Method for generating a partial high beam distribution

Abstract

Method for generating a high beam distribution (18) with at least one high beam gap (19) by means of at least one front headlight (1) which has at least two high-resolution pixel light sources (2.1, 2.2, 2.3, 2.4) which illuminate adjacent areas on a roadway (8), and which includes at least one controllable image sensor (4), wherein a size (b) of the high beam gap (19) is adapted depending on its position with respect to the area of ​​the pixel light sources (2.1, 2.2, 2.3, 2.4), characterized in that the high beam gap (19) is specified as larger in the case of its position at a transition (7) between two of the high-resolution pixel light sources (2.1, 2.2, 2.3, 2.4) than in the case of its position in the middle of one of the pixel light sources (2.1, 2.2, 2.3, 2.4).

Description

The invention relates to a method for generating a high beam distribution with at least one high beam gap according to the type defined in more detail in the preamble of claim 1.A method and an arrangement for generating a partial high-beam light distribution, i.e. a light distribution in which a vehicle traveling ahead or approaching via a high-beam gap can be deblended, is known, for example, from DE 10 2008 060 949 A1 by the applicant. In this case, the distance and the angular position of an object to be dimmed is determined via a surroundings sensor system of the vehicle in a manner known per se. Based on these data, a high beam gap is then generated by an adjustable dark region in the high beam, so that the vehicle traveling ahead or in particular approaching is not dimmed, but the regions surrounding the approaching vehicle are nevertheless illuminated ideally. The driver of the vehicle in which the partial far-light distribution has been generated is thus given the best possible view.In the advancing technology for headlights, increasingly high-resolution pixel light sources are used to illuminate a roadway accordingly, wherein the term roadway is also intended to include regions adjoining the roadway that are illuminated by the light of the vehicle. The pixel light sources with high resolution that are usually used can be based on LCD and / or LED technology, or can have so-called DMD (Digital Micro Mirror Device) elements, which represent the high-resolution pixel light source via a targeted reflection of light from an illumination source. A further possibility is the use of LCoS chips (liquid crystal on silicon), which are constructed similar to an LCD screen but have a segmented pixel structure, in which each individual pixel can be driven and reflects or does not reflect depending on the control voltage. Here too, the light of an illumination source is then reflected by the component in a similar manner to the DMD, so that these together represent the pixel light source. The construction of the headlights allows in principle two embodiment variants, on the one hand with an imager in the manner of a diaphragm, for example an LCD shutter, which allows light to pass only at the desired locations, or in that the imager is integrated into the pixel light source, for example via DMD or LCoS chips or else via micro-AFS chips, so that light is emitted in the desired direction only at the locations in which this is predefined by a computer of a light controller.In this context, reference may be made purely by way of example to DE 20 2016 102 988 U1. In one of its exemplary embodiments, this describes the use of two pixel light sources in the form of LCoS chips illuminated via a common light source, the light distribution of the two chips being correspondingly superimposed in order to achieve the light as bright as possible with the least possible waste heat in the headlight.Furthermore, DE 10 2015 005 649 A1 describes a headlight device and a method for operating a headlight device. The aim here is to generate a high beam gap which matches the oncoming traffic as exactly as possible for the purpose of deblending it. For this purpose, a pixel light source is divided on a substrate into a plurality of luminous segments which are driven in accordance with the target.It is now further known from the general prior art that a plurality of such pixel light sources can also be used adjacent to one another in order to illuminate adjacent regions of the roadway and its environment. The light of the adjacent pixel light sources is therefore not combined to form a single brighter illuminated area, but rather is emitted adjacently into the surroundings of the headlight in order to illuminate a largest or broad area possible. In this context, for example, two or preferably more such pixel light sources are combined with one another in order to enable a larger illuminated region.The inventors have now recognized that, in the case of such adjacently arranged pixel light sources which directly or indirectly illuminate adjacent regions in the vicinity of the headlight, the optical imaging quality suffers from the transition region between two pixel light sources on the basis of the principle. In addition, the pixels in the transition region are often not perfectly aligned with each other, due to the very small size of the individual pixels and the positioning tolerances of the individual pixel light sources, so that an offset between adjacent pixels or