Skid control system

Claim 2

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake means responsive to an applied skid signal for controlling said braking system to relieve the braking forces on said wheels; means for providing first and second wheel speed signals having values respectively representative of the wheel speed of the first and second wheels; means for receiving said wheel speed signals and providing therefrom a high wheel speed signal representative of the speed of the faster wheel and a low wheel speed signal representative of the speed of the slower wheel; and logic circuit means for providing a skid signal when a predetermined percentage of the magnitude of the high wheel speed signal differs from that of the low wheel speed signal, and wherein said logic circuit means includes first circuit means for deriving a percentage signal having a magnitude which is a fixed percentage of the magnitude of said high wheel speed signal, and signal comparing means for comparing the magnitude of said percentage signal with that of said low speed signal and providing a skid signal when the percentage signal exhibits a greater magnitude than said low speed signal, and further including means for delaying application of said skid signal to said brake control means for a time duration that varies as a function of the speed of the faster wheel.

Claim 3

A skid control system as set forth in claim 1, wherein said delaying means includes circuit means for delaying application of said skid signal for a time duration which varies inversely with deceleration of said faster wheel.

Claim 4

A skid control system as set forth in claim 1, including circuit means for developing a high wheel deceleration singal having a value representative of the deceleration of said faster wheel, and said delaying means includes circuit means responsive to said high wheel deceleration signal for delaying application of a said skid signal to said brake means for a time duration which varies inversely with the value of said high wheel deceleration signal.

Claim 5

A skid control system as set forth in claim 3, wherein said circuit means includes skid signal gating means interposed between said logic circuit means and said brake control means, said gating means having a normal high impedance condition preventing passage of a said skid signal and an actuated low impedance condition for passing a said skid signal for application to said brake control means, and timing means responsive to a said skid signal for timing a delay period dependent on the value of said high wheel deceleration signal and then actuating said gating means to its said low impedance condition.

Claim 6

A skid control system as set forth in claim 3 and further comprising low speed cutoff means connected to receive said high wheel speed signal from said means for providing a high wheel speed signal, said cutoff means being connected for providing a signal to said high wheel deceleration circuit means, and operative for effectively blocking said high wheel speed signal for wheel speeds of said faster wheel below a predetermined level.

Claim 7

A skid control system for a vehicle having at least first and second independently rotatable spaced apart wheels and having a braking system for applying braking forces to said wheels and comprising: brake control means responsive to a skid signal for controlling said braking system to relieve the braking forces on said wheels; means for providing first and second wheel speed signals having values respectively representative of the wheel speed of said first and second wheels; means responsive to said first and second wheel speed signals for providing an average wheel deceleration signal having a value in dependence upon the average deceleration of said first and second wheels; means for providing a high wheel deceleration signal having a vaLue in dependence upon the deceleration of the faster of said first and second wheels; and logic circuit means for providing a skid signal when the greater of said average deceleration signal and said high wheel deceleration signal is greater than that of a reference signal.

Claim 8

A skid control system for a vehicle having at least first and second independently rotatable spaced apart wheels and having a braking system for applying braking forces to said wheels and comprising: brake control means responsive to a skid signal for controlling said braking system to relieve the braking forces on said wheels; means for providing first and second wheel speed signals having values respectively representative of the wheel speed of said first and second wheels; means responsive to said first and second wheel speed signals for providing an average wheel deceleration signal having a value in dependence upon the average deceleration of said first and second wheels; means for providing a high wheel deceleration signal having a vaLue in dependence upon the deceleration of the faster of said first and second wheels; and logic circuit means for providing a skid signal when the greater of said average deceleration signal and said high wheel deceleration signal is greater than that of a reference signal.

Claim 9

A skid control system as set forth in claim 6 including means for providing a said reference signal having a magnitude which varies in dependence upon the speed of the faster wheel.

Claim 10

A skid control system as set forth in claim 6, including delay means for delaying application of said skid signal to said brake control means for a time duration which varies in dependence upon a function of the speed of the faster wheel.

Claim 11

A skid control system as set forth in claim 8, wherein said delay means includes circuit means responsive to a said skid signal for delaying application of said skid signal for a time duration dependent on the deceleration level of the faster wheel.

