KR20150012151A - System and method for engine clutch learning of hybrid vehicle - Google Patents

Abstract

The present invention is to disclose an engine clutch learning method of a hybrid vehicle which optimally performs controlling engine clutch junction (coupling) by learning a torque transmission starting point of the engine clutch in a hybrid vehicle. The engine clutch learning method of a hybrid vehicle according to the present invention comprises the processes of: securing initial fill by applying a base pressure set in the engine clutch; applying a target hydraulic pressure to the engine clutch, and determining whether a maximum value of the target hydraulic pressure reaches a hydraulic pressure providing junction of a clutch friction element; and learning a base pressure as the torque transmission starting point of the engine clutch when the maximum value of the target hydraulic pressure reaches the maximum value providing the junction of the clutch friction element.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and method for learning an engine clutch of a hybrid vehicle,

The present invention relates to an apparatus and method for learning an engine clutch of a hybrid vehicle, and more particularly, to an apparatus and method for learning an engine clutch of a hybrid vehicle that learns a torque transmission starting point of an engine clutch that provides a transition from an EV mode to an HEV mode, The present invention relates to an apparatus and method for learning an engine clutch of a hybrid vehicle.

The demand for environmentally friendly automobiles is increasing due to the demand for continuous improvement of fuel economy for automobiles and the strengthening of exhaust gas regulations of each country. Hybrid vehicles are being offered as a real alternative to this.

A hybrid vehicle is distinguished from a fuel cell vehicle and an electric vehicle in a narrow sense, but in the present specification, the meaning of a hybrid vehicle is an electric vehicle and a fuel cell vehicle, in which one or more batteries are provided, Refers to a vehicle used as a driving force.

Hybrid vehicles are powered by engines and drive motors, which provide fuel economy improvements and reduced emissions by demonstrating the characteristics of the engine and drive motor depending on the driving situation.

The hybrid vehicle can be provided with the optimum output torque according to how the two power sources composed of the engine and the driving motor are operated in harmony in the course of driving.

Hybrid vehicles are usually powered by TMED (Transmission Mounted Electric Device) powertrain with drive motor and transmission.

The hybrid vehicle includes an EV (Electric Vehicle) mode in which an engine clutch is provided between an engine and a drive motor and the vehicle is driven by the torque of only the drive motor depending on whether the engine clutch is engaged or not, And a hybrid electric vehicle (HEV) mode in which the vehicle is driven by the vehicle.

The joint of the engine clutch in the hybrid vehicle is executed as follows.

5 is a view showing a joint control of an engine clutch in a conventional hybrid vehicle.

5, when the state of charge (SOC) of the battery is switched from the EV mode to the HEV mode supporting the discharge torque that can support the driver's required torque, the base oil pressure To secure an initial fill.

Thereafter, the flow rate supplied to the engine clutch is increased to a predetermined slope, and the drive motor speed MS and the engine speed ES are controlled to converge with each other. In accordance with the control of the drive motor speed MS and the engine speed ES, When the engine speed is within a predetermined speed difference, the engine clutch is slip-controlled.

It is determined that the drive motor speed MS and the engine speed ES are synchronized when the predetermined time t3 elapses after the slip control of the engine clutch is started t2 and the engine clutch is fully engaged to switch to the HEV mode .

When the charging state (SOC) of the battery is low and the discharge torque is limited to make it impossible to drive the EV mode, the engine is started up and the oil pressure is supplied to the engine clutch. When the speed difference is reached, the engine clutch is slip-controlled.

When a predetermined time has elapsed since the start of the slip of the engine clutch, it is determined that the engine speed and the drive motor speed are synchronized, and the engine clutch is fully engaged to complete the shift to the HEV mode.

As described above, when joining the engine clutch for switching from the EV mode to the HEV mode, when the speed difference between the driving motor speed and the engine speed is large or the speed of the power clutch is rapidly increased without the slip section, Nonlinear driving characteristics such as stuttering occur.

