Method for controlling at least one headlight of a motor vehicle and motor vehicle with a headlight system

Abstract

The present invention relates to a method for controlling at least one headlight of a motor vehicle (1), wherein the headlight is configured to generate a light distribution (4) with a glare-reduction region (41) around another motor vehicle (3) traveling ahead in a front-side vehicle environment. Furthermore, the invention relates to a motor vehicle (1) having a headlight system. The method comprises controlling the headlight such that the glare-reduction region (41) is adjusted depending on a current distance value if the current distance value lies within an individual tolerance band.

Description

The present invention relates to a method for controlling at least one headlight of a motor vehicle, wherein the headlight is configured to generate a light distribution with a glare suppression area around another motor vehicle driving in front of the vehicle surroundings. The invention further relates to a motor vehicle having a headlight system.Nowadays, headlight systems are known which make it possible to flexibly adapt the light distribution in front of the motor vehicle. In order to avoid glare from other road users, in particular from other motor vehicles traveling ahead, it is necessary to save them in the generated light distribution. Avoiding the glare of other road users by such a recess is also referred to as masking and the light recess is generally referred to as a masking area. This means that if an object to be deblended, for example a preceding other motor vehicle, is detected by the motor vehicle, the light intensity in the direction of the preceding other motor vehicle is reduced to a nonblending value or even no light intensity is emitted into the region of the object to be deblended.The adaptation of the anti-glare region is often carried out in the case of a preceding other motor vehicle on the basis of a distance of the motor vehicle from the preceding other motor vehicle. The distance of the other motor vehicle driving ahead from the motor vehicle can be determined by systems present in the motor vehicle, such as driver assistance systems of the motor vehicle. Different systems for determining the distance are known from the prior art. For example, DE 10 2017 129 627 A1 describes a distance determination based on different depth of field ranges at different focus settings of an objective. DE 10 2017 100 506 A1 discloses an optoelectronic position detection system and method for position determination. CN 11 455 0118 B discloses further prior art.It is also known from an internal prior art to determine a distance or a distance value representing the distance from another motor vehicle driving ahead via an image evaluation of a front camera of the motor vehicle which is configured to capture the vehicle environment at the front.It is problematic when adapting the anti-glare region as a function of a distance to the other motor vehicle driving ahead that errors can occur when ascertaining the distance, in particular based on an evaluation of camera images, which errors can lead to jumps in the distances or distance values ascertained. This can lead to the possibility of an erroneous adaptation of the anti-glare region, which can lead to a risk to other road users and also to a risk to the occupants of the motor vehicle.In principle, it is known from an internal prior art to check, in particular to plausibilize, the determined distance values, wherein the checking algorithm provides for comparing the current distance value with a distance value which is upstream in time in order to discard the current distance value depending on the result of the comparison, thus not to use it for adapting the anti-glare region, or to use it, thus to use it for adapting the anti-glare region. This can be effected, for example, on the basis of established, in particular static, limit values for an absolute deviation or relative deviation of the distance values.However, such a method can lead to unsatisfactory results with regard to the adaptation of the anti-glare region, in particular in dynamic driving situations.It is an object of the present invention to specify a method, improved in this respect, for controlling at least one headlight. It is a further object of the invention to specify a motor vehicle which is improved in this respect.These objects are achieved by the subject matters of the independent claims. The dependent claims relate to advantageous further developments.The method according to the invention serves for controlling at least one headlight of a motor vehicle. The head lamp is configured to generate a light distribution with a masking area around another motor vehicle driving in front in a vehicle environment around the front, wherein the masking area can be adapted by controlling the head lamp, wherein the motor vehicle has a distance determination device, wherein the distance determination device is configured to determine a distance value representing a distance to the other motor vehicle driving in front, wherein the method has the following method steps:determining a current distance value by means of the distance determination device,determining an individual tolerance band for the current distance value, wherein the individual tolerance band is determined based on the temporal development of distance values determined by means of the distance determination device, which distance values are temporally upstream of the current distance value,checking whether the current distance value lies within the individual tolerance band for the current distance value,driving the headlight in such a way that the anti-glare region is adjusted depending on the current distance value if the current distance value lies within the individual tolerance band.In contrast to a method in which a check of the distance value is made to determine whether the current distance value lies within a defined range, whether it is absolute or also percentage, with respect to a preceding distance value and only takes into account the current distance value if the current distance value lies within the defined range, the development over time of the