APPARATUS AND METHOD FOR CONTROLLING CLUTCH IN ENVIRONMENTALLY FRIENDLY VEHICLE

An apparatus for controlling a clutch in an environmentally friendly vehicle includes: a clutch configured to transfer or block power generated in a power generator; a clutch actuator configured to measure a pressure of the clutch using a pressure sensor embedded therein; and a controller configured to compare the pressure measured through the pressure sensor with reference data and inspect whether or not abrasion occurs in the clutch depending on the comparison.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims the benefit of priority to Korean Patent Application. No. 10-2015-0169391, filed on Nov. 30, 2015 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The present disclosure relates to an apparatus and a method for controlling a clutch in a hybrid vehicle in which an abrasion state of a clutch disk is confirmed and driving of the clutch is compensated for.

BACKGROUND

In an environmentally friendly vehicle such as a hybrid vehicle, various power transfer structures may be configured using an engine and a motor as power sources. The hybrid vehicle is driven in an electric vehicle (EV) mode in which it is driven using only power of the motor or is driven in a hybrid electric vehicle (HEV) mode in which it is driven using both of power of the engine and power of the motor.

The hybrid vehicle includes a separate engine clutch actuator mounted in order to actuate an engine clutch intermitting power between the engine and the motor. The engine clutch actuator has been used in a double clutch transmission (DCT) based hybrid system.

The DCT based hybrid vehicle requires structures of the engine clutch actuator and a clutch slave cylinder (CSC) in order to engage or disengage the engine clutch. When abrasion occurs in the clutch disk, a clutch load is changed depending on clutch characteristics, which has an influence on transfer force of the actuator, which is an actuating apparatus.

In addition, according to the related art, required transfer power of the actuator becomes large due to the abrasion of the clutch disk, and thus, it is very important to inspect an abrasion state of the clutch disk

SUMMARY

An aspect of the present disclosure provides an apparatus and a method for controlling a clutch in a hybrid vehicle in which an abrasion state of a clutch disk is confirmed using a pressure sensor of a clutch actuator and driving of the clutch is compensated for on the basis of a confirmation result.

According to an exemplary embodiment in the present disclosure, an apparatus for controlling a clutch in an environmentally friendly vehicle includes: a clutch transferring or blocking power generated in a power generator; a clutch actuator measuring a pressure of the clutch using a pressure sensor embedded therein; and a controller configured to compare the pressure measured through the pressure sensor with reference data and inspect whether or not abrasion occurs in the clutch depending on the comparison.

The clutch may be an engine clutch installed between an engine and a motor and transferring or blocking engine power.

The clutch may be a double clutch transferring power generated in a motor to a transmission or blocking the power transferred to the transmission.

The controller may perform compensation for the abrasion of the clutch when the abrasion occurs in the clutch.

The controller may transmit a rotation command of an actuator motor corresponding to an abrasion amount of the clutch to the clutch actuator.

The reference data may be characteristic information of a clamping load depending on a clamping travel.

The controller may store comparison data between the pressure of the clutch and the reference data in a storage.

According to another exemplary embodiment in the present disclosure, a method for controlling a clutch in an environmentally friendly vehicle includes: actuating a clutch actuator when a driving mode of the environmentally friendly vehicle is switched from a hybrid electric vehicle (HEV) mode into an electric vehicle (EV) mode; measuring a pressure of the clutch using a pressure senor of the clutch actuator; and inspecting whether or not abrasion occurs in the clutch by comparing the pressure of the clutch with reference data.

The method for controlling a clutch in an environmentally friendly vehicle may further include performing compensation for the abrasion of the clutch in the case in which the abrasion occurs in the clutch as an inspection result for whether or not the abrasion occurs in the clutch.

In the performing of the compensation for the abrasion of the clutch, an abrasion amount of the clutch may be calculated on the basis of a comparison result between the pressure of the clutch and the reference data, and a rotation command of an actuator motor corresponding to the calculated abrasion amount of the clutch may be transmitted to the clutch actuator.

The reference data may be characteristic information of a clamping load depending on a clamping travel.

In the inspecting of whether or not the abrasion occurs in the clutch, comparison data between the pressure of the clutch and the reference data may be stored in a storage.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments in the present disclosure will be described in detail with reference to the accompanying drawings.

In the present disclosure, a case in which an abrasion state of an engine clutch disk is inspected using a pressure sensor embedded in an engine clutch actuator and compensation for abrasion of an engine clutch is performed depending on the inspected abrasion state of the engine clutch disk in a double clutch transmission (DCT) based hybrid vehicle (an environmentally friendly vehicle) will be described by way of example in order to assist, in the understanding of the present disclosure.

FIG. 1is a block diagram illustrating an apparatus for controlling a clutch in an environmentally friendly vehicle according to an exemplary embodiment in the present disclosure.

