KR20150127973A - Apparatus for electronic stability control in a vehicle and control method thereof - Google Patents

Abstract

Disclosed are a device for controlling the posture of a vehicle and a control method thereof. The device for controlling the posture of a vehicle according to an embodiment of the present invention comprises: a stop detecting part for detecting whether or not a vehicle has stopped; an inclination angle detecting part for detecting the inclination angle of a slope where the vehicle has stopped; an interface part for receiving information on a drive system including drive torque and a gear state by communicating with an engine ECU for controlling an engine and a transmission ECU for controlling a transmission; a start detecting part for detecting the start of the vehicle; a hydraulic pressure adjusting part for adjusting the braking pressure of the wheel cylinder of each wheel; and an electronic control unit for detecting the inclination angle of the slope via the inclination angle detecting part when the vehicle stops, receiving the information on the drive system by communicating with the engine ECU and the transmission ECU via the interface part, determining the greatest inclination angle such that the vehicle does not move backward even if a driver does not step on a brake pedal, based on the received information on the drive system, and controlling the hydraulic pressure adjusting part to form braking pressure on the wheel cylinder of each wheel depending on the result of comparing the detected inclination angle of the slope with the determined greatest inclination angle so that the vehicle cannot move backward.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vehicle posture control apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vehicle posture control apparatus and a control method thereof, and more particularly, to a vehicle posture control apparatus and a control method thereof for controlling a brake pressure on a wheel cylinder of each wheel.

The Hill Start Assist (HSA) prevents the vehicle from being throttled by automatically releasing the brake pedal and releasing the brake pedal to the point where the driver can start the vehicle by pressing the accelerator pedal It is a function to help start.

In recent years, the convenience of functions has been recognized, and there is a tendency to expand to small class vehicles.

However, in order to apply the HSA function, it is necessary to install additional sensors / switches in addition to the ESC (Electronic Stability Control) system.

According to an embodiment of the present invention, there is provided a vehicle posture control apparatus capable of performing a hill departure assistance (HSA) function without installing a master cylinder pressure sensor and a brake pedal switch, and a control method thereof.

According to an aspect of the present invention, An inclination angle sensing unit for sensing an inclination angle of the hill where the vehicle is stopped; An interface unit for communicating with an engine ECU for controlling an engine and a transmission ECU for controlling a transmission to receive driving system information including a driving torque and a gear state; A departure detection unit for detecting the start of the vehicle; A hydraulic pressure regulating part for regulating the braking pressure of the wheel cylinder of each wheel; And a tilt sensor for detecting a tilt angle of the hill through the tilt angle sensing unit when the vehicle is stationary, receiving the driving system information by communicating with the engine ECU and the transmission ECU via the interface unit, and based on the received driving system information, And determines a maximum inclination angle at which the vehicle can not be pushed back, compares the sensed hill inclination angle with the determined maximum inclination angle, and forms a braking pressure on the wheel cylinder of each wheel to prevent the vehicle from being pushed back according to the comparison result And an electronic control unit for controlling the hydraulic pressure regulator to control the hydraulic pressure regulator.

Further, the electronic control unit may include determining that the driver has a braking intention if the detected hill inclination angle and the maximum inclination angle are exceeded.

In addition, the electronic control unit may include determining that the driver has a braking intention if the sensed hill inclination angle exceeds the determined maximum inclination angle.

The electronic control unit may include a braking pressure being applied to the wheel cylinders of the wheels through the hydraulic pressure regulator when it is determined that the driver has a braking intention.

In addition, the electronic control unit may include determining a predetermined angle to correspond to the number of gears of the received driving system information at the maximum inclination angle.

In addition, the electronic control unit may release the braking pressure formed on the wheel cylinders of the wheels through the hydraulic control unit when the start of the vehicle is detected through the departure detection unit, And releasing the braking pressure applied to the wheel cylinders of the wheels when the predetermined time has elapsed.

According to another aspect of the present invention, there is provided a vehicular drive system for detecting a hill inclination angle at the time of a vehicle stop, communicating with an engine ECU and a transmission ECU to receive drive system information including a drive torque and a gear state from the engine ECU and a transmission ECU, Based on the information, the maximum inclination angle at which the vehicle can not be pushed back even if the driver does not step on the brake pedal is judged. If the detected inclination angle exceeds the maximum inclination angle, the driver is determined to have the braking intention. , It is possible to provide a vehicle posture control method including forming a braking pressure on a wheel cylinder of each wheel so that the vehicle is not pushed backward.

