KR102237073B1 - Engine system and control method for the same - Google Patents

Abstract

The present invention relates to an engine system, and more particularly, to an engine system capable of improving fuel economy by controlling a turbocharger during a driving force, and a control method thereof.
To this end, an engine system according to an embodiment of the present invention includes a turbocharger, an intercooler for cooling a mixer of the turbocharger and an external new device, and a supercharger for compressing intake air and supplying it to the combustion chamber of the engine; A bypass valve provided on a bypass line bypassing the supercharger, a status detector for detecting status data of the engine, and a controller for controlling the turbocharger and the supercharger using the status data, wherein the controller is The target speed according to the boost pressure difference, the intake air flow rate and the supercharger inlet pressure is checked, and at the same time, using the state data, it is determined whether or not the hitting force control entry condition is satisfied, and a correction value is determined according to the hitting force control entry condition. A final control value is determined using a target speed and the correction value, and the supercharger is controlled based on the final control value.

Description

Engine system and its control method {ENGINE SYSTEM AND CONTROL METHOD FOR THE SAME}

The present invention relates to an engine system, and more particularly, to an engine system capable of improving fuel economy by controlling a turbocharger during a driving force, and a control method thereof.

In general, a vehicle introduces outside air and then mixes air and fuel and supplies it to the engine. Such an engine is designed to obtain the power required to drive a vehicle by burning a mixture of fuel and air.

In the process of generating power by driving the engine, the desired output of the engine is obtained only when sufficient external air is supplied for combustion.To improve the output of the engine, a turbocharger or turbocharger that pressurizes and supplies the combustion air charge) is being applied to vehicles.

The turbocharger has a structure that compresses air supplied to the engine using the pressure of exhaust gas discharged from the engine.

In recent years, downsizing engines (supercharged engines) are gradually increasing and being applied to vehicles in order to cope with the regulation of exhaust gas along with reduction of fuel economy due to an increase in oil prices.

In the case of diesel engines, a turbocharger is applied drastically to generate high torque with a small displacement, and the maximum speed and gradeability are greatly improved, but driving a vehicle due to the turbo lag phenomenon that occurs mainly during low-speed acceleration. Sexuality decreases.

In order to prevent such a turbo lag phenomenon and to improve acceleration response, a supercharger that compresses and supplies intake air by driving a compressor using the power of an engine is applied to a vehicle.

However, in the conventional case, the vane opening of the turbocharger was closed in order to improve the responsiveness of the vehicle when the vehicle was re-launched when driving by force, but there was a problem that fuel economy decreased due to an increase in pumping loss, and the driving distance was shortened. I did.

The matters described in this background are prepared to enhance an understanding of the background of the invention, and may include matters other than the prior art already known to those of ordinary skill in the field to which this technology belongs.

An embodiment of the present invention provides an engine system capable of controlling the vane opening degree of a turbocharger when driving by force and a control method thereof.

In addition, an embodiment of the present invention provides an engine system and a control method for controlling a turbocharger when driving and controlling a supercharger when the driving force is released.

In an embodiment of the present invention, a turbocharger; An intercooler for cooling the mixer of the turbocharger and the external fresh air; A supercharger that compresses the intake air and supplies it to the combustion chamber of the engine; A bypass valve provided in a bypass line bypassing the supercharger; A state detector for detecting state data of the engine; And a controller for controlling the turbocharger and the supercharger using the state data, wherein the controller checks the target speed according to the boost pressure difference, the intake air flow rate, and the supercharger inlet pressure, while using the state data It is determined whether the hitting power control entry condition is satisfied, the correction value is determined according to the hitting power control entry condition, the final control value is determined using the target speed and the correction value, and the supercharger is based on the final control value. It is possible to provide an engine system to control.

In addition, the controller may check the vane angle according to the state data and control the turbocharger based on the vane angle when the state data satisfies the force control entry condition.

In addition, the controller may check a hitting force control map including a vane angle matched to each of a plurality of engine speeds, and check the vane angle matched to the engine speed included in the state data through the hitting force control map.

