US5072803A
Expired / Lapsed
US
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Method of setting an assisting force in power-assisted steering
Assignee: Daimler Benz AG
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Filing: 1990-07-09
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Granted: 1991-12-17
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Expires: 2010-07-09
Abstract
Abstract A power-assisted steering method establishes or sets an auxiliary force by taking into account a plurality of variables such as transverse acceleration and vehicle speed characterizing the instantaneous driving conditions. The driving feel with regard to the state of the road surface and the instantaneous driving situation for the vehicle driver are thereby ensured.
Inventors
- 👤 Ulrich Kilian
- 👤 Jurgen Gotz
- 👤 Claus-Michael Hainbuch
- 👤 Berthold Edenhofer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:39
CPC Classifications
B; B62; B62D; B62D6/00
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
177 words
A method for setting an assisting force in a power-assisted steering as a function of actual measured driving=condition parameters, comprising the steps of deriving a desired value for a manual torque to be applied to a steering wheel by a vehicle driver from the actual measured driving-condition parameters, one of the drivingcondition parameters being an actual measured value of transverse acceleration, and a further driving-condition parameter being an actual measured value of vehicle speed, setting the assisting force on an at least approximately continuous basis in the power-assisted steering such that the manual torque and the assisting force, on the basis of the actual measured driving condition parameters, are precisely compensated with steering forces to control the desired value; a least approximately continuously reducing the assisting force in the power-assisted steering as a result of both increasing actual measured values of the transverse acceleration and increasing actual measured values of the vehicle speed; and effecting a greater reduction, at desired transverse acceleration, in the assisting force as the vehicle speed increases, than at another lower transverse acceleration.
Claim 2
Independent Claim
177 words
A method for setting an assisting force in a power-assisted steering as a function of actual measured driving=condition parameters, comprising the steps of deriving a desired value for a manual torque to be applied to a steering wheel by a vehicle driver from the actual measured driving-condition parameters, one of the drivingcondition parameters being an actual measured value of transverse acceleration, and a further driving-condition parameter being an actual measured value of vehicle speed, setting the assisting force on an at least approximately continuous basis in the power-assisted steering such that the manual torque and the assisting force, on the basis of the actual measured driving condition parameters, are precisely compensated with steering forces to control the desired value; a least approximately continuously reducing the assisting force in the power-assisted steering as a result of both increasing actual measured values of the transverse acceleration and increasing actual measured values of the vehicle speed; and effecting a greater reduction, at desired transverse acceleration, in the assisting force as the vehicle speed increases, than at another lower transverse acceleration.
Claim 3
Dependent Claim
32 words
The method according to claim 1, wherein at a certain vehicle speed, a greater reduction in the assisting force, as the transverse acceleration increases, is effected than at a lower vehicle speed.
Claim 4
Dependent Claim
37 words
The method according to claim 1, wherein the reduction in the assisting force relative to a change in the vehicle speed in a region of low vehicle speeds is a greater amount than at higher vehicle speeds.
Claim 5
Dependent Claim
32 words
The method according to claim 3, wherein at a certain vehicle speed, a greater reduction in the assisting force, as the transverse acceleration increases, is effected than at a lower vehicle speed.
Claim 6
Dependent Claim
43 words
The method according to claim 1, wherein when a dynamic limit is reached the reduction in the assisting force relative to a change in the transverse acceleration in a region of low transverse acceleration is a greater amount than at higher transverse acceleration.
Claim 7
Dependent Claim
32 words
The method according to claim 5, wherein at a certain vehicle speed, a greater reduction in the assisting force, as the transverse acceleration increases, is effected than at a lower vehicle speed.
Claim 8
Dependent Claim
37 words
The method according to claim 6, wherein the reduction in the assisting force relative to a change in the vehicle speed in a region of low vehicle speeds is a greater amount than at higher vehicle speeds.
Claim 9
Dependent Claim
63 words
The method according to claim 1, wherein the assisting force is reduced when the driving conditions approach a transversely dynamic limit region, such that the vehicle driver has to apply the manual torque of sufficient amount to the steering wheel so that a drop in the manual torque, when the transversely dynamic limit region is reached, can clearly be sensed by the driver.
Claim 10
Dependent Claim
32 words
The method according to claim 8, wherein at a certain vehicle speed, a greater reduction in the assisting force, as the transverse acceleration increases, is effected than at a lower vehicle speed.
Claim 11
Dependent Claim
37 words
The method according to claim 9, wherein the reduction in the assisting force relative to a change in the vehicle speed in a region of low vehicle speeds is a greater amount than at higher vehicle speeds.
Claim 12
Dependent Claim
43 words
The method according to claim 9, wherein when a dynamic limit is reached the reduction in the assisting force relative to a change in the transverse acceleration in a region of low transverse acceleration is a greater amount than at higher transverse acceleration.
Claim 13
Dependent Claim
49 words
The method according to claim 1, wherein the assisting force is reduced, when roadway slipperiness is determined as a function of the roadway slipperiness such that the vehicle driver can recognize the point at which a transversely dynamic limit region is reached by a drop in the manual torque.
Claim 14
Dependent Claim
32 words
The method according to claim 12, wherein at a certain vehicle speed, a greater reduction in the assisting force, as the transverse acceleration increases, is effected than at a lower vehicle speed.
Claim 15
Dependent Claim
37 words
The method according to claim 13, wherein the reduction in the assisting force relative to a change in the vehicle speed in a region of low vehicle speeds is a greater amount than at higher vehicle speeds.
