Vehicle brake control system

Claim 2

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising first means for providing a first signal having a magnitude indicative of the velocity of at least the one wheel, second means for providing a second signal having a magnitude which is a preselected proportion of said first signal until said second signal attains a predetermined time rate of change whereupon said second signal has a magnitude which decreases at a selected time rate of change approximately less than said predetermined rate of change whereby the magnitude of said first signal and said second signal approach each other, comparator means for comparing the magnitudes of said first and second signals and for providing an output signal after said first and second signals have attained a selected relationship, and modulating means responsive to said output signal for initiating release of the brakes.

Claim 3

The system of claim 1 with said predetermined time rate of change having a magnitude equivalent of the linear deceleration of at least the one wheel in the range of from approximately 10 ft./sec.2 to around 50 ft./sec.2.

Claim 4

The system of claim 2 with said preselected proportion (expressed as a percentage) being in the range of around 94 percent to around 98 percent.

Claim 5

The system of claim 1 with said predetermined time rate of change having a magnitude equivalent to the linear deceleration of at least the one wheel of around 30 ft./sec.2.

Claim 6

The system of claim 4 with said preselected proportion (expressed as a percentage) being in the range of around 94 percent to around 98 percent.

Claim 7

The system of claim 1 with said preselected proportion (expressed as a percentage) being in the range of around 94 percent to around 98 percent.

Claim 8

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition of at least the one wheel, second control means for providing a second output signal in response to the recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal subsequent to said first output signal, said control signal having a first portion of rapidly decreasing magnitude and a second generally flat portion, velocity means for providing a velocity signal having a magnitude indicative of the magnitude of the velocity of at least the one wheel, said second control means comprising comparator means for comparing the magnitude of said velocity signal and of said control signal and for providing said second output signal after said velocity signal and said control signal attain a selected relationship, and modulating means responsive to said first output signal for initiating release of the brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 9

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition of at least the one wheel, second control means for providing a second output signal in response to the recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal subsequent to said first output signal, said control signal having a first portion of rapidly decreasing magnitude and a second generally flat portion, velocity means for providing a velocity signal having a magnitude indicative of the magnitude of the velocity of at least the one wheel, said second control means comprising comparator means for comparing the magnitude of said velocity signal and of said control signal and for providing said second output signal after said velocity signal and said control signal attain a selected relationship, and modulating means responsive to said first output signal for initiating release of the brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 10

The system of claim 7 with said first portion having a time rate of change of magnitude equivalent with the linear deceleration of at least the one wheel in the range of from around 100 ft./sec.2 to around 160 ft./sec.2.

Claim 11

The system of claim 7 with said first portion having a time rate of change of magnitude equivalent with the linear deceleration of at least the one wheel in the range of around 130 ft./sec.2.

Claim 12

The system of claim 9 with said first portion having a duration of from around 0.150 seconds to 0.200 seconds.

Claim 13

The system of claim 7 with said first portion having a time rate of change of magnitude equivalent with the linear deceleration of at least the one wheel in the range of around 140 ft./sec.2.

Claim 14

The system of claim 11 with said first portion having a duration of from around 0.150 seconds to 0.200 seconds.

Claim 15

The system of claim 7 with said first portion having a duration of from around 0.150 seconds to 0.200 seconds.

Claim 16

The system of claim 7 with said second portion having a generally constant magnitude having a time rate of change of magnitude equivalent with the linear deceleration of at least the one wheel of no greater than around 2 ft./sec.2.

Claim 17

The system of claim 7 with said second portion having a time rate of change of magnitude equivalent with the linear acceleration of at least the one wheel of from around 10 ft./sec.2 to no greater than around 20 ft./sec.2.

Claim 18

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to the recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal subsequent to said first output signal having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said second control means including means operative in response to the magnitude of said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of the brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 19

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to the recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal subsequent to said first output signal having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said second control means including means operative in response to the magnitude of said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of the brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 20

The system of claim 16 comprising velocity means for providing a velocity signal having a magnitude indicative of the magnitude of the velocity of at least the one wheel, said means operative in response to the magnitude of said control signal providing said second output signal upon the occurrence of a predetermined relationship between said velocity signal and said control signal.

