Abstract: An electronic braking system for trailers. A control system is incorporated into the braking equipment of a towing vehicle to provide a trailer braking command signal. This signal is regulated so as to balance the braking between the towing vehicle and the trailer through the assessment of forces in the coupling between the two vehicles. The assessment is made indirectly and is calculated from forces measured in the suspension components of at least two axles of the towing vehicle and the changes occurring therein during braking.

Abstract: An electronic braking system which recognizes differential braking across an axle. A stored adaptive capability is provided whereby a braking controller is able to learn the braking imbalance and correct for this by introducing differential pressure adjustments such as increasing braking at the wheel of the lower brake output and/or reducing braking at the wheel with a higher brake output. The learning process is completed over selected parts of several vehicle stops and is repeated continuously.

Abstract: A wear sensing system for the brake linings of a vehicle. Since the sensors are mounted within the brake mechanism, the reduction in the disc thickness must be taken into account to supply an accurate reading. A non-volatile memory stores the position of the brake before replacement and is compared to the position after replacement. However, the latter reading is established only after a predetermined number of brake applications to take up any starting clearances.

Abstract: An electronic braking system for a multi-axle road vehicle, having a foot-operable braking transducer which generates electrical braking demand signals representative of a driver's braking demand, load transducers which generate electrical load signals representative of the respective load on different axles of the vehicle, and in electronic controller which receives the braking demand signals and load signals and generates electrical output signals for controlling the operation of braking devices for the wheels carried by axles, the controller including adaptive load compensation device which acts to modify the output signals of the controller to the various braking devices so as to take account of prevailing loads on the respective axles.

Abstract: An electronic braking system for a vehicle having foundation brakes (137, 138) and a vehicle retarder (129), wherein an electrical braking demand signal (D) is generated from a single brake pedal and wherein the retarder (129) is operated variably or in small steps as the brake pedal movement is increased from a zero or rest position up to a partial point in its movement range which is calculated to give substantially maximum retarder powder based on the total mass of the vehicle. As a result, for a fully loaded condition this partial point occurs at low pedal deflection and, in an unloaded condition where a given retarder will produce a higher deceleration, this point occurs at a higher pedal deflection, wherein in both cases pushing the pedal beyond the calculated partial point causes foundation braking to be commenced to supplement the retarder torque.

Abstract: An electronically controlled braking system wherein improved braking distribution in a multi-axle vehicle is achieved by making allowance for sources of background braking by assessing through measurement the total background braking force and assigning this in a predetermined proportion between the vehicle axles.

Abstract: An electronic braking system for wheeled vehicles comprising an electronic controller which produces, in response to driver braking demands, electronic signals for controlling the braking pressures applied to the vehicle wheels from a source of braking pressure. The system includes a second, back-up braking pressure source which can be selected when required, and means for switching over from the first-mentioned normal source of braking pressure to the back-up pressure source at selected occasions when the vehicle is being braked and has come to rest, provided that the prevailing driver's braking demand is above a predetermined minimum threshold. A test is then performed on the braking pressure signals generated by the system while it is energized by the back-up source and a warning signal is generated if the back-up source is found to be faulty.

Abstract: A trailer braking control system which is adapted to modify trailer braking from a towing vehicle by regulating the coupling head service braking pressure signal generated on the towing vehicle in response to driver's demand pressure and measured values of longitudinal force exerted on the trailer coupling just before and during braking. At least two adaptive variables are developed on the towing vehicle, and on selected qualifying stops of the towing vehicle/trailer combination, one of these adaptive variables is chosen to be corrected at the end of that stop using average trailer thrust error signals for use in regulating trailer braking on subsequent stops.

Abstract: An electrically controlled braking system, in which the operation of the brake actuation is split into three bands depending upon the brake demand level, such that at low demand in a first band the braking pressures are set to generate equal wear at the vehicle axles, and at higher demands in a third band braking pressures are set to apportion braking between axles dependent upon the axle loads being carried, while in a second band, located intermediate the first and second bands, the braking is gradually changed from being equal to being fully apportioned, the extent of this change-over depending upon the actual level of demand within this second band.

Abstract: An electronic braking system in a motor vehicle capable of towing a standard trailer not having its own EBS system has a separate pressure control channel for the generation of a trailer service brake pressure signal in the event that a driver's braking demand is sensed at any axle of the towing vehicle. The pressure signal level is set in the towing vehicle so as to be a function of the driver's electrical demand signal modified in dependence upon the load exerted by the trailer on the towing vehicle as measured at a towing link therebetween.

Abstract: An electronic braking system (EBS) for a towing vehicle which provides for trailer service brake pressure supply via an additional EBS sub-system, and wherein, in order to speed up the application of trailer braking, the electrical signal representing the driver's braking demand is processed to generate an additional pressure pre-pulse of predetermined amplitude to pressurise the trailer braking circuit in advance of the proportional pressure setting determined by the driver. The pre-pulse is made up of two parts, a preset fixed duration pulse followed without break by a variable duration continuation pulse. The variable duration of the variable duration pulse is determined primarily by the rate of increase of the driver's demand signal.

