Method and apparatus for detecting vehicle distance

• US 20040080450A1
• Filed: 05/19/2003
• Published: 04/29/2004
• Est. Priority Date: 10/28/2002
• Status: Active Grant

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Cheong, Hyuck-Jin
• Granted Patent: US 6,795,014 B2
• Time in Patent Office: Days
• US Class Current: 342/118
• CPC Class Codes: G01S 13/867 Combination of radar systems with cameras
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9322 using additional data, e.g. driver condition, road state or weather data
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 7/4026 Antenna boresight
• CPC Class Codes: G01S 7/4034 in elevation, i.e. in the vertical plane
• CPC Class Codes: G01S 7/4091 during normal radar operation

Abstract

Stableness in detecting the distance to a preceding vehicle by calculating the distance to the preceding vehicle using reflected waves of a radar beam scanned at a scanning angle that is adjusted based on lane markers extracted from a road image obtained by a camera.

Claims

1. A method for a vehicle equipped with a radar for detecting distance to a preceding vehicle, comprising:

receiving a signal of a road image from a camera;

extracting lane markers from the road image;

adjusting a scanning angle of a radar based on the extracted lane markers; and

calculating a distance to a preceding vehicle using reflected waves of a radar beam scanned at the adjusted scanning angle.

2. The method of claim 1, wherein said adjusting a scanning angle comprises:

calculating a height within said image at which a horizontal distance between the extracted lane markers is a predetermined distance;

calculating a slope of the road based on the calculated height; and

adjusting a scanning angle of the radar based on the calculated slope of the road.

3. The method of claim 2, wherein said calculating a slope of a road calculates the slope of the road based on a difference between the calculated height and a reference height.

4. The method of claim 3, wherein the reference height is an average value of the calculated height over a predetermined period.

5. An apparatus for a vehicle for detecting distance to a preceding vehicle, the apparatus comprising:

a radar for scanning a radar beam from the vehicle;

a scanning angle adjustor for adjusting a scanning angle of the radar;

a camera for acquiring a road image; and

an electronic control unit activated by predetermined software wherein said predetermined software comprises instructions for;

receiving a signal of a road image from the camera;

extracting lane markers from the road image;

adjusting the scanning angle of the radar based on the extracted lane markers; and

calculating a distance to the preceding vehicle using reflected waves of the radar beam scanned at the adjusted scanning angle.

6. The apparatus of claim 5, wherein said adjusting scanning angle comprises:

calculating a height at which a horizontal distance between the extracted lane markers is a predetermined distance;

calculating slope of a road based on the calculated height; and

adjusting a scanning angle of the radar based on the calculated slope of the road.

7. The apparatus of claim 6, wherein said calculating slope of a road calculates the slope of the road based on a difference between the calculated height and a reference height.

8. The apparatus of claim 7, wherein the reference height is an average value of the calculated height over a predetermined period.

9. A method for calculating distance to a preceding vehicle, comprising:

acquiring an image of a forthcoming road;

adjusting a scanning angle of a radar in accordance with said image of a forthcoming road; and

calculating a distance to a preceding vehicle based on reflected radar waves from said radar projected at said adjusted scanning angle.

10. The method of claim 9, wherein said image includes lane markers.

11. The method of claim 10, further comprising, before said adjusting, extracting lane markers from said image.

12. The method of claim 11, further comprising before said calculating a distance, calculating a height within said image corresponding to lane markers separated by a horizontal distance substantially equal to a predetermined distance.

13. The method of claim 12, further comprising, before said calculating a distance, calculating a slope of the road based on said calculated height within said image.

14. The method of claim 13, wherein said calculating of a slope of the road is based on the difference between the calculated height within said image and a reference height corresponding to lane markers separated by a predetermined distance.

15. The method of claim 13, wherein said calculating of a slope of the road is based on an average value of the calculated height within said image corresponding to lane markers separated by a predetermined distance of at least two sets of lane markers.