Further, since the torque transmission starting point (Kiss point) is formed differently depending on the vehicle, such as the deviation of the hydraulic pump, the hydraulic pressure line, and the machining variation of the engine clutch, applying the torque transmission starting point to all the vehicles under the same conditions can cause drivability have.

Patent Registration No. 0906905 (Jul. 1, 2009) Patent Registration No. 1000424 (2010.12.06.)

SUMMARY OF THE INVENTION The present invention has been developed in order to solve such a problem, and it is an object of the present invention to measure the profile of a hydraulic pressure for pushing a return spring pushing a return spring completely and contacting a clutch friction material when applying an oil pressure for joining an engine clutch To learn the torque transmission starting point of the engine clutch and to apply the learned torque transmission starting point so that the joint control of the engine clutch can be provided under the optimum conditions.

According to an embodiment of the present invention, there is provided a motor vehicle comprising: a power source including an engine and a drive motor; An engine clutch applied between the engine and the drive motor; And a hybrid controller for controlling the releasing or joining of the engine clutch to provide an operation in an EV mode or an HEV mode,

The hybrid controller controls the oil pressure applied to the engine clutch so as to push the return spring completely and push the return spring completely to measure the profile of the hydraulic pressure to couple the clutch friction element to learn the torque transmission starting point of the engine clutch An engine clutch learning device for a hybrid vehicle is provided.

The hybrid controller can learn the base pressure as the torque transmission starting point of the engine clutch when the maximum value of the target hydraulic pressure reaches the hydraulic pressure providing the engagement of the clutch friction element when the target hydraulic pressure is applied after applying the base pressure to the engine clutch have.

If the maximum value of the target hydraulic pressure does not reach the hydraulic pressure providing the engagement of the clutch friction element when the target hydraulic pressure is applied after applying the base pressure to the engine clutch, the hybrid controller increases and corrects the base pressure stepwise, Torque transmission starting point can be learned.

According to another aspect of the present invention, there is provided a method for controlling an internal combustion engine, comprising the steps of: A step of applying a target hydraulic pressure to the engine clutch and determining whether a maximum value of the target hydraulic pressure has reached a hydraulic pressure which provides a coupling of the clutch friction element; And learning the base pressure to the torque transmission starting point of the engine clutch when the maximum value of the target hydraulic pressure reaches the maximum value which provides the engagement of the clutch friction element.

A step of incrementally correcting the base pressure when the maximum value of the target oil pressure has not reached the maximum value that provides the engagement of the clutch friction element; Applying a target hydraulic pressure to the engine clutch based on the increase corrected base pressure and determining whether the maximum value of the target hydraulic pressure has reached the hydraulic pressure providing the engagement of the clutch friction element; And learning the increased base pressure as the torque transmission starting point of the engine clutch when the maximum value of the target hydraulic pressure reaches the maximum value that provides the engagement of the clutch friction element.

As described above, the present invention can precisely learn and apply the torque transmission starting point of the engine clutch using the profile of the hydraulic pressure for operating the engine clutch in the hybrid vehicle, thereby providing the joint control of the engine clutch under the optimum conditions.

Further, by applying the learning of the torque transmission starting point of the engine clutch, it is possible to secure a stable performance in the engagement of the engine clutch and secure the robustness to the slip control.

1 is a view schematically showing an engine clutch learning apparatus for a hybrid vehicle according to an embodiment of the present invention.
2 is a flowchart schematically illustrating an engine clutch learning procedure of a hybrid vehicle according to an embodiment of the present invention.
3 is a graph illustrating a step-by-step engine clutch learning procedure in a hybrid vehicle according to an embodiment of the present invention.
4 is a diagram showing a typical structure of an engine clutch applied to a hybrid vehicle.
5 is a view showing an engine clutch joint control procedure of a conventional hybrid vehicle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are given the same reference numerals throughout the specification.

