METHOD OF ADJUSTING MOTOR VEHICLE HEADLIGHTS FOR ROAD TOPOGRAPHY

Abstract

A method for adjusting a distribution of light from a headlight of a first motor vehicle in order to avoid the headlight blinding of dazzling a driver of a leading vehicle travelling ahead of and in the same direction as the first vehicle. The method includes: detecting a following distance between the vehicle and the leading vehicle on an initial road section; operating the headlight at a first illumination range less than or equal to the following distance; detecting a directionally-deviating road section ahead of and having a direction different from the initial road section; detecting that the leading vehicle has moved beyond a transition between the initial road section and the directionally-deviating road section; operating the headlight at a second illumination range not extending beyond the transition; and operating the headlight at the first illumination range after the vehicle reaches the transition.

Claims

1. A method for controlling a headlight of a vehicle, comprising: detecting a following distance between the vehicle and a leading vehicle traveling ahead of the vehicle on an initial road section; operating the headlight at a first illumination range less than or equal to the following distance; detecting a directionally-deviating road section ahead of and having a direction different from the initial road section; detecting that the leading vehicle has moved beyond a transition between the initial road section and the directionally-deviating road section; operating the headlight at a second illumination range not extending beyond the transition; and operating the headlight at the first illumination range after the vehicle reaches the transition.

2. The method of claim 1, wherein the direction of the directionally-deviate road section deviates from the initial road section in a vertical plane and corresponds to a hilltop.

3. The method of claim 2, wherein the hilltop is detected by determining an incline of the initial road section and an incline of a road section ahead of the vehicle.

4. The method of claim 1, wherein the directionally-deviating road section is detected using topographical information.

5. The method of claim 4, wherein at least a portion of the topographical information is transmitted to the vehicle from the leading vehicle.

6. The method of claim 4, wherein at least a portion of the topographical information is transmitted to the vehicle from a traffic management system.

7. A method for controlling a headlight of a vehicle, comprising: detecting a following distance between the vehicle and a leading vehicle traveling ahead on an initial road section; setting a headlight maximum illumination range to the following distance; detecting that the leading vehicle has moved onto a directionally-deviating road section ahead of the initial road section; setting the headlight maximum illumination range to short of a start of the directionally-deviating road section; detecting that the vehicle has reached the start; and setting a headlight maximum illumination range to the following distance.

8. The method of claim 7, wherein the directionally-deviating road section changes direction from the initial road section in a vertical plane, and the start corresponds to a hilltop.

9. The method of claim 8, wherein the hilltop is detected by determining an incline of the initial road section and an incline of a road section ahead of the vehicle.

10. The method of claim 7, wherein the directionally-deviating road section is detected using topographical information.

11. The method of claim 10, wherein at least a portion of the topographical information is transmitted to the vehicle from the leading vehicle.

12. The method of claim 10, wherein at least a portion of the topographical information is transmitted to the vehicle from a traffic management system.

13. A method comprising: detecting a following distance between a vehicle having a headlight and a leading vehicle traveling on a road section; setting a headlight illumination range to the following distance; detecting that the leading vehicle has moved onto a directionally-deviating road section; setting the illumination range to short of a start of the directionally-deviating road section; detecting the vehicle reaching the start; and setting the illumination range to the following distance.

14. The method of claim 13, wherein the directionally-deviating road section changes direction in a vertical plane, and the start corresponds to a hilltop.

15. The method of claim 14, wherein the hilltop is detected by determining an incline of the road section and an incline of a road section ahead of the vehicle.

16. The method of claim 13, wherein the directionally-deviating road section is detected using topographical information.

17. The method of claim 16, wherein at least a portion of the topographical information is transmitted to the vehicle from the leading vehicle.

18. The method of claim 16, wherein at least a portion of the topographical information is transmitted to the vehicle from a traffic management system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 illustrates a stretch of road having two motor vehicles shortly prior to traversing a hilltop; and

[0025] FIG. 2 illustrates a flow diagram describing a method disclosed herein.

DETAILED DESCRIPTION

[0026] An exemplary embodiment is described below with reference to the figures for adjusting a distribution of light of a headlight 3 of a first motor vehicle 1 in such a manner that a leading motor vehicle 2 (traveling ahead of and in the same direction as the first motor vehicle) is not dazzled by the light distribution 12 of the headlight 3.

[0027] FIG. 2 illustrates a flow diagram that illustrates the method in accordance with the invention of a distribution of light of a headlight 3 of a first motor vehicle 1. In the present exemplary embodiment, the road section that changes the direction of the road (referred to as the directionally-deviating section) is a hilltop 11. The present invention involves the steps of determining and storing the length 13 of the stretch of road between the leading vehicle 2 and the following motor vehicle 1 (also referred to as the following distance), passing of the hilltop 11 first by the leading vehicle 2 and subsequently by the following motor vehicle 1, and illuminating the road after the two motor vehicles 1, 2 have traversed the hilltop 11 in such a manner that the leading vehicle 2 is not dazzled.

