KR20180068571A - Apparatus and method for controlling engine of vehicle - Google Patents

Abstract

The present invention relates to an apparatus for controlling an engine of a vehicle, and specifically, relates to an apparatus and a method for controlling an engine of a vehicle capable of generating a target air volume to control the engine on the basis of a compensation factor to which a vehicle state is reflected at the time of transient operation. For this, the apparatus for controlling an engine of a vehicle according to an embodiment of the present invention comprises: an engine having an intake manifold for receiving air and an exhaust manifold for discharging exhaust gas; an exhaust gas recirculation valve for recirculating some of the exhaust gas to the intake manifold and controlling the amount of the recirculated exhaust gas; and a controller for controlling the exhaust gas recirculation valve. The controller sets up a basic target air volume according to an operating point of the engine, generates a torque change amount based on a change amount of an acceleration pedal, decides transient operation based on the torque change amount, generates the final target air volume based on a compensation factor according to the basic target air volume and the torque change amount if it is a transient operation, and controls the exhaust gas recirculation valve based on the final target air volume.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an engine control apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine control apparatus for a vehicle, and more particularly, to an apparatus and method for controlling an engine of a vehicle capable of controlling an engine by generating a target air amount based on a correction factor reflecting a vehicle condition during a transient operation.

Generally, the exhaust gas of the engine contains a large amount of harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). Particularly, when the combustion temperature of the engine is increased, the amount of nitrogen oxide produced increases. Therefore, in order to reduce the amount of nitrogen oxide in the exhaust gas, it is necessary to reduce the combustion temperature of the engine.

The reason why the engine has a high combustion temperature is that the flame propagation speed of the ignition plug is increased at a high density of the mixture in the combustion chamber, and instantaneous high temperature heat is generated, which is the main reason for increasing the combustion temperature of the engine.

In order to reduce the combustion temperature of the engine in order to reduce the amount of nitrogen oxides in the exhaust gas, a part of the exhaust gas is introduced into the combustion chamber by introducing a part of the exhaust gas into the combustion chamber to reduce the density of the mixture without changing the air- There is an exhaust gas recirculation (EGR) method for lowering the combustion temperature.

The exhaust gas recirculation method is used not only to reduce the amount of nitrogen oxides in the exhaust gas but also to improve the fuel economy of the engine. In the exhaust gas recirculation method, the temperature of the combustion chamber is lowered to reduce the amount of nitrogen oxides, and at the same time, the ignition timing can be advanced by avoiding the knock generation region. Thus, the vehicle to which the exhaust gas recirculation method is applied can improve the output of the engine and improve the fuel efficiency.

In order to precisely control the exhaust gas recirculation, it is necessary to control the EGR recirculated to the intake manifold.

The method of controlling the EGR is based on the target air amount based on the engine rotation speed and the fuel injection amount, and controlled based on the target air amount.

However, in the conventional case, when the boost pressure is not sufficiently formed during the transient operation in the direction of increasing the torque, or when the boost pressure does not follow the target boost pressure during normal operation, if the target air amount determined by the fuel injection amount is followed There is a problem that the EGR rate is decreased and the nitrogen oxide is increased more than the intention.

In addition, in the conventional case, there is a problem that the boost pressure is excessively excessive in the transient operation in the direction of decreasing the torque, the EGR rate is excessively increased, the particulate matter (PM) increases, and the fuel efficiency is lowered.

In the conventional case, when the target air amount is intentionally set low to prevent the above phenomenon, the particulate matter increases in the normal operation state, and vice versa.

The matters described in the background section are intended to enhance the understanding of the background of the invention and may include matters not previously known to those skilled in the art.

Patent Registration No. 10-1036715 (May 17, 2011)

An embodiment of the present invention provides an apparatus and method for controlling an engine of a vehicle that can control an engine by generating a target air amount based on a correction factor that reflects a vehicle state during a transient operation.

The embodiment of the present invention provides an engine control apparatus and method of a vehicle capable of controlling an exhaust gas recirculation valve based on an end target air amount using a correction factor according to a basic target air amount and a vehicle state according to an engine operating point .

