Electromechanical brake and method of operating the same

A method of operating an electromechanical brake,

• wherein the electromechanical brake comprises:
• a piston configured to advance and retreat to press a brake pad;
• a power transmission unit configured to receive a driving force from an actuator to convert a rotational motion into a linear motion, and provide the converted driving force to the piston;
• a position adjustment unit configured to adjust a relative position of the piston with respect to the power transmission unit;
• an electronic control unit configured to control operation of the actuator;
• and
• a detection unit configured to detect an engaging force between the brake pad and a disc rotating together with a wheel;
• wherein the power transmission unit comprises a spindle rotating by receiving the driving force from the actuator, and a nut connected to the spindle and moving forward or backward by rotation of the spindle in a first direction or a second direction to advance and retreat the piston,
• wherein the position adjustment unit comprises a first screw thread formed on an outer circumferential surface of the nut, a second screw thread formed on an inner circumferential surface of the piston and meshing with the first screw thread, and an adjuster provided between the spindle and the nut and configured to rotate the nut in the first direction or the second direction by rotation of the spindle to advance and retreat the relative position of the piston, and
• the method comprising:
• in response to that the engaging force between the disc and the brake pad detected by the detection unit in a braking state of the vehicle is less than a predetermined value,
• determining, by the electronic control unit, that wear of the brake pad presents, and
• entering, by the electronic control unit, a first mode for advancing the relative position of the piston.