KR101188606B1 - Electro-mechanical brake and control method thereof - Google Patents

Abstract

Disclosed are an electric brake apparatus for a vehicle and a control method thereof for improving braking response. The control method of the electric brake apparatus according to an embodiment determines the driver's braking intention, and if the driver's braking intention exists, the brake pad is moved in the disc direction to prepare for braking for a predetermined time.
Therefore, the present invention can improve the braking response of the electric brake system through the determination of the braking preparation of the driver and the braking preparation process.

Description

Electric brake system and control method {ELECTRO-MECHANICAL BRAKE AND CONTROL METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric braking device and a control method thereof, and more particularly, to an electric braking device and a control method for braking a vehicle by pressing a disk with a brake pad.

A brake system of a vehicle is a device for decelerating or stopping a driving vehicle and maintaining a parking state.

Such a brake system typically uses a friction brake system that converts kinetic energy into thermal energy using friction force and releases it into the atmosphere to brake the disk. It is pressed by the braking.

However, the conventional hydraulic brake system is implemented by pushing the pad strongly toward the disc by using the hydraulic pressure during braking, so that the master cylinder is operated through a booster that boosts the pedal operation force and generates hydraulic pressure, and the hydraulic line leading to the wheel cylinder. Of course, there are inevitably complicated configurations made of various devices for controlling and assisting them, and there are vulnerabilities that have some limitations such as complexity of the configuration and enhanced reliability and stability of braking performance according to hydraulic use.

Accordingly, the use of an electro-mechanical brake (EMB) system that can realize the simplicity of the hydraulic brake and enhance the reliability of braking performance is increasing.

In the electric brake system, when the electronic control unit (ECU) receiving the electronic pedal information during braking drives the electric motor to generate an axial movement force, the piston coupled to the electric motor is moved in the axial direction and the disc is moved to the brake pad. Pressurized to achieve braking.

Recently, research activities have been actively conducted to further improve the braking response of the electric brake system. However, in order to improve the braking response of the electric brake system, it is inevitable to enlarge the motor, and there is a problem of increasing the residual braking force due to the position of the brake pad close to the disk.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric braking device and a control method thereof, which improve braking responsiveness through a braking preparation step of moving a brake pad to a predetermined position in a disc direction when a driver's braking intention is detected.

The control method of the electric braking apparatus according to an aspect of the present invention for achieving the above object is the step of sensing the movement of the driver's foot before the actual braking, whether the driver's willingness to prepare braking through the movement of the sensed driver's foot And a braking preparation step of moving the brake pad to a predetermined position before contacting the disc in the disc direction when it is determined that the driver's braking intention is present.

On the other hand, the braking preparation step may be characterized in that, when the preset time is exceeded, the brake pad is returned to the position before braking preparation to end braking preparation.

In addition, the sensing of the movement of the driver's foot may be characterized by sensing the movement of the driver's foot to retreat from the accelerator pedal or approaching the brake pedal.

Also, in the determining whether the driver's braking intention exists, if there is a movement to retreat from the accelerator pedal of the driver's foot or a movement approaching the brake pedal of the driver's foot, it may be determined that the driver's braking intention exists.

Motorized braking device according to another aspect of the present invention for achieving the above object is the sensor unit for sensing the movement of the driver's foot before the actual braking, there is a willingness to prepare the driver through the movement of the driver's foot sensed from the sensor unit And a control unit for controlling the braking preparation operation and an actuator for performing the braking preparation operation for moving the brake pad to a predetermined position before contacting the disc in the disc direction by the controller.

On the other hand, it may further include a timer for calculating the time the braking preparation operation is performed.

The controller may return the brake pad to a position before the braking preparation and terminate the braking preparation when the braking preparation operation calculated by the timer exceeds a preset time.

In addition, the sensor unit may include an accelerator pedal sensor that senses a movement of the driver's foot retreating from the accelerator pedal, and a brake pedal sensor that senses a movement of the driver's foot approaching the brake pedal.

The controller may determine that the driver's willingness to brake is present when the movement of the driver's foot retreating from the accelerator pedal is sensed by the accelerator pedal sensor or the movement of the driver's foot approaching the brake pedal is sensed by the brake pedal sensor. You can do

According to the present invention, when the driver's braking intention is detected, the braking response of the electric braking device can be improved by moving the brake pad to a predetermined position in the disc direction.

1 is a block diagram showing a schematic configuration of an electric brake device according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the configuration of the actuator shown in FIG. 1. FIG.
FIG. 3 is a block diagram showing control of the electric brake shown in FIG. 1.
4 is a flowchart illustrating a control method of an electric brake device according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a schematic configuration of an electric brake device according to an embodiment of the present invention.

The motorized braking apparatus 100 according to the present embodiment includes a central ECU 110, a sensor unit 120, an EMB ECU 130, and an actuator 140.