The determination of the maximum inclination angle may include determining a predetermined angle corresponding to the number of gears of the received driving system information as the maximum inclination angle.

Determining whether or not a predetermined time has elapsed since the braking pressure was established if the vehicle departure is not sensed, and if the predetermined time has elapsed And releasing the braking pressure applied to the wheel cylinders of the wheels.

According to an aspect of the present invention, a hill departure assist (HSA) function can be performed without installing a master cylinder pressure sensor and a brake pedal switch, so that the HSA function can be implemented even for a low-cost vehicle without increasing the cost burden Thereby improving the driver's convenience.

1 is a brake hydraulic circuit diagram of a vehicle posture control apparatus according to an embodiment of the present invention.
2 is a control block diagram of a vehicle posture control apparatus according to an embodiment of the present invention.
3 is a view for explaining a maximum inclination angle at which a vehicle equipped with a vehicle posture control apparatus according to an embodiment of the present invention can maintain a stop without pushing on a brake pedal when the vehicle is stopped.
4 is a control flowchart for explaining a hill start assist (HSA) function in the vehicle posture control apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below are provided by way of example so that those skilled in the art will be able to fully understand the spirit of the present invention. The present invention is not limited to the embodiments described below, but may be embodied in other forms. In order to clearly explain the present invention, parts not related to the description are omitted from the drawings, and the width, length, thickness, etc. of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

The expression " and / or " is used herein to mean including at least one of the elements listed before and after. Also, the expression " coupled / connected " is used to mean either directly connected to another component or indirectly connected through another component. The singular forms herein include plural forms unless the context clearly dictates otherwise. Also, components, steps, operations and elements referred to in the specification as " comprises " or " comprising " refer to the presence or addition of one or more other components, steps, operations, elements, and / or devices.

BACKGROUND ART [0002] Generally, an electronic brake system of a vehicle is provided with an anti-lock brake system (hereinafter abbreviated as ABS) that prevents a slip of a vehicle during braking to effectively obtain a strong and stable braking force, A Traction Control System (hereinafter referred to as TCS) that prevents slippage of the drive wheels when the vehicle suddenly rises or suddenly accelerates, a vehicle that improves the stability of the vehicle by controlling the brake hydraulic pressure by combining ABS and TCS And an electronic stability control system (ESC system).

Among them, the ESC system is basically designed to control the yaw behavior of the vehicle, and controls the braking device and the engine in a dangerous driving situation reaching the contact limit of the tire when the vehicle is turning, thereby guiding the driver to turn the desired trajectory Device.

1 is a brake hydraulic circuit diagram of a vehicle posture control apparatus according to an embodiment of the present invention.

1, the vehicle posture control apparatus is connected to the master cylinder MC through a hydraulic line. The brake fluid is supplied from the master cylinder MC, and the brake fluid is supplied to the wheel cylinders Wfr, Wrl, Wfl, Wrr).

The vehicle posture control apparatus further includes hydraulic pumps HP1 and HP2 that pump the brake fluid of the reservoir LRS and supply the brake fluid to the wheel cylinders Wfr, Wrl, Wfl and Wrr, Pressure accumulators LPA1 and LPA2 for temporarily storing the brake fluid pumped by the master cylinder MC and a brake fluid supplied from the master cylinder MC to the wheel cylinders Wfr, Wrl, Wfl, and Wrr or returning them to the reservoir LRS And solenoid valves TC1, TC2, ESV1, ESV2, IN1 to IN4, OUT1 to OUT4.

More specifically, the master cylinder MC has two chambers, and the wheel cylinders Wfr and Wrl provided in the first chamber of the master cylinder MC and the front wheel right wheel FR and the rear wheel left wheel RL, respectively, A normally open type traction control valve (TC1) is provided on the hydraulic line between the two. The normal open type traction control valve TC1 controls the brake fluid transmitted from the master cylinder MC to the wheel cylinders Wfr and Wrl of the respective wheels.

The normally open type traction control valve TC2 is provided on the hydraulic line between the second chamber of the master cylinder MC and the wheel cylinders Wfl and Wrr provided on the front left wheel FL and the rear right wheel RR . The normally open type traction control valve TC2 controls the brake fluid transmitted from the master cylinder MC to the wheel cylinders Wfl and Wrr of the wheels FL and RR.

