Method for determining the articulation angle of a combination

Patent metadata

Field	Value
Publication number	US-11048962-B2
Application number	US-201816610412-A
Country	US
Kind code	B2
Filing date	May 3, 2018
Priority date	May 3, 2017
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

The invention relates to a method and to a device for determining the articulation angle of a combination, consisting of a towing vehicle and a trailer attached using a tongue, by identifying the hitch tongue using a digital back-up camera with variable exposure times, the following steps being carried out: a) recording a first color image of the rear environment of the towing vehicle, the color image being based on the HSY color space, b) analyzing the hue values, saturation values and brightness values of adjacent surfaces of a vehicle-environment region that is to be evaluated, c) determining the tongue from the first color image using an edge detection method in order to determine the articulation angle if the hue values, saturation values and brightness values of adjacent surfaces in the region that is to be evaluated are substantially equal, “substantially equal” meaning that the values of hue, saturation and brightness of adjacent surfaces differ by at most a first threshold in percent, d) recording a second color image in the HSY color space if in the first color image the hue values and saturation values of adjacent surfaces in the region that is to be evaluated are substantially equal while the brightness values of the adjacent surfaces deviate greatly from each other, “deviate greatly from each other” meaning that the brightness values of adjacent surfaces differ from each other by more than a second threshold in percent, the exposure time of the second color image being selected in such a way that the brightness values of the adjacent surfaces within the vehicle-environment region that is to be evaluated are substantially equal, e) determining the tongue from the second color image by means of an edge detection method in order to determine the articulation angle.

First claim

What is claimed is:

1. A method for determining the articulation angle of a combination consisting of a towing vehicle and a trailer attached using a drawbar by recognizing the trailer drawbar with a digital backup camera with variable exposure times, wherein the method has the following steps:
a) recording a first color image of the rear environment of the towing vehicle, wherein the color image is based on the HSV color space;
b) analyzing the color values H, saturation values S and brightness values V of adjacent surfaces of an area of the vehicle environment to be evaluated;
c) determining the drawbar from the first color image using an edge detection method for determining the articulation angle if the color values H, saturation values S and brightness values of adjacent surfaces are substantially the same in the area to be evaluated, wherein “substantially the same” is defined in that the respective values of color, saturation and brightness of adjacent surfaces are distinguished by a maximum of a first threshold in percent;
d) recording a second image in the HSV color space if the color values H and the saturation values S of adjacent surfaces in the area to be evaluated in the first color image are substantially the same, whereas the brightness values V of the adjacent surfaces deviate strongly from each other, wherein “strongly deviating from each other” is defined in that the brightness values V of adjacent surfaces differ from each other by more than a second threshold in percent, wherein the exposure time of the second color image is selected such that the brightness values V of the adjacent surfaces are substantially the same within the area of the vehicle environment to be evaluated; and
e) determining the drawbar from the second color image using an edge detection method to determine the articulation angle.

2. The method of claim 1 , wherein the area to be evaluated comprises the drivable surface in the area of the drawbar.

3. The method of claim 2 , wherein the first threshold is 1%.

4. The method of claim 2 , wherein the second threshold is 10%.

5. The method of claim 2 , wherein an HDR-capable backup camera is used.

6. The method of claim 1 , wherein the first threshold is 1%.

7. The method of claim 6 , wherein the second threshold is 10%.

8. The method of claim 6 , wherein an HDR-capable backup camera is used.

9. The method of claim 1 , wherein the second threshold is 10%.

10. The method of claim 9 , wherein an HDR-capable backup camera is used.

11. The method of claim 1 , wherein an HDR-capable backup camera is used.

12. A device for determining the articulation angle of a combination consisting of a towing vehicle and a trailer attached by a drawbar, wherein the device is configured and designed to perform the method of claim 1 , having:
a backup camera with variable exposure times for generating color images for observing the rear environment of the towing vehicle;
an apparatus for transforming the recorded color images into the HSV color space;
an apparatus for comparing the color values H, brightness values V and saturation values S of adjacent surfaces in an area to be evaluated of the HSV-transformed color images;
an apparatus for calculating an exposure time as a function of the comparisons of the color values H, saturation values S and brightness values V of adjacent surfaces of the area to be evaluated; and
an apparatus for determining the articulation angle by an edge detection method from the color images.

13. The device of claim 12 , wherein an HDR-capable backup camera is used.

14. Use of the device of claim 12 in a trailer maneuvering assist.

15. A trailer maneuvering assist with a device of claim 12 .

Assignees

• Volkswagen Ag

Inventors

• Jähnisch Marco
• Berger Oliver
• Erfurth Christoph

Classifications

• B60D1/62 Primary

  involving supply lines, electric circuits or the like · CPC title

• H04N23/73

  by influencing the exposure time · CPC title

• H04N23/71

  Circuitry for evaluating the brightness variation · CPC title

• G06V20/56

  exterior to a vehicle by using sensors mounted on the vehicle · CPC title

• B60R2300/808

  for facilitating docking to a trailer · CPC title