A first ECU estimates whether the operation of a second actuator has been started, based on the variation of the hydraulic pressure with respect to the flow rate of hydraulic fluid outputted from a first actuator. Even in a case where the operation information of the second actuator is not received, the first ECU sets the control mode to a simultaneous operation mode, when it is estimated that the operation of the second actuator has been started. In the simultaneous operation mode, a controlled parameter of linear control valves on assumption that the second actuator is operating is set up, and a stop instruction of regenerative braking is transmitted to a hybrid ECU.