Claim 16
Dependent Claim
43 words
The method according to claim 14, wherein when a dynamic limit is reached the reduction in the assisting force relative to a change in the transverse acceleration in a region of low transverse acceleration is a greater amount than at higher transverse acceleration.
Claim 17
Dependent Claim
32 words
The method according to claim 15, wherein at a certain vehicle speed, a greater reduction in the assisting force, as the transverse acceleration increases, is effected than at a lower vehicle speed.
Claim 18
Dependent Claim
71 words
The method according to claim 12, wherein the step of determining the roadway slipperiness comprises at least one of the steps of analyzing measuring signals or its effects from at least one of an antilock braking system and a drive-slip control; and comparing a force in the steering linkage or a variable proportional to this force with a reference value under optimum static-friction conditions between a wheel and the roadway surface.
Claim 19
Dependent Claim
47 words
The method according to claim 12, further including a step of determining the dependency of the point at which the transversely dynamic limit region is reached on the measuring signal used, and deriving a quantity for the reduction of the assisting force from the used measuring signal.
Claim 20
Dependent Claim
71 words
The method according to claim 18, wherein the step of determining the roadway slipperiness comprises at least one of the steps of analyzing measuring signals or its effects from at least one of an antilock braking system and a drive-slip control; and comparing a force in the steering linkage or a variable proportional to this force with a reference value under optimum static-friction conditions between a wheel and the roadway surface.
Claim 21
Dependent Claim
47 words
The method according to claim 1, wherein the assisting force is reduced as a function of height of a vehicle center of gravity such that a drop in the manual torque, when a transversely dynamic limit region is reached, can clearly be sensed by the vehicle driver.
Claim 22
Dependent Claim
32 words
The method according to claim 20, wherein at a certain vehicle speed, a greater reduction in the assisting force, as the transverse acceleration increases, is effected than at a lower vehicle speed.
Claim 23
Dependent Claim
37 words
The method according to claim 21, wherein the reduction in the assisting force relative to a change in the vehicle speed in a region of low vehicle speeds is a greater amount than at higher vehicle speeds.
Claim 24
Dependent Claim
43 words
The method according to claim 22, wherein when a dynamic limit is reached the reduction in the assisting force relative to a change in the transverse acceleration in a region of low transverse acceleration is a greater amount than at higher transverse acceleration.
Claim 25
Dependent Claim
63 words
The method according to claim 23, wherein the assisting force is reduced when the driving conditions approach a transversely dynamic limit region, such that the vehicle driver has to apply the manual torque of sufficient amount to the steering wheel so that a drop in the manual torque, when the transversely dynamic limit region is reached, can clearly be sensed by the driver.
Claim 26
Dependent Claim
49 words
The method according to claim 24, wherein the assisting force is reduced, when roadway slipperiness is determined as a function of the roadway slipperiness such that the vehicle driver can recognize the point at which a transversely dynamic limit region is reached by a drop in the manual torque.
Claim 27
Dependent Claim
71 words
The method according to claim 25, wherein the step of determining the roadway slipperiness comprises at least one of the steps of analyzing measuring signals or its effects from at least one of an antilock braking system and a drive-slip control; and comparing a force in the steering linkage or a variable proportional to this force with a reference value under optimum static-friction conditions between a wheel and the roadway surface.
Claim 28
Dependent Claim
47 words
The method according to claim 26, further including a step of determining the dependency of the point at which the transversely dynamic limit region is reached on the measuring signal used, and deriving a quantity for the reduction of the assisting force from the used measuring signal.
Claim 29
Dependent Claim
21 words
The method according to claim 1, wherein the assisting force is higher in a maneuvering region than during a driving operation.
Claim 30
Dependent Claim
24 words
The method according to claim 28, wherein in the maneuvering region is recognizable by a low vehicle speed and a relatively low transverse acceleration.
Claim 31
Dependent Claim
34 words
The method according to claim 1, wherein a neutral steering behavior with regard to the vehicle loading can be sensed by the vehicle driver by increasing the assisting force as the vehicle loading increases.
Claim 32
Dependent Claim
28 words
The method according to claim 30, including the step of sensing weight on the steered axle to determine the vehicle loading influencing the steering behavior of the vehicle.
Claim 33
Dependent Claim
31 words
The method according to claim 30, including the step of interpolating with a monotonically increasing function to increase the assisting force as loading influencing the steering behavior of the vehicle increases.
Claim 34
Dependent Claim
28 words
The method according to claim 32, including the step of sensing weight on the steered axle to determine the vehicle loading influencing the steering behavior of the vehicle.
Claim 35
Dependent Claim
15 words
The method according to claim 32, wherein the monotonically increasing function is a straight line.
Claim 36
Dependent Claim
33 words
The method according to claim 1, including the step of taking into consideration a high angular velocity of the steering wheel in a driving situation having a need for a greater assisting force.
Claim 37
Dependent Claim
45 words
The method according to claim 1, including the step of functionally checking the power assisted steering by comparing the manual torque to be applied by the vehicle driver with a desired value of the manual torque set on the basis of a controlled assisting force.
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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) | 1994-12-16 | 1995-06-17 | 1995-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-16 | 1999-06-17 | 1999-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-16 | 2003-06-17 | 2003-12-17 | $7700.00 | Window Closed / Lapsed |