KR20220167834A - System and method for controlling damper clutch of hybrid vehicles - Google Patents

Abstract

The present invention relates to a method for controlling a damper clutch of a hybrid vehicle, which improves fuel efficiency by adding a directly connectable region of the damper clutch according to a battery SOC in a low-speed driving section, and a system thereof. The method for controlling the damper clutch of the hybrid vehicle introduced in the present invention comprises the following steps of: determining a fastening status of the damper clutch; and controlling the damper clutch to fully engage when an APS, a driving mode, and a battery SOC satisfy a damper clutch complete engagement condition when determining whether the damper clutch is released.

Description

Damper clutch control method and system for hybrid vehicles {System and method for controlling damper clutch of hybrid vehicles}

The present invention relates to a method and system for controlling a damper clutch of a hybrid vehicle that improves fuel efficiency by adding a direct connectable region of a damper clutch according to a battery SOC in a low-speed driving section.

Fuel efficiency is improved by applying a damper clutch (direct clutch) to compensate for the low efficiency of the torque converter in engine vehicles equipped with AT.

1 shows an operating area of the damper clutch.

Referring to the drawings, the completely direct connection area is a power on area and corresponds to an area in which the vehicle is driven at constant speed and accelerated.

In the direct slip area, fuel efficiency is improved by improving driveability and expanding the direct area.

The deceleration direct connection region is a power off region, and corresponds to an engine fuel cut and a region in which the vehicle is driven at a reduced speed.

The release area corresponds to an area in which the damper clutch is opened and released in order to sense start/run acceleration and prevent NVH. For reference, the damper clutch is also released in the reverse and shifting ranges.

In each operating area, the actual operation of the damper clutch is performed through hydraulic duty control according to shift/engine/vehicle driving.

On the other hand, when the damper clutch is directly connected, engine vibration and shock are introduced into the transmission input side, and a rapid torque change appears on the drive shaft.

For this reason, since the damper clutch must be fastened within a range that does not impede drivability, the area where the damper clutch can be directly connected is inevitably limited.

However, since an effective method for improving fuel efficiency in a vehicle to which a torque converter is applied is to expand the direct connection area, there is a need to expand the direct connection area of the damper clutch.

The matters described as the background art above are only for improving understanding of the background of the present invention, and should not be taken as an admission that they correspond to prior art already known to those skilled in the art.

KR 10-2244551 B1

The present invention has been made to solve the above-described problems, to provide a damper clutch control method and system for a hybrid vehicle that improves fuel efficiency by adding a direct connection area of the damper clutch according to the battery SOC in a low-speed driving section. is in

The configuration of the damper clutch control system for a hybrid vehicle of the present invention for achieving the above object is a damper clutch of a hybrid vehicle capable of driving in an EV mode by driving force of a motor and having a torque converter connected between the motor and the transmission As a method of controlling, the control unit, the fastening state determination step of determining the fastening state of the damper clutch; When the control unit determines that the damper clutch is released, a complete fastening step of controlling the damper clutch to be fully fastened when the APS, the driving mode, and the battery SOC satisfy the fully fastened condition of the damper clutch; there is.

The fully engaged conditions of the damper clutch may be that APS is less than or equal to the reference value, the driving mode is the EV mode, and the battery SOC is greater than or equal to the reference value.

When it is determined that the damper clutch is released, a slip fastening step of controlling the damper clutch to slip fasten when the APS is equal to or less than the reference value and the driving mode is the HEV mode; may be further included.

A slip fastening step of controlling the damper clutch to slip fasten when the APS is less than the reference value, the driving mode is the EV mode, and the battery SOC is less than the reference value when it is determined that the damper clutch is released is further included.

When determining whether the damper clutch is released, the damper clutch complete engagement condition may be determined when the gear shift state, the oil temperature, and the communication state satisfy the damper clutch engagement preparation condition.

The preparation conditions for engaging the damper clutch may be that shifting is not in progress, oil temperature is higher than a reference value, and communication is normal.

When determining whether the damper clutch is fastened, if at least one of the APS, vehicle speed, engine state, and battery SOC satisfies the damper clutch release condition, the complete engagement release step of controlling the damper clutch to be fully engaged is released; can

The damper clutch release condition may be that APS is greater than or equal to a reference value, vehicle speed is less than or equal to a reference value, or battery SOC is less than or equal to a reference value while the engine is running.

Upon determining the slip engagement of the damper clutch, when the driving mode is switched to the EV mode, the damper clutch may be controlled to be fully engaged.