The central ECU 110 transmits a control signal for electric braking to the EMB ECU 130 according to sensing information related to various vehicle state information input through the sensor unit 120.

In addition, the central ECU 110 receives the state of the vehicle such as the driving state of the vehicle, the motor characteristics, and determines the amount of braking. In particular, the central ECU 110 in this embodiment detects the driver's braking will. In addition, when the driver's braking intention is detected, the central ECU 110 prepares the braking for a preset time by moving the brake pad in the disc direction.

 The EMB ECU 130 performs electric braking according to the control signal of the central ECU 110. At this time, the number of EMB ECU 130 may be one, may be provided as the number of each wheel.

In addition, the actuator 140 includes an electric motor, a disk, a brake pad, and the like, and brakes the front wheels FR and FL and the rear wheels RR and RL of the vehicle by the EMB ECU 130. The detailed configuration of the actuator 140 will be described in detail with reference to FIG. 2.

FIG. 2 is a cross-sectional view showing the configuration of the actuator shown in FIG. 1. FIG.

The actuator 140 according to the present embodiment is coupled to the vehicle body and has a pair of brake pads 141a and 141b installed therein so as to be spaced apart from each other by a predetermined interval, and the carrier 141 is installed to be moved forward and backward. In order to press the two brake pads (141a, 141b) with the disk (D), one side is provided with a cylinder portion 143 is provided with a piston 142 to move forward and backward, and the other side is provided with a caliper housing with a finger portion 144 145.

In addition, the actuator 140 also includes a parking device to perform the function of the parking brake. The parking lot has a spindle 146 rotatably installed in the cylinder portion 143 of the caliper housing 145 and the piston 142 to press or release the piston 142 while moving forward and backward by the rotation of the spindle 146. It includes a nut adjuster 147 installed inside, and an electric motor 148 which is a driving source for rotating the spindle 146.

On the other hand, the cylinder 143 extends the circumferentially extended flange 146a of the spindle 146 so that the spindle 146 rotating in the cylinder 143 does not contact the inner wall 143a of the cylinder 143. Assembling apart from the inner wall.

In the present embodiment, when the driver's braking intention is detected, the brake pads 141a and 141b are moved from the initial position m to the predetermined position l in the direction of the disk D.

On the other hand, the initial position (m) means the position of the brake pads (141a, 141b) before starting braking. In addition, the predetermined position (1) is adjustable according to the design, it is preferable to adjust so that the brake pads (141a, 141b) and the disk (D) close enough without the driver can feel the braking force.

FIG. 3 is a block diagram showing control of the electric brake shown in FIG. 1.

Referring to FIG. 3, the controller 220 provides a brake preparation control signal to the actuator 250 based on various vehicle state information provided from the sensor unit 210, the timer 230, and the memory unit 240. The actuator 250 provided with the braking preparation control signal performs a braking preparation operation of moving the brake pad to a predetermined position.

In detail, the sensor unit 210 includes a brake pedal proximity sensor 211 and an accelerator pedal sensor 212.

The brake pedal proximity sensor 211 is a proximity sensor that can sense the approach of an object other than the conductor, and detects a movement approaching the brake pedal of the driver's foot. The brake pedal proximity sensor 211 may be provided as a capacitive proximity sensor.

The accelerator pedal sensor 212 senses a movement of the driver's foot to retreat from the accelerator pedal.

The controller 220 determines whether a driver's braking will exist.

Specifically, the control unit 220 determines the driver's braking preparedness based on the movement and the speed signal approaching the brake pedal of the driver's foot provided from the brake pedal proximity sensor 211. In addition, the controller 220 determines the driver's willingness to prepare for braking based on a speed signal and a movement retreating to the driver's foot accelerator pedal provided from the accelerator pedal sensor 212.

That is, the controller 220 determines that the driver has a willingness to prepare for braking if there is a movement in which the driver's foot retracts from the accelerator pedal or approaches the brake pedal.

If the controller 220 determines that the driver's braking will exist, the controller 220 controls the braking preparation operation. That is, the controller 220 moves the brake pad in the disc direction when the driver's willingness to prepare for braking exists.

Specifically, the control unit 220 may move ① the brake pad to a certain position at a very slow speed in the disc direction, or ② move the brake pad to a certain position at a high speed in the disc direction, and retreat from the predetermined position based on the disc direction. You can move it.

On the other hand, the controller 220 performs the braking preparation operation control for a predetermined time. Specifically, after the braking preparation operation starts, the controller 220 increases the value of the timer 230 and compares whether the increased value of the timer 230 and the threshold value stored in the memory unit 240 are equal to each other. Determine whether it has started. In this case, whether or not actual braking is started is determined based on whether the brake pedal is pressed.

