KR102161505B1 - Engine clutch slip control method and apparatus - Google Patents

Abstract

The present invention relates to a method and apparatus for controlling slip of an engine clutch. A method for controlling slip of an engine clutch according to an embodiment of the present invention includes: monitoring a rotation speed of a motor and a rotation speed of the engine while driving; Calculating a change in rotational speed of the motor and a change in rotational speed of the engine; Operating the engine clutch in a slip state when the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are opposite to each other; And when the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are the same, operating the engine clutch in a lock-up state. It characterized in that it comprises a.
Problems such as generation of vibrations of a vehicle caused by an anti-phase phenomenon can be solved by the method and apparatus for controlling the slip of the engine clutch.

Description

Engine clutch slip control method and apparatus TECHNICAL FIELD

The present invention relates to a method for controlling an engine clutch of a hybrid vehicle, and more particularly, to a method and apparatus for controlling slip when an engine clutch is joined.

The hybrid vehicle can configure various power transmission devices using an engine and a motor as power sources. In such a power transmission device, the engine serves only as a generator, and a series-type powertrain in which driving is carried out by driving a motor, a parallel-type powertrain that combines the power of the engine and motor to make driving, and the engine and motor power are used together. Depending on the driving situation, there is a series-parallel powertrain in which the power of a motor or engine is distributed.

The serial-parallel powertrain of a hybrid vehicle can provide an electric vehicle (EV) mode and a hybrid electric vehicle (HEV) mode. The EV driving mode is a mode in which the vehicle is driven only by driving the motor and is based on battery power. The HEV driving mode is a mode in which high-speed driving is performed using the engine power in addition to the motor power, and the engine power is transmitted through the engine clutch.

Mode conversion between EV mode and HEV mode in a hybrid vehicle is one of the major functions, and is a factor that affects the drivability, fuel economy, and power performance of the hybrid vehicle. Therefore, sophisticated mode conversion control is essential, and optimal mode conversion suitable for driving conditions is required.

In this mode conversion control, engine clutch control is important. If the engine clutch is open, the drive shaft is driven by the motor, and if the engine clutch is locked up, the drive shaft is driven by the engine and motor. . The slip state of the engine clutch is a state in which the engine clutch is not completely joined and the torque of the engine is transmitted while the rotational speed of the engine and the motor are different.

On the other hand, when switching from EV mode to HEV mode or when shock torque from the engine side occurs during acceleration/deceleration even without mode switching, the phases of the motor rotation speed (RPM) fluctuation and the engine rotation speed fluctuation occur in reverse. An inverse phase phenomenon may occur. Such an inverse phase phenomenon causes vibration in the vehicle while driving and makes the driver feel a bad ride.

In order to solve this problem, hardware methods such as increasing engine clutch hysteresis can be used, but hysteresis deviation between samples and power loss problems occur, and an additional cost is incurred for hardware change, so reverse phase through control of the engine clutch Suggest a way to solve the problem.

The present invention was devised to solve the problems of the prior art described above, and an object of the present invention is to provide a method and apparatus for controlling engine clutch slip.

The present invention provides a method and apparatus for monitoring whether or not an out-of-phase phenomenon occurs in real time while driving and using slip control of an engine clutch when an out-of-phase phenomenon is detected.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present invention belongs from the following description. I will be able to.

In order to solve the above technical problem, a slip control method of an engine clutch according to an embodiment of the present invention includes: monitoring a rotation speed of a motor and a rotation speed of an engine while driving; Calculating a change in rotational speed of the motor and a change in rotational speed of the engine; Operating the engine clutch in a slip state when the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are opposite to each other; And when the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are the same, operating the engine clutch in a lock-up state. It may include.

According to an embodiment, the step of operating the engine clutch in a slip state may include operating a clutch of a dual clutch transmission (DCT, Dual 　 Clutch 　 Transmission) in a slip state; It may further include.

According to an embodiment, the step of operating the engine clutch in a slip state may be performed by controlling the torque Ta that can be transmitted by the engine clutch.

