Patent ID: 6241324
Filing Date: 2001-06-05
Classification: B60T

Abstract:
A method of controlling an anti-lock brake system for vehicles during emergency braking in response to a change in a road surface parameter, the method comprising:effecting a brake liquid pressure increasing mode of operation wherein brake liquid pressure is increased;repeatedly detecting the road surface parameter by measuring wheel speed .omega. and change in wheel speed d.omega./dt, said road surface parameter being one of a road surface friction force F and a road surface friction coefficient .mu.;determining that an optimum control start point is arrived at when said road surface parameter increases in level above a predetermined value due to the increased brake liquid pressure, as determined from one of a drop in the wheel speed .omega. or an increase in the change in wheel speed d.omega./dt; andshifting to a pressure decreasing mode reducing the brake liquid pressure upon reaching said optimum control start point and maintaining reducing the brake liquid pressure until a current level of said road surface parameter is reduced to a predetermined proportion of a level of said road surface parameter detected immediately prior to said determination of arrival at said optimum control start point.