In addition, since the components shown in the drawings are arbitrarily shown for convenience of explanation, the present invention is not necessarily limited to those shown in the drawings.

1 is a view schematically showing an engine clutch learning apparatus for a hybrid vehicle according to an embodiment of the present invention.

Referring to FIG. 1, an embodiment of the present invention includes an operation information detecting unit 101, a hybrid controller 102, an inverter 103, a battery 104, a battery manager 105, a clutch controller 106, 107, an engine 108, a hybrid starter and generator (HSG) 109, an engine clutch 110, and a transmission 111.

The operation information detecting unit 101 detects a general operation request including the vehicle speed, the speed change stage, the displacement of the accelerator pedal, the displacement of the brake pedal, and the like, and provides it to the hybrid controller 102 in the operation of the hybrid vehicle.

The hybrid controller 102 is an uppermost controller that integrally controls the controllers connected to the network and controls the operation of the battery 104 provided in the battery manager 105 and the operation request provided by the operation information detector 101, The engine clutch 110 to be mounted between the engine 108 and the drive motor 107 via the clutch controller 106 is connected to the engine 110 via the clutch 108. [ To provide HEV mode operation.

The hybrid controller 102 measures the profile of the hydraulic pressure that fully presses the return spring and the return spring pushing the return spring to apply the clutch friction element when applying the hydraulic pressure for joining the engine clutch 110, And provides the joint control by applying the learned torque transmission starting point

The hybrid controller 102 secures an initial fill that fills the chamber by applying the base oil pressure to the engine clutch 110 in the learning mode of the engine clutch 110. When the initial fill is secured, .

The target hydraulic pressure is set to a pressure that fully pushes the return spring inside the engine clutch 110 and provides the engagement of the friction element and is set taking into account the tolerance of the vehicle-specific engine clutch specifications.

For example, as can be seen from Fig. 4, the hydraulic pressure supplied to the engine clutch 110 from an unillustrated oil pump fills the chamber and then pushes the plate 3 to overcome the rigidity of the return spring 5, (7) is provided.

The hybrid controller 102 detects a target hydraulic pressure supplied to the engine clutch 110 by a hydraulic pressure sensor (not shown) to determine whether the target hydraulic pressure has reached a maximum value.

That is, it is determined whether the friction element constituting the engine clutch 110 has reached the pressure at which it is joined.

The hybrid controller 102 detects a pressure change rate (change in pressure value per unit time) when the target hydraulic pressure supplied to the engine clutch 110 reaches a maximum value at which the friction elements are joined, .

The hybrid controller 102 learns and stores the base oil pressure as a torque transmission starting point when the hybrid controller 102 is in a stabilized state in which no pressure change occurs.

If the target hydraulic pressure supplied to the engine clutch 110 does not reach the maximum value at which the friction elements are joined, the hybrid controller 102 corrects the base pressure by a constant pressure (?) And corrects the above procedure, .

The increase correction value AP of the base pressure can be set to a minimum change amount that permits the resolution of the oil pressure sensor to fall within an allowable range.

When the torque transmission starting point of the engine clutch 110 is learned, the Singh hybrid controller 102 provides driving of the HEV mode with the joint control applied thereto.

The inverter 103 is composed of a plurality of power switching elements and converts the DC voltage supplied from the battery 104 to a three-phase AC voltage in accordance with a control signal applied from the hybrid controller 102 to drive the driving motor 107 .

The power switching device constituting the inverter 103 may be any one of an IGBT (Insulated Gate Bipolar Transistor), a MOSFET, a transistor, and a relay.

The inverter (103) includes a protection circuit. The protection circuit monitors the flow of the power source and distributes or cuts off the power when overvoltage or overcurrent flows into the power supply due to various reasons such as collision, collision, Thereby protecting all the systems provided in the hybrid vehicle and stably protecting the occupant from high pressure.

The battery 104 is composed of a plurality of unit cells, and the DC high voltage supplied to the drive motor 107 is stored.