According to an embodiment, in order to operate the engine clutch in a slip state, the torque Ta that can be transmitted by the engine clutch is controlled to be smaller than the input torque Te of the engine clutch calculated by monitoring the rotational speed of the motor. Step to do; It may further include.

According to an embodiment, the torque Ta that can be transmitted by the engine clutch may be determined by a force Fa applied to the joint of the engine clutch.

According to an embodiment, the torque Ta that can be transmitted by the engine clutch is a clutch surface friction coefficient (u) of the engine clutch, a friction surface number (n), an effective torque transmission radius (R), and the lock-up state It can be determined by the force (Fs) applied in the direction of the engine clutch.

According to an embodiment, the present invention can provide a computer-readable recording medium in which a program for executing the method described above is recorded.

In addition, an apparatus for controlling slip of an engine clutch according to an embodiment of the present invention includes: a monitoring unit for monitoring a rotation speed of a motor and a rotation speed of the engine while driving; A change amount calculation unit for calculating a change amount of the rotation speed of the motor and a change amount of the rotation speed of the engine; And when the sign of the rotation speed change amount of the motor and the rotation speed change amount of the engine are opposite, the engine clutch is operated in a slip state, and the sign of the rotation speed change amount of the motor and the rotation speed change amount of the engine A control unit for operating the engine clutch in a lock-up state when the signs of are the same; It may include.

According to an embodiment, when operating the engine clutch in a slip state, the controller may operate a clutch of a dual clutch transmission (DCT) in a slip state.

According to an embodiment, the control unit may operate the engine clutch in a slip state by controlling the torque Ta that can be transmitted by the engine clutch.

According to an embodiment, the control unit is configured that the torque Ta that can be transmitted by the engine clutch to operate the engine clutch in a slip state is greater than the input torque Te of the engine clutch calculated by monitoring the rotational speed of the motor. It can be controlled to be small.

According to an embodiment, the torque Ta that can be transmitted by the engine clutch may be determined by a force Fa applied to the joint of the engine clutch.

According to an embodiment, the torque Ta that can be transmitted by the engine clutch is a clutch surface friction coefficient (u) of the engine clutch, a friction surface number (n), an effective torque transmission radius (R), and the lock-up state It can be determined by the force (Fs) applied in the direction of the engine clutch.

An effect of the method and apparatus for controlling engine clutch slip according to the present invention will be described as follows.

First, the present invention solves the occurrence of the reverse phase problem between the engine and the motor, thereby reducing vibration of the vehicle and providing a good ride comfort to the driver.

Second, the present invention monitors the rotational speeds of the engine and the motor in real time to reduce vehicle vibration, thereby enabling effective power transmission, thereby increasing fuel efficiency.

Third, the present invention solves the reverse phase problem by controlling the engine clutch without changing the hardware, so that no additional cost is incurred.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those of ordinary skill in the art from the following description. will be.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are provided to aid understanding of the present invention and provide embodiments of the present invention together with a detailed description. However, the technical features of the present invention are not limited to a specific drawing, and features disclosed in each drawing may be combined with each other to constitute a new embodiment.
1 is a view for explaining generation of an inverse phase when the engine clutch is controlled from an open state to a closed state.
2 is a flowchart illustrating a method of controlling an engine clutch slip according to an embodiment of the present invention.
3 is a view for explaining the effect of the slip control method of the engine clutch according to an embodiment of the present invention.
4 is a block diagram illustrating an engine clutch control system that performs slip control of an engine clutch according to an embodiment of the present invention.
5 is a flow chart illustrating a specific method of performing slip control of an engine clutch according to an embodiment of the present invention.
6 is a block diagram illustrating an apparatus for controlling slip of an engine clutch according to an embodiment of the present invention.

Hereinafter, an apparatus and various methods to which embodiments of the present invention are applied will be described in more detail with reference to the drawings. The suffixes "module" and "unit" for components used in the following description are given or used interchangeably in consideration of only the ease of preparation of the specification, and do not have meanings or roles that are distinguished from each other.