Claim 21

A skid control system for cOntrolling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal, said control signal having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said second control means operative in response to said control signal for generating a variable time delay signal operative with said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 22

A skid control system for cOntrolling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal, said control signal having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said second control means operative in response to said control signal for generating a variable time delay signal operative with said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 23

The system of claim 18 with said time delay signal providing a time delay of from around zero to a determinable maximum.

Claim 24

The system of claim 19 with the magnitude of time delay being varied as a function of the magnitude of acceleration during spin-up of at least the one wheel.

Claim 25

The system of claim 20 with the magnitude of time delay being decreased for increasing magnitudes of acceleration.

Claim 26

The system of claim 21 with the magnitude of time delay being a function of the cumulative effect of acceleration during spin-up.

Claim 27

The system of claim 22 with the cumulative effect being initiated substantially with the initiation of spin-up.

Claim 28

The system of claim 22 comprising velocity means for providing a velocity signal having a magnitude indicative of the magnitude of the velocity of at least the one wheel, the cumulative effect being initiated upon attainment of a preselected relationship between said velocity signal and said control signal.

Claim 29

The system of claim 22 with the cumulative effect being initiated substantially in time coincidence with said time delay signal.

Claim 30

The system of claim 21 with said time delay signal being available only after a preselected time after occurrence of said first control signal.

Claim 31

The system of claim 26 with said preselected time delay being greater than around one fourth of the duration of said first portion of said control signal.

Claim 32

The system of claim 21 with the magnitude of time delay being decreased non-linearly at a greater rate for increasing magnitudes of acceleration.

Claim 33

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition of at least the one wheel, second control means for providing a second output signal in response to the recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal, said control signal being a preprogrammed signal having generally the same shape from one cycle of brake release and reapplication to the next and having a first portion of rapidly decreasing magnitude and a second generally flat portion, velocity means for providing a velocity signal having a magnitude indicative of the magnitude of the velocity of at least one wheel, said second control means comprising comparator means for comparing the magnitude of said velocity signal and of said control signal and for providing said output signal after said velocity signal and said control signal attain a selected relationship, and modulating means responsive to said first output signal for initiating release of the brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 34

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition of at least the one wheel, second control means for providing a second output signal in response to the recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal, said control signal being a preprogrammed signal having generally the same shape from one cycle of brake release and reapplication to the next and having a first portion of rapidly decreasing magnitude and a second generally flat portion, velocity means for providing a velocity signal having a magnitude indicative of the magnitude of the velocity of at least one wheel, said second control means comprising comparator means for comparing the magnitude of said velocity signal and of said control signal and for providing said output signal after said velocity signal and said control signal attain a selected relationship, and modulating means responsive to said first output signal for initiating release of the brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 35

The skid control system of claim 29 with said control signal being initiated generally concurrently with said first output signal.

Claim 36

The system of claim 30 with said first portion having a time rate of change of magnitude equivaLent with the linear deceleration of at least the one wheel in the range of from around 100 ft./sec.2 to around 160 ft./sec.2.

Claim 37

The system of claim 31 with said first portion having a duration of from around 0.150 seconds to 0.200 seconds.

Claim 38

The system of claim 32 with said second portion having a generally constant magnitude having a time rate of change of magnitude equivalent with the linear deceleration of at least the one wheel of no greater than around 2 ft./sec.2.

Claim 39

The system of claim 32 with said second portion having a time rate of change of magnitude equivalent with the linear acceleration of at least the one wheel of from around 10 ft./sec.2 to no greater than around 20 ft./sec.2.

Claim 40

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to the recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a preprogrammed control signal having generally the same shape from one cycle of brake release and reapplication to the next and having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said second control means including means operative in response to said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of the brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 41

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to the recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a preprogrammed control signal having generally the same shape from one cycle of brake release and reapplication to the next and having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said second control means including means operative in response to said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of the brakes and responsive to said second output signal for initiating reapplication of the brakes.

