An electric parking brake system, comprising:
- a brake that includes a rotating body which has a friction face, the rotating body being configured to rotate together with a wheel, a friction member which is fitted to a non-rotating body so as to be movable relative to the non-rotating body and which friction member is configured to suppress a rotation of the rotating body when being pushed against the friction face of the rotating body, and a pushing mechanism configured to push the friction member against the friction face of the rotating body;
- an electric motor;
- a motion conversion mechanism configured to convert a rotation of a rotating shaft of the electric motor into a linear motion of an output member of the motion conversion mechanism;
- a connection unit that is connected at one end to the output member of the motion conversion mechanism, and that is connected at the other end to the pushing mechanism;
- a maintaining mechanism configured to maintain a friction member pushing force that is a force with which the friction member is pushed against the friction face in the brake, when electric current is not supplied to the electric motor;
- and
- a pushing force control unit configured to control the electric motor such that the friction member pushing force in the brake approaches a target value that is set based on a moving force applied to a vehicle,
- wherein the pushing force control unit includes
- a tentative target value setting unit configured to set a tentative target value of the friction member pushing force each time a predetermined condition is satisfied while the brake is on;
- and
- a final target value setting unit configured to set a target value in a current routine to a target value in an immediately preceding routine when the tentative target value in the current routine, which is set by the tentative target value setting unit, is equal to or smaller than the target value in the immediately preceding routine, the final target setting unit being further configured to set the target value in the current routine to the tentative target value in the current routine, which is set by the tentative target value setting unit, when the tentative target value in the current routine is larger than the target value in the immediately preceding routine.