Normally open type solenoid valves IN1 and IN2 are provided on the hydraulic lines between the normal open type traction control valve TC1 and the wheel cylinders Wfr and Wrl of the wheels FR and RL, Normally open type solenoid valves IN3 and IN4 are provided on hydraulic lines between the wheel cylinders W1 and TC2 and the wheel cylinders Wfl and Wrr of the wheels FL and RR.

Normally closed solenoid valves OUT1 and OUT2 are provided on the exit sides of the wheel cylinders Wfr and Wrl of the wheels FR and RL and the normally closed solenoid valves OUT1 and OUT2 are provided on the wheel cylinders Wfl and Wrr of the wheels FL and RR, On the outlet side, normally closed type solenoid valves OUT3 and OUT4 are provided.

A low pressure accumulator LPA1 for temporarily storing the brake fluid discharged from the wheel cylinders Wfr and Wrl of the wheels FR and RL is provided at the outlet side of the normally closed type solenoid valves OUT1 and OUT2, A low pressure accumulator LPA2 for temporarily storing the brake fluid discharged from the wheel cylinders Wfl and Wrr of the wheels FL and RR is provided at the outlet side of the valves OUT3 and OUT4.

Two hydraulic pumps HP1 and HP2 for pumping the brake fluid stored in the low pressure accumulators LPA1 and LPA2 and forcibly returning the brake fluid to the wheel cylinders Wfr, Wrl, Wfl and Wrr, and two hydraulic pumps HP1 and HP2 One motor M is provided.

On the other hand, normally closed type electromagnetic shuttle valves ESV1 and ESV2 are provided on the auxiliary hydraulic line between the suction side of the two hydraulic pumps HP1 and HP2 and the chambers of the master cylinder MC.

Thus, when the normally closed type electromagnetic shuttle valves ESV1 and ESV2 are opened, the auxiliary hydraulic line between the master cylinder MC and each of the hydraulic pumps HP1 and HP2 is opened and the normally closed type electromagnetic shuttle valves ESV1 and ESV2 The auxiliary hydraulic line between the master cylinder MC and the master cylinder MC and each of the hydraulic pumps HP1 and HP2 is closed.

Here, the normally open type valve (NO: Normally Open) valve opens the valve flow path before energization, closes the valve flow path when energized, and closes the valve flow path before the energization, Lt; / RTI >

The vehicle posture control apparatus according to the embodiment of the present invention controls the normal open solenoid valves IN1 to IN4 in response to an instruction from the electronic control unit 20 when the hydraulic braking force of the wheel cylinders Wfr, Wrl, Wfl, Wrl, Wfl, Wrr through the normally open solenoid valves IN1-IN4 by driving the hydraulic pumps HP1, HP2 so that the brake fluid of the reservoir LRS or the low-pressure accumulators LPA1, LPA2 is supplied to the wheel cylinders Wfr, To increase the pressure of the wheel cylinders Wfr, Wrl, Wfl, Wrr. At this time, the wheel cylinders Wfr, Wrl, Wfl, and Wrr are moved from the reservoir LRS through the hydraulic line connected between the reservoir LRS and the hydraulic pumps HP1 and HP2 without passing through the hydraulic line on the master cylinder MC side. It is possible to supply the pressure directly.

When the hydraulic braking force of the wheel cylinders Wfr, Wrl, Wfl and Wrr is reduced, the hydraulic pumps HP1 and HP2 are stopped and the normally closed solenoid valves OUT1 to OUT4 are opened in response to an instruction from the electronic control unit 20 The pressure in the wheel cylinders Wfr, Wrl, Wfl, Wrr is reduced by causing the brake fluid of the wheel cylinders Wfr, Wrl, Wfl, Wrr to be returned to the reservoir LRS through the normally closed solenoid valves OUT1-OUT4 . At this time, the brake fluid discharged from the wheel cylinders Wfr, Wrl, Wfl and Wrr may be temporarily stored in the low-pressure accumulators LPA1 and LPA2.

1, the normally open type traction control valves TC1 and TC2, the normally closed type electromagnetic shuttle valves ESV1 and ESV2, the normal open solenoid valves IN1 and IN4, the normally closed solenoid valves OUT1 and OUT4, , HP2) is operated by an electronic control unit (ECU) 20 that performs a control mode such as an ESC mode to increase, decrease or maintain the braking pressure of the wheel.

