Patent ID: 8322798

Claim:
A parking brake control unit that performs parking brake control using a brake system that includes: an electric parking brake that generates a pressing force for pressing a friction member against a friction receiving member attached to a wheel by driving an electric motor, and generates a brake force by friction between the friction member and the friction receiving member; and a service brake that is actuated by operation of a brake pedal, and generates a brake force by moving the friction member toward the friction receiving member, the parking brake control unit comprising: a lock control unit that performs lock control in which, after the pressing force is generated by driving the electric motor and the brake force of the electric parking brake is generated by the pressing force, the lock control unit stops the drive of the electric motor on condition that the pressing force reaches a target pressing force at which the drive of the electric motor is stopped, and locks the electric parking brake while maintaining the brake force, wherein the lock control unit includes a correction unit that corrects the target pressing force such that as the brake force generated by the service brake becomes larger, the target pressing force becomes smaller, wherein the lock control unit detects, as a physical quantity corresponding to the pressing force, a motor current that flows through the electric motor, sets as a no load current the motor current generated before the friction member comes into contact with the friction receiving member, sets as the target pressing force a value obtained by adding a target motor current value increase amount to the no load current, and stops the drive of the electric motor when an increase amount of the motor current from the no load current exceeds the target motor current value increase amount, and wherein the correction unit corrects the target pressing force by correcting the target motor current value increase amount such that as the brake force generated by the service brake becomes larger, the target motor current value increase amount becomes smaller.