Abstract: An anti-lock ABS braking system for a road vehicle includes a respective dump valve for each brake actuator which enables pressure to be selectively dumped from that actuator to release the braking action of the relevant rear wheel. Whether a given rear wheel of the vehicle is still operating in a stable condition is established, as is the aggregate dump valve time of the rear wheel opposite to that under consideration. The brake pressure at the still stable rear wheel is allowed to continue to rise for a prescribed period and then its dump valve is actuated for a period corresponding to the measured aggregate dump time of the opposite rear wheel.

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 anti-skid braking system for wheeled vehicles having fluid actuated brakes associated with the vehicle wheels, speed sensors associated with the vehicle wheels and a cyclically operating control device which is responsive to speed signals from the speed sensors to actuate a pressure dump device to periodically release the fluid pressure applied to the brake of any wheel which is determined to be about to lock and to later re-apply the actuating pressure to that brake when the tendency of that wheel to lock has reduced, and wherein the pressure dump phase is arranged to be cancelled during wheel-lock when the aggregate dump time for the current cycle exceeds a limit value based upon a weighted-average dump time of previous cycles.

Abstract: An anti-skid braking system for a vehicle comprising a supply of fluid for actuating a plurality of wheel brakes, a skid control unit interposed between the fluid supply and the brakes, sensors to detect the skidding of a plurality of wheels and actuating means responsive to skid signals from the sensors and adapted to actuate the skid control unit to relive the fluid pressure at the brake of the wheel at impending lock by means of a plurality of successive first brake release periods. In order to reduce yawing, when an impending skid condition is detected at one wheel, the skid control unit is arranged to induce second, shorter brake release periods in one or more of the brakes of the wheels not at impending lock.