[0028] FIG. 1 illustrates a stretch of road 10 including a crest or hilltop 11. Two motor vehicles 1, 2 are located on the road 10 shortly prior to traversing the hilltop 11. The following motor vehicle 1 detects the leading vehicle 2, (FIG. 2, step 100). The leading vehicle 2 and the following motor vehicle 1 are separated by a following distance 13. The headlight 3 of the vehicle 1 is operated so as to project a light distribution 12 having a maximum range limited to illuminate a stretch of road that does not extend beyond the following distance 13 (FIG. 2, step 101). The driver of the leading vehicle 2 is, as a consequence, not dazzled by the light distribution 12 of the headlamp 3 being visible in a rear-view mirror. The following distance 13 is stored in the following motor vehicle 1 (FIG. 2, step 102). The road beyond the stretch of road equal to distance 13 must not be illuminated so that the leading vehicle 2 is not dazzled.

[0029] The following motor vehicle 1 detects the hilltop 11 in the road ahead, (FIG. 2, step 103). The leading vehicle 2 now passes beyond or over the hilltop 11 and due to passing beyond the crest of the hilltop moves out of the detection range or zone of the following motor vehicle 1 (FIG. 2, step 104). The following motor vehicle 1 is therefore no longer able to detect the leading vehicle 2 using its on-board sensor system. The following motor vehicle 1 now only detects the hilltop 11. When the following motor vehicle 1 is approaching the hilltop 11, the illumination distance of the road 10 provided by the headlight 3 is reduced in such a manner that the region above the hilltop 11 is not illuminated (FIG. 2, step 105). This means that the distribution of light of the headlight 3 illuminates only the portion of the road 10 between the following motor vehicle 1 and the start or peak of the hilltop 11. The maximum illumination range provided by the headlight 3 is adjusted such that the upper limit of the light pattern it does extend beyond the crest or apex of the hilltop. Light that would otherwise have passed above the hilltop 11 may be shielded by way of example by means of screens in the headlight 3 which limit the upper edge of the light beam. Alternatively, it is also possible to tilt the headlight 3 in the direction of the road 10 with the result that the upper edge or limit of the light beam from the headlight 3 does not illuminate the region above the hilltop 11. The illumination between the following motor vehicle 1 and the crest of the hilltop 11 is therefore adjusted in a dynamic manner as the vehicle 1 approaches the hilltop. The closer the following motor vehicle 1 comes to the crest of the hilltop 11, the more intense the reduction in the illumination. As soon as the following motor vehicle 1 passes the hilltop 11 (FIG. 2, step 106), the illumination range ahead of the following motor vehicle 1 increases.

[0030] In accordance with the disclosed method, the illumination distance of the roadway ahead of the following motor vehicle 1 is limited. In contrast with conventional methods, in this case the road 10 ahead of the following motor vehicle 1 is not illuminated to its maximum extent. As soon as the following motor vehicle 1 has passed the hilltop 11, there is a particularly high probability that the leading vehicle 2 will reenter the detection range or zone of the following motor vehicle 1. In order to prevent the leading vehicle 2 from becoming dazzled, the stretch of road ahead of the following motor vehicle 1 is illuminated only to a range which corresponds to the previously determined following distance 13 (FIG. 2, step 108). As described above, the illuminated road length 13 corresponds to the following distance between the leading vehicle 2 and the following motor vehicle 1. For this purpose, after the following motor vehicle 1 has passed the crest of the hilltop 11, the stretch of road length 13 is called up (FIG. 2, step 107), wherein the following motor vehicle 1 consequently only illuminates to the maximum extent the stretch of road having the stretch of road length 13. A leading vehicle 2 is therefore not dazzled, even if the leading vehicle 2 has temporarily moved out of the detecting range or zone of the following motor vehicle 1 as a result of traversing the hilltop 11.

[0031] A hilltop 11 in the road ahead 10 may be determined via an incline of a road section below the first motor vehicle 1 and via an incline of a road section far ahead of the first motor vehicle 1. A hilltop 11 that is present in the road ahead 10 of the first motor vehicle 1 is detected by means of comparing the two inclines. However, the hilltop may also be detected with the aid of topographical information. This topographical information may on the one hand be transmitted by at least one further motor vehicle to the first motor vehicle 1 or said topographical information may be transmitted with the aid of a traffic management system from said motor vehicle to the first motor vehicle 1. Alternatively, the information regarding a presence of a hilltop 11 may also be transmitted to the first motor vehicle 1 both by multiple motor vehicles as well as in conjunction with a traffic management system. As a further alternative, it is possible that the hilltop is detected by means of a camera system and image evaluating software.

[0032] The first motor vehicle 1 comprises at least two wheels. It is preferred that the method in accordance with the invention may be used in a first motor vehicle 1 having four wheels. The leading vehicle 2 comprises at least two wheels and is preferably a motor vehicle having four wheels. The leading vehicle 2 may consequently be a motor vehicle having two wheels, such as by way of example a motorbike, or alternatively may be a motor vehicle having more than four wheels, such as by way of example a passenger car or a truck.

[0033] The present invention has been described in detail with reference to an exemplary embodiment for explanatory purposes. However, a person skilled in the art recognizes that deviations from the exemplary embodiment are possible. By way of example, the method may be used on other motor vehicles that by way of example drive on field paths and are not actively involved in traffic. The invention is therefore not to be limited to the exemplary embodiment but rather is only to be limited by means of the attached claims.