Patent US4089564A successfully refreshed from Google Patents.
US4089564A
Expired / Lapsed
US
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Method and apparatus for predicting vehicle speed in braking control systems for wheeled vehicles
Assignee: Saab AB
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Filing: 1976-10-06
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Granted: 1978-05-16
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Expires: 1996-10-06
Abstract
Abstract A method for predicting vehicle speed in a braking control system for wheeled vehicles, where a signal representing wheel speed before braking is used to trigger charging of a capacitor in an electronic unit. The capacitor voltage is reduced during braking in response to a predetermined retardation value in order to correspond to an instantaneous value for the vehicle speed. The vehicle speed signal is compared with a wheel speed signal, which comparison triggers, when the wheel speed signal exceeds the vehicle speed signal, up-dating of the capacitor voltage level to a value corresponding to the actual wheel speed signal. When up-dating the vehicle speed signal, the preselected retardation value is gradually lowered by a value corresponding to the magnitude of the actual up-dating.
Inventors
- 👤 Ulf Erik Oberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:12
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/172; B60T2250/00; B60T2250/04
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
258 words
A method for generating a predicted speed signal representative of a predicted vehicle speed during braking for use in an anti-skid braking system, said method comprising the steps of: generating a predicted speed signal representative of the actual speed of a vehicle prior to the initiation of a braking operation; decreasing the value of said predicted speed signal at a first preselected empirical rate upon the initiation of a braking operation; performing an updating step including comparing said predicted speed signal to an actual speed signal representative of the actual instantaneous peripheral speed of a wheel of said vehicle and generating an updating signal each time said actual speed signal indicates that the actual instantaneous peripheral speed of said wheel is greater than the predicted speed as determined by said predicted speed signal; increasing the value of said predicted speed signal each time a new up-dating signal is generated until said predicted speed signal reaches a value which is representative of a speed which is greater than the actual instantaneous peripheral speed of said wheel; and thereafter decreasing the value of said predicted speed signal at an up-dated rate proportional to the time period extending from the time when said last up-dating signal was generated until the time when said predicted speed of said vehicle as indicated by the predicted speed signal last rose above a value which was equal to the instantaneous peripheral speed of said wheel; and continuously increasing the rate at which said predicted speed signal is decreased during the time between successive updating steps.
Claim 2
Independent Claim
258 words
A method for generating a predicted speed signal representative of a predicted vehicle speed during braking for use in an anti-skid braking system, said method comprising the steps of: generating a predicted speed signal representative of the actual speed of a vehicle prior to the initiation of a braking operation; decreasing the value of said predicted speed signal at a first preselected empirical rate upon the initiation of a braking operation; performing an updating step including comparing said predicted speed signal to an actual speed signal representative of the actual instantaneous peripheral speed of a wheel of said vehicle and generating an updating signal each time said actual speed signal indicates that the actual instantaneous peripheral speed of said wheel is greater than the predicted speed as determined by said predicted speed signal; increasing the value of said predicted speed signal each time a new up-dating signal is generated until said predicted speed signal reaches a value which is representative of a speed which is greater than the actual instantaneous peripheral speed of said wheel; and thereafter decreasing the value of said predicted speed signal at an up-dated rate proportional to the time period extending from the time when said last up-dating signal was generated until the time when said predicted speed of said vehicle as indicated by the predicted speed signal last rose above a value which was equal to the instantaneous peripheral speed of said wheel; and continuously increasing the rate at which said predicted speed signal is decreased during the time between successive updating steps.
Claim 3
Independent Claim
273 words
A method for generating a predicted speed signal representative of a predicted vehicle speed during braking for use in an anti-skid braking system, said method comprising the steps of: generating a predicted speed signal representative of the actual speed of a vehicle prior to the initiation of a braking operation; decreasing the value of said predicted speed signal at a first preselected empirical rate upon the initiation of a braking operation; performing an updating step including comparing said predicted speed signal to an actual speed signal representative of the actual instantaneous peripheral speed of a wheel of said vehicle and generating an up-dating signal each time said actual speed signal indicates that the actual instantaneous peripheral speed of said wheel is greater than the predicted speed as determined by said predicted speed signal; increasing the value of said predicted speed signal each time a new up-dating signal is generated until said predicted speed signal reaches a value which is representative of a speed which is greater than the actual instantaneous peripheral speed of said wheel; and thereafter decreasing the value of said predicted speed signal at an up-dated rate proportional to the time period extending from the time when said last up-dating signal was generated until the time when said predicted speed of said vehicle as indicated by the predicted speed signal last rose above a value which was equal to the instantaneous peripheral speed of said wheel; and measuring the time intervals between the generation of successive up-dating signals and decreasing the value of said predicted speed signal at said first preselected empirical rate whenever said interval exceeds a predetermined time period.
