Method and apparatus for automatic steering control of automobile

• US 5,163,002 A
• Filed: 05/16/1991
• Issued: 11/10/1992
• Est. Priority Date: 05/18/1990
• Status: Expired due to Term

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kurami, Kunihiko
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/700,707
• Time in Patent Office: 544 Days
• Field of Search: 364/424.02, 364/460, 364/461, 364/424.05, 180/167, 180/168, 180/169, 358/103, 318/587
• US Class Current: 701/28
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means

Abstract

A method and an apparatus for automatic steering control of an automobile, which can be carried out efficiently by using only one regression equation for calculating a steering angle. In the apparatus, a white line drawn on a road is detected by camera; a distance of the detected white line with respect to a view axis of the camera is determined; the determined distance is transformed into a corresponding distance of the white line with respect to a prescribed point on a central axis of the automobile; a steering angle is calculated according to the obtained corresponding distance; and a steering of the automobile is controlled according to the calculated steering angle such that the automobile follows the white line.

Claims

1. A method of automatic steering control of an automobile, comprising the steps of:

detecting a white line drawn on a road by camera means;

determining a distance of the white line detected at the detecting step with respect to a view axis of the camera means;

transforming the distance determined at the determining step into a corresponding distance of the white line with respect to a prescribed point on a central axis of the automobile;

calculating a steering angle according to the corresponding distance obtained at the transforming step; and

controlling a steering of the automobile according to the steering angle calculated at the calculating step such that the automobile follows the white line.

2. The method of claim 1, wherein the camera means comprises a plurality of camera units oriented along mutually different directions, and wherein at the detecting step, the white line is detected by one of the camera units.

3. The method of claim 1, wherein the camera means comprises a single camera unit which can change its own orientation, and wherein at the detecting step, the white line is detected at a particular orientation of the single camera unit.

4. The method of claim 1, wherein at the calculating step, the steering angle is calculated by using a regression equation for calculating the steering angle from distances with respect to the prescribed point of the central axis of the automobile.

5. The method of claim 1, wherein at the determining step, the distance of the white line with respect to the view axis of the camera means is determined as a distance from a point on the view axis of the camera means to an intersection point of a line perpendicular to the view axis of the camera means at said point and the white line.

6. The method of claim 5, wherein the determining step includes a step of adjusting a coordinate of said point on the view axis of the camera means before determining the distance, such that a projection of the intersection point onto the central axis of the automobile in a direction perpendicular to the central axis of the automobile substantially coincides with the prescribed point on the central axis of the automobile.

7. The method of claim 6, wherein at the adjusting step, a coordinate of the projection of the intersection point is determined from a coordinate of said point on the view axis of the camera means and the distance of the white line with respect to the view axis of the camera means determined at the determining step.

8. The method of claim 6, wherein at the transforming step, the distance determined at the determining step is transformed according to a coordinate of the prescribed point on the central axis of the automobile and the distance of the white line with respect to the view axis of the camera means determined at the determining step.

9. An apparatus for automatic steering control of an automobile, comprising:

at least one camera means for detecting a white line drawn on a road;

means for determining a distance of the white line detected by the camera means with respect to a view axis of the camera means;

means for transforming the distance determined by the determining means into a corresponding distance of the white line with respect to a prescribed point on a central axis of the automobile;

means for calculating a steering angle according to the corresponding distance obtained by the transforming means; and

means for controlling a steering of the automobile according to the steering angle calculated by the calculating means such that the automobile follows the white line.

10. The apparatus of claim 9, wherein the camera means comprises a plurality of camera units oriented along mutually different directions, and the white line is detected by one of the camera units.

11. The apparatus of claim 9, wherein the camera means comprises a single camera unit which can change its own orientation, and the white line is detected at a particular orientation of the single camera unit.

12. The apparatus of claim 9, wherein the calculating means calculates the steering angle by using a regression equation for calculating the steering angle from distances with respect to the prescribed point of the central axis of the automobile.

13. The apparatus of claim 9, wherein the determining means determines the distance of the white line with respect to the view axis of the camera means as a distance from a point on the view axis of the camera means to an intersection point of a line perpendicular to the view axis of the camera means at said point and the white line.

14. The apparatus of claim 13, wherein the determining means includes means for adjusting a coordinate of said point on the view axis of the camera means before determining the distance, such that a projection of the intersection point onto the central axis of the automobile in a direction perpendicular to the central axis of the automobile substantially coincides with the prescribed point on the central axis of the automobile.

15. The apparatus of claim 14, wherein the adjusting means determines a coordinate of the projection of the intersection point from a coordinate of said point on the view axis of the camera means and the distance of the white line with respect to the view axis of the camera means determined by the determining means.

16. The apparatus of claim 14, wherein the transforming means transforms the distance determined by the determining means according to a coordinate of the prescribed point on the central axis of the automobile and the distance of the white line with respect to the view axis of the camera means determined by the determining means.