Upon determining the slip engagement of the damper clutch, if the APS is greater than the reference value and the vehicle speed is greater than the reference value, the damper clutch may be controlled to be fully engaged.

The configuration related to the damper clutch control method of the hybrid vehicle of the present invention is a system for controlling the damper clutch of a hybrid vehicle capable of driving in EV mode by driving force of a motor and having a torque converter connected between a motor and a transmission, the damper clutch a determination unit for determining the fastening state of; When the damper clutch is released, an operation control unit that controls the damper clutch to be fully engaged when the APS, the driving mode, and the battery SOC satisfy the fully engaged condition of the damper clutch.

Through the above problem solving means, the present invention has the effect of improving fuel efficiency by expanding the direct connection area of the damper clutch by directly connecting the damper clutch when driving at low speed in the EV mode in a situation where the battery SOC is high.

In addition, since the battery SOC is sufficient, the motor torque is increased to implement the torque multiplication effect obtained through the torque converter slip, thereby preventing the deterioration of the acceleration performance compared to the previous one while driving.

1 is a view showing an operating area of a conventional damper clutch;
2 is a diagram schematically illustrating a powertrain system of a hybrid vehicle to which a damper clutch according to the present invention is applied.
3 is a system configuration diagram for controlling a damper clutch of a hybrid vehicle according to the present invention.
4 is a flowchart showing a damper clutch control process of a hybrid vehicle according to the present invention.
5 is a view showing an operating area of a damper clutch according to the present invention.
6 to 8 are diagrams showing an operating region of a damper clutch in a specific driving condition of a hybrid vehicle according to the present invention.

Specific structural or functional descriptions of the embodiments of the present invention disclosed in this specification or application are merely illustrated for the purpose of explaining the embodiments according to the present invention, and the embodiments according to the present invention may be implemented in various forms. It may be and should not be construed as being limited to the embodiments described in this specification or application.

Embodiments according to the present invention can apply various changes and can have various forms, so specific embodiments are illustrated in the drawings and described in detail in this specification or application. However, this is not intended to limit the embodiments according to the concept of the present invention to specific disclosures, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The above terms are only for the purpose of distinguishing one component from another component, e.g., without departing from the scope of rights according to the concept of the present invention, a first component may be termed a second component, and similarly The second component may also be referred to as the first component.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle. Other expressions describing the relationship between elements, such as "between" and "directly between" or "adjacent to" and "directly adjacent to", etc., should be interpreted similarly.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "having" are intended to designate that the described feature, number, step, operation, component, part, or combination thereof exists, but one or more other features or numbers However, it should be understood that it does not preclude the presence or addition of steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined herein, they are not interpreted in an ideal or excessively formal meaning. .

A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram schematically showing a powertrain system of a hybrid vehicle to which a damper clutch according to the present invention is applied.

In the hybrid vehicle shown in the drawing, the engine clutch 3 is connected between the engine 1 and the motor 5 to regulate the speed, and the torque converter 7 is connected between the motor 5 and the transmission 9 to enable the engine The driving force provided by (1) and the motor (5) is transmitted to the transmission (9) through the torque converter (7).

When the engine clutch 3 is released, the driving force of the engine 1 is not transmitted to the motor 5, so that the hybrid vehicle can drive in the EV mode by driving the vehicle only with the motor 5.

Meanwhile, FIG. 3 is a system configuration diagram for controlling a damper clutch of a hybrid vehicle according to the present invention.

Referring to the drawing, the engine control unit 20 (ECU) transmits information related to engine on/off, engine speed, and engine torque to the transmission control unit 10.

The battery management system 30 (BMS) transmits information related to a battery state of charge (SOC) and battery output to the transmission control unit 10.

The motor control unit 40 (MCU) transmits information related to the number of motor revolutions and motor torque to the transmission control unit 10.

The vehicle management system 50 (VMS) transmits information related to the vehicle speed and the accelerator pedal to the transmission control unit 10.

The transmission control unit 10 (TCU) transmits to the damper clutch control unit 100 information related to the shift timing, gear stage, shift status, and transmission input stage speed.

The damper clutch control unit 100 controls the damper clutch based on information received from each unit and the management system, including the transmission control unit 10, and the damper clutch control unit 100 operates with the determination unit 110 described later It may be configured to include the control unit 120.

Here, the damper clutch control unit 100 controls a device capable of directly connecting/disengaging the damper clutch, which may mean controlling a solenoid valve or an actuator.