the like may occur here.The object of the present invention is to improve a method for generating a high beam distribution having at least one high beam gap in comparison with the prior art, for use in front headlights having a plurality of adjacent high-resolution pixel light sources.According to the invention, this object is achieved by a method having the features in claim 1, and here in particular in the characterizing part of claim 1. Advantageous embodiments and further developments are evident from the dependent claims dependent thereon. In addition, a computer program and a computer program product for executing the method according to the invention by means of devices for data processing achieve the object.In the method, it is the case that the size, and here, according to an advantageous development of the concept, in particular the horizontal width, of the high beam gap is adapted as a function of its position with respect to the pixel light sources. As explained at the outset in the disadvantages of the general prior art, the pixel light sources provide a reduced optical imaging quality in their transition region, since more optical errors naturally arise in the edge region of an optical imaging, on the one hand due to the fact that there is a transition between two components here and, on the other hand, due to positioning tolerances, so that the adjacent edge pixels of the at least two pixel light sources are not positioned exactly as the pixels within a single one of the pixel light sources. Due to this optical "deficiency" in the transition region, it can now occur in the case of a high-beam gap that the end-blocked object is not completely blocked, since it is always attempted to keep the high-beam gap as small as possible in order not to unnecessarily impair the vision of the driver of the vehicle emitting the partial high-beam light. However, the optical distortion can now lead to inadequate sharpness in the region of the edge of the high beam gap.By adjusting the size of the high beam gap in dependence on the position of the high beam gap with respect to the surface of the pixel light sources in the method, such an imprecision in the imaging of the light on the roadway, which is generated by the hardware construction of the pixel light sources, can be compensated for, so that the ideal width of the high beam gap can always be selected, regardless of which position of the surface of the pixel light source it is associated with.According to the invention, it is provided that the high beam gap becomes larger for the case of its position at the transition between two of the high-resolution pixel light sources than for the case of its position in the center of one of the pixel light sources. A very small high beam gap, which is associated with an inner position of one of the pixel light sources, is also still possible in the method according to the invention. If, however, the position of the high beam gap with respect to the pixel light sources is in a transition region between two of the pixel light sources, then the high beam gap is provided to be larger, that is to say is designed correspondingly wider, in particular with respect to its horizontal width, in order to deblend the object which has been deblended reliably and reliably in any case.According to a further very advantageous embodiment of the concept, it can furthermore be provided that the size of the high beam gap is additionally adapted as a function of the distance of the object to be dimmed by the high beam gap. Such a consideration of the distance has previously been known from the prior art only with regard to the vertical size of the high beam gap, so that it is illuminated practically as far as in front of the object to be dimmed, but this object itself is no longer illuminated or is no longer illuminated with the full light intensity. In the invention, the size, and here again in particular in the form of the horizontal width of the high beam gap, can now additionally be adjusted accordingly as a function of this distance. The optical system of the headlight typically has a focal point and, depending on the distance of the current light distribution on the roadway from this focal point, this light distribution becomes more or less blurred, since the individual pixels are imaged more or less blurred. In principle, such unsharp imaging is wanted in order to obtain a light distribution that is as homogeneous as possible and not to illuminate the environment with individual pixels. Depending on the unsharpness, which is now in turn determined by the distance of the object to be dimmed from the front headlight bzqw. However, in this advantageous embodiment of the invention, the size, and here again in particular the horizontal width, of the high beam gap can be adjusted accordingly in order to reliably deblend the object to be deblended by a sufficiently large high beam gap despite the unsharpness in this region.A very advantageous implementation of the method according to the invention provides that tolerances and optical errors in the transition region of adjacent pixel light sources are stored in a location matrix as system-dependent correction factors. Each individual point of the surface of the adjacent pixel light sources can thus be linked with a corresponding correction factor in a location