Vehicle brake system

1. A vehicle brake system comprising:

first and second electric brakes, each of the first and second electric brakes including at least one unit of an electric actuator that presses a friction pad toward a rotor side;

a first driver that drives the electric actuator of the first electric brake;

a second driver that drives the electric actuator of the second electric brake;

a control device including a plurality of controllers connected to one another,

the first electric brake being provided to a first wheel of a vehicle, and

the second electric brake being provided to a second wheel of the vehicle,

the plurality of controllers including:

a master controller including a first driver control unit that controls the first and second drivers, a first braking force calculation unit that calculates braking force of the first and second electric brakes, and a behavior control unit that controls behaviors of the vehicle; and

a first sub-controller including a second driver control unit that controls only the first driver, and a second braking force calculation unit that calculates braking force of the first and second electric brakes,

a second sub-controller including a second driver control unit that controls only the second driver, a third braking force calculation unit that calculates braking force of the first and second electric brakes,

the first electric brake being controllable by both the master controller and the first sub-controller, and

the second electric brake being controllable by both the master controller and the second sub-controller,

wherein the behavior control unit is provided only in the master controller and outputs signals for controlling behaviors of the vehicle to the second driver control unit of the first sub-controller and to the third driver control unit of the second sub-controller.

2. The vehicle brake system according to claim 1 , wherein

the first and second wheels are front wheels of the vehicle.

3. The vehicle brake system according to claim 1 , wherein

the control device includes a first control device and a second control device; and

the first control device includes the master controller, the first sub-controller, and the second sub-controller.

4. The vehicle brake system according to claim 3 , further comprising:

a brake pedal;

a stroke simulator connected to the brake pedal; and

a stroke sensor that detects an operation amount of the brake pedal, wherein

the first control device is provided integrally with the stroke simulator and the stroke sensor.

5. The vehicle brake system according to claim 1 , wherein

the first electric brake is provided to the first wheel and includes a plurality of first electric actuators, and the first driver includes a plurality of first drivers that individually drives the plurality of first electric actuators provided to the first wheel,

the master controller controls one of the plurality of first drivers, and

the first sub-controller controls another one of the plurality of first drivers.

6. The vehicle brake system according to claim 1 , wherein

the behavior control unit performs, as a control of behaviors of the vehicle, at least one of a control to prevent locking of the first and second wheels, a control to suppress slippage of the first and second wheels, and a control to suppress sideslip of the vehicle.

7. The vehicle brake system according to claim 1 , wherein

the second electric brake is provided to the second wheel and includes a plurality of second electric actuators, and the second driver includes a plurality of second drivers that individually, drives the plurality of second electric actuators provided to the second wheel,

the master controller controls one of the plurality of second drivers, and

the second sub-controller controls another one of the plurality of second drivers.