In addition, in describing the present invention, if it is determined that the subject matter of the present invention may be unnecessarily obscured as matters apparent to those skilled in the art with respect to related known technologies, detailed descriptions thereof will be omitted.

Looking at the series-parallel powertrain of a typical hybrid vehicle, the engine may be connected to a motor by an engine clutch, and a dual clutch transmission (DCT) may be connected to the engine and the shaft of the motor. The engine clutch is disposed between the engine and the motor and selectively connects the engine and the motor according to the driving mode of the hybrid vehicle. In the dual clutch transmission, the sum of the output torque of the engine and the output torque of the motor, which is determined according to the open state and lock-up state of the engine clutch, is supplied as an input torque. Output to the wheel to keep driving.

In FIG. 1, the occurrence of an inverse phase phenomenon that occurs when the engine clutch is controlled from an open state to a closed state is examined, and in FIG. 2, a slip control method of the engine clutch for eliminating the reverse phase phenomenon will be described. In FIG. 3, an effect of eliminating an inverse phase phenomenon by performing the slip control will be described.

Hereinafter, in FIGS. 4 and 5, as an embodiment according to the present invention, a specific sleep control method will be described, and in FIG. 6, the structure of the sleep control device and functions of each component will be described in detail.

1 is a view for explaining generation of an inverse phase when the engine clutch is controlled from an open state to a closed state.

Even in EV mode, on the premise that the engine is active, an out-of-phase phenomenon occurs in the transitions of states A (EV mode), B, C, and D (HEV mode).

The A state is a driving state in the EV mode. In the EV mode, the engine clutch is open and the DCT clutch is locked-up and closed, so that driving is performed only with the motor.

State B is a state in which mode conversion from EV mode to HEV mode starts. The DCT clutch is slipped for mode conversion.

In the C state, when the DCT clutch is slipped, the engine clutch is also momentarily locked up to synchronize the rotation speed of the engine and the motor.

When the engine clutch is momentarily locked up, the engine clutch may have a shock caused by the difference between the inertia of the motor and the DCT and the engine inertia. When a shock occurs, a so-called reverse phase phenomenon occurs in which the rotation speed fluctuations of the engine and the motor are opposite as shown in the graph, and the vibration is transmitted to the vehicle side. This makes the driver feel that the ride is bad.

In the D state, the DCT clutch is also locked up while the engine clutch is locked, and the rotation speed of the engine, motor and DCT is synchronized, and the mode conversion to HEV mode is terminated. In HEV mode, the engine clutch is locked up so that both engine and motor power are transmitted.

Even if the rotation speed of the engine and the rotation speed of the motor are synchronized just before the lock-up of the engine clutch in the C state, if there is a difference in the gradient of each rotation speed, a difference occurs in the inertia of each engine and the motor rotation body. It may cause a change in the rotational speed between the whole, and in the end, the amount of change in the momentum, that is, the amount of impact, is increased. Therefore, it is necessary to synchronize the rotational speed of the engine and the rotational speed of the motor and simultaneously take the same change.

To this end, an embodiment of the present invention proposes slip control of the engine clutch when converting from EV mode to HEV mode, and to control the engine clutch, Open, Slip, and Lock-up ), etc. It is most important to accurately monitor the current clutch status.

Hereinafter, a method of controlling the slip of an engine clutch to eliminate an inverse phase phenomenon will be described in FIGS. 2 and 3.

2 is a flowchart illustrating a method of controlling an engine clutch slip according to an embodiment of the present invention.

The slip control device of the engine clutch monitors the rotational speed of the motor and the engine in real time while driving (S110).

The reverse phase problem can be solved by locking up the engine clutch after slip control at the beginning of the conversion from EV mode to HEV mode.However, in order to improve the reverse phase phenomenon that occurs during acceleration/deceleration driving when engine torque suddenly enters during HEV mode driving, Monitoring is necessary. In addition, even when the reverse phase problem does not occur when switching from the EV mode to the HEV mode during high-speed driving, continuous monitoring is necessary in that if an unconditional engine clutch slip is performed, fuel economy may decrease due to unnecessary power consumption.