Claim 42

The system of claim 35 comprising velocity means for providing a velocity signal having a magnitude indicative of the magnitude of the velocity of at least the one wheel, said means operative in response to said control signal providing said second output signal upon the occurrence of a predetermined relationship between said velocity signal and said control signal for providing said second output signal, said means for generating said control signal initiating said control signal generally concurrently with said first output signal.

Claim 43

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal, said control signal being a preprogrammed signal having generally the same shape from one cycle of brake release and reapplication to the next and having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said second control means operative in response to said control signal for generating a variable time delay signal operative with said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of brakes and responsive to said second output signal for initiating reapplication of the brakes, said time delay signal providing a time delay from around zero to a determined maximum.

Claim 44

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to recovery of at least the one wheel from the incipient skid condition, said second control means comprising means for generating a control signal, said control signal being a preprogrammed signal having generally the same shape from one cycle of brake release and reapplication to the next and having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said second control means operative in response to said control signal for generating a variable time delay signal operative with said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of brakes and responsive to said second output signal for initiating reapplication of the brakes, said time delay signal providing a time delay from around zero to a determined maximum.

Claim 45

The system of claim 37 with said second control means comprising control circuit means for generating said control signal and including energy storage means having a chanage the magnitude of which determines said control signal, bleed circuit means connected to said energy storage means and having a first bleed rate for determining said first portion of said control signal and a second bleed rate for determining said second portion of said control signal.

Claim 46

The system of claim 38 with said first bleed rate having a time rAte of change of a magnitude equivalent with the linear deceleration of at least the one wheel in the range from around 100 ft./sec.2 to around 160 ft./sec.2.

Claim 47

The system of claim 39 with said second bleed rate having a time rate of change of a magnitude equivalent with the linear deceleration of at least the one wheel of no greater than around 2 ft./sec.2.

Claim 48

The system of claim 39 with said second bleed rate having a time rate of change of a magnitude equivalent with the linear deceleration of at least the one wheel of from around 10 ft./sec.2 to no greater than around 20 ft./sec.2.

Claim 49

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to recovery of at least the one wheel from the incipient skid condition, said second control means comprising control circuit means for generating a control signal, said control signal being a preprogrammed signal having generally the same shape from one cycle of brake release and reapplication to the next and having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said control circuit means including energy storage means having a change the magnitude of which determines said control signal, bleed circuit means connected to said energy storage means and having a first bleed rate having a time rate of change of a magnitude equivalent with the linear deceleration of at least the one wheel in the range from around 100 ft./sec.2 to around 160 ft./sec.2 for determining said first portion of said control signal and a second bleed rate for determining said second portion of said control signal, and timing circuit means operable for switching said bleed circuit means from said first bleed rate of said second bleed after a period of from around 0.150 seconds to 0.200 seconds, said second control means operative in response to said control signal for generating a variable time delay signal operative with said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of brakes and responsive to said second output signal for initiating reapplication of the brakes, said time delay signal providing a time delay from around zero to a determined maximum.

Claim 50

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first control means for providing a first output signal in response to the occurrence of an incipient skid condition at least at the one wheel, second control means for providing a second output signal in response to recovery of at least the one wheel from the incipient skid condition, said second control means comprising control circuit means for generating a control signal, said control signal being a preprogrammed signal having generally the same shape from one cycle of brake release and reapplication to the next and having a first portion of rapidly decreasing magnitude and a second, generally flat portion, said control circuit means including energy storage means having a change the magnitude of which determines said control signal, bleed circuit means connected to said energy storage means and having a first bleed rate having a time rate of change of a magnitude equivalent with the linear deceleration of at least the one wheel in the range from around 100 ft./sec.2 to around 160 ft./sec.2 for determining said first portion of said control signal and a second bleed rate for determining said second portion of said control signal, and timing circuit means operable for switching said bleed circuit means from said first bleed rate of said second bleed after a period of from around 0.150 seconds to 0.200 seconds, said second control means operative in response to said control signal for generating a variable time delay signal operative with said control signal for providing said second output signal, and modulating means responsive to said first output signal for initiating release of brakes and responsive to said second output signal for initiating reapplication of the brakes, said time delay signal providing a time delay from around zero to a determined maximum.