The wheel speed sensors WS1 to WS4 provided on the front wheel left and right wheels FL and FR and the rear wheel left and right wheels RL and RR are electrically connected to the electronic control unit (ECU) 20 so as to provide the detected wheel speed Lt; / RTI >

2 is a control block diagram of a vehicle posture control apparatus according to an embodiment of the present invention.

2, the electronic control unit 20 is electrically connected to the input sensing unit 10, the inclination sensor 11, the interface unit 12, and the start sensing unit 13. The hydraulic control unit 30 is electrically connected to the output side of the electronic control unit 20. [

The fixed-gear detecting unit 10 includes wheel speed sensors WS1 to WS4 mounted on the vehicle, and detects whether the vehicle is stopped by the wheel speed sensor.

The inclination angle sensing unit 11 includes a longitudinal acceleration sensor installed in the vehicle longitudinal direction to output a signal value in accordance with a longitudinal (longitudinal) inclination of the vehicle, and detects the inclination angle of the hill.

The interface unit 12 communicates with an engine ECU that controls the engine operation of the vehicle and / or a transmission ECU that controls the transmission operation of the vehicle, and receives the torque information, the RPM information, the gear status information, and the like.

The departure detection unit 13 includes an acceleration pedal detection sensor mounted on the vehicle, and detects the start of the vehicle by the driver. The departure detection unit 13 may communicate with the engine ECU via the interface unit 12 instead of the accelerator pedal detection sensor to detect the departure of the vehicle from RPM information provided from the engine ECU.

The hydraulic pressure regulator 30 regulates the pressure by increasing or decreasing the hydraulic pressure force supplied from the master cylinder MC to the wheel cylinders Wfr, Wrl, Wfl, Wrr in accordance with the control signal of the electronic control unit 20. [ The hydraulic pressure regulator 30 includes a normally open type traction control valve TC1 and TC2, a normally closed type electromagnetic shuttle valve ESV1 and ESV2, a normally open solenoid valve IN1 to IN4, a normally closed solenoid valve OUT1 to OUT4, And a motor M for operating the hydraulic pumps HP1 and HP2.

The electronic control unit 20 determines whether or not the vehicle is stopped based on the information sensed through the acceleration sensing unit 10. [ The electronic control unit 20 can calculate the vehicle speed using the wheel speeds sensed by the wheel speed sensors WS1 to WS4 and determine whether the vehicle is stopped based on the calculated vehicle speed.

Further, the electronic control unit 20 senses the inclination angle of the hill where the vehicle is present through the inclination angle sensing unit 11. The electronic control unit 20 can determine the inclination angle corresponding to the longitudinal acceleration value sensed by the longitudinal acceleration sensor to be the inclination angle SA of the hill on which it is located.

The electronic control unit 20 calculates the inclination angle SA and the maximum inclination angle SA_max of the hill detected through the inclination angle sensing unit 11 when the inclination angle SA of the detected hill is equal to or greater than a predetermined angle SA_ref The driver's braking will is determined. For example, when the detected inclination angle SA of the hill exceeds the maximum inclination angle SA_max, the electronic control unit 20 determines that the driver has a braking intention and the inclination angle SA of the detected hill is the maximum inclination angle SA_max), it is determined that the driver does not have the brake force.

At this time, the maximum inclination angle SA_max is a maximum angle at which the vehicle can be stopped without pushing the brake pedal when the vehicle is stopped, and can be determined according to the driving system information when the vehicle is turned on. In the state that the accelerator pedal is not depressed, the drive torque that can be produced by the engaged gear stages is limited. Therefore, when the vehicle is stationary, it is possible to calculate the maximum inclination angle (SA_max) at which the vehicle can be stopped without stepping on the brake pedal. For example, when the number of gears is D, the driving torque value corresponding to the D-stage is predetermined, and the maximum inclination angle SA_max at which the vehicle can maintain the vehicle without jogging due to the driving torque value is determined in advance Can be obtained. Therefore, if only the number of gears is known, the maximum inclination angle SA_max corresponding thereto can be determined.

3 is a view for explaining a maximum inclination angle at which a vehicle equipped with a vehicle posture control apparatus according to an embodiment of the present invention can maintain a stop without pushing on a brake pedal when the vehicle is stopped.

3, the dotted line indicates the driving torque force according to the number of gears of the vehicle, and the solid line indicates the value corresponding to the maximum inclination angle SA_max, which indicates the force pushed down from the hill when the vehicle does not step on the brake pedal .