determined distance values, for example, in a monotonically increasing or monotonically decreasing manner, is taken into account in the check, so that a reliable adaptation of the masking range is made possible even in the case of a dynamic driving situation, for example, braking maneuvers and acceleration maneuvers. If the previous distance values are already strongly falling, for example if the motor vehicle driving in front brakes, a tolerance band is determined which has a tendency toward small distance values, so that those distance values which have a relatively large downward jump are also classified as permissible during the test and are therefore used for adapting the anti-glare region. By contrast, distance values with an upward jump are classified as impermissible during the checking and therefore are not used for adapting the anti-glare region. The same applies, for example, if the motor vehicle driving ahead is strongly accelerating.Because the tolerance band is dependent on the temporal development of the distance values, for example decreasing or increasing monotonically, a dynamic of the change is taken into account in the determination of the tolerance band and thus in the checking of the current distance value, as a result of which an improved adaptation of the anti-glare region, in particular in the case of a dynamic driving situation, can be achieved.The above-mentioned process steps need not necessarily be performed in the above order. It is thus conceivable, for example, for the individual tolerance band to be determined before the current distance value is determined.The motor vehicle can certainly have a plurality of headlights.It is considered to be particularly advantageous if at least three distance values temporally preceding the current distance value are taken into account in the determination of the individual tolerance band for the current distance value. It is considered to be particularly advantageous if at least five, preferably at least ten, in particular at least fifteen distance values temporally preceding the current distance value are taken into account in the determination of the individual tolerance band for the current distance value.In a particularly preferred embodiment, it is provided that the distance determination device has a camera, wherein the camera is configured to capture the front-side vehicle environment. The camera can be, in particular, a camera of a driver assistance system of the motor vehicle. The use of a camera is to be regarded as particularly advantageous in that, in particular during travel in poor lighting conditions, for example in darkness, the tail lamps of a motor vehicle driving in front can be reliably detected and a distance to the motor vehicle driving in front can be determined on the basis of the recordings or camera images of the camera on the basis of the tail lamps.In a particularly preferred embodiment, it is provided that the distance determination device is configured to determine the distance values based on an image evaluation of images captured by the camera. An image evaluation can be used to determine a distance value and, in particular, a development over time of the distance values in a particularly reliable manner.It is considered to be particularly advantageous if the motor vehicle has a lane detection device for detecting a lane in which the motor vehicle is driving, wherein the headlight is controlled in such a way that the light distribution in the region of the lane causes a lane illumination. In particular in connection with a lane lightening, the method according to the invention offers advantages since a dynamic driving situation can occur in the case of another motor vehicle traveling ahead, which is located in the same lane as the motor vehicle, such as, for example, an acceleration or braking, which require an adaptation of the masking area, in particular a shortening or lengthening of the lane lightening. Braking or acceleration can lead to large jumps in the distance values, which, however, do not represent erroneous distance values. Due to the consideration of the temporal development of the distance values, these distance values are also reliably taken into account in the adaptation of the anti-glare region and are not discarded as faulty, since the tolerance band is dependent on the temporal development of the distance values stored in front of the time.It is considered to be particularly advantageous if the adaptation of the anti-glare region comprises an adaptation of the extent of the lane illumination along the lane. Adapting the extent of the lane illumination in particular involves shortening or lengthening the lane illumination along the lane and thus along the direction of travel X of the motor vehicle.It is considered to be particularly advantageous if the headlight is controlled in such a way that the currently present anti-glare region is maintained if the current distance value lies outside the individual tolerance band.In principle, however, it is also conceivable that, if the current distance value lies outside the individual tolerance band, a corrected distance value is determined based on the current distance value and the individual tolerance band, wherein the masking range is adapted depending on the corrected distance value. For example, it is conceivable that, in the case of a deviation of the distance value from a lower limit of the tolerance band, the lower limit value of the tolerance band is used as a corrected distance value and, in the case of a deviation of the distance value from an upper limit of the tolerance band, the upper limit value of the tolerance band is used as a corrected distance value. This has an advantageous effect on the adaptation of the masking range.In a particularly preferred embodiment, it is provided that the distance values are determined with computer assistance.It is considered to be particularly advantageous if the headlight has a multiplicity of individually controllable light sources. A plurality of individually controllable light sources enables a particularly good adaptation of the light distribution, in particular of the anti-glare region.In particular in this context, it is considered to be particularly