Claim 51

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first means for providing a first signal having a magnitude indicative of the velocity of at least the one wheel, second means for providing a second signal having a magnitude which is a preselected proportion of said first signal until said second signal attains a predetermined time rate of change whereupon said second signal has a magnitude which decreases at a selected time rate of change approximately less than said predetermined rate of change whereby the magnitude of said first signal and said second signal approach each other, comparator means for comparing the magnitudes of said first and second signals and for providing an output signal after said first and second signals have attained a selected relationship, and modulating means responsive to said output signal for initiating release of the brake means for preventing said first signal from falling below a preselected magnitude indicative of a preselected minimum velocity of at least the one wheel.

Claim 52

A skid control system for controlling the brakes to at least one wheel of a wheeled vehicle comprising: first means for providing a first signal having a magnitude indicative of the velocity of at least the one wheel, second means for providing a second signal having a magnitude which is a preselected proportion of said first signal until said second signal attains a predetermined time rate of change whereupon said second signal has a magnitude which decreases at a selected time rate of change approximately less than said predetermined rate of change whereby the magnitude of said first signal and said second signal approach each other, comparator means for comparing the magnitudes of said first and second signals and for providing an output signal after said first and second signals have attained a selected relationship, and modulating means responsive to said output signal for initiating release of the brake means for preventing said first signal from falling below a preselected magnitude indicative of a preselected minimum velocity of at least the one wheel.

Claim 53

The system of claim 43 with said preselected magnitude being around 5 miles per hour.

Claim 54

The skid control system of claim 16 with said first control means comprising first means for providing a first signal having a magnitude indicative of the velocity of the one wheel, second means for providing a second signal having a Magnitude which is a preselected proportion of said first signal until said second signal attains a predetermined time rate of change whereupon said second signal has a magnitude which decreases at a selected time rate of change approximately less than said predetermined rate of change whereby the magnitude of said first signal and said second signal approach each other, said first and second control means including comparator means for comparing the magnitudes of said first and second signals and for providing said first output signal after said first and second signals have attained a selected relationship, and for comparing the magnitudes of said first signal and said control signal for providing said second output signal.

Claim 55

A skid control system for a vehicle having at least one wheel and a brake for said wheel comprising: detecting means for providing a first signal representative of changes in the speed of at least one wheel; reference generating means for generating a reference signal representing a first predetermined wheel deceleration in response to an output signal; and control means responsive to said first signal for providing said output signal at least in part in response to the exceeding of a second predetermined wheel deceleration which is less than said first predetermined wheel deceleration, said control means further responsive to said first signal and said reference signal for effecting the release of the brakes upon the attainment of a predetermined relationship between said first signal and said reference signal.

Claim 56

A skid control system for a vehicle having at least one wheel and a brake for said wheel comprising: detecting means for providing a first signal representative of changes in the speed of at least one wheel; reference generating means for generating a reference signal representing a first predetermined wheel deceleration in response to an output signal; and control means responsive to said first signal for providing said output signal at least in part in response to the exceeding of a second predetermined wheel deceleration which is less than said first predetermined wheel deceleration, said control means further responsive to said first signal and said reference signal for effecting the release of the brakes upon the attainment of a predetermined relationship between said first signal and said reference signal.

Claim 57

A skid control system according to claim 46 wherein said means for generating said reference signal generates said reference signal prior to the provision of said output signal and alters said reference signal to represent said first predetermined wheel deceleration in response to said output signal.

Claim 58

A skid control system according to claim 7 wherein said control means compares the magnitude of said first signal and the magnitude of said reference signal and provides said output signal when the magnitude of said first signal attains a predetermined relationship with the magnitude of said reference signal.

Claim 59

A skid control system according to claim 46 wherein said control means compares the magnitude of said first signal and the magnitude of said reference signal and releases said brakes when the magnitude of said first signal attains a predetermined relationship with the magnitude of said reference signal.