According to an embodiment of the present invention, there is provided an engine including an intake manifold that receives air and an exhaust manifold that exhausts exhaust gas; An exhaust gas recirculation valve for recirculating a part of the exhaust gas to an intake manifold, and regulating the amount of the recirculated exhaust gas; And a controller for controlling the exhaust gas recirculation valve, wherein the controller sets a basic target air amount according to an operating point of the engine, generates a torque change amount based on a change amount of the accelerator pedal, The control unit controls the exhaust gas recirculation valve to control the exhaust gas recirculation valve based on the final target air amount based on the correction factor based on the basic target air amount and the torque change amount, A control device can be provided.

The controller may generate the final target air amount based on the basic target air amount, the first correction factor according to the torque change amount, the second correction factor according to the gear stage, and the third correction factor according to the engine operation point.

Also, the controller may set a first correction factor according to the torque variation amount through a first correction control map set in advance.

Also, the controller may set a second correction factor according to the gear stage through a second correction control map set in advance.

Also, the controller may set a third correction factor according to an operating point of the engine through a third correction control map set in advance.

In addition, the controller can set a basic target air amount according to an operating point of the engine through a preset air amount control map.

Further, the controller can determine that the engine is in an overdrive operation when the torque change amount is equal to or greater than the reference value.

In addition, the controller may generate a torque change amount based on a displacement change amount of the accelerator pedal.

According to another embodiment of the present invention, there is provided a method of detecting an operating point of an engine, Setting a basic target air amount according to an operating point of the engine; Generating a torque change amount based on a displacement change amount of the accelerator pedal; Determining whether a transient operation is performed based on the torque change amount; Generating a final target air amount based on a correction factor according to a basic target air amount and the torque change amount in the transient operation; And controlling the exhaust gas recirculation valve based on the final target air amount. It is possible to provide an engine control method of a vehicle including the vehicle.

The embodiment of the present invention can improve the fuel efficiency by generating the target air amount based on the correction factor reflecting the vehicle condition during the transient operation and controlling the engine.

In addition, the exhaust gas recirculation valve can be controlled based on the final target air amount by using the correction factor according to the basic target air amount and the vehicle state according to the engine operating point, thereby reducing nitrogen oxides and particulate matter.

In addition, effects obtainable or predicted by the embodiments of the present invention will be directly or implicitly disclosed in the detailed description of the embodiments of the present invention. That is, various effects to be predicted according to the embodiment of the present invention will be disclosed in the detailed description to be described later.

1 is a schematic view of an engine control apparatus for a vehicle according to an embodiment of the present invention.
2 is a block diagram illustrating input and output of a controller in an engine control apparatus for a vehicle according to an embodiment of the present invention.
3 is a flowchart illustrating an engine control method of a vehicle according to an embodiment of the present invention.
4 is a view illustrating an example of a method for controlling an engine of a vehicle according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an operation principle of an embodiment of an apparatus and method for controlling an engine of a vehicle according to the present invention will be described in detail with reference to the accompanying drawings and description. It should be understood, however, that the drawings and the following detailed description are exemplary and explanatory of various embodiments for effectively illustrating the features of the present invention. Therefore, the present invention should not be limited to the following drawings and descriptions.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The terms used below are defined in consideration of the functions of the present invention, which may vary depending on the user, intention or custom of the operator. Therefore, the definition should be based on the contents throughout the present invention.

In order to efficiently explain the essential technical features of the present invention, the following embodiments will appropriately modify, integrate, or separate terms to be understood by those skilled in the art to which the present invention belongs , And the present invention is by no means thereby limited.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view of an engine control apparatus for a vehicle according to an embodiment of the present invention.

1, a vehicle engine control apparatus includes an engine 100, a throttle valve 120, an exhaust gas recirculation (EGR) valve 180, a catalyst 150, a turbocharger 160, (250).

The engine 100 converts chemical energy into mechanical energy by burning a mixture in which fuel and air are mixed.

