out of the exhaust valve closed late after the air amount measured by the air flow meter 60 before the throttle valve enters the cylinder, which also causes a deviation between the actual air amount in the cylinder and the measured detected air amount. Therefore, the actual air amount calculation unit 4 first acquires the detected air amount in the cylinder from the air flow meter 60 of fig. 1, and then calculates the actual air amount in the cylinder based on the detected air amount and the air flow rate from the air flow rate calculation unit 3. Specifically, when # QA00A is defined as the actual gas amount and # QA00 as the detected gas amount, # QA00A is calculated by the following formula (5).
[ math figure 5]
#QA00A＝#KSCAVEN×#QA00 (5)
Therefore, the air quantity in the cylinder is corrected, and the influence of the valve overlap angle on air quantity detection in the scavenging mode is eliminated.
The operation and effect of the engine scavenging control apparatus according to the present invention will be described with reference to the pressure characteristic diagram of fig. 6. Fig. 6 shows the in-cylinder pressure of the engine at the acceleration stage as a function of time, in which the solid line indicates the target supercharging pressure in the conventional scavenging mode, and the alternate long and short dash line indicates the target supercharging pressure after the engine scavenging control device of the present invention is used. As shown in fig. 6, after the engine scavenging control device of the present invention is adopted, the actual air quantity in the cylinder is corrected, so that the target supercharging pressure of the air pipe calculated by using the signal from the air inlet pipe pressure sensor 70 in fig. 1 is improved, thereby increasing the air inlet efficiency and increasing the dynamic property of the vehicle compared with the existing scavenging mode.
Further, the later-described fuel injection amount calculation unit 8 calculates the fuel injection amount using the corrected amount of air, and can make the air-fuel ratio more accurate and closer to the optimum air-fuel ratio, thereby preventing an increase in emission due to an unnecessary increase in fuel concentration.
Returning again to fig. 3, the engine scavenging control apparatus 10 may further include a1 st determining portion 5, a2nd determining portion 6, a3 rd determining portion 7, and a fuel injection amount calculating portion 8.
The 1 st determination unit 5 is configured to determine whether or not to permit entry into the scavenging calculation mode.
First, the 1 st judging section 5 obtains the valve overlap angle from the aforementioned intake valve early opening angle and exhaust valve late closing angle, acquires the engine speed from the aforementioned engine speed sensor 50, and acquires information on the shift position, the vehicle speed, the start timing, and the like from the vehicle. A method of acquiring information such as a shift position, a vehicle speed, and a start time is a known technique, and therefore, a description thereof is omitted.
Then, the 1 st judging section 5 makes the following five judgments based on the obtained various information:
(a1) Whether the starting time is greater than or equal to the starting time judgment value
Since the temperature in the combustion chamber is low at the start of the engine, scavenging causes the combustion temperature to be insufficient all the time, affecting the combustion efficiency, and therefore, the system itself does not perform scavenging. The starting time judgment value is a calibratable value, and the unit of the starting time judgment value is "s", for example.
(b1) Whether the vehicle speed is greater than or equal to 0 and less than or equal to the maximum vehicle speed judgment value of the scavenging mode
When the vehicle runs at high speed, such as 100km/h, the engine speed is about 2000r/min, the air intake and exhaust efficiency is kept high, and the air flow change is stable, so that the scavenging calculation mode is not needed. The maximum vehicle speed determination value of the scavenging mode is also a calibratable value, and the unit thereof is "km/h", for example.
(c1) Whether the engine speed is greater than or equal to the minimum speed judgment value of the scavenging mode and less than or equal to the maximum speed judgment value of the scavenging mode
The purpose of the judgment is to prevent the rotation speed from fluctuating greatly due to sudden intervention of a scavenging calculation mode caused by over-low or over-high rotation speed, and avoid flameout when the rotation speed is over-low and influence on drivability when the rotation speed is over-high. The judgment value of the minimum rotation speed of the scavenging mode and the judgment value of the maximum rotation speed of the scavenging mode are also calibratable values, and the units of the two are r/min.
(d1) Whether the gear is D gear (forward gear)
First, the speed is low in the case of the idling N range or the parking P range, and the scavenging calculation mode is not allowed to be entered in order to prevent the idle fluctuation from being caused. Second, backing up the R range is dangerous and therefore, the scavenging calculation mode is not allowed.
(e1) Whether or not the valve overlap angle is greater than 0
This determination is made to ensure that the scavenging calculation mode is entered in the presence of the valve overlap angle.