That is, when signals reflecting the current driving state of the vehicle from each unit and management system mounted on the vehicle are input to the transmission control unit 10 (TCU), the damper clutch control unit 100 within the TCU inputs these information in advance The damper clutch is controlled by comparing and judging with existing data to control vehicle driving in an optimal state.

Subsequently, as shown in FIG. 3, the present invention is capable of driving in the EV mode by the driving force of the motor 5, and the damper clutch of the hybrid vehicle in which the torque converter 7 is connected between the motor 5 and the transmission 9 As a control system, the determination unit 110 for determining the fastening state of the damper clutch; When it is determined that the damper clutch is released, the operation controller 120 controls the damper clutch to be fully engaged when the APS, the driving mode, and the battery SOC satisfy the damper clutch complete engagement condition.

That is, in the EV mode in which the vehicle is driven only by the motor 5 at low speed, the engine 1 is in an off state and the engine clutch 3 is released, so there is no driving source generating vibrations in the driving shaft. This means that the damper clutch can be directly connected without compromising drivability in the EV mode driving section in the low-speed range.

However, when the battery SOC is low, there is a problem in that it is difficult to directly connect the damper clutch because the battery output is not sufficient.

Therefore, in the present invention, when the battery SOC is high while driving in the EV mode, by fully engaging the damper clutch, the fuel efficiency is improved by expanding the area where the damper clutch can be directly connected compared to the conventional damper clutch control.

5 is a view showing the operation area of the damper clutch according to the present invention, and it can be seen that the damper clutch direct connection area is additionally enlarged according to the EV mode section and the battery SOC, compared to FIG. 1 showing the operation area of the existing damper clutch.

Meanwhile, FIG. 4 is a flowchart illustrating a process of controlling a damper clutch of a hybrid vehicle according to the present invention.

Referring to the drawings, in the damper clutch control method of a hybrid vehicle of the present invention, driving in the EV mode by the driving force of a motor 5 is possible, and a torque converter 7 is provided between the motor 5 and the transmission 9 A method of controlling a damper clutch of a connected hybrid vehicle, comprising: an engagement state determination step of determining, by a control unit, an engagement state of a damper clutch; When the control unit determines that the damper clutch is released, a complete fastening step of controlling the damper clutch to be fully fastened when the APS, the driving mode, and the battery SOC satisfy the fully fastened condition of the damper clutch; is configured to include.

In particular, the conditions for fully fastening the damper clutch determined in the fastening state determination step may be that APS is less than or equal to the reference value, the driving mode is the EV mode, and the battery SOC is greater than or equal to the reference value.

For example, FIG. 6 is a view showing an operating area of the damper clutch when the vehicle starts in a state where the battery SOC is high, and shows a driving situation in which the vehicle speed gradually increases by stepping on the accelerator pedal while the vehicle is stopped.

At this time, the driving mode of the vehicle is the EV mode, the engine 1 is turned off and the vehicle travels only with the driving force of the motor 5, so that the damper clutch is fully engaged.

That is, when driving at low speed in the EV mode in a situation where the battery SOC is high, fuel efficiency is improved by expanding the direct connection area of the damper clutch by driving with the damper clutch directly connected.

However, the torque multiplication effect obtained through the torque converter slip disappears because the damper clutch is directly connected, but since the battery SOC is sufficient, it can be replaced by increasing the motor torque. It becomes possible.

For reference, the control unit may be the damper clutch control unit 100 that controls the operation of the damper clutch, and the control unit according to an exemplary embodiment of the present invention is configured to control the operation of various components of the vehicle or the algorithm It may be implemented through a non-volatile memory (not shown) configured to store data related to software instructions for reproducing and a processor (not shown) configured to perform an operation described below using the data stored in the memory. . Here, the memory and the processor may be implemented as individual chips. Alternatively, the memory and processor may be implemented as a single chip integrated with each other. A processor may take the form of one or more processors.

Meanwhile, as shown in FIG. 4 , as a result of the decision in the fastening state determining step, when the damper clutch is released, when the APS is equal to or less than the reference value and the driving mode is the HEV mode, the slip fastening step of controlling the damper clutch to slip fasten; It is composed of more.

In addition, in the present invention, as a result of the judgment in the fastening state determination step, when the damper clutch is released, when the APS is less than the reference value, the driving mode is the EV mode, and the battery SOC is less than the reference value, the damper clutch is slip-engaged to slip It is configured to further include; fastening step.