Claim 12

A skid control system as set forth in claim 9, wherein said circuit means includes skid signal gating means interposed between said logic circuit means and said brake control means, said gating means having a normal signal blocking condition for preventing passage of a skid signal from said logic circuit means to said brake control means and an actuated skid signal passing condition for passing a said skid signal for application to said brake control means, and timing means responsive to a said skid signal for timing a delay period dependent on the value of said high wheel deceleration signal and then actuating said gating means to its said skid signal passing condition.

Claim 13

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake control means responsive to a skid signal for controlling said braking system to release the braking forces on said wheels; means for providing first and second wheel speed signals of values respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for providing a said skid signal in dependence upon a given relationship of the values of said first and second signals; means for receiving said first and second signals and providing a third signal having a value representative of the wheel deceleration of the faster-rotating wheel of said first and second wheels, and providing a fourth signal having a value representative of the wheel deceleration of the slower-rotating wheel; second logic means for providing a said skid signal in dependence upon the value of at least one of said third and fourth signals; and time delay means for receiving a said skid signal from either said first or said second logic circuit means and delaying application of a said received skid signal to said brake control means for a time interval, said time delay means also receiving said third signal and including means for controlling the duration of said time interval to vary as a function of the value of said third signal.

Claim 14

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake control means responsive to a skid signal for controlling said braking system to release the braking forces on said wheels; means for providing first and second wheel speed signals of values respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for providing a said skid signal in dependence upon a given relationship of the values of said first and second signals; means for receiving said first and second signals and providing a third signal having a value representative of the wheel deceleration of the faster-rotating wheel of said first and second wheels, and providing a fourth signal having a value representative of the wheel deceleration of the slower-rotating wheel; second logic means for providing a said skid signal in dependence upon the value of at least one of said third and fourth signals; and time delay means for receiving a said skid signal from either said first or said second logic circuit means and delaying application of a said received skid signal to said brake control means for a time interval, said time delay means also receiving said third signal and including means for controlling the duration of said time interval to vary as a function of the value of said third signal.

Claim 15

A skid control system as set forth in claim 11 including means for receiving said first and second wheel speed signals and providing therefrom a high wheel speed signal representative of the speed of the faster wheel and a low speed signal representative of the speed of the slower of said two wheels and wherein said first logic circuit means includes means for providing a skid signal when a predetermined percentage of the magnitude of the high wheel speed signal differs from that of the low speed signal.

Claim 16

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake means responsive to an applied skid signal for controlling said braking system to relieve the braking forces on said whEels; means for providing first and second wheel speed signals having values respectively representative of the wheel speed of the first and second wheels; means for receiving said wheel speed signals and providing therefrom a high wheel speed signal representative of the speed of the faster wheel and a low wheel speed signal representative of the speed of the slower wheel; and logic circuit means for providing a skid signal when a predetermined percentage of the magnitude of the high wheel speed signal differs from that of the low speed, and including means for delaying application of said skid signal to said brake control means for a time duration which varies as a function of the speed of the faster wheel.

Claim 17

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake means responsive to an applied skid signal for controlling said braking system to relieve the braking forces on said whEels; means for providing first and second wheel speed signals having values respectively representative of the wheel speed of the first and second wheels; means for receiving said wheel speed signals and providing therefrom a high wheel speed signal representative of the speed of the faster wheel and a low wheel speed signal representative of the speed of the slower wheel; and logic circuit means for providing a skid signal when a predetermined percentage of the magnitude of the high wheel speed signal differs from that of the low speed, and including means for delaying application of said skid signal to said brake control means for a time duration which varies as a function of the speed of the faster wheel.

Claim 18

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake means responsive to an applied skid signal for controlling said braking system to relieve the braking forces on said wheels; means for providing first and second wheel speed signals having values respectively representative of the wheel speed of the first and second wheels; means for receiving said wheel speed signals and providing therefrom a high wheel speed signal representative of the speed of the faster wheel and a low wheel speed signal representative of the speed of the slower wheel; and logic circuit means for providing a skid signal when a predetermined percentage of the magnitude of the high wheel speed signal differs from that of the low wheel speed signal; and including low speed cut-off means for effectively disabling said logic circuit means for wheel speeds of said faster wheel below a predetermined level, and further including means for delaying application of a said skid control signal to said brake control means as a function of the speed of the faster wheel.

