Brake system and method of controlling the same

A brake system comprising:

• a piston configured to advance or retract and configured to press a pad plate so that the pad plate is in contact with a brake disc configured to rotate together with a wheel;
• a motor configured to generate a rotational force for operating the piston;
• a ball screw configured to convert a rotational motion of the motor into a rectilinear motion to operate the piston;
• and
• a controller configured to control the motor,
• wherein the controller is configured to control the motor to move a position of the piston to increase a clearance between the pad plate and the brake disc to a first reference clearance, and
• control the motor to move the position of the piston to decrease the clearance to a second reference clearance smaller than the first reference clearance on the basis that at least one of a steering angle, a steering angular velocity, a lateral acceleration, a longitudinal acceleration, or a yaw rate of the vehicle is greater than a predesignated reference value.