That is, in a situation where the battery SOC is low, the engine 1 maintains an on state because the HEV mode is implemented for battery SOC management control. As the engine is turned on and the engine clutch is engaged, the vibration and torque change of the engine are transmitted to the drive shaft, so the damper clutch is slip-engaged in the low speed range.

In addition, as shown in FIG. 4, as a result of the judgment in the fastening state determination step, when the damper clutch is released, the damper clutch complete engagement condition is determined when the shift state, oil temperature, and communication state satisfy the damper clutch engagement preparation condition can do.

Specifically, the damper clutch fastening preparation conditions are when shifting is not in progress, the oil temperature is higher than the reference value, and communication is normal. When these conditions are satisfied, it is determined whether the damper clutch fully fastened conditions are satisfied.

On the other hand, the present invention, upon determining the engagement of the damper clutch, if at least one of APS, vehicle speed, engine state, and battery SOC satisfies the damper clutch release condition, a disengagement step of controlling to release the engagement of the damper clutch; It is composed including.

Specifically, the damper clutch release condition may be when APS is greater than or equal to a reference value, vehicle speed is less than or equal to a reference value, or battery SOC is less than or equal to a reference value while the engine is running.

For example, when the APS is greater than or equal to a reference value while the damper clutch is engaged, the damper clutch is disengaged.

In addition, when the vehicle speed is equal to or less than the reference value, the damper clutch is disengaged.

In addition, when the SOC is lower than the reference value in the engine-on state, the damper clutch is disengaged.

Meanwhile, the present invention may control the damper clutch to be completely engaged when the driving mode is switched to the EV mode upon determining the slip engagement of the damper clutch.

For example, FIG. 7 is a view showing an operating region of the damper clutch during deceleration due to APS reduction in a state where the battery SOC is greater than or equal to a reference value.

That is, when the vehicle travels in the HEV mode, the damper clutch travels in a slip-engaged state.

In this state, when the driving mode is switched to EV mode according to the vehicle speed deceleration due to the decrease in APS, the damper clutch is fully engaged, thereby contributing to the improvement of fuel efficiency.

In addition, the present invention may control the damper clutch to be completely engaged when the slip engagement of the damper clutch is determined, when the APS is greater than or equal to the reference value and the vehicle speed is greater than or equal to the reference value.

For example, FIG. 8 is a diagram illustrating an operating region of a damper clutch when a vehicle is accelerated in a state where the battery SOC is less than a reference value.

That is, as the vehicle travels at medium speed in the HEV mode in a situation where the battery SOC is low, the damper clutch travels in a slip-engaged state.

In this state, when the APS increases and the vehicle speed increases due to the driver's operation of the accelerator pedal, the damper clutch is fully engaged, thereby contributing to improving fuel efficiency.

Hereinafter, a process of controlling the damper clutch of the hybrid vehicle according to the present invention will be described as a whole with reference to FIG. 4 .

When the vehicle is running, a signal reflecting the driving state of the vehicle is input to the TCU from each control unit mounted on the vehicle and the management system (S10).

Therefore, based on the signal input to the TCU, the current engagement state of the damper clutch is checked to determine whether the damper clutch is in a released state (S20).

As a result of the determination in step S20, when it is determined that the damper clutch is released, it is determined whether the damper clutch fastening preparation conditions are satisfied through the shift state of the vehicle, oil temperature, and communication state (S30).

That is, when it is determined that the vehicle is not shifting, the transmission oil temperature is higher than the reference value, and the communication used in the vehicle is normal, it is determined that the damper clutch fastening preparation condition is satisfied.

Accordingly, when the damper clutch fastening preparation condition is satisfied, the vehicle speed is determined (S40).

As a result of the determination in step S40, if the vehicle speed is equal to or greater than the reference value, the damper clutch is controlled to be fully engaged (S50).

On the other hand, as a result of the determination in step S40, if the vehicle speed is less than the reference value, it is determined whether the APS is less than or equal to the reference value (S60).

As a result of the determination in step S60, if the APS is equal to or less than the reference value, it is determined whether the current driving mode is the EV mode (S70).

As a result of the determination in step S70, in the case of the current EV mode, it is determined whether the battery SOC is greater than or equal to a reference value (S80).

And, as a result of the determination in step S80, when the battery SOC is equal to or greater than the reference value, the control moves to step S50 to fully engage the damper clutch.

On the other hand, as a result of the determination in step S60, when the APS exceeds the reference value, control is performed to maintain the release state of the damper clutch as it is.

