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-lock braking system for a road vehicle having a plurality of hydraulically operated brake actuators, a plurality of control channels controlling the supply of hydraulic fluid to the brake actuators, an electrical supply and a hydraulic pump for supplying hydraulic fluid to the brake actuation circuit. The pump is driven by an electric motor energized by the power supply. The magnitude of the operating voltage at the pump motor is compared with a predetermined reference voltage. The physical demand upon the pump motor is reduced by inhibiting the control channels if the measured magnitude of the electric motor voltage is less than the reference value.

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-lock system for vehicle brakes of the type wherein a computer is used to process data received from wheel speed transducers and to control the release of the brake of a particular wheel when the deceleration and/or slip of that wheel exceeds predetermined thresholds. In order to increase the immunity of the system to road irregularities while maintaining skid detection sensitivity, it is arranged that, during periods that anti-lock is not currently evoked, the detection of a road bump at the front axle is used to cause the rear axle anti-lock system to be temporarily de-sensitized just before it would be expected, on the basis of speed and wheel-base, to reach the same bump.

Abstract: In an anti-skid vehicle braking system an electronic control unit is arranged to control the operation of an anti-skid valve assembly for modulating the fluid pressure applied to a brake actuator. A wheel speed sensor measures the speed of a braked wheel and produces a signal which is converted into a deceleration signal by a conditioning circuit and a differentiator and compared in a comparator with a deceleration threshold value. A pressure sensor provides a pressure signal corresponding to the current brake actuator pressure and a pressure signal conditioning circuit modifies the pressure signal to take account of a load signal produced by a load sensor which measures the loading of the braked wheel. The deceleration threshold value is produced by modulation of a constant threshold value in a threshold generator circuit and a threshold modulator circuit in response to the modified pressure signal.

Abstract: In a suspension system which is designed to maintain a nominal ride height between the body and the unsprung parts of a vehicle, the difference in wheel speed on opposite sides of the vehicle produced during cornering is used to inhibit adjustment of ride height.An electrical sensor and control unit is used to control flow of hydraulic fluid to and from a suspension unit by means of solenoid-operated valves, so as to maintain the ride height constant. A cornering sensor compares the sensed speeds of two wheels, preferably mounted on a common axle, and inhibits the control unit when the difference in speeds departs from an expected difference by more than a certain amount. The expected difference may be zero or it may be the average difference derived over a period of time.