ANTISKID CONTROL DEVICE

PROBLEM TO BE SOLVED: To prevent insufficient deceleration and to prevent spinning caused by the difference in the braking force between left and right wheels by obtaining the braking force with the wheels on a high-μ road side while minimizing the influence of brake specification. SOLUTION: When pressure difference is generated linearly by a pressure increase control valve for controlling the increase of the brake hydraulic pressure on a wheel cylinder (W/C pressure) in each wheel and the wheels on a low-μ road side are in a reduced pressure mode, or if the absolute value of the difference in the estimated W/C pressure between the left and right front wheels FR and FL exceeds a threshold Phold, the W/C pressure of the wheels on the high-μ road side is not increased but retained. When the W/C pressure of the wheels on the high-μ road side is increased thereafter, the pressure is gently increased. Since the pressure increase gradient of the W/C pressure varies according to the difference between the brake hydraulic pressure on a master cylinder (M/C pressure) and the W/C pressure just as when the pressure increase control valve, a conventional on/off valve, is used, excessive increase of the W/C pressure or, on the contrary, shortage of the W/C pressure as compared with an original target value, caused by braking when the time to turn off the on/off valve is decided short, can be prevented. COPYRIGHT: (C)2009,JPO&INPIT