Abstract: A trailer braking system for a towing vehicle has a trailer braking valve (26) is fed with a pressurized air supply which is modulated by the opening of the valve, as controlled by a first control pressure regulated by a trailer braking controller (24) in accordance with braking demand signals, to produce a trailer braking pressure. In order that a trailer braking pressure may be generated even if the above trailer braking valve control fails, the valve is supplied with a second control pressure independently of the first, and which is also capable of operating the trailer braking valve (26). In a preferred embodiment, the second control pressure is supplied from a braking line of the towing vehicle, such that the "back up" control pressure is a function of the towing vehicle braking.

Abstract: A dual computer cross-checking system includes a control computer for controlling a process in accordance with input data and a monitoring computer. The two computers are interconnected to exchange check data on a cyclic basis, each computer carrying out a number of processing operations on the received check data before transmitting the data thus processed to the other computer. In addition, each computer checks the received check data against an expected value. An error condition is detected if the result of at least one of these comparisons is found to be incorrect.

Abstract: A vehicle braking system wherein, for avoiding serious brake unbalance under fault conditions which would cause either loss of braking or excessive braking at one wheel, a small bore link pipe is arranged to connect the pressure control elements, for example solenoid actuated relay valves, of respective brake circuits associated with the two wheels at opposite ends of an axle whereby the pressure control elements in each electronically controlled pressure adjustment channel are influenced in such a manner that a correctly functioning channel attempts to influence a faulty channel in such a direction as to reduce the pressure unbalance.

Abstract: A vehicle dual wheel braking system of the type in which a respective electronically controlled pressure adjustment channel is provided for each of the wheels at the opposite ends of an axle of the vehicle for setting the braking pressures individually for each wheel in dependence upon a common electrical signal representative of the braking demand level set by a driver of the vehicle, each channel comprising a pressure control loop containing a pressure controller, a pressure control valve which adjusts the supply of fluid from a reservoir to the brake actuators for applying and releasing the brakes by solenoid control of the inlet and exhaust functions of the pressure control valve, and a feedback transducer which supplies a signal representative of the pressure in the pressure control valve.

Abstract: An electronic braking system for a towing vehicle for towing a standard semi-trailer without such a braking system has a separate pressure control channel for the generation of trailer brake pressure whenever the towing vehicle is braked or if the parking brake of the towing vehicle is applied. The pressure signal level set in the towing vehicle is a function of the driver's electrical demand signal, compensated for trailer load and operating gradient. The compensation for trailer load is evaluated by assessing the total trailer mass from measurements of towing load during acceleration and substracting from this value the portion of the trailer load being supported by the towing vehicle as sensed by vertical force protection means on the towing means.

Abstract: A vehicle braking system of the type having an electronic control computer for determining the extent of application of the vehicle brakes in accordance with given driver braking demands, includes a plurality of analogue transducers which provide analogue input signals to the electronic control computer representative of a corresponding plurality of variable operating parameters, such as driver braking demand, axle load, applied braking pressure, and vehicle decelerations. In order to enable recalibration of said transducers new zero/tare figures from each transducer are entered into the control computer and provided they pass a process of checking, are arranged to override the existing zero/tare data, whereupon they are used by the system until the next zero/tare recalibration service operation is selected.

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.

Abstract: A vehicle braking system of the electronically compensated type in which driver demand signals to inner closed loop pressure systems for the front and rear brakes are adjusted in accordance with load signals obtained from load sensors associated with front and rear axles of the vehicle respectively, these load signals themselves being modified to take account of the weight transfer effect from the rear axle to the front axle during braking. Weight transfer is calculated from the expression: ##EQU1## the deceleration, gross vehicle weight, height of the center of gravity of the vehicle and the vehicle wheel base being calculated and stored and manipulated electronically to provide dynamic load apportioning between the various inner closed loop pressure systems controlling the front and rear brakes, respectively.

Abstract: A closed loop vehicle deceleration control system comprising a plurality of pressure control channels controlled by a fed forward driver's demand signal representing a deceleration requirement, and a closed loop feedback circuit which is adapted to produce a deceleration error signal representative of the difference between a deceleration level demanded by the driver and the actual vehicle deceleration. The driver's demand signal is arranged to be adjusted by means of a correction signal dependent on an integral function of the deceleration error. Adjustment of the demand signals is made by way of a multiplier in which one input is the driver's demand signal and the other input is a correction signal derived from a deceleration integrator. The correction signal is provided continuously by the integrator which the closed deceleration loop is adapted to be disabled at any selected time by disconnection of the deceleration error from the integrator input.