In addition, the controller determines whether or not the force release condition is satisfied using the state data, and if the state data satisfies the force release condition, determines a correction value according to the boost pressure difference, the intake air flow rate, and the supercharger inlet pressure, The target speed and the correction value may be added and used to determine a final control value.

In addition, in the controller, the vehicle speed of the state data is greater than or equal to the reference speed, the shift level is greater than or equal to the reference level, the position value of the accelerator pedal corresponds to the first reference value, and the position value of the brake pedal corresponds to the second reference value, If the gradient is within the set range, it can be determined that the hitting force control entry condition is satisfied.

In addition, the controller may control the supercharger by setting the correction value to 0 when the state data does not satisfy the condition for entering force control.

In addition, the boost pressure difference represents a difference between a target boost pressure and a detected boost pressure, and the target boost pressure may be set according to an engine speed and an amount of injected fuel.

In addition, the state detector includes an engine sensor that detects the speed of the engine; A speed sensor that detects the speed of the vehicle; A shift stage sensor that detects a shift stage fastened to the transmission; An accelerator pedal position sensor detecting a position value of the accelerator pedal; A brake pedal position sensor for detecting a position value of the brake pedal; And at least one of a gradient sensor that detects a gradient of the road.

In another embodiment of the present invention, determining whether the engine is started; Checking a target speed according to a boost pressure difference, an intake air flow rate, and a supercharger inlet pressure when the engine is started, and determining whether or not a hitting force control entry condition is satisfied using state data; Determining a correction value according to the force control entry condition; Determining a final control value using the target speed and the correction value; And controlling a supercharger based on the final control value.

According to an exemplary embodiment of the present invention, fuel economy may be improved by controlling the vane opening degree of a turbocharger when driving by force.

In addition, it is possible to increase the driving distance by controlling the turbocharger when driving by controlling the driving force, and improving vehicle responsiveness by controlling the supercharger when the driving force is released.

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

1 is a block diagram showing an engine system according to an embodiment of the present invention.
2 is a block diagram showing an engine system according to an embodiment of the present invention.
3 is a flowchart illustrating an engine system control method according to an embodiment of the present invention.

Hereinafter, an operation principle of an engine system and a control method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings and description. However, the drawings shown below and the detailed description to be described later relate to one preferred embodiment among various embodiments for effectively describing the features of the present invention. Therefore, the present invention will not be limited only to the following drawings and description.

In addition, in the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of users or operators. Therefore, the definition should be made based on the overall contents of the present invention.

In addition, the following embodiments will use appropriately modified, integrated, or separated terms so that those of ordinary skill in the art can clearly understand in order to efficiently describe the key technical features of the present invention. However, the present invention is by no means limited thereto.

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

1 is a block diagram showing an engine system according to an embodiment of the present invention, and FIG. 2 is a configuration diagram showing an engine system according to an embodiment of the present invention.

1 and 2, the engine system includes a condition detector 10, an engine 50, a turbocharger 100, an air cleaner box 110, an intercooler 120, a supercharger 130, and a bypass valve. 140, a throttle valve 150, a post-treatment device 160, a low pressure exhaust gas recirculation (LP-EGR) cooler 170 and a controller 200.

The state detector 10 detects state data for controlling the turbocharger and supercharger 130. To this end, the state detector 10 is a pressure sensor 13, a boost pressure sensor 15, a flow sensor 17, a speed sensor 19, an accelerator pedal position sensor (hereinafter referred to as'APS' collectively, 21) A brake pedal position sensor (hereinafter collectively referred to as'BPS', 23), an engine sensor 25, a shift stage sensor 27, and a gradient sensor 29 are included.

The pressure sensor 13 is provided in front of the supercharger of the intake line 125. The pressure sensor 13 detects the pressure at the front end of the supercharger 130 and provides it to the controller 200.

The boost pressure sensor 15 is provided on the intake manifold 53 of the engine 50. The boost pressure sensor 15 detects the boost pressure of the engine 50 and provides the detected boost pressure to the controller 200.

The flow sensor 17 detects the flow rate of intake air flowing into the manifold of the engine 50. The flow sensor 17 provides the detected intake air flow rate to the controller 200.

The speed sensor 19 detects the speed of the vehicle and provides the detected vehicle speed to the controller 200.

