Method, comprising calculating a frequency representation of an image of a projection surface, for depth perception based on vehicle headlights arranged on both sides

• US 10,821,875 B2
• Filed: 06/17/2019
• Issued: 11/03/2020
• Est. Priority Date: 07/09/2018
• Status: Active Grant

• Current Assignee: Dr Ing hc F Porsche AG (Volkswagen AG)
• Original Assignee: Dr Ing hc F Porsche AG (Volkswagen AG)
• Inventors: Soehner, Sebastian, Schneider, Christian
• Primary Examiner(s): Alaeddini, Borna
• Application Number:
  US16/442,596
• Publication Number:
  US 20200010011A1
• Time in Patent Office: 505 Days
• CPC Class Codes: B60Q 1/0023 the element being a sensor, e.g. distance sensor, camera
• CPC Class Codes: B60Q 1/08 automatically
• CPC Class Codes: B60Q 1/085 due to special conditions, e.g. adverse weather, type of road, badly illuminated road signs or potential dangers B60Q1/10, B60Q1/12, B60Q1/1423 take precedence
• CPC Class Codes: B60Q 2300/41 preceding vehicle
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: B60Q 2300/45 Special conditions, e.g. pedestrians, road signs or potential dangers
• CPC Class Codes: F21S 41/60 characterised by a variable light distribution
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence
• CPC Class Codes: G01B 11/2513 with several lines being projected in more than one direction, e.g. grids, patterns
• CPC Class Codes: G01S 17/48 Active triangulation systems, i.e. using the transmission and reflection of electromagnetic waves other than radio waves
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: G08G 1/00 Traffic control systems for road vehicles arrangement of road signs or traffic signals E01F9/00 ; automatic vehicle control B62D

Abstract

A method for depth perception based on vehicle headlights arranged on both sides of a vehicle includes projecting, by a first vehicle headlight, a first characteristic light pattern onto a projection surface and projecting, by a second vehicle headlight, a second characteristic light pattern. The method also includes capturing an image of the projection surface using an image capturing unit of the vehicle, calculating a frequency representation of the first and second characteristic light patterns in the captured image, and calculating, by evaluating frequency components in the frequency representation of the first and second characteristic light patterns, a coverage coefficient which is correlated with the degree of mutual covering of the first and second characteristic light patterns. The method further includes comparing the coverage coefficient with a coverage threshold value and displacing the first and second characteristic light patterns relative to one another if there is insufficient mutual covering.

Claims

1. A method for depth perception based on vehicle headlights arranged on both sides of a vehicle, the method comprising:

projecting, by a first vehicle headlight, a first characteristic light pattern onto a projection surface and projecting, by a second vehicle headlight, a second characteristic light pattern onto the projection surface;

capturing an image of the projection surface using an image capturing unit of the vehicle;

calculating a frequency representation of the first and second characteristic light patterns in the captured image;

calculating, by evaluating frequency components in the frequency representation of the first and second characteristic light patterns, a coverage coefficient which is correlated with a degree of mutual covering of the first and second characteristic light patterns;

comparing the coverage coefficient with a coverage threshold value; and

displacing the first and second characteristic light patterns relative to one another if the comparing the coverage coefficient with the coverage threshold value shows that there is insufficient mutual covering between the first and second characteristic light patterns.

2. The method as claimed in claim 1, wherein the first and second characteristic light patterns are the same light pattern.

3. The method as claimed in claim 1, wherein the first and second characteristic light patterns have a chessboard pattern in which each light-filled segment corresponds to a characteristic structure.

4. The method as claimed in claim 1, wherein the first and second characteristic light patterns are formed by pulse-width modulated actuation of the first and second vehicle headlights.

5. The method as claimed in claim 1, wherein the calculating the coverage coefficient includes calculating a sum of amplitudes of the frequency components in the frequency representation of the first and second characteristic light patterns in the captured image.

6. The method as claimed in claim 1, wherein the coverage threshold value represents an overlap of the first and second characteristic light patterns, in which characteristic structures of the characteristic light patterns substantially cover one another.

7. The method as claimed in claim 1, wherein there is insufficient mutual covering between the first and second characteristic light patterns if the coverage coefficient is greater than the coverage threshold value.

8. The method as claimed in claim 1, further comprising:

detecting at least one characteristic structure arranged in an overlap region of the first and second characteristic light patterns; and

assigning the detected characteristic structure to a first segment of the first headlight and to a second segment of the second headlight, wherein the first segment of the first headlight produces the overlap region of the first characteristic light pattern and the second segment of the second headlight produces the overlap region of the second characteristic light pattern.

9. The method as claimed in claim 8, further comprising:

calculating one respective triangulation ray for each of the first and second headlights, wherein each respective triangulation ray is defined by a first point, which corresponds to a position of the detected characteristic structure in a space, and a second point, which corresponds to a position of one of the first segment of the first headlight or the second segment of the second headlight; and

calculating a distance between the vehicle and the projection surface by triangulation using the two calculated triangulation rays and a baseline that corresponds to the distance between the two headlights of the vehicle.

10. The method as claimed in claim 1, wherein the projecting, by the first vehicle headlight, the first characteristic light pattern onto the projection surface and the projecting, by the second vehicle headlight, the second characteristic light pattern is performed such that the first and second characteristic light patterns overlap one another at least partially.

11. A motor vehicle comprising:

a vehicle camera configured to capture an image of a projection surface onto which a first characteristic light pattern is projected by a first vehicle headlight and onto which a second characteristic light pattern is projected by a second vehicle headlight; and

a light pattern evaluator configured to;

calculate a frequency representation of the first and second characteristic light patterns in the captured image;

calculate, by evaluating frequency components in the frequency representation of the first and second characteristic light patterns, a coverage coefficient which is correlated with the degree of mutual covering of the first and second characteristic light patterns;

compare the coverage coefficient with a coverage threshold value, and

displace the first and second characteristic light patterns relative to one another if the comparing the coverage coefficient with the coverage threshold value shows that there is insufficient mutual covering between the first and second characteristic light patterns.