The slip control device of the engine clutch calculates the amount of change in the monitored motor and the rotational speed of the engine, and determines whether the sign of the change in the rotational speed of the motor and the change in the rotational speed of the engine is the same (S120).

When the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are opposite (Yes path in S120), the slip control device performs slip control of the engine clutch through control of the hydraulic actuator (S130).

When the sign of the change in the rotation speed of the motor and the change in the rotation speed of the engine are the same (no path in S120), the slip control device does not control the slip of the engine clutch and transmits the engine power through lock-up control. The same sign of the amount of change in the rotational speed means that the difference in rotational inertia between the motor and the engine is not large, and when the difference in rotational inertia is small, a reverse rotation problem does not occur, and lockup control is not a problem.

Hereinafter, the effect of eliminating the occurrence of an inverse phase phenomenon by performing slip control of the engine clutch in FIG. 3 will be described.

3 is a view for explaining the effect of the slip control device of the engine clutch according to an embodiment of the present invention.

In Fig. 3, as shown in Fig. 1, it is assumed that the engine is activated in the EV mode. A (EV mode), B, C(2), C(1), C(2), and D (HEV mode) state transition, a momentary out-of-phase phenomenon occurs in the C(2) state, but C(1) The difference from FIG. 1 is that the reverse phase phenomenon is eliminated by the state.

The A state is a driving state in the EV mode. In the EV mode, the engine clutch is open and the DCT clutch is locked-up and closed, so that driving is performed only with the motor.

State B is a state in which mode conversion from EV mode to HEV mode starts. The DCT clutch is slipped for mode conversion.

In the C(2) state, the initial lockup of the engine clutch is performed. Thereafter, as the out-of-phase phenomenon is monitored, slip control of the engine clutch is immediately performed in the C(1) state.

When the engine clutch is locked up, the reverse phase phenomenon occurs as shown in FIG. 1, but the reverse phase phenomenon disappears through immediate slip control of the engine clutch.

After C(1), the reverse phase phenomenon disappears, and the engine clutch is locked up again in C(2) state, so that the rotation speed of the engine and the motor is synchronized.

In the D state, the DCT clutch is also locked up while the engine clutch is locked, and the rotation speed of the engine, motor and DCT is synchronized, and the mode conversion to HEV mode is terminated. In HEV mode, the engine clutch is locked up so that both engine and motor power are transmitted.

Hereinafter, a specific configuration for performing slip control of the engine clutch in FIG. 4 will be described, and in FIG. 5, a method for performing slip control in the configuration of FIG. 4 will be described.

4 is a configuration diagram illustrating an engine clutch control system for performing slip control of an engine clutch according to an embodiment of the present invention, and FIG. 5 is a diagram illustrating a slip control of an engine clutch according to an embodiment of the present invention. This is a flow chart to explain the method.

The slip control of the clutch requires not only the problem of deterioration of durability of the joint, but also the precise control in order to prevent a decrease in ride comfort due to an impact that may occur during slip control.

4, the engine clutch control system includes a hydraulic actuator 100, an engine clutch controller 200, a diaphragm 300, a clutch cover 400, an engine clutch 500, and a flywheel 600. I can.

Since the components shown in FIG. 4 are not essential, an engine clutch control system having more or fewer components than that may be implemented.

The engine clutch slip control device generates a torque Fa that can be transmitted by the engine clutch by operating the hydraulic actuator 100 when an inverse phase of the change in the rotational speed of the motor and the engine occurs while driving (S210).

The hydraulic actuator 100 may generate hydraulic pressure in a pipe connecting the hydraulic actuator and the engine clutch controller 200 under control of a hybrid control unit (HCU), which is a top controller (S220).