The battery manager 105 manages the state of charge (SOC) by detecting the current, voltage, temperature, etc. of each cell within the operating range of the battery 104, controls the charge / discharge voltage of the battery 104, And the life of the battery is prevented from being shortened due to overcharging beyond the limit voltage.

The clutch controller 106 controls the actuator provided in the transmission 111 according to the control signal applied through the network from the hybrid controller 102 to control the joining of the target speed change stage and to control the fluid supplied to the engine clutch 110 So that the operation of the EV mode and the HEV mode can be provided by slipping, splicing and releasing the engine clutch 110. [

The drive motor 107 is operated by the three-phase alternating-current voltage applied from the inverter 103 to generate torque, and operates as a generator in a case of traveling on another line to supply regenerative energy to the battery 104. [

The HSG 109 is operated as a starter and a generator and performs start-on of the engine 108 in accordance with a control signal applied from the hybrid controller 102 and operates as a generator in a state in which the engine 108 is kept on And provides the generated voltage to the battery 104 via the inverter 103 as a charging voltage.

The engine clutch 110 is disposed between the engine 108 and the drive motor 107 so that operation of the EV mode and the HEV mode can be provided according to the engagement and disengagement.

The transmission 111 is applied as an automatic transmission or a continuously variable transmission, and the engagement element and the release element are operated by the operation of the hydraulic pressure under the control of the clutch controller 106 to engage the target speed change stage.

The engine clutch learning operation in the hybrid vehicle according to the present invention including the functions described above is executed as follows.

2 is a flowchart illustrating an engine clutch learning procedure of a hybrid vehicle according to an embodiment of the present invention.

In the hybrid vehicle to which the present invention is applied, the hybrid controller 102 secures an initial fill that fills the chamber by applying the base oil pressure to the engine clutch 110 in the learning mode of the engine clutch 110 (S101).

The hybrid controller 102 applies the target oil pressure to the hybrid controller 102 at a predetermined slope when the initial pressure is secured by the application of the base oil pressure in S101 (S102).

The target hydraulic pressure is set to a pressure that fully pushes the return spring inside the engine clutch 110 and provides the engagement of the friction element and is set taking into account the tolerance of the vehicle-specific engine clutch specifications.

For example, as can be seen from Fig. 4, the hydraulic pressure supplied to the engine clutch 110 from an unillustrated oil pump fills the chamber and then pushes the plate 3 to overcome the rigidity of the return spring 5, (7) is provided.

The hybrid controller 102 detects the target hydraulic pressure supplied to the engine clutch 110 from the hydraulic pressure sensor in the state in which the target hydraulic pressure is applied in S102 (S103), and determines whether the target hydraulic pressure has reached the maximum value.

If the target hydraulic pressure supplied to the engine clutch 110 reaches the maximum value at which the engagement of the friction element is reached, the hybrid controller 102 calculates the pressure change rate (change in the pressure value per unit time) (S105) It is determined whether the state is a stabilized state in which no pressure change occurs (S106).

The hybrid controller 102 learns and stores the base oil pressure as a torque transmission starting point if the state is a stable state in which no pressure change occurs (S107).

However, if the target hydraulic pressure supplied to the engine clutch 110 in S103 does not reach the maximum value for providing the engagement of the friction element, the hybrid controller 102 increases the base pressure by a predetermined amount DELTA P S104) The procedure described above is repeated to learn the starting point of torque transmission.

When the torque transmission starting point of the engine clutch 110 is learned in accordance with the above-described procedure, the traveling of the HEV mode can be provided by the joint control applying the torque transmission starting point.

3 is a graph illustrating a step-by-step engine clutch learning procedure in a hybrid vehicle according to an embodiment of the present invention.