matrix. According to an advantageous development of the concept, this location matrix can be generated in particular from a sequential or parallel light density measurement, so that this can be determined individually for each headlight, since, however, the position tolerances of the individual pixel light sources and their relative position with respect to one another can also deviate from one another within the scope of the predefined tolerances in each headlight.According to an advantageous development of the concept, such a correction factor can now describe the required size of the high beam gap in degrees. According to an advantageous development of the concept, this angle indication then makes it possible for a masking algorithm to determine the high-beam gap and in the process to take into account the correction factor and in particular the distance of the object to be masked when determining the high-beam gap. As a result, the partial high beam light can be used ideally by calculating an ideal size of the high beam gap depending on the distance and positioning of the high beam gap with respect to the surface of the adjacent pixel light sources, in order on the one hand to ensure reliable and reliable deblending of the object to be deblended, that is to say of a vehicle driving in front or in particular approaching, and on the other hand to keep the high beam gap so small that the partial high beam light offers the best possible and efficient view for the driver of the vehicle, such that the partial high beam light achieves high acceptance and is accordingly frequently used. This in turn serves to ensure the safety of road traffic in poor lighting conditions, in particular in darkness.The present method according to the invention can be realized as a method in any desired manner, but in particular by a computer program and / or as a computer program product. The method according to the invention can be carried out by a suitable combination of hardware and / or software. In addition, the present invention can be embodied as a computer program product on a computer-usable storage medium having computer-readable program code, it being possible to use various computer-readable storage media such as hard disks, CD-ROMs, optical or magnetic storage elements, etc.Further advantageous embodiments of the method according to the invention are evident from the remaining dependent dependent claims and become clear with reference to the exemplary embodiments which are described in more detail below with reference to the figures.The following are shown: FIG. 1 shows a first embodiment of a headlight in a possible embodiment for use with the method according to the invention; FIG. 2 shows a second embodiment of a headlight in a possible embodiment for use with the method according to the invention; FIG. 3 shows the distribution of the light intensity of four adjacent pixel light sources with errors due to optical distortion; FIG. 4 shows the distribution of the light intensity of four adjacent pixel light sources with errors due to positioning tolerances; FIG. 5 shows a schematic illustration of a section of a road traffic network having a plurality of road sections and a plurality of vehicles; and FIG. 6 shows a schematic illustration of a high beam distribution with a high beam gap.In the illustration of FIG. 1, a first possible embodiment of a front headlight denoted by 1 for a vehicle 9, not illustrated here, can be seen in a schematic illustration. The vehicle 9 will typically have two such headlights 1 in its front area. The headlight 1 itself consists of a light source 2 which is designed in the form of a plurality of high-resolution pixel light sources. In the exemplary embodiment of FIG. 1 shown here, these are three individual pixel light sources 2.1, 2.2 and 2.3. These can in principle be implemented in any desired manner, for example as an array of LEDs, for example in the form of a so-called micro-AFS, that is to say an LED chip with very many individually controllable individual light points, for example LED chip with 256 individual light points developed within the scope of the micro-AFS project. However, other pixel light sources, for example in the form of LCDs or DMDs or LCoS chips, which are optionally illuminated from an additional illumination source and then reflect this light as the pixel light source 2.1, 2.2, 2.3, are also conceivable.The light of each individual pixel light source 2.1, 2.2, 2.3 reaches an imager 4, which can be designed, for example, as an LCD shutter, via an optional optical unit 3.1, 3.2, 3.3 in the exemplary embodiment illustrated here, so that the latter transmits only the light which is desired. This light transmitted by the imager 4 then reaches the environment U of the headlight 1 and here in particular onto a roadway 8 via a further optional optical system 5, wherein the term roadway 8 here does not exclusively include the surface of the roadway but also the illuminated areas of the environment U surrounding the roadway. The common imager 4 is illuminated by the light of the individual pixel light sources 2.1, 2.2, 2.3 in such a way that its light illuminates adjacent regions of the imager 4. The light is therefore essentially not superimposed, but rather also illuminates adjacent regions in the environment U.The actuation of the imager 4 