Then, as a result of the determination in steps S70 and S80, if the current driving mode is not the EV mode or the battery SOC is less than the reference value, the damper clutch is controlled to slip (S90).

Meanwhile, as a result of the determination in step S20, when it is determined that the damper clutch is fastened, it is determined whether the damper clutch release condition is satisfied through APS, vehicle speed, engine state, and battery SOC (S100).

That is, it is determined that the release condition of the damper clutch is satisfied when the APS is greater than or equal to the reference value, the vehicle speed is less than or equal to the reference value, or the SOC is less than or equal to the reference value in the engine-on state.

Accordingly, when the damper clutch release condition is satisfied, the damper clutch is released and operated (S110).

As described above, the present invention improves fuel efficiency by expanding the direct connection area of the damper clutch by directly connecting the damper clutch when driving at low speed in the EV mode in a situation where the battery SOC is high.

In addition, since the battery SOC is sufficient, the motor torque is increased to implement the torque multiplication effect obtained through the torque converter slip, thereby enabling driving while preventing deterioration of acceleration performance compared to the previous one.

On the other hand, although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention, and it is natural that these changes and modifications fall within the scope of the appended claims. .

1 : engine
3: engine clutch
5: motor
7: Torque converter
9 : Transmission
10: transmission control unit
20: engine control unit
30: battery management system
40: motor control unit
50: vehicle management system
100: damper clutch control unit
110: judgment unit
120: operation control unit

Claims (11)

A method for controlling a damper clutch of a hybrid vehicle capable of driving in EV mode by driving force of a motor and having a torque converter connected between a motor and a transmission,
A fastening state determination step in which the control unit determines the fastening state of the damper clutch;
When the control unit determines to release the damper clutch, a complete engagement step of controlling the damper clutch to fully engage when the APS, the driving mode, and the battery SOC satisfy the damper clutch complete engagement condition; damper clutch of a hybrid vehicle including control method. The method of claim 1,
The damper clutch control method of the hybrid vehicle, characterized in that the fully engaged condition of the damper clutch, APS is less than the reference value, the driving mode is the EV mode, and the battery SOC is greater than the reference value. The method of claim 1,
A slip coupling step of controlling the damper clutch to slip engage when the damper clutch is released when the APS is equal to or less than the reference value and the driving mode is the HEV mode. The method of claim 1,
A slip engagement step of controlling the damper clutch to slip engage when the damper clutch is determined to be released, when the APS is less than the reference value, the driving mode is the EV mode, and the battery SOC is less than the reference value. Damper clutch control method. The method of claim 1,
A damper clutch control method for a hybrid vehicle, characterized in that when it is determined that the damper clutch is released, the damper clutch complete engagement condition is determined when the shift state, the oil temperature, and the communication state satisfy the damper clutch engagement preparation condition. The method of claim 5,
The damper clutch control method of the hybrid vehicle, characterized in that the damper clutch fastening preparation conditions are not shifting, the oil temperature is greater than a reference value, and communication is normal. The method of claim 1,
When determining the engagement of the damper clutch, when at least one of APS, vehicle speed, engine state, and battery SOC satisfies a damper clutch release condition, a complete engagement release step of controlling the damper clutch to be fully engaged; including Damper clutch control method of a hybrid vehicle, characterized in that. The method of claim 7,
The damper clutch release condition is a damper clutch control method for a hybrid vehicle, characterized in that APS is greater than or equal to a reference value, vehicle speed is less than or equal to a reference value, or battery SOC is less than or equal to a reference value while the engine is running. The method of claim 1,
A damper clutch control method for a hybrid vehicle, characterized in that, when determining the slip engagement of the damper clutch, when the driving mode is switched to the EV mode, the damper clutch is fully engaged. The method of claim 1,
The damper clutch control method of a hybrid vehicle, characterized in that, when it is determined that the slip engagement of the damper clutch is determined, the damper clutch is fully engaged when the APS is greater than a reference value and the vehicle speed is greater than the reference value. A system for controlling a damper clutch of a hybrid vehicle capable of driving in EV mode by the driving force of a motor and having a torque converter connected between the motor and transmission,
Determination unit for determining the fastening state of the damper clutch;
A damper clutch control system for a hybrid vehicle comprising: an operation control unit for controlling the damper clutch to be fully engaged when the damper clutch is released, when the APS, the driving mode, and the battery SOC satisfy the damper clutch complete engagement condition.

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