Vehicle control device

A vehicle control device applicable to a vehicle brake device which includes;

• a master cylinder wherein a master piston is driven to move by a servo pressure in a servo chamber and by the movement of the master piston, a master pressure in a master chamber is changed;
• a servo pressure generating device formed by a high pressure source, a pressure increasing control valve disposed between the high pressure source and the servo chamber for controlling a flow of a brake fluid from the high pressure source to the servo chamber and a first pressure decreasing control valve disposed between a low pressure source and the servo chamber for controlling the flow of the brake fluid from the servo chamber to the low pressure source, generating the servo pressure in the servo chamber;
• a servo pressure sensor which detects the servo pressure;
• a plurality of wheel cylinders which applies a braking force to respective corresponding vehicle wheels in response to respective wheel cylinder pressures;
• and
• a brake actuator disposed between the master cylinder and the plurality of wheel cylinders and structured so that a target wheel cylinder pressure which is the wheel cylinder pressure in response to a desired braking force is individually applicable to the respective wheel cylinders by a holding control valve and a second pressure decreasing control valve both of which are provided at each corresponding wheel cylinder based on the master pressure of the master cylinder, wherein,
• the vehicle control device controls the pressure increasing control valve and the first pressure decreasing control valve so that an actual servo pressure detected by the servo pressure sensor becomes a target servo pressure;
• and, while a brake operating member is not operated and a wheel cylinder pressure supplying control is executed to supply the target wheel cylinder pressure to the respective wheel cylinders individually, the vehicle control device sets the target servo pressure to a first predetermined target servo pressure which is set to a value smaller than a maximum output pressure of the servo pressure generating device;
• calculates a target wheel cylinder maximum value which is a maximum value among the target wheel cylinder pressures to be applied to the respective vehicle wheels;
• and when the execution of the wheel cylinder pressure supplying control starts, sets the target servo pressure to be the target wheel cylinder maximum value when a firstly occurred rising inclination of the target wheel cylinder maximum value is equal to or more than a minimum increment of an output of the servo pressure generating device per unit time and at the same time when the target wheel cylinder pressure is smaller than the first determined target servo pressure.