Electronic parking brake with fail-safe function and control method thereof

摘要

An electronic parking brake with a fail-safe function and control method thereof are provided to add a control method based on displacement by detecting a rotational quantity of a screw assembly to the control method based on a weight detected by a tensile force which applies an operation for an actuator of an electronic parking brake to a cable; to further strengthen the fail-safe function applied to the parking brake system; and to fundamentally block a worry over a loss of a function of the actuator. The said present invention comprises: a driving motor (12); a reducer (14) installed to be able to be interlocked; a driving gear (15) which rotates by a driving force provided by the reducer (14); a screw assembly (16) installed to be able to be interlocked with the driving gear (15); bolt screws (18, 20) combined with the screw assembly (16) with a screw; a parking cable (22) connected respectively to each of the bolt screws (18, 20); a weight sensor (24) which detects the tensile force applied to the parking cable (22); a displacement sensor (26) which detects the quantity of rotation of the driving gear (15); and a control unit (28) which controls the rotation of the driving motor (12) based on a normal detected value from among the signals entered from each of the weight sensor (24) and the displacement sensor (26).