Abstract: A vehicle train comprising a tractor and at least two trailers wherein each trailer has a brake sub-system. The brake sub-system includes a pressure transducer on the trailer responsive to pressure of a fluid pressure brake demand signals supplied thereto to provide an electrical brake demand signal and an electronic controller on the trailer responsive to the electrical brake demand signal to provide an electrical brake operating signal. The brake sub-system also includes a brake valve on the trailer responsive to the electrical brake operating signal supplied to the brake valve by the electronic controller to supply fluid to an actuator to operate a trailer brake under a brake pressure, from a primary source, determined in accordance with the electrical brake operating signal.

Abstract: A braking system for a vehicle, having a transducer capable of responding to a fluid pressure brake demand signal to provide an electrical brake demand signal to an electronic control means which is responsive to the electrical brake demand signal to provide an electrical brake operating signal. The electrical brake operating signal is supplied to an electrically operable valve means which is arranged to supply a fluid pressure brake operating signal from a source of fluid under pressure to control a supply valve which supplied fluid from the source to at least one actuator for brake application under a brake pressure determined in accordance with the electrical brake operating signal. An electrically operable fluid pressure brake demand signal control valve controls the supply of the fluid pressure brake demand signal to the supply valve as a substitute for the fluid pressure brake operating signal originating from the source.

Abstract: A method of increasing the immunity of an automotive electronic control system to electromagnetic interference, comprises the steps of measuring the impedance of means conducting an input to a control circuit (4) of the system, and adapting the circuit so as at least substantially to match the input impedance of the control circuit (4) in relation to that input to the measured impedance of said means (2) conducting said input. The invention also provides an automotive electronic control system comprising a control circuit (4) having its input impedance at least substantially the same as, and preferably at least substantially matched to, the impedance of means (2) conducting the relevant input to the control circuit.

Abstract: An electronically controlled braking system having a driver operated control 11 for providing an electrical braking demand signal and a fluid pressure back-up supply; an electronic control 10, 139 is responsive to the electrical braking demand signal, and brake valves 12, 13, 14, 15 are responsive to an instructing signal supplied to the brake valves by the electronic control 10, 139 to control supply of fluid under pressure from a source 20 to at least one actuator 16, 17, 18, 19 for brake application. The fluid pressure back-up supply is also fed to the brake valve and a shuttle valve 134 is provided to feed the back-up supply to the actuator 16, 17, 18, 19 if the electronic control 10, 139 fails.

Abstract: A vehicle braking system comprising a controller responsive to wheel speed signals from at least two wheel speed sensors for sensing skid conditions of at least two wheels and for generating skid control instructions; a plurality of wheel brakes responsive to fluid pressure, hereinafter referred to as brake pressure, supplied thereto; a supply device, comprising a common supply valve, for supplying brake pressure to the brakes from a fluid pressure supply in accordance with a brake operating signal; and a skid controller controlled by the skid control instructions for controlling the brake pressure in a plurality of cycles each of which comprises a pressure reduction phase and a pressure increase phase, and a first comparitor to compare the co-efficient of friction of the lower friction surface with a predetermined threshold, and/or a second comparitor to compare the relative values of the co-efficients of friction of the surfaces with which at least two of the wheels are engaged and a device to operate the s

Abstract: A vehicle braking system has a controller responsive to wheel speed signals for sensing skid conditions of the wheels and for generating skid control instructions. A primary fluid pressure supply includes a fluid pressure source and a fluid pressure reservoir and wheel brakes are responsive to brake pressure supplied to the brakes by supply valves, each of which is adapted to supply fluid brake pressure to a different wheel brake or brakes from the primary supply in accordance with a brake operating signal which can be modulated by skid control units. Each pair of supply valve and skid control unit is adapted to control the fluid pressure of a different wheel brake or brakes. A plurality of brake operating signals are generated, independently of the skid control units, as a function of a brake command signal and a brake operating signal is supplied for each of the supply valves. All the components are connected together so as to be mountable on the vehicle as a discrete unit.

Abstract: A vehicle braking system including a braking sub-system comprising; a brake actuator responsive to a brake operating pressure supplied thereto to operate a brake; a supply valve having a fluid pressure inlet and a brake operating pressure outlet connected to the actuator; a control line connected to the supply valve to supply a fluid pressure control signal to which the supply valve is responsive to supply brake operating pressure to the actuator; a pair of solenoid valves in the control line and a managing device responsive to a wheel speed signal to energize the solenoid valves so as to effect one ofa) interruption in the supply of the brake operating pressure to the actuator;b) interruption in the supply of the brake operating pressure to the actuator and exhaust of the brake operating pressure from the actuator;characterized by the provision of a plurality of the braking sub-systems and by the managing device being arranged to energize the solenoid valves of the sub-systems such that the current consumpti