STEERING APPARATUS, AUTOMOTIVE VEHICLE WITH THE SAME, AND STEERING CONTROL METHOD

• US 20080249686A1
• Filed: 03/25/2008
• Published: 10/09/2008
• Est. Priority Date: 04/06/2007
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Miura, Masahiro, Tamasho, Tadashi, Okubo, Toru, MIKURIYA, Yutaka, Kamada, Tetsurou
• Granted Patent: US 8,255,120 B2
• Time in Patent Office: Days
• US Class Current: 701/42
• CPC Class Codes: B62D 6/002 computing target steering angles for front or rear wheels B62D7/159 takes precedence
• CPC Class Codes: B62D 6/003 in order to control vehicle yaw movement, i.e. around a vertical axis B62D6/007 takes precedence
• CPC Class Codes: B62D 7/159 characterised by computing methods or stabilisation processes or systems, e.g. responding to yaw rate, lateral wind, load, road condition

Abstract

An automotive vehicle with a steering apparatus includes a steering wheel, front and rear steerable road wheels, and a steering mechanism for steering the front and rear steerable road wheels. The steering apparatus measures a steering wheel angle of the steering wheel; sets a desired position of a center of rotation about which the vehicle is to rotate for changing a heading angle of the vehicle with respect to a path of the vehicle; sets a desired turning behavior of the vehicle in accordance with the measured steering wheel angle and the desired position of the center of rotation; sets the desired front and rear road wheel steer angles in accordance with the desired turning behavior; and controls the steering mechanism in accordance with the desired front and rear road wheel steer angles.

Claims

1. A steering apparatus for a vehicle including a steering input device, front and rear steering output devices, and a steering mechanism for steering the front and rear steering output devices, the steering apparatus comprising:

a measurement section arranged to measure a steering input of the steering input device; and

a control section configured to;

set a desired position of a center of rotation about which the vehicle is to rotate for changing a heading angle of the vehicle with respect to a path of the vehicle;

set desired front and rear steering outputs in accordance with the measured steering input and the desired position of the center of rotation; and

control the steering mechanism in accordance with the desired front and rear steering outputs.

2. The steering apparatus as claimed in claim 1, wherein:

the steering input device includes a steering wheel;

the steering input includes a steering wheel angle of the steering wheel;

the front and rear steering output devices include front and rear steerable road wheels;

the desired front and rear steering outputs include desired front and rear road wheel steer angles; and

the control section is further configured to;

set a desired turning behavior of the vehicle in accordance with the measured steering input and the desired position of the center of rotation; and

set the desired front and rear steering outputs in accordance with the desired turning behavior.

3. The steering apparatus as claimed in claim 2, wherein the control section is further configured to:

set a desired turning radius of the vehicle in accordance with the measured steering input;

set a desired heading angle of the vehicle with respect to the path in accordance with the desired turning radius; and

set the desired turning behavior in accordance with the desired turning radius, the desired heading angle, and the desired position of the center of rotation.

4. The steering apparatus as claimed in claim 3, wherein the control section is further configured to set the desired turning radius in accordance with the measured steering input and a speed of the vehicle.

5. The steering apparatus as claimed in claim 1, wherein:

the control section is further configured to;

set the desired position of the center of rotation at a first position, when allowing the vehicle to rotate for changing the heading angle in a direction of turning of the vehicle; and

set the desired position of the center of rotation at a second position, when allowing the vehicle to rotate for changing the heading angle in a direction opposite to the direction of turning of the vehicle; and

the first position is ahead of the second position along a longitudinal direction of the vehicle.

6. The steering apparatus as claimed in claim 1, wherein the control section is further configured to:

set the desired position of the center of rotation at a position ahead of a predetermined reference point along a longitudinal direction of the vehicle, when allowing the vehicle to rotate for changing the heading angle in a direction of turning of the vehicle; and

set the desired position of the center of rotation at a position behind the predetermined reference point along the longitudinal direction of the vehicle, when allowing the vehicle to rotate for changing the heading angle in a direction opposite to the direction of turning of the vehicle.

7. The steering apparatus as claimed in claim 6, wherein the predetermined reference point is located at a center of mass of the vehicle.

8. The steering apparatus as claimed in claim 6, wherein the predetermined reference point is located at a driver'"'"'s seat of the vehicle.

9. The steering apparatus as claimed in claim 6, wherein the control section is further configured to set the desired position of the center of rotation at a position within a predetermined distance with respect to the predetermined reference point along the longitudinal direction of the vehicle.

10. A steering apparatus for a vehicle including a steering input device, front and rear steering output devices, and a steering mechanism for steering the front and rear steering output devices, the steering apparatus comprising:

means for measuring a steering input of the steering input device;

means for setting a desired position of a center of rotation about which the vehicle is to rotate for changing a heading angle of the vehicle with respect to a path of the vehicle;

means for setting desired front and rear steering outputs in accordance with the measured steering input and the desired position of the center of rotation; and

means for controlling the steering mechanism in accordance with the desired front and rear steering outputs.

11. A steering apparatus for a vehicle including a steering input device, and front and rear steering output devices, the steering apparatus comprising:

a sensor for measuring a steering input of the steering input device;

a steering mechanism for steering the front and rear steering output devices in accordance with desired front and rear steering outputs; and

a controller connected for signal communication to the sensor and the steering mechanism, and configured to;

set a desired path of the vehicle in accordance with the measured steering input;

set a desired sideslip angle of the vehicle in accordance with the measured steering input;

set a corrected desired sideslip angle of the vehicle in accordance with the desired sideslip angle;

set a desired yaw rate of the vehicle in accordance with the desired path and a rate of change of the corrected desired sideslip angle; and

set the desired front and rear steering outputs in accordance with the desired sideslip angle and the desired yaw rate.

12. An automotive vehicle comprising:

a steering input device;

front and rear steering output devices;

a steering mechanism for steering the front and rear steering output devices;

a measurement section arranged to measure a steering input of the steering input device; and

a control section configured to;

set a desired position of a center of rotation about which the vehicle is to rotate for changing a heading angle of the vehicle with respect to a path of the vehicle;

set desired front and rear steering outputs in accordance with the measured steering input and the desired position of the center of rotation; and

control the steering mechanism in accordance with the desired front and rear steering outputs.

13. A steering control method for a vehicle including a steering input device, front and rear steering output devices, and a steering mechanism for steering the front and rear steering output devices, the steering control method comprising:

measuring a steering input of the steering input device;

setting a desired position of a center of rotation about which the vehicle is to rotate for changing a heading angle of the vehicle with respect to a path of the vehicle;

setting desired front and rear steering outputs in accordance with the measured steering input and the desired position of the center of rotation; and

controlling the steering mechanism in accordance with the desired front and rear steering outputs.

14. The steering control method as claimed in claim 13, wherein the setting the desired front and rear steering outputs is implemented by:

setting a desired turning behavior of the vehicle in accordance with the measured steering input and the desired position of the center of rotation; and

setting the desired front and rear steering outputs in accordance with the desired turning behavior.

15. The steering control method as claimed in claim 14, wherein the setting the desired turning behavior is implemented by:

setting a desired turning radius of the vehicle in accordance with the measured steering input;

setting a desired heading angle of the vehicle with respect to the path in accordance with the desired turning radius; and

setting the desired turning behavior in accordance with the desired turning radius, the desired heading angle, and the desired position of the center of rotation.