Claim 19

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake means responsive to an applied skid signal for controlling said braking system to relieve the braking forces on said wheels; means for providing first and second wheel speed signals having values respectively representative of the wheel speed of the first and second wheels; means for receiving said wheel speed signals and providing therefrom a high wheel speed signal representative of the speed of the faster wheel and a low wheel speed signal representative of the speed of the slower wheel; and logic circuit means for providing a skid signal when a predetermined percentage of the magnitude of the high wheel speed signal differs from that of the low wheel speed signal; and including low speed cut-off means for effectively disabling said logic circuit means for wheel speeds of said faster wheel below a predetermined level, and further including means for delaying application of a said skid control signal to said brake control means as a function of the speed of the faster wheel.

Claim 20

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake control means responsive to a skid signal for controlling said braking system to release the braking forces on said wheels; means for providing first and second wheel speed signals of values respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for providing a said skid signal in dependence upon a given relationship of the values of said first and second signals; means for receiving said first and second signals and respectively providing third and fourth signals having values respectively representative of the wheel deceleration of said first and second wheels; said logic means for providing a said skid signal in dependence upon the value of at least one of said third and fourth signals; and time delay means for receiving a said skid signal from either said first or said second logic circuit means and delaying application of said received skid signal to said brake control means for a time duration which varies as a function of the faster of said first and second wheels, means responsive to said first and second wheel speed signals and providing an average deceleration signal having a value in dependence upon the average deceleration of said first and second wheels, means for providing a high wheel deceleration signal having a value representative of the deceleration of the faster of said first and second wheels, and wherein said second logic circuit means includes means for providing a said skid signal when the greater of said average deceleration signal and said high wheel deceleration signal differs from that of a reference signal.

Claim 21

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake control means responsive to a skid signal for controlling said braking system to release the braking forces on said wheels; means for providing first and second wheel speed signals of values respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for providing a said skid signal in dependence upon a given relationship of the values of said first and second signals; means for receiving said first and second signals and respectively providing third and fourth signals having values respectively representative of the wheel deceleration of said first and second wheels; said logic means for providing a said skid signal in dependence upon the value of at least one of said third and fourth signals; and time delay means for receiving a said skid signal from either said first or said second logic circuit means and delaying application of said received skid signal to said brake control means for a time duration which varies as a function of the faster of said first and second wheels, means responsive to said first and second wheel speed signals and providing an average deceleration signal having a value in dependence upon the average deceleration of said first and second wheels, means for providing a high wheel deceleration signal having a value representative of the deceleration of the faster of said first and second wheels, and wherein said second logic circuit means includes means for providing a said skid signal when the greater of said average deceleration signal and said high wheel deceleration signal differs from that of a reference signal.

Claim 22

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels And comprising: brake control means responsive to a skid signal for controlling said braking system to release the braking forces on said wheels; means for providing first and second wheel speed signals of values respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for providing a said skid signal in dependence upon a given relationship of the values of said first and second signals; means for receiving said first and second signals and respectively providing third and fourth signals having values respectively representative of the wheel deceleration of said first and second wheels; second logic means for providing a said skid signal in dependence upon the value of at least one of said third and fourth signals; and time delay means for receiving a said skid signal from either said first or said second logic circuit means and delaying application of a said received skid signal to said brake control means for a time duration which varies as a function of the faster of said first and second wheels, and wherein said time delay means includes circuit means for varying said time delay inversely with variations in the deceleration of the high speed wheel.

Claim 23

A skid control system for use with a vehicle having at least first and second spaced apart independently rotatable wheels and having a braking system for applying braking forces to said wheels And comprising: brake control means responsive to a skid signal for controlling said braking system to release the braking forces on said wheels; means for providing first and second wheel speed signals of values respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for providing a said skid signal in dependence upon a given relationship of the values of said first and second signals; means for receiving said first and second signals and respectively providing third and fourth signals having values respectively representative of the wheel deceleration of said first and second wheels; second logic means for providing a said skid signal in dependence upon the value of at least one of said third and fourth signals; and time delay means for receiving a said skid signal from either said first or said second logic circuit means and delaying application of a said received skid signal to said brake control means for a time duration which varies as a function of the faster of said first and second wheels, and wherein said time delay means includes circuit means for varying said time delay inversely with variations in the deceleration of the high speed wheel.