The apparatus for controlling a clutch in an environmentally friendly vehicle includes an engine110, a first clutch120, an engine clutch actuator130, a motor140, a second clutch150, a transmission160, a differential gear (DG)170, a battery180, and a controller190. The environmentally friendly vehicle uses the engine110and the motor140as a power generator generating power.

The engine110burns a fuel to generate power required to drive the vehicle. The engine110is cranked to an external power source (for example, a start-up electric motor) to start driving. An output torque (an engine torque or engine power) of the engine110is controlled depending on a control of the controller190.

The first clutch120is an engine clutch disposed between the engine110and the motor140and intermitting the power (the output torque) of the engine110.

The engine clutch actuator130controls an operation of the first clutch120. In other words, the engine clutch actuator130engages or disengages the first clutch120to transfer the power (the engine power) generated by the engine110to driving wheels or block the power transferred to the driving wheels.

For example, the engine clutch actuator130engages the first clutch120to transfer the power (the engine power) by the engine110to the driving wheels, and disengages the first clutch120to block the engine power transferred to the driving wheels.

The engine clutch actuator130includes a pressure sensor131measuring a pressure (hereinafter, referred to as a clutch pressure) of an engine clutch disk. The pressure sensor131is mounted in an actuator master cylinder (not illustrated) of the engine clutch actuator130. The engine clutch actuator130transmits the clutch pressure (the measured pressure) measured through the pressure sensor131to the controller190.

The motor140receives electric power supplied from the battery180to generate power (motor power) and transfers the generated power to the driving wheels. The motor140is actuated depending on a control the controller190, such that an output torque (a motor torque or motor power) is adjusted.

The motor140is used as a power generator charging the battery180by generating counter electromotive force when a state of charge (SOC) of the battery is insufficient or at the time of regenerative braking. In addition, the motor140may also serve to crank the engine110in the environmentally friendly vehicle such as the hybrid vehicle.

The second clutch150is a double clutch including an odd-shift clutch and an even-shift clutch. For example, the odd-shift clutch transfers the power to an input shaft connected to 1-shift, 3-shift, and 5-shift gears, and the even-shift clutch transfers the power to an input shaft connected to 2-shift, 4-shift, and 6-shift gears.

The odd-shift clutch and the even-shift clutch of the second clutch150are engaged or disengaged depending on a control of the controller190to transfer the engine torque and/or the motor torque to the transmission160or block the engine torque and/or the motor torque transferred to the transmission160. Although the case in which the controller190controls an operation of the second clutch150has been described in the present exemplary embodiment, the apparatus for controlling a clutch in an environmentally friendly vehicle according to an exemplary embodiment in the present disclosure is not limited thereto, but may also be implemented to separately include a motor actuator, controlling an operation of the second clutch150.

The transmission160adjusts a gear ratio by gear shifting depending on actuation of the second clutch150. The transmission160, which is a double clutch transmission (DCT), changes rotational torques and rotational speeds of the engine and the motor or the motor.

The differential gear170is an apparatus appropriately distributing revolutions per minute (RPM) of different wheels and driving the wheels when the wheels move forward or rotate on a rugged portion of a road.

The battery180, which serves to supply the electric power required for driving the vehicle, is implemented by a high voltage battery.

The controller190, which is an apparatus controlling the entire driving of the vehicle, generally controls the respective controllers connected through a vehicle network. Here, the vehicle network may be a controller area network (CAN), a FlexRay, a media oriented system transport (MOST) , local interconnection network (LIN), and the like.

The controller190switches a driving mode through the engagement or the disengagement of the first clutch120and the second clutch130. The driving mode is divided into an electric vehicle (EV) mode and a hybrid electric vehicle (HEV) mode. The EV mode is a mode in which the engine clutch120is disengaged to block the engine power, thereby driving the vehicle by only the motor power, and the HEV mode is a mode in which the engine clutch120is engaged, thereby driving the vehicle by the engine power and the motor power.

The controller190actuates the engine clutch actuator130when the driving mode of the vehicle is switched from the HEV mode into the EV mode. The controller190measures the pressure of the engine clutch disk through the pressure sensor131of the engine clutch actuator130.

The controller190compares the pressure measured by the pressure sensor131with reference data to confirm whether or not abrasion occurs in the engine clutch disk. The controller190performs a control compensate for the actuation of the engine clutch120depending on an abrasion amount of the engine clutch disk when it is decided that the abrasion occurs in the engine clutch disk.

The reference data, which are pre-stored in a storage (not illustrated), are characteristic information of a clamping load. In other words, the reference data are a clamping load depending on a clamping travel of the engine clutch actuator130. The clamping load, which is force of a diaphragm spring of the engine clutch120a pressure plate, is a load of the pressure plate pressing the clutch disk. The clamping travel is an actuation stroke of the engine clutch required in order to implement a required driving torque of the vehicle.

