ELECTRONIC BRAKE SYSTEM AND CONTROL METHOD THEREFOR

1 . An electronic brake system comprising:

a hydraulic pressure supply device including a motor, and configured to generate a hydraulic pressure by rotating the motor to move a piston in a first direction or a second direction;

a hydraulic circuit configured to guide the hydraulic pressure generated by the hydraulic pressure supply device to a wheel cylinder;

a motor position sensor configured to detect a rotation of the motor;

a pressure sensor configured to detect a hydraulic pressure of the hydraulic circuit; and

a controller configured to identify a position of the piston based on the rotation of the motor, and if the detected hydraulic pressure is greater than or equal to a reference pressure, identify whether a target pressure is securable based on the position of the piston, and control a direction change of the piston based on whether the predetermined target pressure is securable.

2 . The electronic brake system of claim 1 , wherein the controller is configured to: identify a target stroke change amount of the piston for securing the target pressure, and identify whether the predetermined target pressure is securable based on the position of the piston and the target stroke change amount.

3 . The electronic brake system of claim 2 , wherein the controller is configured to, if the position of the piston is located within a reference range in which the target stroke change amount is securable in a moving direction of the piston, identify that the target pressure is securable.

4 . The electronic brake system of claim 3 , wherein the controller is configured to determine a range in a direction opposite to the moving direction of the piston with respect to a reference position for securing the target stroke change amount as the reference range in which the target stroke change amount is securable.

5 . The electronic brake system of claim 2 , further comprising a storage configured to store a characteristic map of a stroke of the piston and hydraulic pressure,

wherein the controller is configured to determine the target stroke change amount of the piston corresponding to the target pressure based on the characteristic map.

6 . The electronic brake system of claim 1 , wherein the controller is configured to, if the target pressure is securable, control the motor such that the moving direction of the piston is maintained.

7 . The electronic brake system of claim 1 , wherein the controller is configured to, if the target pressure is not securable, control the motor such that the moving direction of the piston is changed.

8 . The electronic brake system of claim 1 , wherein the controller is configured to determine whether the target pressure is securable based on the position of the piston if a vehicle speed is greater than or equal to a predetermined reference speed.

9 . The electronic brake system of claim 1 , wherein the controller is configured to determine whether the target pressure is securable based on the position of the piston if an anti-lock brake system (ABS) control or an electronic stability control system (ESC) control is performed.

10 . The electronic brake system of claim 1 , wherein the controller is configured to determine whether the target pressure is securable based on the position of the piston if a user input is received.

11 . The electronic brake system of claim 1 , wherein the controller is configured to determine whether the target pressure is securable based on the position of the piston if a hydraulic pressure of a pressurized medium discharged as the piston moves in a forward direction is greater than or equal to the reference pressure.

12 . The electronic brake system of claim 1 , wherein the hydraulic circuit further includes a hydraulic control unit including a first hydraulic circuit configured to control a hydraulic pressure transferred to a first wheel cylinder and a second hydraulic circuit configured to control a hydraulic pressure transferred to a second wheel cylinder, and

wherein the hydraulic control unit includes a first valve configured to control a flow of pressurized medium from a first pressure chamber located at one side of the piston and a second valve configured to control a flow of pressurizing medium from a second pressure chamber located at an other side of the piston.

13 . The electronic brake system of claim 12 , further comprising a valve driver configured to open or close the first and second valves, and

wherein the controller is configured to, if the detected hydraulic pressure is greater than or equal to the reference pressure, control the valve driver to open the first valve and the second valve.

14 . An electronic brake system comprising:

a hydraulic pressure supply device including a motor, and configured to generate a hydraulic pressure by rotating the motor to move a piston in a first direction or a second direction;

a hydraulic circuit configured to guide the hydraulic pressure generated by the hydraulic pressure supply device to a wheel cylinder;

a motor position sensor configured to detect a rotation of the motor; and

a controller configured to, if an operation mode is a high-pressure mode, determine whether a predetermined target pressure is securable based on a position of the piston, determine a moving direction of the piston for transferring a hydraulic pressure to the wheel cylinder based on whether the predetermined target pressure is securable, and control the hydraulic pressure supply device to move the piston in the determined moving direction.

15 . The electronic brake system of claim 14 , further comprising a pressure sensor configured to detect a hydraulic pressure of the hydraulic circuit,

wherein the controller is configured to determine the operation mode as the high-pressure mode based on at least one of the detected hydraulic pressure, a vehicle speed, whether an anti-lock brake system (ABS) control is performed, whether an electronic stability control system (ESC) control is performed, or an input of a user.

16 . The electronic brake system of claim 14 , wherein the hydraulic circuit includes:

a first valve configured to control a flow of pressurized medium from a first pressure chamber located at one side of the piston and a second valve configured to control a flow of pressurizing medium from a second pressure chamber located at an other side of the piston.

17 . The electronic brake system of claim 16 , further comprising a valve driver configured to open or close the first and second valves,

wherein the controller is configured to, if the hydraulic pressure is greater than or equal to a predetermined reference pressure, control the valve driver to open the first valve and the second valve.

18 . A method of controlling an electronic brake system, the method comprising:

generating a hydraulic pressure by rotating a motor to move a piston in a first direction or a second direction;

detecting rotation of the motor;

detecting the generated hydraulic pressure;

identifying a position of the piston based on the rotation of the motor;

if the detected hydraulic pressure is greater than or equal to a reference pressure, identifying whether a target pressure is securable based on the position of the piston; and

changing a moving direction of the piston based on whether the predetermined target pressure is securable.

19 . The method of claim 18 , wherein the identifying of whether the target pressure is securable includes:

identifying a target stroke change amount of the piston for securing the target pressure; and

identifying whether the target pressure is securable based on the position of the piston and the target stroke change amount.

20 . The method of claim 18 , wherein the changing of the moving direction of the piston includes:

if the target pressure is securable, controlling the motor such that the moving direction of the piston is maintained; and

if the target pressure is not securable, controlling the motor such that the moving direction of the piston is changed.