US5058019A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle speed estimation using wheel speed measurements
Assignee: Motors Liquidation Co
•
Filing: 1990-01-25
•
Granted: 1991-10-15
•
Expires: 2010-01-25
Abstract
Abstract A vehicle speed estimation system estimates vehicle speed from wheel speed prior to an incipient wheel lockup condition. When an incipient wheel lockup condition is sensed, the estimated speed is increased by a determined amount and then decreased based on an estimated vehicle deceleration. The estimated vehicle deceleration during the incipient wheel lockup condition is based on wheel deceleration at a time preceding the time the incipient wheel lockup condition is sensed. When in incipient wheel lockup condition is sensed, a forgetting period during which wheel deceleration is not representative of vehicle deceleration is determined. The estimated vehicle deceleration during the incipient wheel lock condition is then based on wheel deceleration prior to the forgetting period.
Inventors
- 👤 Bakhtiar Litkouhi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:30
CPC Classifications
B; B60; B60T; B60T8/00; B60T8/17; B60T8/172; B60T2250/00; B60T2250/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
160 words
A method of estimating vehicle speed during braking of a wheel of a vehicle traveling over a road surface, the wheel being braked by application of brake pressure to a wheel brake, the method comprising the steps of: sensing the speed of the wheel; determining the occurrence of an incipient wheel lock condition of the wheel in response to excessive slip between the wheel and the road surface; estimating vehicle speed prior to the determined occurrence of an incipient wheel lock condition based on the sensed wheel speed; determining a wheel deceleration value at a point in time preceding the determined occurrence of the incipient wheel lock condition whereat the wheel deceleration is a measure of the vehicle deceleration; and estimating the vehicle speed after the determined occurrence of an incipient wheel lock condition in accord with (a) the vehicle speed estimated prior to the determined occurrence of an incipient wheel lock condition and (b) the determined wheel deceleration value.
Claim 2
Independent Claim
160 words
A method of estimating vehicle speed during braking of a wheel of a vehicle traveling over a road surface, the wheel being braked by application of brake pressure to a wheel brake, the method comprising the steps of: sensing the speed of the wheel; determining the occurrence of an incipient wheel lock condition of the wheel in response to excessive slip between the wheel and the road surface; estimating vehicle speed prior to the determined occurrence of an incipient wheel lock condition based on the sensed wheel speed; determining a wheel deceleration value at a point in time preceding the determined occurrence of the incipient wheel lock condition whereat the wheel deceleration is a measure of the vehicle deceleration; and estimating the vehicle speed after the determined occurrence of an incipient wheel lock condition in accord with (a) the vehicle speed estimated prior to the determined occurrence of an incipient wheel lock condition and (b) the determined wheel deceleration value.
Claim 3
Dependent Claim
40 words
The method of claim 1 further including the step of determining the time preceding the determined occurrence of the incipient wheel lock condition whereat the wheel deceleration is a measure of the vehicle deceleration as a function of predetermined parameters.
Claim 4
Dependent Claim
23 words
The method of claim 2 wherein the predetermined parameters include wheel speed, rate of change in the brake pressure and the predetermined threshold.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein the occurrence of an incipient wheel lock condition is determined in response to excessive slip represented by a predetermined slip threshold.
Claim 6
Independent Claim
177 words
A method of estimating vehicle speed during braking of a wheel of a vehicle traveling over a road surface, the wheel being braked by application of brake pressure to a wheel brake, the method comprising the steps of: sensing the speed of the wheel; determining the occurrence of an incipient wheel lock condition of the wheel in response to excessive slip between the wheel and the road surface; estimating vehicle speed prior to the determined occurrence of an incipient wheel lock condition based on the sensed wheel speed; determining a wheel deceleration value at a point in time preceding the determined occurrence of the incipient wheel lock condition whereat the wheel deceleration is a measure of the vehicle deceleration; and estimating the vehicle speed after the determined occurrence of an incipient wheel lock condition by (a) increasing the value of the vehicle speed estimated prior to the determined occurrence of an incipient wheel lock condition and (b) decreasing the increased value of the estimated vehicle speed at a rate in accord with the determined wheel deceleration value.
Claim 7
Independent Claim
177 words
A method of estimating vehicle speed during braking of a wheel of a vehicle traveling over a road surface, the wheel being braked by application of brake pressure to a wheel brake, the method comprising the steps of: sensing the speed of the wheel; determining the occurrence of an incipient wheel lock condition of the wheel in response to excessive slip between the wheel and the road surface; estimating vehicle speed prior to the determined occurrence of an incipient wheel lock condition based on the sensed wheel speed; determining a wheel deceleration value at a point in time preceding the determined occurrence of the incipient wheel lock condition whereat the wheel deceleration is a measure of the vehicle deceleration; and estimating the vehicle speed after the determined occurrence of an incipient wheel lock condition by (a) increasing the value of the vehicle speed estimated prior to the determined occurrence of an incipient wheel lock condition and (b) decreasing the increased value of the estimated vehicle speed at a rate in accord with the determined wheel deceleration value.
References Cited (Backward Citations)
US4933858A
Cited
US4485545A
Cited
US4673226A
Cited
US4783127A
Cited
US4755946A
Cited
US4859002A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-10-14 | 1995-04-15 | 1995-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-14 | 1999-04-15 | 1999-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-14 | 2003-04-15 | 2003-10-15 | $7700.00 | Window Closed / Lapsed |