The speed sensor 19 may be mounted on a drive wheel of a vehicle. Meanwhile, when the speed sensor 19 is not provided, the controller 200 may calculate the vehicle speed using a GPS signal received from GPS.

The APS 21 measures the degree to which the driver depresses the accelerator pedal. That is, the APS 21 measures the position value of the accelerator pedal (the degree to which the accelerator pedal is pressed) and provides a signal for this to the controller 200. When the accelerator pedal is completely depressed, the accelerator pedal position value is 100%, and when the accelerator pedal is not depressed, the accelerator pedal position value is 0%.

Instead of using the APS 21, the position value of the accelerator pedal may be checked based on the opening degree of the throttle valve 150 mounted in the intake passage.

The BPS 23 measures the degree to which the driver depresses the brake pedal. That is, the BPS 23 measures the position value of the brake pedal (the degree to which the brake pedal is pressed) and transmits the measured value to the controller 200. When the brake pedal is completely depressed, the position value of the brake pedal may be 100%, and when the brake pedal is not depressed, the position value of the brake pedal may be 0%.

The engine sensor 25 detects the speed of the engine 50 and provides the detected engine speed to the controller 200.

The shift stage sensor 27 detects the shift stage currently fastened to the transmission and provides it to the controller 200.

The gradient sensor 29 detects the gradient of the road on which the vehicle is located, and provides the detected gradient to the controller 200. At this time, the gradient can be expressed in %.

The engine 50 converts chemical energy into mechanical energy by burning a mixture of fuel and air. This engine 50 includes an intake manifold 53 and an exhaust manifold 55.

The turbocharger 100 supercharges intake air using energy of exhaust gas, and includes a turbine and a compressor.

The air cleaner box 110 purifies foreign substances contained in the outside air. That is, fresh air purified through the air cleaner box 110 is provided to the supercharger 130 through the intake line 125.

The intercooler 120 cools the fresh air supplied from the turbocharger 100. That is, the intercooler 120 cools the turbocharger 100 and the mixer of the external fresh air, and is cooled by the running wind.

The supercharger 130 is provided at the rear of the intercooler 120 and is provided on the intake line 125 together with the intercooler 120.

The supercharger 130 compresses the intake air provided from the intercooler 120 and supplies it to the combustion chamber of the engine 50. That is, the supercharger 130 compresses the fresh air provided from the intercooler 120 through the compressor 135 and introduces it into the throttle valve 150.

The motor 133 may store electric energy generated while the compressor 135 of the supercharger 130 rotates in a battery (not shown).

The bypass valve 140 is provided in the bypass line 127 bypassing the supercharger 130. The fresh air purified by the air cleaner box 110 is provided to the throttle valve 150.

The throttle valve 150 introduces air that has passed through the supercharger and bypass valve 140 into the intake manifold 53. That is, the throttle valve 150 controls the amount of intake air supplied to the intake manifold 53 of the engine 50. The amount of intake air is determined according to the opening degree of the throttle valve 150, and the opening degree of the throttle valve 150 may be expressed as a percentage. For example, when the opening degree of the throttle valve 150 is 100%, the throttle valve 150 is fully open, and when the opening degree of the throttle valve 150 is 0%, the throttle valve 150 is completely closed. have.

The post-treatment device 160 may purify and discharge the exhaust gas burned in the engine 50. The post-treatment device 160 may be implemented in various forms, such as a Die Particulate Filter (DPF), Lean NOx Trap (LNT), Selective Catalytic Reduction (SCR), and a three way catalytic converter rhodium.

The LP-EGR cooler 170 cools the exhaust gas supplied from the post-treatment device 160. That is, a part of the exhaust gas may be mixed with an external fresh air through the LP-EGR cooler 170 through the control of the LP-EGR valve 180, compressed in the turbocharger 100, and cooled in the intercooler 120. .

The controller 200 controls components of the engine system. In other words, the controller 200 receives state data from the state detector 10. The controller 200 controls the turbocharger and supercharger 130 using the state data. That is, the controller 200 determines whether the force control entry condition is satisfied by using the state data, and if the force control entry condition is satisfied, checks the vane angle according to the state data.

