Steering assistance system and method

Patent metadata

Field	Value
Publication number	US-2018281848-A1
Application number	US-201815941239-A
Country	US
Kind code	A1
Filing date	Mar 30, 2018
Priority date	Mar 31, 2017
Publication date	Oct 4, 2018
Grant date	—

Abstract

A method for determining a steering angle amplitude of a steering wheel of a vehicle likely to occur during a lane change, including determining a steering angle measured value of a steering wheel of a vehicle at a time of measurement during a lane change; determining a steering angular velocity measured value of the steering wheel at the time of measurement; and determining a steering angle amplitude likely to occur during the lane change at a later point in time than the time of measurement based on the at least the steering angle measured value at the steering angular velocity measured value at the time of measurement.

First claim

What is claimed is:

1 . A method for determining a steering angle amplitude of a steering wheel of a vehicle likely to occur during a lane change, comprising:
determining a steering angle measured value of a steering wheel of a vehicle at a time of measurement during a lane change; determining a steering angular velocity measured value of the steering wheel at the time of measurement; and determining a steering angle amplitude likely to occur during the lane change at a later point in time than the time of measurement based on the steering angle measured value and the steering angular velocity measured value at the time of measurement.

2 . The method of claim 1 wherein the determination of the likely occurring steering angle amplitude includes weighting at least the steering angular velocity measured value with a normalization factor dependent on an estimated steering frequency value.

3 . The method of claim 2 wherein the estimated steering frequency value is between 0.6 Hz and 0.8 Hz.

4 . The method of claim 2 wherein the estimated steering frequency value is determined as

f
est

=

min


(

f
max

,

1

2


(

t
m

-

t
0

)

)

,

when t 0 ≤t m ≤t 1 , wherein t m is the time of measurement, t 0 is the point in time of the beginning of steering to begin the lane change, t 1 is the point in time of the beginning of a counter-steering to terminate the lane change, and f max is an estimated maximum steering frequency value.

5 . The method of claim 2 wherein the likely occurring steering angle amplitude is determined as

Δ
est

=

α
stw
2

+

(

1

2

π




f
est



α
.

stw

)

2

,

wherein α stw is the steering angle measured value, {dot over (α)} stw is the steering angular velocity measured value, and f est is the estimated steering frequency value.

6 . The of claim 2 wherein the likely occurring steering angle amplitude is determined as

Δ
est

=

max


(



α
stw



,



1

2

π




f
est



α
.

stw



)

,

wherein α stw is the steering angle measured value, {dot over (α)} stw is the steering angular velocity measured value, and f est is the estimated steering frequency value.

7 . The method of claim 1 including a steering assistance system that generates an additional steering torque during the lane change.

8 . The method of claim 1 wherein the determination of the steering angle measured value, the determination of the steering angular velocity measured value, and the determination of the steering angle amplitude likely to occur during the lane change at a later point in time than the time of measurement take place at least over a measurement period for multiple times of measurement.

9 . The method of claim 8 wherein the determination of the likely occurring steering angle amplitude includes an averaging of multiple likely occurring steering angle amplitudes determined in the measurement period at different times of measurement
or includes a low-pass filtering of a steering angle amplitude determined continuously over the measurement period.

10 . The method of claim 7 wherein if the likely occurring steering angle amplitude is greater than a stability threshold value assigned to a stable driving state of the vehicle the steering torque additionally generated by the steering assistance system is disengaged.

11 . The method of claim 10 wherein the stability threshold value depends on a speed of the vehicle.

12 . The method of claim 7 including:
determining a required steering angle amplitude; an

Assignees

• Ford Global Tech Llc

Inventors

• Zegelaar Peter W A
• Bosch Helmuth
• Schiebahn Michael

Classifications

• B62D6/003 Primary

  in order to control vehicle yaw movement, i.e. around a vertical axis (B62D6/007 takes precedence) · CPC title

• B60W50/00

  Details of control systems for road vehicle drive control not related to the control of a particular sub-unit {, e.g. process diagnostic or vehicle driver interfaces} · CPC title

• B60W2050/0019

  Control system elements or transfer functions · CPC title

• B60W2710/20

  Steering systems · CPC title

• B62D15/0255

  Automatic changing of lane, e.g. for passing another vehicle · CPC title