Patent attributes
Disclosed is an electric brake system. The electric brake system includes a master cylinder including first and second chambers, and first and second pistons disposed at the first and second chambers, respectively; a simulation device connected to the master cylinder and configured to provide a reaction force according to pedal effort of a brake pedal; a hydraulic pressure supply device configured to generate a hydraulic pressure by a hydraulic piston which is operated by an electrical signal that is output to correspond to displacement of the brake pedal; a hydraulic pressure control unit configured to deliver the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided at each of wheels; a first backup flow path and a second backup flow path configured to connect the master cylinder and the hydraulic pressure control unit; a first cut valve and a second cut valve configured to control delivery of a hydraulic pressure of the first and second backup flow paths; an electronic control unit (ECU); a first pressure sensor installed between the first chamber of the master cylinder and the first cut valve; and a second pressure sensor installed at the first hydraulic flow path, the second hydraulic flow path, or the hydraulic pressure control unit, wherein, in a state in which the second cut valve is closed and the outlet valve, which is connected to the second backup flow path, is opened, to discharge the hydraulic pressure in the hydraulic pressure control unit connected to the second hydraulic flow path, the ECU operates the hydraulic pressure supply device to generate a pressure in the first chamber, and when a measured value of the second pressure sensor is less than an expected value, the ECU determines that the second piston of the master cylinder is stuck.