That is, if the actual braking is not started even after the preset time elapses, the controller 220 returns the brake pad to the initial position before the braking preparation and ends the braking preparation operation.

Therefore, the control unit 220 is located in advance close to the disk before the start of braking, it is possible to provide a quick braking response when the actual braking.

The timer 230 calculates the time for which the braking preparation operation is performed. That is, the value of the timer 230 is increased after the braking preparation operation is started by the controller 220, and the timer 230 transmits the numerical information signal to the controller 220. In addition, when the braking preparation operation is terminated by the controller 220, the numerical value of the timer 230 is initialized.

The memory unit 240 stores the execution time of the braking preparation operation as a threshold value. Therefore, the controller 220 compares the threshold value stored in the memory unit 240 with the value of the timer 230 and determines whether to terminate the braking preparation operation. In addition, the memory unit 240 senses the driver's braking intention, and when the braking intention is detected, stores the control factor for performing braking preparation for a predetermined time.

4 is a flowchart illustrating a control method of an electric brake device according to an embodiment of the present invention.

The control method of the electric braking apparatus according to the present embodiment includes a step of initializing a timer, a driver's braking intention detection step, and a braking preparation step.

The driver braking intention detection step senses a movement in which the driver's foot retreats from the accelerator pedal (311) and senses a movement in which the driver's foot approaches the brake pedal (312).

When the movement of the driver's foot retreating from the accelerator pedal is sensed and the movement approaching the brake pedal is sensed, the driver braking ready detection step detects the presence of the driver's braking ready.

The braking preparation step is performed when it is detected that the braking ready will exist in the driver's braking ready detection phase.

The braking preparation step 1) determines whether the timer exceeds a preset threshold (321), 2) determines whether the actual braking is started (323), and 3) performs the braking preparation operation.

1) Determining whether the timer exceeds a preset threshold 321 controls the braking preparation step to be performed for a preset time. Therefore, when the timer exceeds the preset threshold, the brake pad is moved to the initial position before braking is started 322 and the braking preparation step ends.

2) Step 323 of determining whether to start the actual braking is determined based on whether the brake pedal is pressed. Accordingly, when it is determined that the actual braking has started, the braking control starts 324, and if the braking is started before the braking preparation operation is performed.

3) The braking preparation operation may include determining whether the brake pad has reached a predetermined position (325), stopping the movement of the brake pad (326) if the brake pad is at a predetermined position, and fixing the position of the brake pad. Otherwise, the step 327 advances the brake pad to a predetermined position.

On the other hand, the constant position means a position before the brake pad and the disk contact each other. Therefore, the braking preparation operation of moving the brake pad to the predetermined position makes it possible to expect a quick braking response effect in the actual braking operation.

FR, FL: Front wheels
RR, RL: rear wheel
100: electric braking device
110: central ECU
120:
130: EMB ECU
140: actuator

Claims (9)

Sensing movement of the driver's foot before actual braking is started;
Determining whether there is a driver's willingness to prepare for braking based on the sensed movement of the driver's foot; And
And a braking preparation step of moving the brake pad to a predetermined position before contacting the disc in the disc direction when it is determined that the driver's braking intention exists. The method of claim 1,
The braking preparation step
And if the preset time is exceeded, returning the brake pad to the position before the braking preparation and ending the braking preparation. The method of claim 1,
Sensing the movement of the driver's foot
A control method for an electric braking device, characterized in that the driver's foot senses a retreating movement or a approaching brake pedal. The method of claim 3, wherein
Determining whether the driver's braking will exist
And controlling the braking intention of the driver if there is a movement to retreat from the accelerator pedal of the driver's foot or approaching the brake pedal of the driver's foot. A sensor unit sensing a movement of a driver's foot before actual braking is started;
A controller for determining whether a braking ready will exist for a driver through movement of the driver's foot sensed by the sensor unit, and controlling a braking ready operation if the braking ready will exist; And
And an actuator configured to perform the brake preparation operation of moving, by the controller, the brake pad to a predetermined position before contacting the disk in the disk direction. 6. The method of claim 5,
And a timer for calculating a time for performing the braking preparation operation. The method according to claim 6,
The control unit
And the braking preparation is terminated by returning the brake pad to a position before the braking preparation when the time for performing the braking preparation operation calculated by the timer exceeds a preset time. 6. The method of claim 5,
The sensor unit
An accelerator pedal sensor for sensing a movement of the driver's foot from the accelerator pedal; And
And a brake pedal sensor configured to sense a movement of a driver's foot approaching the brake pedal. The method of claim 8,
The control unit
If the movement of the driver's foot retreating from the accelerator pedal is sensed by the accelerator pedal sensor or the movement of the driver's foot approaching the brake pedal is sensed by the brake pedal sensor, it is determined that the driver's willingness to brake is present. Electric brake device characterized in that.

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