Only when all of the five determination results are yes, the 1 st determining unit 5 finally determines that the scavenging calculation mode is allowed to be entered. On the contrary, if one of the five determination results is "no", the 1 st determining unit 5 determines that the scavenging calculation mode is not allowed.
The 2nd determination unit 6 is configured to determine whether or not to start entering the scavenging calculation mode.
First, the 2nd determination unit 6 acquires an accelerator pedal signal from the vehicle when the determination result of the 1 st determination unit 5 indicates that the scavenging calculation mode is permitted. A method of acquiring the accelerator pedal signal is a known technique, and therefore, description thereof is omitted.
Then, the 2nd determination unit 6 makes the following three determinations based on the obtained accelerator pedal signal:
(a2) Whether the opening of the accelerator pedal is larger than or equal to the judgment value of the opening of the accelerator
When the accelerator pedal is increased from 0, the air pipe pressure response is slow, and therefore, the scavenging correction is not performed. The accelerator opening determination value is also a calibratable value, and is expressed in percentage (%), for example.
(b2) Whether the current accelerator pedal opening is larger than the accelerator pedal opening before 20 milliseconds
(c2) Whether the current accelerator pedal opening is larger than or equal to the accelerator pedal opening before 50 milliseconds
Both the above conditions (b 2) and (c 2) are to detect that the current acceleration state is present, the rotation speed changes from low to high, and the air flow changes greatly. The opening degree of the accelerator pedal before 20 milliseconds and the opening degree of the accelerator pedal before 50 milliseconds are both calibratable judgment values.
Only when all of the three determination results are yes, the 2nd determination unit 6 finally determines that the scavenging calculation mode is started. On the other hand, if one of the three determination results is "no", the 2nd determination unit 6 determines not to enter the scavenging calculation mode. Alternatively, when the scavenging calculation mode is entered, if it is determined that one of the three determination results is "no", in order to prevent the pressure from fluctuating due to sudden stop of the scavenging correction and to maintain the scavenging correction after acceleration for a certain period of time, a delay time is set to elapse, and the scavenging calculation mode is exited after the pressure has stabilized for a certain period of time.
The reason why the 1 st and 2nd determination units 5 and 6 are provided separately is that the determination of whether the engine condition permits the air amount correction is made on the large premise, and the determination of whether the engine condition satisfies the correction requirement is made on the small premise that the correction is made when the acceleration operation occurs.
The 3 rd determination unit 7 determines whether to exit the scavenging calculation mode.
First, the 3 rd determining unit 7 obtains a valve overlap angle from the aforementioned early intake valve opening angle and late exhaust valve closing angle, obtains the engine speed from the aforementioned engine speed sensor 50, and obtains a start/stop signal and a brake signal from the vehicle. The method of acquiring the start-stop signal and the brake signal is a known technique, and therefore, the description thereof is omitted.
Then, the 3 rd judging unit 7 makes the following four judgments:
(a3) Whether the brake pedal is stepped on
When the brake pedal is depressed to brake, it is determined that the vehicle is in a deceleration state.
(b3) Judging whether the vehicle enters a start-stop state or not according to the start-stop signal
When the vehicle enters the start-stop state, the brake pedal is judged to be pressed down, and the engine stops acting.
(c3) Whether the engine speed is 0
When the engine speed is 0, it is determined that the engine is off.
(d3) Whether or not the valve overlap angle is 0 or less
The fuel injection quantity calculation unit 8 calculates the fuel injection quantity, outputs the calculated fuel injection quantity to the fuel injector 200, and controls the fuel injector 200 to inject a corresponding quantity of fuel into the cylinder. Specifically, when all the determination results of the 1 st determining unit 5 are yes (i.e., it is determined that the engine, the vehicle condition, and the valve overlap angle satisfy the scavenging calculation mode), and all the determination results of the 2nd determining unit 6 are yes (i.e., it is determined that the acceleration condition is established), the fuel injection amount calculating unit 8 calculates the fuel injection amount from the optimum air-fuel ratio based on the actual air amount calculated by the actual air amount calculating unit 4. When the result of any determination by the 3 rd determining unit 7 is "yes" (that is, the scavenging mode exit condition is satisfied), or the result of any determination by the 1 st determining unit 5 is "no", or the result of any determination by the 2nd determining unit 6 is "no", the fuel injection amount calculating unit 8 obtains the detected air amount from, for example, the air flow meter 60, and calculates the fuel injection amount from the optimum air-fuel ratio based on the detected air amount without correcting the air flow rate in the cylinder.