advantageous if the headlight comprises a plurality of LEDs, preferably the headlight comprises a matrix LED headlight.The motor vehicle according to the invention has a headlight system. The headlight system has at least one headlight, wherein the headlight system is configured to generate a light distribution with a masking area around another motor vehicle driving in front in a front vehicle environment, wherein the masking area can be adjusted by controlling the headlight, wherein the headlight system has a control system for controlling the headlight, wherein the headlight system has a distance determination device, wherein the distance determination device is configured to determine a distance value representing a distance to the other motor vehicle driving in front, wherein the headlight system is configured to execute the method according to the invention or one of the preferred embodiments of the method.The explanations relating to the method and its developments apply accordingly to the motor vehicle and vice versa.In the following figures, the invention is explained in more detail on the basis of exemplary embodiments without being restricted to these. The following are shown: FIG. 1 shows a motor vehicle in a view in the transverse direction of the vehicle, FIG. 2 shows a system of the motor vehicle with a headlight system in a schematic illustration, FIG. 3 shows method steps of a method for activating a headlight of a motor vehicle in a schematic illustration, FIG. 4 shows the motor vehicle in a top view in a first driving situation, FIG. 5 shows the motor vehicle in a top view in a second driving situation.FIG. 1 shows a motor vehicle 1 in a view in the vehicle transverse direction Y. The motor vehicle 1 has a headlight system 2, this headlight system 2 being schematically illustrated in FIG. 2. The headlight system 2 comprises two headlights 21, wherein the respective headlight 21 is embodied as a matrix LED headlight. In this case, the individual LEDs or individual clusters of LEDs can be controlled independently of one another, with the result that a light distribution 4 of the headlights 21 is variable, insofar as the front-side environment of the vehicle can be illuminated variably. As a result, it is possible to adapt a light distribution 4 to the driving situation and, in particular, not to illuminate objects such as, for example, another motor vehicle 3 or pedestrian driving ahead, in that the light distribution 4 has a masking region 41. The anti-glare region 41 can be adjusted by individually driving the headlights 21. For this purpose, the headlight system 2 has a control system 22 for controlling the headlights 21. The headlight system 2 has a distance determination device 23, wherein the distance determination device 23 is configured to determine a distance value representing a distance D to the other motor vehicle 3 driving in front, wherein the headlight system 2 is configured to carry out the method steps illustrated in FIG. 3 and described below.In a first step S 1, provision is made for: ascertaining a current distance value by means of the distance ascertainment device 23.In a second step S 2, provision is made for: determining an individual tolerance band for the current distance value, wherein the individual tolerance band is determined on the basis of the temporal development of distance values determined by means of the distance determination device 23, which distance values are temporally upstream of the current distance value.In a third step S 3, it is provided that the current distance value lies within the individual tolerance band for the current distance value.In a fourth step S 4, the headlights 21 are controlled in such a way that the anti-glare region 41 is adjusted depending on the current distance value if the current distance value is within the individual tolerance band.The above steps S 1 to S 4 do not necessarily need to be performed in the above order. It is thus conceivable, for example, for step S 2 to be carried out before step S 1.FIGS. 4 and 5 show the motor vehicle 1 and the light distribution 4 in different driving situations.FIG. 4 shows the motor vehicle 1 in a plan view in a first driving situation. In the first driving situation, the motor vehicle 1 is located on a road in the present case with three lanes, wherein the motor vehicle 1 travels on a middle lane of the three lanes. The headlights 21 generate a light distribution 4 in the front-side environment of the vehicle.The light distribution 4 has a lane lightening 42, wherein the lane lightening 42 serves for better illumination of the middle lane traveled by the motor vehicle 1. In the present case, the lane lightening 42 is designed in the form of a substantially rectangular light carpet. The average lane traveled by the motor vehicle 1 is thus clearly illuminated in the region between the lane marking 5 delimiting the average lane. The lane lightening 42 allows hazardous objects to be recognized at an early stage and reduces unconcentrated lane changes of other road users to the lane traveled by the motor vehicle 1.In the first driving situation illustrated in FIG. 3, the light distribution 4 does not have a masking area 41, since in the front-side environment of the vehicle there is no object to be masked, such as another motor vehicle 3 driving in front.FIG. 5 shows the motor vehicle 1 in a top view in a second driving situation, wherein this second driving situation differs from the first driving situation essentially in that a preceding other motor vehicle 3 is located in the front-side vehicle environment. As described above, the headlights 21 are controlled in such a way that the headlights 21 generate a light distribution 4 with a masking area 41 around the other motor vehicle 3 driving in front, this masking area 41 being adapted depending on the current distance value if the current distance value is within the individual tolerance band for the current distance value. If the current distance value is outside the individual tolerance band for the current distance value, on the other hand, the currently present anti-glare region 41 is retained. Here, the lane lightening 42 is shortened to thereby provide the anti-glare region 41.

