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DE-102014117845-B4 - Headlight adjustment procedure

DE102014117845B4DE 102014117845 B4DE102014117845 B4DE 102014117845B4DE-102014117845-B4

Abstract

Method for adjusting the headlights of a motor vehicle, in particular for generating difference images, with a headlight designed to produce at least one vehicle-specific light distribution, wherein the light distribution has a characteristic contour with characteristic points (p), and a camera used to record the light distribution of the headlight, characterized in that that the headlight is controlled, in particular moved, depending on the contour of the light distribution, such that the characteristic contour of the light distribution becomes visible in a difference image (d), in particular completely, The following step is performed to determine the headlight setting: a) Determining the coordinates of the characteristic points (p) in a coordinate system of the headlight, taking into account the current setting of the headlight.

Inventors

  • Boris Kubitza
  • Carsten Wilks

Assignees

  • HELLA GmbH & Co. KGaA

Dates

Publication Date
20260513
Application Date
20141204

Claims (9)

  1. A method for adjusting the headlights of a motor vehicle, in particular for generating difference images, comprising a headlight designed to produce at least one vehicle-specific light distribution, wherein the light distribution has a characteristic contour with characteristic points (p), and a camera used to capture the light distribution of the headlight, characterized in that the headlight is controlled, in particular moved, depending on the contour of the light distribution such that the characteristic contour of the light distribution becomes visible in a difference image (d), in particular completely, wherein the following step is performed to determine the headlight setting: a) Determining the coordinates of the characteristic points (p) in a coordinate system of the headlight, whereby a current setting of the headlight is read.
  2. Procedure according to Claim 1 , characterized in that the following step is performed to determine the headlight setting: b) Transformation of the coordinates of the characteristic points (p) into a coordinate system of the camera.
  3. Method according to one of the preceding claims, characterized in that the following step is performed to determine the headlight setting: c) Determining direction vectors (v) of the characteristic points (p) in the coordinate system of the camera, and d) in particular normalizing the direction vectors of the characteristic points in the coordinate system of the camera.
  4. Method according to one of the preceding claims, characterized in that the following step is carried out to determine the headlight setting: e) Determining the direction of movement (r) of the headlight such that the difference area (f) generated when moving the headlight has a maximum (fmax) through all direction vectors, and in particular that the difference areas (f1, f2) of the direction vectors (v) do not overlap.
  5. Procedure according to one of the Claims 1 until 3 , characterized in that the following step is carried out to determine the headlight setting: e) Determining the direction of movement (r) of the headlight by bisecting an angle (α), in particular the largest angle (α), of two adjacent direction vectors (v1, v2).
  6. Procedure according to one of the Claims 4 or 5 , characterized in that the following step is performed to determine the headlight setting: f) Transformation of the direction of movement (r) to Claim 4 or 5 into the coordinate system of the headlight.
  7. Method according to one of the preceding claims, characterized in that the following step is performed to determine the headlight setting: g) Representing the coordinates of the characteristic points (p) in the coordinate system of the headlight.
  8. Method according to one of the preceding claims, characterized in that at least one of the following steps is performed for headlight adjustment: h) capturing a first image (1) at a first time (t1), i) controlling or moving the headlight according to one of the preceding claims, j) capturing a second image (2) at a second time (t2), k) calculating a difference image (d) between the first image (1) and the second image (2).
  9. Method according to one of the preceding claims, characterized in that at least one of the following steps is performed for headlight adjustment: I) Calculating the deviation between the current and the desired headlight position, in particular by comparing with predetermined patterns of light distribution, m) Controlling, in particular moving, the headlight to compensate for the deviation to the desired headlight position.

Description

The invention relates to a method for adjusting the headlights of a motor vehicle, in particular for generating difference images, with a headlight designed to generate at least one vehicle-specific light distribution, wherein the light distribution has a characteristic contour with characteristic points, and a camera used to capture the light distribution of the headlight. It is well known that headlights are used in motor vehicles to illuminate the road ahead. A crucial prerequisite for good visibility in the dark is correct headlight adjustment. Only with properly adjusted headlights can it be ensured that other road users are not dazzled and that the road is optimally illuminated. Headlights produce different light functions, such as high beam, low beam, and the like, which must comply with specific legal regulations depending on the traffic situation. However, over the course of vehicle use, and especially during operation, the headlight positions can deviate from their original settings. This can be caused, for example, by temperature-related volume changes and settling processes in the headlight materials. These deviations can ultimately lead to an undesirable shift in the light distribution and unacceptable glare. Therefore, after a certain period, the headlights must be readjusted. A method for headlight adjustment, such as differential image analysis, can be used for this purpose. In this method, a camera can record successive image sequences and analyze the differences between the images to determine the current position of the headlights. The camera can project the light distribution onto a measuring wall or directly in front of the vehicle. This creates a light-dark boundary between the illuminated and dark areas, which has a specific characteristic contour for each light distribution. In the case of a glare-free light distribution, which can also be referred to as high beam distribution, the light-dark boundary exhibits a characteristic kink between a horizontal and a vertical area. In the case of low beam distribution, the light-dark boundary shows a characteristic rise between a slightly lower and a slightly higher horizontal area, and so on. Using the headlight adjustment function, the camera is intended to first detect incorrectly adjusted headlights, after which an automatic adjustment can be performed. A crucial requirement for automatic headlight adjustment is the robust detection of the relevant light-dark boundary. Thus, accurate determination of the light-dark boundary has a significant influence on the adjustment result. However, this can be particularly difficult in unsuitable environments. A disadvantage that has emerged is that the light-dark boundary is often difficult to define and recognize. In particular, detecting the relevant light-dark boundary is difficult on surfaces with unevenness and/or markings, or in the presence of interfering ambient light. This unfortunately leads to unsatisfactory headlight alignment results and to glare for oncoming traffic. WO 2012 / 048 795 A1 discloses a method for adjusting and/or calibrating at least one headlight of a vehicle. It is therefore an object of the present invention to overcome at least one of the disadvantages described above, at least in part. In particular, it is an object of the present invention to provide a method for adjusting the headlights of a motor vehicle which enables improved generation of difference images and more precise headlight adjustment. The aforementioned problem is solved by a method with the features of independent claim 1. Advantageous embodiments of the invention are specified in the dependent claims. The invention includes the technical teaching that the headlight can be controlled, in particular moved, depending on the contour (or shape) of the light distribution, such that the characteristic contour of the light distribution becomes visible, in particular completely, in a difference image. The combination of difference image analysis in conjunction with targeted headlight movement or control advantageously leads to robust detection of the headlight's light-dark boundary. To recognize the characteristic contour of the light distribution in the difference image, it is important to move the headlights in a direction appropriate to the respective situation and the respective light distribution. In the case of an LED headlight, the LED matrix or the individual LEDs can be controlled according to the invention such that the characteristic contour of the light distribution becomes visible in the difference image. The direction of movement or control of the headlights depends on the contour of the respective light distribution, so that there is a suitable direction of movement or control for each light distribution, in which the light-dark boundary moves in the image. needs to move in order to achieve the best results. The method according to the invention advantageously serves to determine an optimal head