Adaptive braking system

Claim 2

In a vehicle having an axle, a pair of wheels rotatable on said axle, and fluid pressure operated brake means controlling each of said wheels, an adaptive braking system to control actuation of said brake means comprising: means for generating a first speed signal proportional to the rotational velocity of the faster rotating wheel and a second speed signal proportional to the rotational velocity of the slower rotating wheel; means for comparing said first speed signal with a first reference signal and said second speed signal to a second reference signal, and generating an unbalanced mode signal when said first signal is greater than the first reference signal and said second signal is less than the second reference signal; control means generating a synchronous signal after the speed of said faster rotating wheel is substantially synchronous with the speed of said vehicle after generation of said unbalanced mode signal; said comparing means including means responsive to said synchronous signal to again compare said second signal with the second reference signal and generating an output signal if the second speed signal is greater than the second reference signal; means for selecting one of said speed signals, said selecting means selecting said second signal when said output signal is generated; and said control means including means responsive to said selected signal for controlling actuation of said brake means when adaptive control of the latter is initiated.

Claim 3

The invention of claim 1: means insuring initiation of adaptive control of said brake means when said selecting means selects said second signal.

Claim 4

The invention of claim 1: said comparing means generating a signal resetting said selecting means after the latter has selected said second signal if said unbalanced mode signal is generated, whereby said selecting means thereafter selects said first speed signal.

Claim 5

The invention of claim 1; and means for resetting said selecting means upon termination of adaptive control of said brake means if said selecting means has selected said second speed signal.

Claim 6

The invention of claim 1; said control means including means for differentiating said selected signal to provide a signal proportional to acceleration and deceleration of the corresponding wheel, means for comparing said last-mentioned signal with an acceleration reference signal representing an acceleration level slightly greater than zero acceleration, and means for generating said synchronous signal when said signal proportional to acceleration and deceleration drops below said acceleration reference signal from a value greater than said acceleration reference signal.

Claim 7

The invention of claim 1: said comparing means generating a locked mode signal when said first speed signal drops below said first speed reference signal; said control means generating a control signal of varying values in response to said selected signal; means responsive to said control signal after an adaptive braking cycle is initiated to control the rate of change of fluid pressure operating said brake means as a function of the value of said control signal; said control means being responsive to said lock mode signal to freeze the value of said control signal, and being responsive to generation of said synchronous signal after generation of said locked mode signal to again compare the value of said first speed signal with said first speed reference signal and terMinating adaptive control of said brake means if the value of said first speed signal is less than said first speed reference signal.

Claim 8

The invention of claim 6; and means cancelling said unbalanced mode signal upon generation of said locked mode signal.

Claim 9

The invention of claim 6; and means preventing generation of said locked mode signal after adaptive control of said brake means is initiated until said synchronous signal is generated.

Claim 10

The invention of claim 1; said control means including means responsive to said unbalanced mode signal to decay braking pressure at a predetermined rate.

Claim 11

In a vehicle having an axle, a pair of wheels rotatable on said axles and fluid pressure operated brake means controlling each of said wheels, an adaptive braking system to control actuation of said brake means comprising: means for generating a first speed signal proportional to the rotational velocity of the faster rotating wheel and a second speed signal proportional to the rotational velocity of the slower rotating wheel; control means responsive to one of said speed signals for generating a control signal of varying values dependent upon the condition sensed by said control means in response to said one speed signal; means responsive to said control signal after an adaptive braking cycle is initiated to control the rate of change of fluid pressure operating said brake means as a function of the value of said control signal; said control means including means for generating a synchronous signal after the speed of said faster rotating wheel is substantially synchronous with the speed of said vehicle; and means for comparing said first speed signal with a speed reference signal and generating a locked mode signal if the value of said first speed signal is less than the value of the reference signal, said control means being responsive to generation of said synchronous signal after generation of said locked mode signal to again compare the value of said first speed signal with said speed reference signal and terminating adaptive control of said brake means if the value of said first speed signal is less than said speed reference signal.