The engine 100 includes an intake manifold 103 and an exhaust manifold 105.

The intake manifold 103 is connected to the intake pipe 10 to receive air. Here, it should be understood that the intake pipe 10 includes all the pipes, hoses and ducts connected to the intake manifold 103 to supply air to the intake manifold 103. [

The intake pipe 10 is equipped with a filter 110 and a throttle valve 120.

The filter 110 is mounted on the intake pipe 10 and filters the material contained in the intake air supplied through the intake pipe 10 to the filter 110.

The throttle valve 120 is mounted on the intake pipe 10. The throttle valve 120 regulates the amount of intake air supplied through the intake pipe 10. The amount of such intake air is determined according to the opening degree of the throttle valve 120, and the opening degree of the throttle valve 120 can be expressed as a percentage. For example, if the opening degree of the throttle valve 120 is 100%, the throttle valve 120 is fully opened. If the opening degree of the throttle valve 120 is 0%, the throttle valve 120 can be completely closed have.

The exhaust gas generated in the combustion process is collected in the exhaust manifold 105 and then discharged to the outside of the engine. The exhaust manifold 105 is connected to the exhaust pipe 20 to exhaust the exhaust gas to the outside of the vehicle. Here, the exhaust pipe 20 should be understood to include all pipes, hoses and ducts connected to the exhaust manifold 105 for exhausting the exhaust gas to the outside of the vehicle.

The exhaust pipe 20 is equipped with a soot filter 140 and a catalyst 150.

The soot filter 140 is mounted on the exhaust pipe 20 and collects particulate matter contained in the exhaust gas. Typically, the soot filter 140 includes a plurality of inlet and outlet channels.

One end of the inlet channel is opened, and the other end thereof is closed, so that the exhaust gas is introduced. One end of the outlet channel is closed and the other end thereof is opened to exhaust the exhaust gas inside the particulate filter 140 to the outside of the particulate filter 140. [

The exhaust gas flowing into the particulate filter 140 through the inlet channel enters the outlet channel through the porous partition dividing the inlet channel and the outlet channel, and is discharged to the particulate filter 140 through the outlet channel. Particulate matter contained in the exhaust gas is collected during the passage of the exhaust gas through the porous partition wall.

On the other hand, a differential pressure sensor (not shown) is mounted on the exhaust pipe 20.

The differential pressure sensor measures the pressure difference between the front end and the rear end of the soot filter 140 and provides a signal to the controller 250. At this time, the controller 250 can control to regenerate the soot filter 140 when the pressure difference measured by the differential pressure sensor is equal to or higher than the set pressure. In this case, the particulate matter trapped in the particulate filter 140 can be burned by injecting fuel in an injector (not shown).

The catalyst 150 is mounted to the exhaust pipe 20 at the rear end of the soot filter 140. The catalyst 150 purifies the harmful substances (HC, CO, NOx) included in the exhaust gas. In particular, when the catalyst 150 purifies the nitrogen oxide, the catalyst 150 includes a basic substance. At this time, the sulfur oxide contained in the exhaust gas can also be occluded in the catalyst 150. As the sulfur oxides are occluded in the catalyst 150, the ability to purify nitrogen oxides falls. Therefore, when the amount of sulfur oxides occluded in the catalyst 150 is equal to or higher than the predetermined amount, the sulfur oxides must be removed by raising the temperature of the exhaust gas. This is referred to as desulfurization of the catalyst (150). Generally, the desulfurization of the catalyst 150 proceeds following the regeneration of the soot filter 140. In an embodiment of the present invention, catalyst 150 may be, but is not limited to, a Selective Catalytic Reduction (SCR) catalyst.

In addition, the position of the catalyst 150 on the exhaust pipe 20 may vary depending on the type thereof. For example, if the catalyst 150 is a Lean NOx Trap (LNT) catalyst, the catalyst 150 may be mounted on the front end exhaust pipe 20 of the particulate filter 140. Therefore, the position of the catalyst 150 is not limited to that exemplified in this embodiment.