Assuming that the vehicle is fixed at the same gear position and the vehicle is moving up the hill, if the driving torque of the vehicle is assumed to be the same, when the hill inclination angle is? 1 as when the vehicle starts to climb the hill, And the hill inclination angle is greater than the angle θ1, the two forces are the same. If the hill inclination angle is the inclination angle θ3 higher than the angle θ2, the force pushed down from the hill is larger than the driving torque force.

Therefore, when the driver does not step on the brake pedal, if the hill inclination angle is? 1, the hill inclination angle is lower than the maximum inclination angle? Sa_max corresponding to the drive torque, so the vehicle will advance forward. Further, when the hill inclination angle is? 2, the hill inclination angle is equal to the maximum inclination angle? Sa_max, so the vehicle will maintain the stopped state. Further, when the hill inclination angle is? 3, the hill inclination angle exceeds the maximum inclination angle? Sa_max, so the vehicle will be pushed down the hill.

Thus, when the hill inclination angle exceeds the maximum inclination angle corresponding to the drive torque corresponding to the gear step number, the driver will step on the brake pedal so as to prevent the vehicle from being pushed back, so that it can be determined that there is a driver's braking effort. As described above, it is possible to determine the braking will of the driver by comparing the inclination angle of the hill and the maximum inclination angle corresponding to the drive torque according to the number of gears without installing the brake pedal and the pressure sensor of the master cylinder. Therefore, the HSA function can be implemented in a low-pressure hydraulic braking device without brake pedal and master cylinder pressure sensor.

4 is a control flowchart for explaining a hill start assist (HSA) function in the vehicle posture control apparatus according to an embodiment of the present invention.

Referring to FIG. 4, first, in the operation mode 100, the electronic control unit 20 determines whether the vehicle is stopped using information sensed through the acceleration sensing unit 10 (100).

When the vehicle is stopped, the electronic control unit 20 in the operation mode 102 senses the inclination angle SA of the hill to which the vehicle is stopped through the inclination angle sensing unit 11 (102).

After sensing the inclination angle SA of the hill, the electronic control unit 20 determines in operation mode 104 whether the detected hill inclination angle SA exceeds a preset angle SA_ref (104).

If the detected hill inclination angle SA exceeds the predetermined angle SA_ref as a result of the determination in the operation mode 104, the electronic control unit 20 communicates with the engine ECU and the transmission ECU via the interface unit 12 to drive the engine Torque, RPM, gear state, and the like (106). At this time, driveline information such as engine drive torque, RPM, gear state, etc. may be performed before operation mode 104. [

Then, in the operation mode 108, the electronic control unit 20 determines the maximum inclination angle SA_max (108). The maximum inclination angle SA_max is a maximum angle at which the vehicle can be kept stationary without depressing the brake pedal when the vehicle is stationary as described above. The electronic control unit 20 finds the drive torque value corresponding to the gear stage number, and determines the preset angle corresponding to the drive torque as the maximum inclination angle SA_max. The maximum inclination angle may be preset to correspond to the number of gears. In this case, the electronic control unit 20 can recognize the number of gears and determine the maximum inclination angle according to the number of gears recognized.

After determining the maximum inclination angle SA_max, the electronic control unit 20 in the operation mode 110 compares the hill inclination angle SA detected in the operation mode 102 with the maximum inclination angle SA_max determined in the operation mode 110, SA) exceeds the determined maximum inclination angle SA_max (110).

If the detected hill inclination angle SA exceeds the maximum inclination angle SA_max as a result of the determination in the operation mode 110, the electronic control unit 20 checks the gear state in the operation mode 112 and selects the gear in the direction to raise the inclination (112). For example, when the vehicle is stopped in the direction of raising the tilt, the D stage, the first stage, and the second stage are the gears in the direction to tilt up the slope.

If it is determined that the gear in the direction to raise the inclination is selected as a result of the determination in the operation mode 110, the electronic control unit 20 controls the wheel of each wheel through the hydraulic pressure control unit 30 so as to brake the wheel so as to prevent the vehicle from being pushed back. A braking pressure is applied to the cylinder (114). Thus, the HSA function is performed to prevent the vehicle from being pushed back even if the driver does not step on the brake pedal.

After the braking pressure is applied to the wheel cylinders of the wheels so as to brake the wheels so as to prevent the vehicle from being pushed back in the operation mode 114, the electronic control unit 20, (116). ≪ / RTI >

If the start of the vehicle is detected as a result of the determination in the operation mode 116, the electronic control unit 20 releases 118 the braking pressure formed in each wheel cylinder through the hydraulic control unit 30. [ Thus, the HSA function is terminated.