Claims

Method for controlling at least one front headlight (21) of a motor vehicle (1), wherein the front headlight (21) is configured to generate a light distribution (4) with a glare-suppression region (41) around another motor vehicle (3) driving in front, wherein the glare-suppression region (41) can be adjusted by controlling the front headlight (21), wherein the motor vehicle (1) has a distance-determining device (23), wherein the distance-determining device (23) is configured to determine a distance value representing a distance (D) to the other motor vehicle (3) driving in front, wherein the method has the following method steps: - determining a current distance value by means of the distance-determining device (23), - determining an individual tolerance band for the current distance value, wherein the individual tolerance band is determined based on the temporal development of distance values determined by means of the distance determination device (23), which distance values are temporally upstream of the current distance value, - checking whether the current distance value lies within the individual tolerance band for the current distance value, - driving the headlight (21) such that the anti-glare region (41) is adapted depending on the current distance value if the current distance value lies within the individual tolerance band.Method according to Claim 1, wherein at least three distance values temporally preceding the current distance value are taken into account in the determination of the individual tolerance band for the current distance value.Method according to Claim 1 or 2, wherein the distance determination device (23) has a camera, wherein the camera is configured to capture the front-side vehicle environment.Method according to Claim 3, wherein the distance determination device (23) is configured to determine the distance values on the basis of an image evaluation of images captured by the camera.Method according to one of Claims 1 to 4, wherein the motor vehicle (1) has a lane detection device for detecting a lane in which the motor vehicle is driving, wherein the headlight (21) is actuated in such a way that a lane lightening (42) is effected by the light distribution (4) in the region of the lane.The method of claim 5, wherein the adjusting of the anti-glare region (41) comprises adjusting the extent of the lane illumination (42) along the lane.Method according to one of Claims 1 to 6, wherein the headlight (21) is actuated in such a way that the currently present anti-glare region (42) is retained if the current distance value lies outside the individual tolerance band.Method according to one of Claims 1 to 7, wherein the headlight (21) has a multiplicity of individually controllable light sources.Method according to any one of claims 1 to 8, wherein the headlight (21) comprises a plurality of LEDs, preferably the headlight (21) comprises a matrix LED headlight.Motor vehicle (1) having a headlight system (2), wherein the headlight system (2) has at least one headlight (21), wherein the headlight system (2) is configured to generate a light distribution (4) with a glare-removing region (41) around another motor vehicle (3) in front of the vehicle, wherein the glare-removing region (41) is adjustable by actuating the headlight (2), wherein the headlight system (2) has a control system (22) for actuating the headlight (21), wherein the headlight system (2) has a distance-determining device (23), wherein the distance-determining device (23) is configured to determine a distance value representing a distance (D) to the other motor vehicle (3) in front, wherein the headlight system (2) is configured to determine a distance value representing a distance (D) to the other motor vehicle (3) in front, The method of any one of claims 1 to 9.

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