Patent ID: 7699411

Claim:
An antiskid control apparatus for a vehicle comprising: antiskid control means for continuously performing an antiskid control a plurality of times, the antiskid control including pressure-reducing control which is first performed and pressure-increasing control which is performed after the pressure-reducing control, the pressure-reducing control being performed by controlling a pressure-reducing valve, interposed in a first hydraulic circuit between a wheel cylinder and a reservoir, with a pressure-increasing valve, interposed in a second hydraulic circuit between the wheel cylinder and a master cylinder, kept closed so as to reduce wheel cylinder pressure, and the pressure-increasing control being performed by controlling the pressure-increasing valve with the pressure-reducing valve kept closed so as to increase the wheel cylinder pressure; first obtaining means for obtaining an estimated initial wheel cylinder pressure value, which is an estimated value representing the wheel cylinder pressure at the start of a first-time antiskid control; second obtaining means for obtaining an estimated value representing the wheel cylinder pressure, which varies throughout the antiskid control, by making use of at least the estimated initial wheel cylinder pressure value; third obtaining means for obtaining an estimated value representing the differential pressure between a master cylinder pressure and the wheel cylinder pressure on the basis of the difference between the estimated initial wheel cylinder pressure value and the estimated wheel cylinder pressure value; pressure-increasing-valve control means for controlling the pressure-increasing valve during the pressure-increasing control on the basis of the estimated differential pressure value; wherein the first obtaining means obtains the estimated initial wheel cylinder pressure value in consideration of a wheel cylinder pressure at which lock of a wheel occurs and which is obtained on the basis of vehicle body deceleration of the vehicle; and the first obtaining means obtains the estimated initial wheel cylinder pressure value in consideration of a time interval between the start of the driver's brake operation and the start of the first-time antiskid control.