Claim 24

A skid control system for use with a vehicle having at least first and second spaced apart, independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake means responsive to an applied skid signal for controlling said braking system to relieve the braking forces on said wheels; means for providing first and second wheel speed signals respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for utilizing at least one of said first and second wheel speed signals to determine an incipient skid condition of at least one of said wheels and providing a first skid signal in dependence upon a said determination; second logic circuit means for providing a second skid signal when the acceleration of the faster of said first and second wheels exceeds a first reference acceleration level; and said second logic circuit means including amplifier means having an output circuit for carrying a said second signal only when the acceleration of the faster wheel exceeds said first reference level; means responsive to a said first skid signal for passing a said second skid signal for application to said brake control means, said passing means including circuit means interposed between said output circuit and said brake means for passing a said second skid signal, and means for inhibiting said second logic means from providing a said second skid signal when the acceleration of the faster wheel exceeds a second acceleration level representative of a greater acceleration than that of said first acceleration level.

Claim 25

A skid control system for use with a vehicle having at least first and second spaced apart, independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake means responsive to an applied skid signal for controlling said braking system to relieve the braking forces on said wheels; means for providing first and second wheel speed signals respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for utilizing at least one of said first and second wheel speed signals to determine an incipient skid condition of at least one of said wheels and providing a first skid signal in dependence upon a said determination; second logic circuit means for providing a second skid signal when the acceleration of the faster of said first and second wheels exceeds a first reference acceleration level; and said second logic circuit means including amplifier means having an output circuit for carrying a said second signal only when the acceleration of the faster wheel exceeds said first reference level; means responsive to a said first skid signal for passing a said second skid signal for application to said brake control means, said passing means including circuit means interposed between said output circuit and said brake means for passing a said second skid signal, and means for inhibiting said second logic means from providing a said second skid signal when the acceleration of the faster wheel exceeds a second acceleration level representative of a greater acceleration than that of said first acceleration level.

Claim 26

A skid control system for use with a vehicle having at least first and second spaced apart, independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake means responsive to an applied skid signal for controlling said braking system to relieve the braking forces on said wheels; means for providing first and second wheel speed signals respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for utilizing at least one of said first and second wheel speed signals to determine an incipient skid condition of at least one of said wheels and providing a first skid signal to said brake means to relieve said braking forces in dependence upon a said determination; second logic circuit means for providing a second skid signal when the acceleration of the faster of said first and second wheels exceeds a first reference acceleration level; said first logic circuit means comprising means for providing said first skid signal irrespective of said second skid signal; means responsIve to a said first skid signal for passing a said second skid signal for application to said brake control means to relieve said braking forces; and latching means connected with the output of said passing means and responsive to at least said second signal when said second signal is passed by said passing means, for maintaining said passing means in a passing condition to pass said second signal.

Claim 27

A skid control system for use with a vehicle having at least first and second spaced apart, independently rotatable wheels and having a braking system for applying braking forces to said wheels and comprising: brake means responsive to an applied skid signal for controlling said braking system to relieve the braking forces on said wheels; means for providing first and second wheel speed signals respectively representative of the wheel speeds of said first and second wheels; first logic circuit means for utilizing at least one of said first and second wheel speed signals to determine an incipient skid condition of at least one of said wheels and providing a first skid signal to said brake means to relieve said braking forces in dependence upon a said determination; second logic circuit means for providing a second skid signal when the acceleration of the faster of said first and second wheels exceeds a first reference acceleration level; said first logic circuit means comprising means for providing said first skid signal irrespective of said second skid signal; means responsIve to a said first skid signal for passing a said second skid signal for application to said brake control means to relieve said braking forces; and latching means connected with the output of said passing means and responsive to at least said second signal when said second signal is passed by said passing means, for maintaining said passing means in a passing condition to pass said second signal.