Claim 4
Independent Claim
273 words
A method for generating a predicted speed signal representative of a predicted vehicle speed during braking for use in an anti-skid braking system, said method comprising the steps of: generating a predicted speed signal representative of the actual speed of a vehicle prior to the initiation of a braking operation; decreasing the value of said predicted speed signal at a first preselected empirical rate upon the initiation of a braking operation; performing an updating step including comparing said predicted speed signal to an actual speed signal representative of the actual instantaneous peripheral speed of a wheel of said vehicle and generating an up-dating signal each time said actual speed signal indicates that the actual instantaneous peripheral speed of said wheel is greater than the predicted speed as determined by said predicted speed signal; increasing the value of said predicted speed signal each time a new up-dating signal is generated until said predicted speed signal reaches a value which is representative of a speed which is greater than the actual instantaneous peripheral speed of said wheel; and thereafter decreasing the value of said predicted speed signal at an up-dated rate proportional to the time period extending from the time when said last up-dating signal was generated until the time when said predicted speed of said vehicle as indicated by the predicted speed signal last rose above a value which was equal to the instantaneous peripheral speed of said wheel; and measuring the time intervals between the generation of successive up-dating signals and decreasing the value of said predicted speed signal at said first preselected empirical rate whenever said interval exceeds a predetermined time period.
Claim 5
Dependent Claim
169 words
Apparatus for predicting vehicle speed of a wheeled vehicle to provide for a series of periodic reductions in braking force under electronic control comprising: charge storage means; wheel speed means for generating a signal level representing the speed of a wheel; comparator means for charging said charge storage means whenever the signal level generated by said wheel speed means is greater than the level of charge stored by said charge storage means; discharging means coupled to said charge storage means for discharging said charge storage means at a rate determined by a control level applied to its control input; discharge rate control means responsive to said comparator means for applying a control level at said control level at said control input to reduce the discharge rate when the wheel speed signal level is reduced; said discharge rate control means comprising means for storing a control level, said level being decreased each time said wheel speed is reduced and being maintained at the decreased level for the next braking operation.
Claim 6
Dependent Claim
169 words
Apparatus for predicting vehicle speed of a wheeled vehicle to provide for a series of periodic reductions in braking force under electronic control comprising: charge storage means; wheel speed means for generating a signal level representing the speed of a wheel; comparator means for charging said charge storage means whenever the signal level generated by said wheel speed means is greater than the level of charge stored by said charge storage means; discharging means coupled to said charge storage means for discharging said charge storage means at a rate determined by a control level applied to its control input; discharge rate control means responsive to said comparator means for applying a control level at said control level at said control input to reduce the discharge rate when the wheel speed signal level is reduced; said discharge rate control means comprising means for storing a control level, said level being decreased each time said wheel speed is reduced and being maintained at the decreased level for the next braking operation.
Claim 7
Dependent Claim
85 words
The apparatus of claim 3 wherein said storing means further comprises second storage means and means for charging said second storage means responsive to initiation of a braking operation; second comparison means responsive to said second storage means and the level of said first storing means for resetting said discharge rate control means; means controlling the charging rate of said second storage means to cause resetting after a time delay which exceeds the normal time interval for up-dating the level of said first storing means.
Claim 8
Dependent Claim
46 words
The apparatus of claim 3 further comprising disabling means responsive to the level of said first storing means for generating a disabling signal to disable the electronic control and thereby restore normal braking when the level of said first charging means drops below a predetermined threshold.
Claim 9
Dependent Claim
24 words
The apparatus of claim 5 further comprising means coupled to said disabling means for resetting said discharge control means responsive to said disabling signal.
Claim 10
Dependent Claim
21 words
The apparatus of claim 3, wherein said first storing means includes a capacitor and said discharge control means comprises an integrator.