The controller 200 controls the turbocharger 100 based on the vane angle. In addition, the controller 200 controls the supercharger 130 when the state data satisfies the triggering release condition.

The controller 200 may be implemented as one or more microprocessors operated by a set program, and the set program executes a series of commands for performing each step included in the engine system control method according to an embodiment of the present invention to be described later. It can be said to include. This engine system control method will be described in more detail with reference to FIG. 3.

Hereinafter, a method of controlling the engine system will be described with reference to FIG. 3.

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

3, the controller 200 determines whether the engine 50 is started (S305).

On the other hand, the controller 200 monitors whether the engine 50 is started by returning to step S305 when the engine 50 is in an off state.

When the engine 50 is started, the controller 200 determines whether the conditions for entering force control are satisfied using the state data (S310). Specifically, the controller 200 receives state data from the state detector 10. The controller 200 determines whether the vehicle speed of the state data is greater than or equal to the reference speed. In this case, the reference speed may represent a speed that becomes a reference to determine whether the attack force control entry condition is satisfied.

If the vehicle speed is higher than the reference speed, the controller 200 determines whether the shift stage is higher than the reference speed. In this case, the reference stage may be a number of stages serving as a reference in order to determine whether the hitting force control entry condition is satisfied.

The controller 200 determines whether the position value of the accelerator pedal corresponds to the first reference value when the shift stage is greater than or equal to the reference stage. In this case, the first reference value is a value that serves as a reference for determining whether the force control entry condition is satisfied, and may be 0%.

When the position value of the accelerator pedal corresponds to the first reference value, the controller 200 determines whether the position value of the brake pedal corresponds to the second reference value. Here, the second reference value is a value that serves as a reference for determining whether the force control entry condition is satisfied, and may be 0%.

When the position value of the brake pedal corresponds to the second reference value, the controller 200 determines whether the gradient is within a set range. In this case, the setting range represents a range set to determine whether it is a flat ground or a gentle slope, and may be -4% to +4%.

The controller 200 determines whether the auto cruise setting is off when the gradient is within the setting range.

When all the conditions described above are satisfied, the controller 200 may determine that the force control entry condition is satisfied.

The controller 200 sets a correction value when the state data does not satisfy the condition for entering force control (S315). That is, the controller 200 sets the correction value for setting the final value to 0 if the condition for entering the hitting force control is not satisfied. In this case, the correction value is a value for compensating through the supercharger 130 for the vane angle of the turbocharger 100 used when the attack force control entry condition is performed, and may be set to 0 because the attack force control entry condition is not performed. have.

The controller 200 checks the vane angle of the turbocharger 100 when the state data satisfies the condition for entering the driving force control (S320). In other words, the controller 200 checks a preset force control map. In this case, the attack power control map is a control map set to control the turbocharger 100 in the power mode, and includes vane angles matched to each of the plurality of engine speeds.

The controller 200 checks the vane angle matched to the engine speed included in the state data through the attack force control map.

The controller 200 controls the turbocharger 100 using the checked vane angle.

The controller 200 uses the state data to determine whether or not the force release condition is satisfied (S325). In other words, the controller 200 receives state data from the state detector 10 every set time, and determines whether the received state data satisfies the triggering force release condition. That is, the controller 200 may be configured such that the vehicle speed is less than the set value, the shift stage is less than the reference stage, the accelerator pedal position value does not correspond to the first reference value, the brake pedal position value does not correspond to the second reference value, If the gradient does not exist within the set range, or if the auto cruise setting is on, it may be determined that the strike force release condition is satisfied.

The controller 200 determines a correction value when the state data satisfies the triggering force release condition (S330). Specifically, the controller 200 determines the boost pressure difference, the intake air flow rate, and the supercharger inlet pressure. At this time, the boost pressure difference represents the difference between the target boost pressure and the detected boost pressure, and the detected boost pressure can be checked by being provided from the boost pressure sensor 15 of the state detector 10, and the target boost pressure is dependent on the engine speed and the amount of fuel injected. Can be set accordingly.

The intake air flow rate can be checked by being provided from the flow rate sensor 17 of the condition detector 10, and the supercharger inlet pressure can be checked by being provided from the pressure sensor 13 of the condition detector 10.