The hydraulic pressure transmitted through the pipe advances the bearing of the engine clutch controller 200 to generate a torque Fa that the engine clutch 500 can transmit toward the clutch cover 400 (S230).

The engine clutch controller 200 may be a CSC (Concentric Slave Cylinder) that improves operating efficiency by uniting the operating parts of the engine clutch into a single module.

The clutch cover 400 is opened by the torque Fa that the engine clutch can transmit, and the slip control of the engine clutch 500 is performed (S240).

In performing the slip control, a method of determining the hydraulic pressure generated by the hydraulic actuator 100 will be described.

In general, in the hydraulic actuator 100, when the slip of the engine clutch occurs, power transmission is lost, so the engine clutch 500, which is Ta (torque that can be transmitted by the engine clutch)> Te (engine clutch input torque), is locked up. Generate hydraulic pressure to be However, in an embodiment of the present invention, when an inverse phase phenomenon occurs in which the sign of the rotational speed change amount of the motor and the engine is opposite during driving, the hydraulic actuator 100 controls the hydraulic pressure generation so that the slip control with Ta <Te is performed. .

The torque Ta that can be transmitted by the engine clutch is the friction coefficient of the clutch surface of the engine clutch (u), the number of friction surfaces (n), the effective torque transmission radius (R), and the force applied in the direction of the engine clutch to proceed to the lockup state ( Fs), it is determined by the force (Fa) transmitted to the clutch cover side by the hydraulic actuator.

First, Ta must first calculate F by including F as a factor. F can be obtained as in Equation 1 below.

Ta can be obtained as in Equation 2 below.

Thereafter, when it is confirmed that the reverse phase phenomenon of the rotational speed change amount of the motor and engine is resolved, the hydraulic actuator 100 removes the hydraulic pressure Fa so that it is reduced to a state of Ta> Te.

Hereinafter, a slip control device that performs slip control of an engine clutch will be described.

6 is a block diagram illustrating an apparatus for controlling slip of an engine clutch according to an embodiment of the present invention.

Referring to FIG. 6, the slip control apparatus 900 of the engine clutch may include a monitoring unit 910, a change amount calculating unit 920, a memory 930, and a control unit 940.

Since the components shown in FIG. 6 are not essential, the slip control apparatus 900 of the engine clutch may be implemented having more components or fewer components.

Hereinafter, the above components will be described in detail.

The monitoring unit 910 monitors the rotation speed of the motor and the rotation speed of the engine while driving.

The change amount calculation unit 920 calculates the amount of change in the rotational speed of the motor and the amount of change in the rotational speed of the engine.

The memory 930 is a space in which a predetermined program code for controlling the overall operation of the slip control device 900 of the engine clutch and data input/output when an operation by the program code is performed, and/or storage As a generic term for an area, it is provided in the form of an EEPROM (Electrically Erasable and Programmable Read Only Memory), FM (Flash Memory), and a Hard Disk Drive.

The control unit 940 may perform data processing and calculation in order to control the overall operation of the slip control device 900 of the engine clutch.

In one embodiment, when the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are opposite, the control unit 940 operates the engine clutch in a slip state, and the sign of the rotational speed change amount of the motor and When the sign of the engine rotational speed change amount is the same, the engine clutch is operated in a locked-up state.

The engine clutch slip control device 900 outputs a control signal to regulate the opening, lockup, and slip of the engine clutch and the dual clutch mechanism. The engine clutch slip control apparatus 900 may perform an engine clutch slip control method through cooperative control between various controllers provided in a hybrid vehicle. Controllers include, for example, HCU (Hybrid Control Unit), which is the highest level controller, ECU (Engine Control Unit) that controls the overall operation of the engine, MCU (Motor Control Unit) that controls the overall operation of the driving motor, and the transmission. TCU (Transmission Control Unit), etc.