Claim 60

A skid control system for a vehicle having at least one wheel and a brake for said wheel comprising: detecting means for providing a first signal representative of changes in the speed of at least one wheel; reference generating means for generating a reference signal, said reference signal being altered to represent a first predetermined wheel deceleration in response to an output signal, said reference signal representing a second predetermined magnitude of wheel deceleration before said reference signal is altered which is of substantially decreased magnitude relative to said first predetermined magnitude of wheel deceleration; and control means responsive to said first signal for providing said output signal at least in part in response to the exceeding of a second predetermined wheel deceleration which is less than said first predetermined wheel deceleration, said control means further responsive to said first signal and said reference signal for effecting the release of the brakes upon the attainment of a predetermined relationship between said first signal and said reference signal.

Claim 61

A skid control system for a vehicle having at least one wheel and a brake for said wheel comprising: detecting means for providing a first signal representative of changes in the speed of at least one wheel; reference generating means for generating a reference signal, said reference signal being altered to represent a first predetermined wheel deceleration in response to an output signal, said reference signal representing a second predetermined magnitude of wheel deceleration before said reference signal is altered which is of substantially decreased magnitude relative to said first predetermined magnitude of wheel deceleration; and control means responsive to said first signal for providing said output signal at least in part in response to the exceeding of a second predetermined wheel deceleration which is less than said first predetermined wheel deceleration, said control means further responsive to said first signal and said reference signal for effecting the release of the brakes upon the attainment of a predetermined relationship between said first signal and said reference signal.

Claim 62

A skid control system according to claim 50 wherein said second predetermined magnitude of wheel deceleration is between 10 and 50 feet per second2 and said first predetermined magnitude of wheel deceleration is between 100 and 160 feet per second2.

Claim 63

A skid control system for a vehicle having at least one wheel and a brake for said wheel cOmprising: detecting means for providing a first signal representative of changes in the speed of at least one wheel; reference generating means for generating a reference signal including means for altering said reference signal in response to an output signal; control means for providing a brake release signal and a brake reapplication signal, said control means including means responsive to said first signal and said reference signal for providing said output signal a predetermined delay after the attainment of a predetermined relationship therebetween, said last means further responsive to said first signal and said altered reference signal for providing said brake reapplication signal upon the attainment of a predetermined relationship between said first signal and said altered reference signal; and brake modulating means responsive to said brake release signal for effecting the release of said brakes and responsive to said brake reapplication signal for effecting the reapplication of said brakes.

Claim 64

A skid control system for a vehicle having at least one wheel and a brake for said wheel cOmprising: detecting means for providing a first signal representative of changes in the speed of at least one wheel; reference generating means for generating a reference signal including means for altering said reference signal in response to an output signal; control means for providing a brake release signal and a brake reapplication signal, said control means including means responsive to said first signal and said reference signal for providing said output signal a predetermined delay after the attainment of a predetermined relationship therebetween, said last means further responsive to said first signal and said altered reference signal for providing said brake reapplication signal upon the attainment of a predetermined relationship between said first signal and said altered reference signal; and brake modulating means responsive to said brake release signal for effecting the release of said brakes and responsive to said brake reapplication signal for effecting the reapplication of said brakes.

Claim 65

A skid control system according to claim 52 wherein said means for altering said reference signal alters said reference signal to represent a wheel deceleration of decreased magnitude in response to said output signal.

Claim 66

A skid control system according to claim 53 wherein said reference signal represents a first predetermined magnitude of wheel deceleration before said reference signal is altered and said altered reference signal represents a second predetermined magnitude of wheel deceleration which is of substantially decreased magnitude relative to said first predetermined magnitude of wheel deceleration.

Claim 67

A skid control system according to claim 54 wherein said first predetermined magnitude of wheel deceleration is between 100 and 160 feet per second2.

Claim 68

A skid control system according to claim 55 wherein said second predetermined magnitude of wheel deceleration is between 0 and 6 feet per second2.

Claim 69

A skid control system according to claim 52 wherein said control means compares the magnitude of said first signal and the magnitude of said reference signal and provides said output signal said predetermined delay after the magnitude of said first signal attains a predetermined relationship with the magnitude of said reference signal.