Next, the operation of the engine scavenging control device 10 according to the present invention will be described.
Fig. 7 is a flowchart showing the operation of the engine scavenging control apparatus according to the present invention. As shown IN fig. 7, when the engine starts to operate, first, the intake valve early opening angle # IN _ VVTADVMX and the exhaust valve late closing angle # EX _ vvtdmx are obtained by the engine scavenging control apparatus 10, for example, from signals from the camshaft position sensor 30, the engine water temperature sensor 40, the engine speed sensor 50, and the air flow meter 60, and from a table look-up of the engine operating conditions, and the valve overlap angle is calculated from the formula # OVERLAPA = # EX _ VVTRTDMX- # IN _ VVTADVMX (step ST 1).
Then, the process proceeds to the 1 st judgment step. In the 2nd determination step, the 1 ST determination unit 5 acquires the calculated valve overlap angle # OVERLAPA, acquires information on the shift position, the vehicle speed, the start time, and the engine speed, determines whether the start time is equal to or greater than the start time determination value, determines whether the vehicle speed is equal to or greater than 0 and equal to or less than the scavenging mode maximum vehicle speed determination value, determines whether the engine speed is equal to or greater than the scavenging mode minimum speed determination value and equal to or less than the scavenging mode maximum speed determination value, determines whether the shift position is the D position, determines whether the valve overlap angle is greater than 0, and determines whether the engine, the vehicle condition, and the valve overlap angle satisfy the request for entering the scavenging calculation mode (step ST 2).
If all the determination results in the 1 st determination step are yes, it is determined that the engine, the vehicle condition, and the valve overlap angle satisfy the request for entering the scavenging calculation mode, and the routine proceeds to the 2nd determination step. In the 2nd determination step, the 2nd determination unit 6 acquires an accelerator pedal signal, determines whether or not the accelerator pedal opening is equal to or larger than an accelerator opening determination value based on the accelerator pedal signal, determines whether or not the current accelerator pedal opening is equal to or larger than the accelerator opening before 20 milliseconds, and determines whether or not the current accelerator pedal opening is equal to or larger than the accelerator opening before 50 milliseconds, thereby determining whether or not the acceleration is established (step ST 3).
If all the determination results in the 2nd determination step are yes, it is determined that the acceleration is established, and the process proceeds to the intake valve opening degree calculation step. IN the intake valve opening degree calculating step, the intake valve actual angle # IN _ RLVVT, the intake valve advanced opening angle # IN _ VVTADVMX, and the exhaust valve retarded closing angle # EX _ VVTRTDMX of the engine are acquired by the intake valve opening degree calculating portion 1, the outlet valve overlap angle # OVERLAPA is calculated from # OVERLAPA = # EX _ VVTRTDMX- # IN _ VVTADVMX, and the intake valve opening degree x is calculated from the above equation (1) (step ST 4).
Then, the process proceeds to the calculation parameter acquisition step. In the calculation parameter acquisition step, the atmospheric pressure # PATM, the pre-turbo temperature # THA, the post-turbo temperature # THA2ND, and the intake pipe target pressure # TAGTPM1 are acquired as calculation parameters by the calculation parameter acquisition section 2 (step ST 5).
Thereafter, the flow rate calculation step is proceeded to. In the air flow rate calculation step, the air flow rate ratio # KSCAVEN (i.e., y) corresponding to the intake valve opening degree x is calculated in real time by the air flow rate ratio calculation unit 3 based on the calculation parameters acquired in the calculation parameter acquisition step and based on the expressions (2) to (4) (step ST 6).
And then, the actual gas amount calculation step is carried out. In the actual gas amount calculating step, the detected gas amount # QA00 in the cylinder is acquired from the air flow meter 60 by the actual gas amount calculating unit 4, and the actual gas amount # QA00A in the cylinder is calculated based on the above equation (5) (step ST 7).
Thereafter, the process proceeds to decision step 3. In the 3 rd judging step, the 3 rd judging section acquires the valve overlap angle # OVERLAPA, acquires the start-stop signal, the brake signal, and the engine speed, judges whether the brake pedal is stepped on based on the brake signal, judges whether the vehicle enters the start-stop state based on the start-stop signal, judges whether the engine speed is 0, judges whether the valve overlap angle # OVERLAPA is 0, and judges whether the scavenging mode exit condition is satisfied (step ST 8).
