Antilock brake control system in vehicle

Abstract

An antilock brake control system in a vehicle is designed to retard the pressure increasing timing in one of front and rear wheel braking liquid pressure regulating devices which corresponds to a wheel having a smaller load share, until the wheel speed of such wheel is started to be reduced while following an actual vehicle speed after being restored to near the actual vehicle speed, when both of front and rear wheels are in antilock brake-controlled state. In this antilock brake control system, when the vehicle deceleration calculated based on a presumed vehicle speed is equal to or lower than a preset deceleration during retarding of the pressure increasing timing in a condition in which both of front and rear wheel brakes are in antilock brake controlled state, the braking liquid pressure control mode is switched over to a maintaining mode, but when the vehicle deceleration is higher than the preset deceleration, the control mode is switched over to a reducing mode, thereby controlling one of the front and rear wheel braking liquid pressure regulating devices which corresponds to the wheel having the smaller load share. Thus, when both of the front and rear wheels are in the antilock brake controlled states, a very accurate presumed vehicle speed can be calculated and moreover, the decrease in total braking force can be inhibited to the utmost.