Claim 12

In a vehicle having an axle, a pair of wheels rotatable on said axles and fluid pressure operated brake means controlling each of said wheels, an adaptive braking system to control actuation of said brake means comprising: means for generating a first speed signal proportional to the rotational velocity of the faster rotating wheel and a second speed signal proportional to the rotational velocity of the slower rotating wheel; control means responsive to one of said speed signals for generating a control signal of varying values dependent upon the condition sensed by said control means in response to said one speed signal; means responsive to said control signal after an adaptive braking cycle is initiated to control the rate of change of fluid pressure operating said brake means as a function of the value of said control signal; said control means including means for generating a synchronous signal after the speed of said faster rotating wheel is substantially synchronous with the speed of said vehicle; and means for comparing said first speed signal with a speed reference signal and generating a locked mode signal if the value of said first speed signal is less than the value of the reference signal, said control means being responsive to generation of said synchronous signal after generation of said locked mode signal to again compare the value of said first speed signal with said speed reference signal and terminating adaptive control of said brake means if the value of said first speed signal is less than said speed reference signal.

Claim 13

The invention of claim 10: said control means being responsive to said locked mode signal to freeze the value of said control signal to thereby maintain the rate of change of braking pressure constant.

Claim 14

The invention of claim 10; and means preventing generation of said locked mode signal after adaptive control of said brake means is initiated until said synchronous signal is generated.

Claim 15

The invention of claim 10: said control means including means for differentiating said one signal to provide a signal proportional to acceleration and deceleration of the corresponding wheel, means for comparing said last-mentioned signal with an acceleration reference signal representing an acceleration level slightly greater than zero acceleration, and means for generating said synchronous signal when said signal proportional to acceleration and deceleration drops below said acceleration reference level from a value greater than said acceleration reference signal.

Claim 16

In a vehicle having an axle, a pair of wheels rotatable on said axle, and fluid pressure operated brake means controlling each of said wheels, an adaptive braking system to control actuation of said brake means comprising: means for generating a first speed signal proportional to the rotational velocity of the faster rotating wheel and a second speed signal proportional to the rotational velocity of the slower wheel; means for selecting one of said speed signals; control means responsive to said selected signal for controlling actuation of said brake means when adaptive control of the latter is initiated, said control means including means for differentiating said selected signal to provide a signal proportional to acceleration and deceleration of the corresponding wheel, means for comparing said last-menTioned signal with an acceleration reference signal representing an acceleration level slightly greater than zero acceleration, and means for generating an output signal when said signal proportional to acceleration and deceleration drops below said acceleration reference signal from a value greater than said acceleration reference signal; means for comparing said first speed signal with a first reference signal and said second speed signal to a second reference signal, and generating an unbalanced mode signal relieving braking pressure when said first signal is greater than the first reference signal and said second signal is less than the second reference signal, said comparing means including means responsive to said output signal to again compare said second signal with the second reference signal and generating a selecting signal if second signal is greater than said second reference signal; said selecting means being responsive to said selecting signal to select said second speed signal.

Claim 17

In a vehicle having an axle, a pair of wheels rotatable on said axle, and fluid pressure operated brake means controlling each of said wheels, an adaptive braking system to control actuation of said brake means comprising: means for generating a first speed signal proportional to the rotational velocity of the faster rotating wheel and a second speed signal proportional to the rotational velocity of the slower wheel; means for selecting one of said speed signals; control means responsive to said selected signal for controlling actuation of said brake means when adaptive control of the latter is initiated, said control means including means for differentiating said selected signal to provide a signal proportional to acceleration and deceleration of the corresponding wheel, means for comparing said last-menTioned signal with an acceleration reference signal representing an acceleration level slightly greater than zero acceleration, and means for generating an output signal when said signal proportional to acceleration and deceleration drops below said acceleration reference signal from a value greater than said acceleration reference signal; means for comparing said first speed signal with a first reference signal and said second speed signal to a second reference signal, and generating an unbalanced mode signal relieving braking pressure when said first signal is greater than the first reference signal and said second signal is less than the second reference signal, said comparing means including means responsive to said output signal to again compare said second signal with the second reference signal and generating a selecting signal if second signal is greater than said second reference signal; said selecting means being responsive to said selecting signal to select said second speed signal.

Claim 18

The invention of claim 14: means insuring initiation of adaptive control of said brake means when said selecting means selects said second signal.

Claim 19

The invention of claim 14: said comparing means generating a signal resetting said selecting means after the latter has selected said second signal if said unbalanced mode signal is generated, whereby said selecting means thereafter selects said first speed signal.

