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US5010488A
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Bear-wheel control method for a motor vehicle with a four-wheel steering system
Assignee: Subaru Corp
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Filing: 1989-05-15
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Granted: 1991-04-23
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Expires: 2009-05-15
Abstract
Abstract Rear wheels are controlled based on rear-wheel slip angle (βr). A desired rear-wheel steering angle (δr) is expressed as δr=-G(S)krβr, where G(S) is a derivative transfer function and kr is a steering coefficient. The desired rear-wheel steering angle is applied to a rear-wheel steering control system for controlling the rear wheels to the desired rear-wheel steering angle.
Inventors
- 👤 Saiichiro Ohshita
- 👤 Kazuhiro Fukamachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:06
CPC Classifications
B; B62; B62D; B62D7/00; B62D7/06; B62D7/14; B62D7/15; B62D7/159; B62D7/1581
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
92 words
A method for controlling rear wheels of a four-wheel steering vehicle having a rear-wheel steering control system, comprising the steps of; detecting rear-wheel slip angle (βr); providing a transfer function (G(s)) including at least a derivative element; calculating a desired rear-wheel steering angle (δr) upon an equation based on said rear-wheel slip angle and said transfer function expressed as δr=-G(S) kr βr where kr is a steering coefficient; and applying the desired rear-wheel steering angle to the rear-wheel steering control system for controlling the rear wheels to the desired rear-wheel steering angle.
Claim 2
Independent Claim
92 words
A method for controlling rear wheels of a four-wheel steering vehicle having a rear-wheel steering control system, comprising the steps of; detecting rear-wheel slip angle (βr); providing a transfer function (G(s)) including at least a derivative element; calculating a desired rear-wheel steering angle (δr) upon an equation based on said rear-wheel slip angle and said transfer function expressed as δr=-G(S) kr βr where kr is a steering coefficient; and applying the desired rear-wheel steering angle to the rear-wheel steering control system for controlling the rear wheels to the desired rear-wheel steering angle.
Claim 3
Dependent Claim
35 words
The method according to claim 1, wherein said transfer function is ##EQU31## where T is a predetermined time constant of the derivative element, α is an optional proportional gain and S is a Laplace operator.
Claim 4
Dependent Claim
42 words
The method according to claim 1, wherein said transfer function includes a proportional element and is expressed as ##EQU32## where T is a predetermined time constant of the derivative element, α is an optional proportional gain and S is a Laplace operator.
Claim 5
Dependent Claim
14 words
The method according to claim 3, wherein the proportional gain (α) is 0<α<(1-kr)/kr (0<kr<1)
References Cited (Backward Citations)
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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) | 1994-04-22 | 1994-10-22 | 1995-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-22 | 1998-10-22 | 1999-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-22 | 2002-10-22 | 2003-04-23 | $7700.00 | Window Closed / Lapsed |