Patent ID: 6089682
Filing Date: 2000-07-18
Classification: B60T

Abstract:
An antilock brake control system for a vehicle, comprising wheel speed detecting means for detecting a wheel speed, vehicle speed calculating means for calculating a presumed vehicle speed based on the wheel speed detected by the wheel speed detecting means, slip rate calculating means for calculating a slip rate based on the wheel speed detected by the wheel speed detecting means and the presumed vehicle speed calculated in the vehicle speed calculating means, and a control start determining means for calculating a start determination threshold value as a function of the presumed vehicle speed calculated in the vehicle speed calculating means and for determining that an antilock brake control should be started, in response to the slip rate calculated in the slip rate calculating means exceeding the start determination threshold value, whereinsaid antilock brake control system further includes road surface friction coefficient determining means for determining a friction coefficient of a road surface, and bad-road determining means for determining whether the vehicle is traveling on a bad road, andsaid control start determining means is arranged to change the function of the presumed vehicle speed for calculating the start determination threshold value, based on a state of an antilock brake control for a wheel other than a wheel which is subjected to the determination by the control start determining means, and results of determinations by the road surface friction coefficient determining means and the bad-road determining means.