If all the determination results in the 3 rd determination step are "no", it is determined that the scavenging mode exit condition is not satisfied, and the routine proceeds to the fuel injection amount calculation step. In the fuel injection amount calculating step, the fuel injection amount is calculated from the optimum air-fuel ratio based on the actual air amount # QA00A calculated in the actual air amount calculating step (step ST 9).
On the other hand, when the result of any determination in the 3 rd determination step is yes, or the result of any determination in the 1 ST determination step is no, or the result of any determination in the 2nd determination step is no, the routine proceeds to a fuel injection amount calculation step, and the detected air amount # QA00 is acquired from the air flowmeter 60 (step ST 10), and then the fuel injection amount is calculated from the optimum air-fuel ratio based on the detected air amount # QA00 (step ST 11).
Finally, the engine scavenging control device 10 outputs the fuel injection amount calculated by the fuel injection amount calculation portion 8 to the fuel injector 200, controls the fuel injector 200 to inject the corresponding amount of fuel into the cylinder, and starts the fuel injection control to enter the fuel injection control routine (step ST 12).
According to the engine scavenging control device, the engine scavenging control system and the engine scavenging control method, the concept of air flow ratio is added in the original system, the air flow ratio can be calculated according to the actual opening angle of the air inlet valve, the valve overlap angle and the like, and the air flow ratio is multiplied by the detected air quantity measured by the air flow meter, so that the actual air quantity in the cylinder is obtained. When the vehicle runs normally and the engine is accelerated suddenly under the condition of low rotating speed, the system judges that a scavenging mode needs to be entered to improve the air intake and exhaust efficiency, the air intake valve is opened in advance, the exhaust valve is closed after being delayed, at the moment, when the requirement of entering the scavenging calculation mode is met and the acceleration condition is judged to be met, the system enters air flow ratio calculation, the detected air quantity measured by the air flow meter is corrected to obtain the actual air quantity in the cylinder, and the ECU calculates the fuel injection quantity according to the corrected actual air quantity, so that the air-fuel ratio can reach the best, the engine power is improved, and the emission can be reduced.
As described above, the engine scavenging control device 10 is operated as a part of the ECU100, but the present invention is not limited to this. For example, the engine scavenging control device may be controlled and operated by the ECU as a module separate from the ECU. Further, the program that results in the execution of the engine scavenging control method described above may be stored in various computer-readable media in the form of software, and loaded into, for example, an ECU for execution when necessary. The computer-readable medium is not particularly limited, and examples thereof include optical disks such as HDD, CD-ROM, CD-R, MO, MD, and DVD, IC cards, flexible disks, and semiconductor memories such as mask ROM, EPROM, EEPROM, and flash ROM.
While the embodiments of the present invention have been described above, various omissions, substitutions, and changes may be made without departing from the spirit of the present invention.
Industrial applicability of the invention
The engine scavenging control apparatus, system, method and computer readable medium of the present invention are useful for optimal control of scavenging at the time of acceleration of a vehicle having a direct injection supercharged engine with an intake-exhaust continuously adjusted phaser.