Claim 20

The invention of claim 14; and means for resetting said selecting means upon termination of adaptive control of said brake means if said selecting means has selected said second speed signal.

Claim 21

The invention of claim 14: said control means including means responsive to said unbalanced mode signal to decay braking pressure at a predetermined rate.

Claim 22

The invention of claim 14: said comparing means generating a locked mode signal when said first speed signal drops below said first speed reference signal; said control means generating a control signal of varying values in response to said selected signal; means responsive to said control signal after an adaptive braking cycle is initiated to control the rate of change of fluid pressure operating said brake means as a function of the value of said control signal; said control means being responsive to said locked mode signal to freeze the value of said control signal, and being responsive to generation of said output signal after generation of said locked mode signal to again compare the value of said first speed signal with said first speed reference signal and terminating adaptive control of said brake means if the value of said first speed signal is less than said first speed reference signal.

Claim 23

The invention of claim 19: means cancelling said unbalanced mode signal upon generation of said locked mode signal.

Claim 24

The invention of claim 19: means preventing generation of said locked mode signal after adaptive control of said brake means is initiated until said output signal is generated.

Claim 25

In a vehicle having an axle, a pair of wheels rotatable on said axle, and fluid pressure operated brake means controlling each of said wheels, an adaptive braking system to control actuation of said brake means comprising: means for generating a first speed signal proportional to the rotational velocity of the faster rotating wheel and a second speed signal proportional to the rotational velocity of the slower wheel; control means responsive to one of said signals for generating a control signal of varying values dependent upon the conditions sensed by said control means in response to said one speed signal, said control means including means for differentiating said one signal to provide a signal proportional to acceleration and deceleration of the corresponding wheel, means for comparing said last-mentioned signal with an acceleration reference signal representing an acceleration level slightly greater than zero acceleration, and means for gEnerating an output signal when said signal proportioanl to acceleration and deceleration drops below said acceleration reference signal from a value greater than said acceleration signal; means responsive to said control signal when an adaptive braking cycle is initiated to control the rate of change of fluid pressure operating said brake means as a function of said control signal; and means for comparing said first speed signal with a speed reference signal and generating a locked mode signal if the valve of said first speed signal is less than the value of the reference signal, said control means being responsive to said locked mode signal to freeze the value of said control signal to thereby maintain the rate of change of braking pressure constant, said control means being responsive to generation of said output signal after generation of said locked mode signal to again compare the value of said first speed signal with said speed reference and terminating adaptive control of said brake means if the value of said first speed signal is less than said speed reference signal.

Claim 26

In a vehicle having an axle, a pair of wheels rotatable on said axle, and fluid pressure operated brake means controlling each of said wheels, an adaptive braking system to control actuation of said brake means comprising: means for generating a first speed signal proportional to the rotational velocity of the faster rotating wheel and a second speed signal proportional to the rotational velocity of the slower wheel; control means responsive to one of said signals for generating a control signal of varying values dependent upon the conditions sensed by said control means in response to said one speed signal, said control means including means for differentiating said one signal to provide a signal proportional to acceleration and deceleration of the corresponding wheel, means for comparing said last-mentioned signal with an acceleration reference signal representing an acceleration level slightly greater than zero acceleration, and means for gEnerating an output signal when said signal proportioanl to acceleration and deceleration drops below said acceleration reference signal from a value greater than said acceleration signal; means responsive to said control signal when an adaptive braking cycle is initiated to control the rate of change of fluid pressure operating said brake means as a function of said control signal; and means for comparing said first speed signal with a speed reference signal and generating a locked mode signal if the valve of said first speed signal is less than the value of the reference signal, said control means being responsive to said locked mode signal to freeze the value of said control signal to thereby maintain the rate of change of braking pressure constant, said control means being responsive to generation of said output signal after generation of said locked mode signal to again compare the value of said first speed signal with said speed reference and terminating adaptive control of said brake means if the value of said first speed signal is less than said speed reference signal.

Claim 27

The invention of claim 22: said control means being responsive to said locked mode signal to freeze the value of said control signal to thereby maintain the rate of change of braking pressure constant.

Claim 28

The invention of claim 22: means preventing generation of said locked mode signal after adaptive control of said brake means is initiated until said output signal is generated.