Steering apparatus, automotive vehicle with the same, and steering control method

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

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

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

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;

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 the 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 the desired turning radius in accordance with the measured steering input and a speed of the vehicle.

4. 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.

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 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.

6. The steering apparatus as claimed in claim 5 , wherein the predetermined reference point is located at a center of mass of the vehicle.

7. The steering apparatus as claimed in claim 5 , wherein the predetermined reference point is located at a driver's seat of the vehicle.

8. The steering apparatus as claimed in claim 5 , 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.

9. 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 turning radius of the vehicle in accordance with the measured steering input;

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

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

means for 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;

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.

10. 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 turning radius of the vehicle in accordance with the measured steering input;

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

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

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;

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.

11. 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 turning radius of the vehicle in accordance with the measured steering input;

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

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

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;

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.

12. The steering control method as claimed in claim 11 , wherein the setting the desired front and rear steering outputs is implemented by:

setting the 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.