The turbocharger 160 supercharges the intake air using the energy of the exhaust gas, and includes a turbine and a compressor 165.

The turbo 163 is mounted on the exhaust pipe 20 and rotated by the exhaust gas.

The compressor 165 is coupled to the turbine via an axis and rotates with the turbine. The compressor 165 is mounted on the intake pipe to supercharge the intake air. That is, when the turbine rotates on the exhaust gas, the compressor 165 connected to the turbine rotates and increases the intake air.

The EGR valve 180 is mounted on the exhaust pipe 20 and the intake manifold. The EGR valve 180 regulates the amount of exhaust gas recirculated to the intake manifold. The amount of the recirculated exhaust gas is determined according to the opening degree of the EGR valve 180, and the opening degree of the EGR valve 180 can be expressed as a percentage. For example, if the opening degree of the EGR valve 180 is 100%, the EGR valve 180 is fully opened. If the opening degree of the EGR valve 180 is 0%, the EGR valve 180 can be completely closed have.

The position of the EGR valve 180 shown in FIG. 1 represents one example, and may be located at another position as required. Thus, the EGR valve 180 means all valves capable of regulating the amount of exhaust gas recirculated to the intake manifold.

The controller 250 controls the engine 100, the throttle valve 120, the EGR valve 180, the catalyst 150, and the turbocharger 163, which are components of the engine control apparatus. The controller 250 controls the opening of the EGR valve 180 according to the operating state of the engine 100.

2 is a block diagram illustrating input and output of a controller in an engine control apparatus for a vehicle according to an embodiment of the present invention.

2, the vehicle engine control apparatus further includes an engine speed detecting unit 210, a fuel amount detecting unit 215, an accelerator position sensor (APS) 220, and a gear position detecting unit 225.

The engine speed detection unit 210 detects the speed at which the engine 100 rotates, and provides a signal to the controller 250.

The fuel amount detecting unit 215 detects the amount of fuel injected into the engine 100 and provides a signal to the controller 250. [

The APS 220 detects the degree to which the driver depresses the accelerator pedal. That is, the APS 220 detects the position or displacement of the accelerator pedal (i.e., the degree to which the accelerator pedal is depressed) and provides a signal to the controller 250 about the position or displacement.

Instead of using the APS 220, the opening degree of the throttle valve 120 mounted in the intake passage may be detected and used.

The gear position detecting unit 225 detects the gear position coupled to the transmission (not shown) and provides a signal to the controller 250.

The controller 250 receives the engine speed from the engine speed detecting unit 210 and receives the fuel amount from the fuel amount detecting unit 215. The controller 250 confirms the operating point of the engine 100 through the engine speed and the fuel amount, and confirms the basic target air amount according to the operating point of the engine 100. [ The controller 250 generates a torque variation amount according to the amount of displacement of the accelerator pedal detected by the APS 220, and sets a first correction factor according to the torque variation amount. The controller 250 sets a second correction factor according to the gear stage detected by the gear stage detector 225 and sets a third correction factor according to the operating point of the engine 100. [

The controller 250 generates the final target air amount based on the basic target air amount, the first correction factor, the second correction factor, and the third correction factor. The controller 250 controls the EGR valve 180 based on the final target air amount.

For this purpose, the controller 250 may be implemented with one or more processors operating with the set program, and the set program may be programmed to perform each step of the engine control method according to the embodiment of the present invention.

Such an engine control method will be described in more detail with reference to FIGS. 3 and 4. FIG.

Hereinafter, a method of controlling an engine in a vehicle will be described with reference to FIGS. 3 and 4. FIG.

3 is a flowchart illustrating an engine control method of a vehicle according to an embodiment of the present invention.

Referring to FIG. 3, the controller 250 checks the operating point of the engine 100 when the engine 100 is operating (S310). In other words, the engine speed detection unit 210 detects the speed of the engine 100 and provides a signal to the controller 250. The fuel amount detecting unit 215 detects an amount of fuel injected from the injector and provides a signal to the controller 250. [ The controller 250 receives the engine speed from the engine speed detecting unit 210 and receives the fuel amount from the fuel amount detecting unit 215. The controller 250 confirms the operating point of the engine 100 through the engine speed and the fuel amount.