The present disclosure is to inspect an abrasion state of the engine clutch disk using a feature that the pressure (the clutch pressure) of the engine clutch disk follows the clamping load.

FIG. 2is a graph illustrating a characteristic curve of a clutch disk-diaphragm spring related to the present disclosure.

An abrasion section of the engine clutch120may be divided into a plurality of sections, as illustrated inFIG. 2.

The engine clutch actuator130learns a release load of the engine clutch actuator130and a clamping load of the engine clutch disk under a constant velocity condition in each section. The engine clutch actuator130stores comparison data between the clamping load and the pressure of the engine clutch disk in each section. Here, the engine clutch actuator130measures the pressure of the engine clutch disk using the pressure sensor131.

The engine clutch actuator130transfers constantly learned variables and data to the controller190. When the abrasion occurs in the engine clutch120, the clamping load is changed as compared with that of an initial state, and thus, an abrasion level of the engine clutch disk may be confirmed. When the abrasion occurs in the engine clutch disk, a pressure of an engine clutch cover follows a characteristic curve of the clamping load in sections A to H.

FIG. 3is a flow chart illustrating a method for controlling a clutch in an environmentally friendly vehicle according to an exemplary embodiment in the present disclosure.

The controller190actuates the engine clutch actuator130(S110) when the driving mode of the vehicle is switched from the EV mode into the HEV mode. For example, when an SOC of the battery180drops to a threshold value or less during a period in which the vehicle is driven in the EV mode, the controller190actuates the engine clutch actuator130to engage the first clutch120, thereby switching the driving mode of the vehicle into the HEV mode.

When the driving mode of the vehicle is switched into the HEV mode, the controller190measures the pressure of the engine clutch disk (the clutch pressure) using the pressure sensor131of the engine clutch actuator130(S120).

The controller190compares the measured clutch pressure with the reference data (S130). Here, the reference data are the characteristic information of the clamping load depending on the clamping travel. For example, when the clamping travel is 8 mm, the clamping load is 4 kN (kilo Newton). Therefore, it is confirmed whether or not the clutch pressure is 4×101.97 kgf when the clamping travel is 8 mm.

The controller190confirms whether or not the abrasion occurs in the first clutch120on the basis of the comparison result between the measured clutch pressure and the reference data (S140). For example, the controller190confirms whether or not a pressure characteristic curve of the engine clutch120moves as compared with the characteristic curve of the clamping load. The controller190stores the comparison data between the measured clutch pressure and the reference data in storage (not illustrated) and uses the comparison data as learning data.

The controller190performs a control to compensate for the driving of the first clutch120on the basis of an abrasion amount of the first clutch120(S150) in the case in which the abrasion occurs in the first clutch120. Here, the controller190may calculate an abrasion amount of the first clutch120on the basis of a difference between the measured clutch pressure and the reference data. In addition, the controller190transmits a rotation command of an actuator motor corresponding to the abrasion amount of the first clutch120to the engine clutch actuator130.

When the abrasion does not occur in the first clutch120in S140, the method for controlling a clutch in an environmentally friendly vehicle returns to S120to measure the clutch pressure and inspect whether or not the abrasion occurs in the first clutch120on the basis of the measured clutch pressure.

In the present disclosure, the clutch pressure is sensed using the pressure sensor, the compensation for the abrasion of the clutch is confirmed through a control logic without using a separate abrasion compensation apparatus, and the compensation for the abrasion may be performed through the clutch actuator.

Although the case in which the abrasion state of the engine clutch disk is inspected using the pressure sensor embedded in the engine clutch actuator has been described by way of example in the exemplary embodiments described above, the present disclosure is not limited thereto, but may also be applied to another clutch actuator using a diaphragm.

For example, in the case in which a clutch actuator (not illustrated) controlling an operation of the double clutch in the environmentally friendly vehicle has a pressure sensor embedded therein, the apparatus for controlling a clutch also inspects the abrasion state of the double clutch using the pressure sensor embedded in the clutch actuator.

As described above, according to the exemplary embodiment of the present disclosure, the abrasion station of the clutch disk is confirmed using the pressure sensor of the clutch actuator, and the driving of the clutch is compensated for on the basis of the confirmation result, thereby making it possible to efficiently transfer the power.

In addition, according to the exemplary embodiment in the present disclosure, since the abrasion state of the clutch is inspected using the pressure sensor embedded in the clutch actuator, a separate inspection tool and apparatus are not required.

Further, according to the exemplary embodiment in the present disclosure, drivability and fuel efficiency may be improved due to response characteristics, a consumed current decrease, and the like, depending on compensation for the abrasion of the clutch.