The controller 200 checks a preset correction control map. At this time, the correction control map is a control map set to compensate through the supercharger 130 for the vane angle of the turbocharger 100 used when the force mode is performed, and the boost pressure difference, the intake air flow rate, and the supercharger inlet pressure are applied. It may include a matched correction value.

The controller 200 extracts and checks a correction value matched with the boost pressure difference, the intake air flow rate, and the supercharger inlet pressure through the correction control map.

When the engine 50 is started, the controller 200 sets the target boost pressure (S340). That is, the controller 200 sets the target boost pressure according to the engine speed and the amount of fuel injected.

The controller 200 checks the boost pressure difference using the target boost pressure and the detected boost pressure (S345). That is, the controller 200 checks a boost pressure difference that is a difference between the target boost pressure and the detected boost pressure. In this case, the detection boost pressure may be a value detected by the boost pressure sensor 15 of the state detector 10.

The controller 200 determines whether the supercharger 130 is in an operating area (S350). That is, the controller 200 determines whether or not the supercharger 130 is operating based on the intake air flow rate and the maximum rotational speed of the supercharger 130.

The controller 200 determines whether the boost pressure difference exceeds the first set value if it is the operating area of the supercharger 130 (S355). In this case, the first set value is a preset value to determine whether the supercharger 130 is controlled, and may be set through a preset algorithm (eg, a program and a probability model). The reason for determining whether the boost pressure difference exceeds the first set value is to compensate for the boost pressure difference.

The controller 200 opens the bypass valve 140 when it is not in the operating area of the supercharger 130 or when the boost pressure difference is less than or equal to the first set value (S360). That is, since the controller 200 does not require control of the supercharger 130, the bypass valve 140 is opened to secure the amount of intake air.

The controller 200 checks the target speed when the boost pressure difference exceeds the first set value (S365). In other words, the controller 200 checks the speed control map when the boost pressure difference exceeds the first set value. In this case, the speed control map is a control map set to control the supercharger 130 and may be determined through a target speed matched with a boost pressure difference, an intake air flow rate, and a supercharger inlet pressure.

The controller 200 extracts and checks the target speed matched with the boost pressure difference, the intake air flow rate, and the supercharger inlet pressure through the speed control map.

The controller 200 determines the final control value using the target speed and the correction value (S370). That is, the controller 200 determines the final control value by adding the target speed and the correction value checked in step S365. In this case, the correction value may be 0 in the case of step S315.

The controller 200 determines whether the final control value exceeds the second set value (S375). In this case, the second set value may be a minimum value for driving the supercharger 130. The second set value is a preset value and may be set through a preset algorithm (eg, a program and a probability model).

Meanwhile, the controller 200 may terminate control of the engine system when the final control value exceeds the second set value.

The controller 200 closes the bypass valve 140 when the final control value exceeds the second set value (S380).

The controller 200 controls the supercharger 130 based on the final control value while the bypass valve 140 is closed (S385).

Although the above has been described with reference to a preferred embodiment of the present invention, those of ordinary skill in the relevant technical field can use the present invention in various ways within the scope not departing from the spirit and scope of the present invention described in the following claims. It will be appreciated that it can be modified and changed.

10: state detector
50: engine
100: turbocharger
110: energy cleaner box
120: intercooler
130: supercharger
140: bypass valve
150: throttle valve
170: LP-EGR cooler
180: LP-EGR valve
200: controller

Claims (14)