The controller 250 sets the basic target air amount according to the operating point of the engine 100 (S320). That is, the controller 250 sets the basic target air amount according to the operating point of the engine 100 through the air amount control map. Here, the air amount control map may be a control map that is set to match the basic target air amount at each of the operating points of the plurality of engines 100, and may be set in advance. The air volume control map may be set through a predetermined algorithm (e.g., a program and a probability model).

The controller 250 generates a torque change amount for the driver's request (S330). That is, the controller 250 can generate the torque change amount based on the displacement change amount of the accelerator pedal. However, the generation of the torque variation amount based on the displacement variation of the accelerator pedal is not limited, and the torque variation amount may be generated through other factors.

The controller 250 determines whether it is a transient operation based on the torque change amount (S340). That is, the controller 250 can check whether the torque change amount is equal to or greater than the reference value to determine whether the engine is overspeed. At this time, the reference value may be a reference value for judging whether the driver is over driving or normal driving through the torque change amount. The reference value may be set through a predetermined algorithm (e.g., a program and a probability model).

The controller 250 controls the EGR valve 180 based on the basic target air amount when the normal operation is confirmed through the torque change amount (S350). That is, if the torque change amount is less than the reference value, the controller 250 controls the EGR valve 180 based on the basic target air amount set in step S320.

The controller 250 sets a first correction factor according to the amount of torque change when it is confirmed that the engine is over-driven through the torque change amount (S360). That is, the controller 250 sets the first correction factor according to the torque change amount through the first correction control map. At this time, the first correction control map may be set in advance as a control map in which correction factors are matched to each of the plurality of torque change amounts. The first correction control map may be set through a predetermined algorithm (e.g., a program and a probability model).

The controller 250 sets a second correction factor according to the gear stage (S370). In other words, the controller 250 is provided with a gear stage coupled to the transmission from the gear range detection section 225. [ The controller 250 sets a second correction factor according to the gear stage through the second correction control map. At this time, the second correction control map may be set in advance as a control map in which correction factors are matched to each of a plurality of gear stages. The second correction control map may be set through a predetermined algorithm (e.g., a program and a probability model).

The controller 250 sets a second correction factor according to the operating point of the engine 100 (S380). That is, the controller 250 sets a third correction factor according to the engine speed and the fuel amount through the third correction control map. At this time, the third correction control map may be set through a predetermined algorithm (for example, a program and a probability model).

The controller 250 generates the final target air amount based on the basic target air amount (S390). That is, based on the basic target air amount set in step S320, the first correction factor set in step S360, the second correction factor set in step S370, and the third correction factor set in step S380, Thereby generating an air amount.

The controller 250 controls the EGR valve 180 based on the final target air amount (S400).

Accordingly, the engine control apparatus for a vehicle according to the embodiment of the present invention can control the EGR valve 180 by reflecting the correction factor according to the torque change amount, the gear stage, and the operating point of the engine 100 at the time of the excessive operation, Exhaust gas and fuel economy can be optimized.

4 is a view illustrating an example of a method for controlling an engine of a vehicle according to an embodiment of the present invention.

Referring to FIG. 4, the controller 250 sets the basic target air amount according to the engine speed and the fuel amount through the air amount control map 410.

The controller 250 sets a first correction factor according to the torque change amount through the first correction control map 420 and sets a second correction factor according to the gear position through the second correction control map 430, 3 correction control map 440 to set a third correction factor according to the engine speed and the fuel amount.

Then, the controller 250 generates the final target air amount based on the basic target air amount, the first correction factor, the second correction factor, and the third correction factor. That is, the controller 250 can generate the final target air amount through the following equation (1).