For this purpose, the engine clutch slip control device 900 may be implemented with one or more processors operated by a set program, and the set programs are each step of the method for controlling the engine clutch slip of a hybrid vehicle according to an embodiment of the present invention. It may be programmed to perform

The method according to the above-described embodiment may be produced as a program to be executed on a computer and stored in a computer-readable recording medium. Examples of computer-readable recording media include ROM, RAM, CD-ROM, and magnetic tape. , A floppy disk, an optical data storage device, and the like, and also include those implemented in the form of a carrier wave (for example, transmission through the Internet).

The computer-readable recording medium is distributed over a computer system connected by a network, and computer-readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes and code segments for implementing the above-described method can be easily inferred by programmers in the technical field to which the embodiment belongs.

It is obvious to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention.

Therefore, the detailed description above should not be construed as restrictive in all respects and should be considered as illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention.

100: hydraulic actuator
200: engine clutch controller
300: diaphragm
400: clutch cover
500: engine clutch
600: flywheel
900: engine clutch slip control device
910: monitoring unit
920: change amount calculation unit
930: memory
940: control unit

Claims (13)

Monitoring the rotation speed of the motor and the rotation speed of the engine while driving;
Calculating a change in rotational speed of the motor and a change in rotational speed of the engine;
Operating the engine clutch in a slip state when the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are opposite to each other; And
When the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are the same, operating the engine clutch in a lock-up state;
Containing,
Engine clutch slip control method. The method of claim 1,
Operating the engine clutch in a slip state,
Operating a clutch of a dual clutch transmission (DCT) in a slip state;
Further comprising,
Engine clutch slip control method. The method of claim 1,
Operating the engine clutch in a slip state,
Performed by controlling the torque Ta that the engine clutch can transmit,
Engine clutch slip control method. The method of claim 3,
In order to operate the engine clutch in a slip state,
Controlling the torque Ta that can be transmitted by the engine clutch to be smaller than the input torque Te of the engine clutch calculated by monitoring the rotational speed of the motor;
Further comprising,
Engine clutch slip control method. The method of claim 3,
The torque Ta that can be transmitted by the engine clutch is determined by the force Fa applied to the junction of the engine clutch,
Engine clutch slip control method. The method of claim 3,
The torque Ta that the engine clutch can transmit is,
Determined by the clutch surface friction coefficient (u) of the engine clutch, the number of friction surfaces (n), the effective torque transmission radius (R), and the force (Fs) applied in the direction of the engine clutch to proceed to the lock-up state,
Engine clutch slip control method. A computer-readable recording medium on which a program for executing the method according to any one of claims 1 to 6 is recorded. A monitoring unit that monitors the rotational speed of the motor and the rotational speed of the engine while driving;
A change amount calculation unit calculating a change amount of the rotation speed of the motor and a change amount of the rotation speed of the engine; And
When the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are opposite, the engine clutch is operated in a slip state,
A control unit for operating the engine clutch in a lock-up state when the sign of the rotational speed change amount of the motor and the rotational speed change amount of the engine are the same;
Containing,
Engine clutch slip control device. The method of claim 8,
The control unit,
When operating the engine clutch in a slip state, operating the clutch of a dual clutch transmission (DCT) in a slip state,
Engine clutch slip control device. The method of claim 8,
The control unit,
Operating the engine clutch in a slip state by controlling the torque Ta that can be transmitted by the engine clutch,
Engine clutch slip control device. The method of claim 10,
The control unit,
In order to operate the engine clutch in a slip state, the torque Ta that can be transmitted by the engine clutch is controlled to be smaller than the input torque Te of the engine clutch calculated by monitoring the rotational speed of the motor,
Engine clutch slip control device. The method of claim 10,
The torque Ta that can be transmitted by the engine clutch is determined by the force Fa applied to the junction of the engine clutch,
Engine clutch slip control device. The method of claim 10,
The torque Ta that the engine clutch can transmit is,
Determined by the clutch surface friction coefficient (u) of the engine clutch, the number of friction surfaces (n), the effective torque transmission radius (R), and the force (Fs) applied in the direction of the engine clutch to proceed to the lock-up state,
Engine clutch slip control device.

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