Description of the reference symbols
1. Intake valve opening degree calculation section
2. Calculation parameter acquisition unit
3. Air flow rate ratio calculation unit
4. Actual gas amount calculating unit
5. 1 st judging part
6. The 2nd judging section
7. No. 3 judging section
8. Fuel injection amount calculation unit
10. Engine scavenging control device
20. Crankshaft angle sensor
30. Camshaft position sensor
40. Engine water temperature sensor
50. Engine speed sensor
60. Air flow meter
70. Air inlet pipe pressure sensor
80. Throttle position sensor
90. Front oxygen sensor
91. Rear oxygen sensor
100 ECU
200. Fuel injector
300. An engine.
Claims (9)
1. An engine scavenging control apparatus for a turbocharged engine using an in-cylinder direct injection technique and a variable valve timing system, comprising:
an intake valve opening degree calculation section that acquires an intake valve actual angle, an intake valve advanced opening angle, and an exhaust valve retarded closing angle of the engine, and calculates an intake valve opening degree by dividing a difference between the intake valve actual angle and the intake valve advanced opening angle by a valve overlap angle that is a difference between the exhaust valve retarded closing angle and the intake valve advanced opening angle;
a calculation parameter acquisition unit that acquires atmospheric pressure, a pre-vortex temperature, a post-vortex temperature, and an intake pipe target pressure as calculation parameters;
an air flow rate ratio calculation unit that calculates an air flow rate ratio corresponding to the intake valve opening degree in real time based on the calculation parameter; and
an actual gas amount calculation unit that obtains a detected gas amount in the cylinder and calculates an actual gas amount in the cylinder by multiplying the detected gas amount by the air flow rate ratio,
the air flow ratio calculation unit calculates the air flow ratio by:
assuming that the intake valve opening degree is X, the air flow rate is y, the atmospheric pressure is # PATM, the intake pipe target pressure is # TAGTPM1, the pre-swirl temperature is # THA, and the post-swirl temperature is # THA2ND,
when the intake valve actual angle is equal to or smaller than the intake valve advanced opening angle,
y＝0，
when the intake valve actual angle is larger than the intake valve early opening angle and smaller than the exhaust valve late closing angle,
when the intake valve actual angle is equal to or greater than the exhaust valve retarded closing angle,
y＝1。
2. the engine scavenging control apparatus according to claim 1, further comprising:
a1 st determination unit that acquires the valve overlap angle, acquires a shift position, a vehicle speed, a start time, and an engine speed, determines whether the start time is equal to or greater than a start time determination value, determines whether the vehicle speed is equal to or greater than 0 and equal to or less than a scavenging mode maximum vehicle speed determination value, determines whether the engine speed is equal to or greater than a scavenging mode minimum speed determination value and equal to or less than a scavenging mode maximum speed determination value, determines whether the shift position is a D-range, and determines whether the valve overlap angle is greater than 0;
a2nd judgment part, wherein the 2nd judgment part acquires an accelerator pedal signal, judges whether the accelerator pedal opening is larger than or equal to an accelerator opening judgment value according to the accelerator pedal signal, judges whether the current accelerator pedal opening is larger than the accelerator opening before 20 milliseconds, and judges whether the current accelerator pedal opening is larger than or equal to the accelerator opening before 50 milliseconds;
a3 rd judging part, wherein the 3 rd judging part acquires the valve overlap angle, acquires a start-stop signal, a brake signal and the engine rotating speed, judges whether a brake pedal is stepped according to the brake signal, judges whether a vehicle enters a start-stop state according to the start-stop signal, judges whether the engine rotating speed is 0 and judges whether the valve overlap angle is less than or equal to 0; and
and a fuel injection amount calculation unit that calculates a fuel injection amount from an optimum air-fuel ratio based on the actual gas amount calculated by the actual gas amount calculation unit when all of the determination results of the 1 st determination unit are yes and all of the determination results of the 2nd determination unit are yes, and calculates a fuel injection amount from an optimum air-fuel ratio based on the detected gas amount when any of the determination results of the 3 rd determination unit is yes, or any of the determination results of the 1 st determination unit is no, or any of the determination results of the 2nd determination unit is no.
3. An engine scavenging control system characterized by comprising:
the engine scavenging control apparatus according to claim 1 or 2;
the engine; and
the engine comprises a plurality of sensors, wherein the sensors are arranged on the engine and at least comprise a crankshaft angle sensor, a camshaft position sensor, an engine water temperature sensor, an engine rotating speed sensor, an air flow meter, an atmospheric pressure sensor and a temperature sensor.
4. The engine scavenging control system according to claim 3,
the intake valve opening degree calculation part acquires the intake valve actual angle from the crankshaft angle sensor, and acquires the intake valve early opening angle and the exhaust valve late closing angle according to signals from the camshaft position sensor, the engine water temperature sensor, the engine speed sensor and the air flow meter and a working condition table look-up of an engine.
5. The engine scavenging control system according to claim 3,
the calculation parameter acquisition part acquires the atmospheric pressure from the atmospheric pressure sensor, acquires the pre-vortex temperature and the post-vortex temperature from the temperature sensor, and obtains the intake pipe target pressure according to a table look-up of the working condition of the engine.
6. The engine scavenging control system according to any one of claims 3 to 5,
the actual air volume calculating part acquires the detected air volume from the air flow meter.
