Abstract: An ABS skid detection protection system for a wheeled vehicle detects a predetermined level of deceleration at a wheel; detects, memorizers and holds for a prescribed period the wheel speed value at that predetermined deceleration level; detects whether the angular acceleration of the monitored wheel first falls below and then re-establishes the predetermined deceleration level within the prescribed level; and corrects the memorizsed value of wheel speed by subtracting from it an amount equal to the vehicle deceleration multiplied by either the elapsed time since the wheel speed value was memorized or the elapsed time since the initiation of a short-duration pulse by which the actuating pressure applied to a brake can be temporarily dumped upon detection of the predetermined level of deceleration of the wheel.

Abstract: An apparatus for attenuating wheel speed variation during periods of brake intervention traction control is provided. The speed of the or each driven wheel is monitored and the braking force applied to the or each driven wheel is controlled in accordance with the wheel speed and wheel acceleration. Braking force may be increased when a rate of change of wheel acceleration is increasing and the wheel is accelerating (i.e. between periods B and C of FIG. 5c); whereas braking force may be decreased when the rate of change of wheel acceleration is decreasing and the wheel is decelerating (i.e. between periods D and E of FIG. 5c).