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US 4,712,839 AGranted
Vehicle braking system
AssigneeLucas Industries public limited company
InventorsMalcolm Brearley, Richard B. Moseley
Life of this patent
Estimating the term…
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AssigneeLucas Industries public limited company
InventorsMalcolm Brearley, Richard B. Moseley
Estimating the term…
An electronically controlled braking system for a vehicle in which vehicle load measurements, made dynamically, as used to modify the braking demand, individually for each axle of the vehicle and in which, under predetermined conditions of vehicle speed, braking level and operating gradient, the deceleration error formed between braking demand by the driver and measured actual vehicle deceleration is used gradually, over a number of vehicle stops, to form an adaptive factor for correcting the braking demand in order to restore expected braking performance. No correction to the adaptive factor based on the deceleration error is made during a given stopping operation of the vehicle, but a summation of previous errors is arranged to cause a small increment in correction to be made after each stop until, over a number of vehicle stops, the error formed under the predetermined conditions falls to zero. Braking demands by the driver can be arranged to be compensated by introducing a demand offset dependent on the prevailing gradient on which the vehicle is operating.
An electronically controlled braking system for a vehicle comprising:
An electronically controlled braking system for a vehicle comprising a brake pedal transducer, a plurality of pressure control channels adapted to be controlled by a driver's demand signal from said brake pedal transducer, representing a braking requirement, first sensor means providing dynamic load signals representative of vehicle axle loads, second sensor means forming a signal representative of vehicle deceleration, third sensor means forming a signal G representative of the gradient on which the vehicle is operating, means forming an error signal representative of the difference between braking demand and measured vehicle deceleration, means for modifying the driver's braking demand signals in dependence upon the vehicle axle load measurements from said first sensor means and means for forming from said deceleration error, gradually over a number of vehicle stops and under certain conditions of vehicle speed, braking level and operating gradient, a long term adaptive factor for correcting the braking demand in order to restore expected braking performance.
The method of forming an adaptive factor for correcting braking demand in an electronically controlled braking system comprising performing dynamic measurements of vehicle load, using said load measurements to modify braking demand individually for each axle of the vehicle, and using gradually over a number of stops the deceleration error formed between braking demand by the driver and measured actual vehicle deceleration to form said adaptive factor for correcting the braking demand and thereby restore expected braking performance.
Dependencies are inferred from the claim text.