7. An engine scavenging control method for a turbocharged engine using direct in-cylinder injection and a variable valve timing system, comprising:
an intake valve opening degree calculation step of obtaining an intake valve actual angle, an intake valve advanced opening angle, and an exhaust valve retarded closing angle of the engine, and calculating the intake valve opening degree by dividing a difference between the intake valve actual angle and the intake valve advanced opening angle by a valve overlap angle that is a difference between the exhaust valve retarded closing angle and the intake valve advanced opening angle;
a calculation parameter acquisition step of acquiring atmospheric pressure, a pre-vortex temperature, a post-vortex temperature, and an intake pipe target pressure as calculation parameters;
an air flow rate ratio calculation step of calculating an air flow rate ratio corresponding to the intake valve opening degree in real time based on the calculation parameter; and
an actual gas amount calculating step of acquiring a detected gas amount in the cylinder, multiplying the detected gas amount by the air flow rate ratio, and calculating an actual gas amount in the cylinder,
in the air flow ratio calculating step, the air flow ratio is calculated by:
assuming that the intake valve opening degree is X, the air flow rate is y, the atmospheric pressure is # PATM, the intake pipe target pressure is # TAGTPM1, the pre-swirl temperature is # THA, and the post-swirl temperature is # THA2ND,
when the intake valve actual angle is equal to or smaller than the intake valve advanced opening angle,
y＝0，
when the actual intake valve angle is larger than the advanced intake valve opening angle and smaller than the retarded exhaust valve closing angle,
when the intake valve actual angle is equal to or greater than the exhaust valve retarded closing angle,
y＝1。
8. the engine scavenging control method according to claim 7, further comprising:
a1 st judging step, in the 1 st judging step, acquiring the valve overlap angle, acquiring a gear, a vehicle speed, starting time and an engine rotating speed, judging whether the starting time is greater than or equal to a starting time judging value, judging whether the vehicle speed is greater than or equal to 0 and less than or equal to a scavenging mode maximum vehicle speed judging value, judging whether the engine rotating speed is greater than or equal to a scavenging mode minimum rotating speed judging value and less than or equal to a scavenging mode maximum rotating speed judging value, judging whether the gear is a D gear, and judging whether the valve overlap angle is greater than 0;
a2nd judging step of acquiring an accelerator pedal signal, judging whether the accelerator pedal opening is larger than or equal to an accelerator opening judgment value according to the accelerator pedal signal, judging whether the current accelerator pedal opening is larger than the accelerator opening before 20 milliseconds, and judging whether the current accelerator pedal opening is larger than or equal to the accelerator opening before 50 milliseconds;
a3 rd judgment step, in the 3 rd judgment step, acquiring the valve overlap angle, acquiring a start-stop signal, a brake signal and the engine rotating speed, judging whether a brake pedal is stepped down according to the brake signal, judging whether a vehicle enters a start-stop state according to the start-stop signal, judging whether the engine rotating speed is 0, and judging whether the valve overlap angle is less than or equal to 0; and
a fuel injection amount calculation step of calculating a fuel injection amount from an optimum air-fuel ratio based on the actual gas amount calculated in the actual gas amount calculation step when all of the determination results in the 1 st determination step are yes and all of the determination results in the 2nd determination step are yes, and calculating the fuel injection amount from the optimum air-fuel ratio based on the detected gas amount when any of the determination results in the 3 rd determination step is yes, or any of the determination results in the 1 st determination step is no, or any of the determination results in the 2nd determination step is no.
9. A computer-readable medium storing a program for executing the engine scavenging control method according to claim 7 or 8.
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| JPH0742892B2 (en) * | 1984-12-28 | 1995-05-15 | トヨタ自動車株式会社 | Intake air amount detector |
| US6279550B1 (en) * | 1996-07-17 | 2001-08-28 | Clyde C. Bryant | Internal combustion engine |
| KR100410760B1 (en) * | 2001-08-31 | 2003-12-18 | 현대자동차주식회사 | Predetermined fuel flux control method in diesel engine |
| CN101210504A (en) * | 2006-12-28 | 2008-07-02 | 株式会社日立制作所 | Engine air input control device and engine air input control method |
| JP2010031699A (en) * | 2008-07-25 | 2010-02-12 | Hitachi Ltd | Control device for internal combustion engine |
| JP5118247B2 (en) * | 2009-02-17 | 2013-01-16 | 本田技研工業株式会社 | Cylinder intake air amount calculation device for internal combustion engine |
| WO2014002567A1 (en) * | 2012-06-27 | 2014-01-03 | 日産自動車株式会社 | Control device and control method of internal combustion engine |
| JP5328967B1 (en) * | 2012-10-25 | 2013-10-30 | 三菱電機株式会社 | Cylinder intake air amount estimation device for internal combustion engine |
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