[Equation 1]

G = A + (B x C x D)

ego,

Here, G is the final target air amount, A is the basic target air amount, B is the first correction factor according to the torque change amount, C is the second correction factor according to the gear position, D is the operating point of the engine 100 Lt; / RTI >

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

100: engine
110: filter
120: Throttle valve
140: Soot filter
150: catalyst
180: EGR valve
210: engine speed detector
215: fuel amount detecting section
220: APS
225:
250: controller

Claims (17)

An engine including an intake manifold that receives air and an exhaust manifold that exhausts exhaust gas;
An exhaust gas recirculation valve for recirculating a part of the exhaust gas to an intake manifold, and regulating the amount of the recirculated exhaust gas; And
A controller for controlling the exhaust gas recirculation valve;
, ≪ / RTI &
The controller
Wherein the control unit determines a transitional operation based on the amount of change in the torque based on the basic target air amount based on the operating point of the engine and generates a torque change amount based on the amount of change of the accelerator pedal, Wherein the exhaust gas recirculation valve controls the exhaust gas recirculation valve based on the final target air amount, based on the correction factor according to the amount of change. The method according to claim 1,
The controller
Wherein the control unit generates the final target air amount based on the basic target air amount, the first correction factor according to the torque change amount, the second correction factor according to the gear position, and the third correction factor according to the engine operation point Device. 3. The method of claim 2,
The controller
And sets a first correction factor according to the torque change amount through a first correction control map set in advance. 3. The method of claim 2,
The controller
And sets a second correction factor according to the gear stage through a second correction control map set in advance. 3. The method of claim 2,
The controller
And sets a third correction factor according to an operating point of the engine through a preset third correction control map. The method according to claim 1,
The controller
And sets a basic target air amount corresponding to an operating point of the engine through a preset air amount control map. The method according to claim 1,
The controller
And determines that the engine is in an overdrive operation if the torque change amount is equal to or greater than a reference value. The method according to claim 1,
The controller
And generates a torque change amount based on a displacement change amount of the accelerator pedal. Detecting an operating point of the engine;
Setting a basic target air amount according to an operating point of the engine;
Generating a torque change amount based on a displacement change amount of the accelerator pedal;
Determining whether a transient operation is performed based on the torque change amount;
Generating a final target air amount based on a correction factor according to a basic target air amount and the torque change amount in the transient operation; And
Controlling the exhaust gas recirculation valve based on the final target air amount;
The engine control method comprising the steps of: 10. The method of claim 9,
The step of generating the final target air amount
Setting a first correction factor according to the amount of torque change;
Setting a second correction factor according to the gear stage;
Setting a third correction factor according to an operating point of the engine; And
Generating an end target air amount based on the basic target air amount, the first correction factor, the second correction factor, and the third correction factor;
And a control unit for controlling the engine. 11. The method of claim 10,
The step of setting the first correction factor
And setting a first correction factor according to the torque change amount through a preset first correction control map. 11. The method of claim 10,
The step of setting the second correction factor
And setting a second correction factor according to the gear stage through a preset first correction control map. 11. The method of claim 10,
The step of setting the third correction factor
And setting a third correction factor according to an operating point of the engine through a preset third correction control map. 10. The method of claim 9,
Wherein the final target air amount is generated through the following equation (1).
Here, the expression (1)
G = A + (B x C x D)
ego,
Wherein G is a final target air amount, A is a basic target air amount, B is a first correction factor according to a torque change amount, C is a second correction factor according to a gear position, Lt; / RTI > 10. The method of claim 9,
The step of setting the basic target air amount according to the operating point of the engine
And setting a basic air amount according to an engine speed and a fuel amount included in an operating point of the engine through a preset air amount control map. 10. The method of claim 9,
Wherein the step of determining whether the engine is in the transient state based on the torque change amount
Determining whether the torque change amount is equal to or greater than a reference value and determining whether or not the engine is in a transient state. 10. The method of claim 9,
After the step of determining whether a transient operation is performed based on the torque change amount
Controlling the exhaust gas recirculation valve on the basis of the basic target air amount if the normal operation is performed;
Further comprising the steps of:

Images