Claim 11
Dependent Claim
74 words
The apparatus of claim 7, wherein said integrator comprises an operational amplifier having a feedback path comprising a capacitor coupled between the output and one input of said amplifier; a zener diode being coupled across said capacitor and adapted to provide an initial level representing an empirically determined vehicle retardation value, said value representing a deceleration at a rate in the range between 0.5 and 1.0 g where g is the earth's gravitational acceleration.
Claim 12
Dependent Claim
29 words
The apparatus of claim 7 further comprising means for increasing the output level of the integrator at a slow predetermined rate when said first storing means is being discharged.
Claim 13
Dependent Claim
53 words
The apparatus of claim 3, wherein the output level of said first storing means represents predicted vehicle speed and the output level of said discharge control means represents the rate of vehicle retardation; means responsive to the levels of said predicted vehicle speed and said vehicle retardation for generating a retardation reference level.
Claim 14
Dependent Claim
54 words
The apparatus of claim 3, wherein the output level of said first storing means represents predicted vehicle speed and the output level of said discharge control means represents the rate of vehicle retardation; means responsive to the levels of said predicted vehicle speed and said vehicle retardation for generating a wheel slip reference level.
Claim 15
Independent Claim
293 words
A method for generating a predicted speed signal representative of a predicted vehicle speed during braking for use in an anti-skid braking system, said method comprising the consecutive steps of; a. charging a capacitor to a level representing the speed of said vehicle just prior to the initiation of a braking operation; b. discharging said capacitor at a first predetermined retardation rate upon initiation of a braking operation, said predetermined retardation rate being a preselected empirical vehicle retardation value, said retardation rate altering the voltage across the capacitor to prove a level representing a predetermined vehicle speed during braking; c. releasing the braking force applied to a wheel of said vehicle to permit said wheel to attain a speed representative of the actual speed of said vehicle; d. charging said capacitor to an up-dated level representing the speed of said vehicle as indicated by the rotational speed of said wheel if the speed of said vehicle is greater than a predicted speed of said vehicle as determined by said voltage across said capacitor; e. discharging said capacitor at an up-dated rate proportional to the difference between the speed of said vehicle as indicated by the rotational speed of said wheel and the predicted speed of said vehicle as determined by said voltage across said capacitor; f. reapplying the braking force to said wheel and discharging said capacitor at said new retardation rate during reapplication of the braking force; and continuously decreasing the rate at which said capacitor is discharged each time the predicted speed of said vehicle as determined by said voltage across said capacitor rises above the actual instantaneous speed of said vehicle as indicated by the rotational speed of said wheel and maintaining the decreased rate for the next braking operation.
Claim 16
Independent Claim
293 words
A method for generating a predicted speed signal representative of a predicted vehicle speed during braking for use in an anti-skid braking system, said method comprising the consecutive steps of; a. charging a capacitor to a level representing the speed of said vehicle just prior to the initiation of a braking operation; b. discharging said capacitor at a first predetermined retardation rate upon initiation of a braking operation, said predetermined retardation rate being a preselected empirical vehicle retardation value, said retardation rate altering the voltage across the capacitor to prove a level representing a predetermined vehicle speed during braking; c. releasing the braking force applied to a wheel of said vehicle to permit said wheel to attain a speed representative of the actual speed of said vehicle; d. charging said capacitor to an up-dated level representing the speed of said vehicle as indicated by the rotational speed of said wheel if the speed of said vehicle is greater than a predicted speed of said vehicle as determined by said voltage across said capacitor; e. discharging said capacitor at an up-dated rate proportional to the difference between the speed of said vehicle as indicated by the rotational speed of said wheel and the predicted speed of said vehicle as determined by said voltage across said capacitor; f. reapplying the braking force to said wheel and discharging said capacitor at said new retardation rate during reapplication of the braking force; and continuously decreasing the rate at which said capacitor is discharged each time the predicted speed of said vehicle as determined by said voltage across said capacitor rises above the actual instantaneous speed of said vehicle as indicated by the rotational speed of said wheel and maintaining the decreased rate for the next braking operation.
Claim 17
Dependent Claim
52 words
The method of claim 12 further comprising the repetition of steps (c) through (f) to predict the speed of said vehicle, and measuring the elapsed time intervals between successive up-datings of said capacitor level and automatically resetting said capacitor discharge rate to said empirical value when said intervals exceed a predetermined threshold.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-15 | 1981-11-14 | 1982-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-15 | 1985-11-14 | 1986-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-15 | 1989-11-14 | 1990-05-16 | $7700.00 | Window Closed / Lapsed |