Claim 70

A skid control system according to claim 57 wherein said means for altering said reference current alters said reference signal to represent a wheel deceleration of decreased magnitude in response to said output signal.

Claim 71

A skid control system according to claim 52 wherein said predetermined delay is a period of time.

Claim 72

A skid control system according to claim 59 wherein said means for altering said reference signal alters said reference signal to represent a wheel deceleration of decreased magnitude in response to said output signal.

Claim 73

A skid control system according to claim 60 wherein said reference signal represents a first predetermined magnitude of wheel deceleration before said reference signal is altered to represent a wheel deceleration of increased magnitude, said altered reference signal representing a wheel deceleration of increased magnitude represents a second predetermined magnitude of wheel deceleration which is of substantially greater magnitude than said first predetermined magnitude of wheel deceleration, and said altered reference signal representing a wheel deceleration of decreased magnitude represents a third predetermined magnitude of wheel deceleration which is of substantially decreased magnitude than said first and second predetermined magnitudes of wheel deceleration.

Claim 74

A skid control system according to claim 61 wherein said first predetermined magnitude of wheel deceleration is between 10 and 50 feet per second2 and said second predetermined magnitude of wheel deceleration is between 100 and 160 feet per second2.

Claim 75

A skid control system according to claim 62 wherein saiD third predetermined magnitude of wheel deceleration is between 0 and 2 feet per second2.

Claim 76

A skid control system for a vehicle having at least one wheel and a brake for said wheel comprising: detecting means for providing a first signal representative of changes in the speed of at least one wheel; reference generating means for generating a reference signal representing a wheel deceleration of predetermined magnitude including means for altering said reference signal to represent a wheel deceleration of increased magnitude in response to a second signal and for further altering said reference signal to represent a wheel deceleration of decreased magnitude after a predetermined delay after said output signal; control means responsive to said first signal and said reference signal for providing said second signal upon the attainment of a predetermined relationship therebetween, said control means further responsive to said first signal and said altered reference signal representing a wheel deceleration of increased magnitude for providing a brake release signal upon the attainment of a predetermined relationship between said first signal and said altered reference signal representing a wheel deceleration of increased magnitude, said control means further responsive to said first signal and said altered reference signal representing a wheel deceleration of decreased magnitude for providing a brake reapplication signal upon the attainment of a predetermined relationship between said first signal and said altered reference signal representing a wheel deceleration of decreased magnitude; and brake modulating means responsive to said brake release signal for effecting the release of said brakes and responsive to said brake reapplication signal for effecting the reapplication of said brakes.

Claim 77

A skid control system for a vehicle having at least one wheel and a brake for said wheel comprising: detecting means for providing a first signal representative of changes in the speed of at least one wheel; reference generating means for generating a reference signal representing a wheel deceleration of predetermined magnitude including means for altering said reference signal to represent a wheel deceleration of increased magnitude in response to a second signal and for further altering said reference signal to represent a wheel deceleration of decreased magnitude after a predetermined delay after said output signal; control means responsive to said first signal and said reference signal for providing said second signal upon the attainment of a predetermined relationship therebetween, said control means further responsive to said first signal and said altered reference signal representing a wheel deceleration of increased magnitude for providing a brake release signal upon the attainment of a predetermined relationship between said first signal and said altered reference signal representing a wheel deceleration of increased magnitude, said control means further responsive to said first signal and said altered reference signal representing a wheel deceleration of decreased magnitude for providing a brake reapplication signal upon the attainment of a predetermined relationship between said first signal and said altered reference signal representing a wheel deceleration of decreased magnitude; and brake modulating means responsive to said brake release signal for effecting the release of said brakes and responsive to said brake reapplication signal for effecting the reapplication of said brakes.

Claim 78

A skid control system according to claim 64 wherein said control means compares the magnitude of said first signal and the magnitude of said reference signal and provides said output signal when the magnitude of said first signal attains a predetermined relationship with the magnitude of said reference signal.

Claim 79

A skid control system according to claim 64 wherein said predetermined delay is a period of time.