Anti-blocking and/or wheel slip regulating system

Claim 1

Anti-lock brake control system for controlling slippage of wheels on a vehicle moving at a speed represented by a vehicle speed curve, the wheel slippage versus braking force being represented by a slippage curve having a stable portion (low slippage) where the braking force increases to a maximum as slippage increases, and an unstable portion (high slippage) where the braking force decreases as slippage increases further, said system comprising at least one wheel speed sensor which generate signals corresponding to the wheel speed, an evaluation circuit which receives said wheel speed signals and generates a reference speed and slippage signals for brake pressure control, the curve of the reference speed being approximated to the curve of the vehicle speed, said evaluation circuit means effecting maintaining the brake pressure constant during periods in which the difference between the wheel speed and the reference speed does not exceed a prescribed value, brake pressure control means actuated by said slippage signals and causing a variation in brake pressure depending upon wheel slippage, said brake pressure control means effecting pressure build-up, pressure reduction, and maintaining the pressure constant, and means for effecting a pulse-like brake pressure change during a period in which said evaluation circuit means effects maintaining the pressure constant, means for determining a stability reserve from the reference speed and the wheel speed which result from the pulse-like pressure change, and means for deriving a signal from the stability reserve for changing the brake pressure so as to adjust the slippage to be on the stable portion of the slippage curve and at the maximum braking force.