On the other hand, if the start of the vehicle is not detected as a result of the determination in the operation mode 116, the electronic control unit 20 determines whether a predetermined time has elapsed since the braking pressure was applied to the wheel cylinders of each wheel (120). If it is determined that the predetermined time has not elapsed as a result of the determination in the operation mode 120, the operation mode is moved to the operation mode 114 to perform the following operation mode. On the other hand, if it is determined that the predetermined time has elapsed as a result of the determination in the operation mode 120, the electronic control unit 20 moves to the operation mode 118 and releases 118 the braking pressure formed on each wheel cylinder through the hydraulic control unit 30. When the HSA starts to operate, the vehicle remains stationary, so it can not be determined whether the driver's braking effort has been eliminated. Normally, the HSA releases the braking force after about two seconds when the driver releases the brake. Therefore, the operation time is limited to about 5 to 10 minutes, and if the vehicle does not start until the time limit, the HSA operation is terminated and the operation is suspended until the vehicle stops after the vehicle has moved again.

10: stop detection unit 11: inclination angle detection unit
12: Interface unit 13: Departure sensing unit
20: Electronic control unit 30: Hydraulic regulator

Claims (9)

A charge detector for detecting whether the vehicle is stopped or not;
An inclination angle sensing unit for sensing an inclination angle of the hill where the vehicle is stopped;
An interface unit for communicating with an engine ECU for controlling an engine and a transmission ECU for controlling a transmission to receive driving system information including a driving torque and a gear state;
A departure detection unit for detecting the start of the vehicle;
A hydraulic pressure regulating part for regulating the braking pressure of the wheel cylinder of each wheel; And
And a control unit that detects the inclination angle of the hill through the inclination angle sensing unit when the vehicle is stopped and communicates with the engine ECU and the transmission ECU via the interface unit to receive the driveline information and if the driver does not depress the brake pedal The maximum inclination angle at which the vehicle can not be pushed back is determined and the detected hill inclination angle is compared with the determined maximum inclination angle so as to form a braking pressure on the wheel cylinders of each wheel in order to prevent the vehicle from being pushed back And an electronic control unit for controlling the hydraulic pressure regulator. The method according to claim 1,
Wherein the electronic control unit determines that the driver has a braking commitment if the detected inclination angle of the hill and the maximum inclination angle are exceeded. 3. The method of claim 2,
Wherein the electronic control unit determines that the driver has a braking intention if the sensed hill inclination angle exceeds the determined maximum inclination angle. The method of claim 3,
Wherein the electronic control unit includes a braking pressure generating unit for generating a braking pressure on the wheel cylinders of the wheels through the hydraulic control unit when it is determined that the driver has a braking intention. The method according to claim 1,
Wherein the electronic control unit includes a step of determining a predetermined angle to correspond to the number of gears of the received driving system information at the maximum inclination angle. The method according to claim 1,
Wherein the electronic control unit releases the braking pressure applied to the wheel cylinders of the wheels through the hydraulic pressure regulator when the start of the vehicle is sensed through the departure detection unit,
Determining whether a predetermined time has elapsed since the braking pressure was established if the vehicle departure is not detected, and releasing the braking pressure formed on the wheel cylinders of the wheels when the predetermined time has elapsed. When the vehicle is stopped, the hill inclination angle is detected,
Communicates with the engine ECU and the transmission ECU to receive driving system information including the driving torque and the gear state from the engine ECU and the transmission ECU,
Determines a maximum inclination angle at which the vehicle can not be pushed back even if the driver does not step on the brake pedal based on the received driving system information,
If the detected hill inclination angle and maximum inclination angle are exceeded, it is determined that there is a driver's brake will,
And forming a braking pressure on the wheel cylinders of each wheel so as to prevent the vehicle from being pushed back, if it is determined that there is a braking force of the driver. 8. The method of claim 7,
Wherein the determination of the maximum inclination angle includes determining a predetermined angle corresponding to the number of gears of the received driving system information as the maximum inclination angle. 9. The method according to claim 7 or 8,
And when the start of the vehicle is detected, the braking pressure applied to the wheel cylinders of the wheels is released,
Determining whether a predetermined time has elapsed since the braking pressure was established if the vehicle departure is not detected, and releasing the braking pressure formed on the wheel cylinders of the wheels when the predetermined time has elapsed.

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