Turbocharger;
An intercooler for cooling the mixer of the turbocharger and the external fresh air;
A supercharger that compresses intake air and supplies it to the combustion chamber of the engine;
A bypass valve provided in a bypass line bypassing the supercharger;
A state detector for detecting state data of the engine; And
A controller for controlling the turbocharger and the supercharger using the state data;
Including,
The controller is
The target speed according to the boost pressure difference, the intake air flow rate, and the supercharger inlet pressure is checked, and at the same time, using the state data, it is determined whether the hitting force control entry condition is satisfied, and a correction value is determined according to the hitting force control entry condition. A final control value is determined using the target speed and the correction value, and the supercharger is controlled based on the final control value, but the vehicle speed of the state data is higher than the reference speed, the shift stage is higher than the reference stage, and acceleration An engine system, characterized in that it is determined that the position value of the pedal corresponds to the first reference value, the position value of the brake pedal corresponds to the second reference value, and if the gradient is within a set range, it is determined that the force control entry condition is satisfied. The method of claim 1,
The controller is
When the state data satisfies a condition for entering force control, the vane angle according to the state data is checked, and the turbocharger is controlled based on the vane angle. The method of claim 2,
The controller is
The engine system according to claim 1, wherein the vane angles matched with the engine speed included in the state data are checked through the attrition control map, and the attrition control map including vane angles matched to each of the plurality of engine speeds is checked. The method of claim 2,
The controller is
Using the state data, it is determined whether the force release condition is satisfied, and if the state data satisfies the force release condition, a correction value according to the boost pressure difference, the intake air flow rate, and the supercharger inlet pressure is determined, and the target speed and the correction An engine system that determines the final control value by adding values and using them. delete The method of claim 1,
The controller is
And controlling the supercharger by setting the correction value to 0 when the state data does not satisfy a condition for entering the force control. The method of claim 1,
The boost pressure difference represents a difference between a target boost pressure and a detected boost pressure, and the target boost pressure is set according to an engine speed and an amount of injected fuel. The method of claim 1,
The state detector
An engine sensor that detects the speed of the engine;
A speed sensor that detects the speed of the vehicle;
A shift stage sensor that detects a shift stage fastened to the transmission;
An accelerator pedal position sensor detecting a position value of the accelerator pedal;
A brake pedal position sensor for detecting a position value of the brake pedal; And
A gradient sensor that detects a gradient of the road;
Engine system comprising at least one of. Determining whether the engine is started;
Checking a target speed according to a boost pressure difference, an intake air flow rate, and a supercharger inlet pressure when the engine is started, and determining whether or not a hitting force control entry condition is satisfied using state data;
Determining a correction value according to the force control entry condition;
Determining a final control value using the target speed and the correction value; And
Including; controlling a supercharger based on the final control value,
The determining of the correction value is the step of determining a correction value according to the boost pressure difference, the intake air flow rate, and the supercharger inlet pressure when the condition for entering the force control entry is satisfied. delete The method of claim 9,
The step of determining the correction value
Checking a steering force control map including vane angles matched to each of a plurality of engine speeds when the conditions for entering the force control entry are satisfied;
Checking a vane angle matched with the engine speed included in the state data through the force control map;
Controlling a turbocharger based on the vane angle;
Determining whether or not a force release condition is satisfied using the state data;
Checking a correction control map when the state data satisfies a condition for releasing the force; And
Determining a correction value according to a boost pressure difference indicating a difference between a target boost pressure and a detected boost pressure, an intake air flow rate, and a supercharger inlet pressure through the correction control map;
Engine system control method comprising a. The method of claim 9,
Checking the target speed is
Setting a target boost pressure according to the engine speed and the amount of fuel injected;
Checking a difference in the boost pressure that is a difference between the target boost pressure and the detected boost pressure;
Determining whether the boost pressure difference exceeds a set value;
Checking a speed control map when the boost pressure difference exceeds a set value; And
Checking a target speed according to a boost pressure difference, an intake air flow rate, and a supercharger inlet pressure through the speed control map;
Engine system control method comprising a. The method of claim 9,
The step of determining whether or not the force control entry condition is satisfied using the state data
Determining whether the vehicle speed included in the state data is greater than or equal to a reference speed;
If the vehicle speed is greater than or equal to the reference speed, determining whether a shift level is greater than or equal to the reference level;
Determining whether the position value of the accelerator pedal corresponds to a first reference value when the shift stage is greater than or equal to the reference stage;
Determining whether the position value of the brake pedal corresponds to a second reference value when the position value of the accelerator pedal corresponds to a first reference value; And
Determining whether a gradient degree is within a set range when the position value of the brake pedal corresponds to a second reference value;
Engine system control method comprising a. The method of claim 9,
The step of determining the correction value
The engine system control method, characterized in that the correction value is set to 0 when the state data does not satisfy a condition for entering the force control.

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