Braking control apparatus for vehicle

A braking control apparatus for a vehicle, comprising:

• four wheel braking apparatuses for applying a braking torque to front-right, front-left, rear-right, and rear-left wheels in response to a braking hydraulic pressure supplied to wheel cylinders provided at the respective wheels;
• a first hydraulic pressure generating apparatus including two hydraulic pressure generating chambers each generating a hydraulic pressure in response to a braking operation by a driver of a vehicle;
• a vacuum booster generating an assist force for assisting a breaking operation performed by the driver relative to the first hydraulic pressure generating apparatus;
• a first hydraulic circuit hydraulically connecting one of the hydraulic pressure generating chambers to the two of the wheel braking apparatuses;
• a second hydraulic circuit hydraulically connecting the other one of the hydraulic pressure generating chambers to the other two of the wheel braking apparatuses;
• a second hydraulic pressure generating apparatus being power driven and generating an assist hydraulic pressure that is added to the hydraulic pressure in each of the first hydraulic circuit and the second hydraulic circuit generated by the first hydraulic pressure generating apparatus;
• detecting means for detecting a braking operation variable in response to the braking operation;
• and
• target value determining means for determining, on the basis of the detected braking operation variable, a first assist hydraulic pressure target value in the first hydraulic circuit and a second assist hydraulic pressure target value in the second hydraulic circuit to both increase from zero in association with an increase of the braking operation variable from a value equal to or smaller than a predetermined value at which the assist force by the vacuum booster is started, the target value determining means determining the braking operation variable obtained in a case where each of the first and second assist hydraulic pressure target values reaches a maximum value of the assist hydraulic pressure generated by the second hydraulic pressure generating apparatus to be greater than the braking operation variable obtained in a case where the assist force generated by the vacuum booster reaches a maximum value;
• and
• pressure regulating means for regulating the assist hydraulic pressure in each of the first hydraulic circuit and the second hydraulic circuit to match each of the first assist hydraulic pressure target value and the second assist hydraulic pressure target value determined by the target value determining means.