Referring to FIG. 3, the target hydraulic pressure is applied at a predetermined slope after filling the chamber by applying a predetermined amount of base pressure (P ₀ ). However, the maximum value (A) of the target hydraulic pressure at which the pressure change rate is generated, It is determined that the base pressure P ₀ has not exceeded the torque transmission starting point KP by which the reaction force of the return spring is increased.

At this time, the base pressure is corrected by a certain amount (? P), the corrected base pressure (P ₁ ) is applied to fill the chamber, and then the target hydraulic pressure is applied at a predetermined slope.

However, when the maximum value B of the target hydraulic pressure at which the rate of change of pressure is generated does not reach the hydraulic pressure Pt that provides the engagement of the friction element, the corrected base pressure P ₁ is equal to or greater than the torque It is judged that it has not passed the starting point (KP).

Therefore, the base pressure is corrected again by a predetermined amount (? P), the corrected base pressure (P ₂ ) is applied to fill the chamber, and then the target hydraulic pressure is applied at a predetermined slope.

At this time, when the maximum value C of the target hydraulic pressure reaches the hydraulic pressure Pt that provides the joining of the friction elements and the pressure change rate is generated and stabilized, the corrected base pressure P ₂ is increased Torque transmission start point (KP).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

101: Operation information detecting unit 102: Hybrid controller
103: Inverter 104: Battery
105: battery manager 106: clutch controller
107: drive motor 108: engine
109: HSG 110: engine clutch

Claims (6)

A power source including an engine and a drive motor;
An engine clutch applied between the engine and the drive motor;
A hybrid controller for controlling the releasing or joining of the engine clutch to provide an operation in an EV mode or an HEV mode;
Lt; / RTI >
The hybrid controller controls the oil pressure applied to the engine clutch so as to push the return spring completely and push the return spring completely to measure the profile of the hydraulic pressure to couple the clutch friction element to learn the torque transmission starting point of the engine clutch An engine clutch learning device of a hybrid vehicle. The method according to claim 1,
The hybrid controller includes a hybrid controller that applies a base pressure to an engine clutch, and then applies a base hydraulic pressure to the engine clutch to apply a target hydraulic pressure to the hybrid clutch, and when the maximum value of the target hydraulic pressure reaches a hydraulic pressure providing a coupling of the clutch friction element, Automotive engine clutch learning device. The method according to claim 1,
If the maximum value of the target hydraulic pressure does not reach the hydraulic pressure providing the engagement of the clutch friction element when the target hydraulic pressure is applied after applying the base pressure to the engine clutch, the hybrid controller increases and corrects the base pressure stepwise, An engine clutch learning device for a hybrid vehicle that learns the starting point of torque transmission. A step of securing an initial fill by applying a base pressure set to an engine clutch;
A step of applying a target hydraulic pressure to the engine clutch and determining whether a maximum value of the target hydraulic pressure has reached a hydraulic pressure which provides a coupling of the clutch friction element;
Learning the base pressure to the torque transmission starting point of the engine clutch when the maximum value of the target hydraulic pressure reaches the maximum value that provides the engagement of the clutch friction element;
Wherein the engine clutch is coupled to the engine. 5. The method of claim 4,
A step of incrementally correcting the base pressure when the maximum value of the target oil pressure has not reached the maximum value that provides the engagement of the clutch friction element;
Applying a target hydraulic pressure to the engine clutch based on the increase corrected base pressure and determining whether the maximum value of the target hydraulic pressure has reached the hydraulic pressure providing the engagement of the clutch friction element;
Learning the increased base pressure as the torque transmission starting point of the engine clutch when the maximum value of the target oil pressure reaches the maximum value that provides the engagement of the clutch friction element;
Wherein the engine clutch is coupled to the engine. A power source including an engine and a drive motor;
An engine clutch applied between the engine and the drive motor;
A hybrid controller for controlling the engagement of the engine clutch;
Lt; / RTI >
Wherein the hybrid controller is operated in accordance with a set program to execute the method of any one of claims 4 to 5 to learn a torque transmission starting point of the engine clutch.

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