in order to generate, in particular, a high beam distribution with a high beam gap 19, i.e. a so-called partial high beam light or a partial high beam light distribution 18, takes place via a light control device 6, which actuates the imager 4 accordingly. The data for this, which are indicated accordingly in the illustration of FIG. 1 by an arrow leading to the light control unit 6, originate, for example, from a surroundings sensor system 10 of the vehicle 9 equipped with the headlights 1 and fundamentally control the partial high-beam light distribution 18 only once in a manner known per se and described, for example, in the aforementioned DE 10 2008 060 949 A1 of the applicant.In the illustration of FIG. 2, an alternative embodiment of the headlight 1 can be seen, wherein the same components are provided with the same reference numerals. Therefore, only the differences will be discussed below. In the exemplary embodiment shown here, the light source 2 comprises four individual pixel light sources 2.1, 2.2, 2.3 and 2.4. These pixel light sources 2.1, 2.2, 2.3, 2.4 in turn provide the light emitted into the environment U adjacent to one another, in particular by the primary lenses drawn in for each of the pixel light sources 2.1, 2.2, 2.3, 2.4. Unlike in the design in FIG. 1, in the variant embodiment of FIG. 2, the headlight 1 does not show a common imager 4 for all pixel light sources 2.1, 2.2, 2.3, 2.4, but each of the pixel light sources 2.1, 2.2, 2.3, 2.4 essentially carries the imager 4 integrated therein, in that, by means of the pixel light source, which is designed, for example, as a micro-AFS or as an LCoS, only the pixels emit light into the environment U, which are activated accordingly. As a result, even without an additional imager, a very high-resolution light distribution in the environment U can already be realized. Accordingly, the light control device 6 controls each of the pixel light sources 2.1, 2.2, 2.3, 2.4 with its integrated imager 4 instead of the common imager 4, as in the illustration of FIG. 1.The use of adjacent pixel light sources 2.1, 2.2, 2.3, 2.4 causes problems with the quality of the optical image essentially in the transition region between the individual pixel light sources 2.1, 2.2, 2.3, 2.4. The illustration in FIG. 3 shows an example with four adjacent pixel light sources 2.1, 2.2, 2.3, 2.4. In the respective transition region, which is designated by 7 in the illustration of FIG. 3, optical distortions occur due to the principle of the restricted optical imaging quality, which optical distortions can be detected in the illustration of FIG. 3 by regions of different strength and width in which the light intensity deviates. Furthermore, it is the case that in the case of high-resolution pixel light sources 2.1, 2.2, 2.3, 2.4, the individual pixels are very close to one another. If the adjacent pixel light sources 2.1, 2.2, 2.3, 2.4 are now arranged mechanically next to one another, there are inevitably assembly tolerances which are typically greater than the dimension of a single pixel.In the illustration of FIG. 4, the four pixel light sources 2.1, 2.2, 2.3, 2.4 can again be seen with partially switched on and partially switched off pixels. In particular, in the transition regions between the individual pixel light sources 2.1, 2.2, 2.3, 2.4, which are again denoted here by 7, errors occur in the image caused by the mentioned assembly tolerances.The illustration in FIG. 5 shows a schematic plan view of a section of a road traffic network having a plurality of lanes 8. On the left in the illustration of FIG. 5, there is a multi-lane road having two lanes 8 a, 8 bwhich each with two lanes lead in different directions of travel, for example in the manner of a freeway. In the right-hand region of FIG. 5, a roadway 8 cis located immediately next to it, which roadway is designed with two lanes in different travel directions, for example in the manner of a two-lane land road. These individual lanes 8 a, 8 b, 8 care collectively also referred to as lane 8. On the roadway 8 b, and here on the left-hand lane, the vehicle 9 with the two headlights 1 according to the invention is located. In addition, a surroundings sensor system 10 for detecting the surroundings of vehicle 9 is indicated in principle. To clarify the direction of travel of the vehicle 9, two tail lamps 11 are also indicated. On the roadway 8 further vehicles are shown with their headlights and tail lamps to clarify the direction of travel. These are provided with the reference numerals 12 to 17. The vehicles 12 and 13 travel in the same lane 8 cin front of the vehicle 9 so that the environment sensor system 10 of the vehicle 9 correspondingly detects their tail lamps 121 and 131. Vehicles 14 and 15 are to be recognized on oncoming roadway 8 a,in which the headlights, which are identified here by way of example as 142 and 152, are recognized by environment sensor system 10 of vehicle 9 as respectively approaching vehicles. On the roadway 8 carranged at a distance to the right next to the roadway 8 b, a first vehicle can be seen in the same direction of travel as the vehicle 9. This is denoted by 16. Here too, the tail lamps 161 can be seen for the environment sensor system 10. A further oncoming vehicle on the roadway 8 cis denoted by 17, its recognizable headlights correspondingly by 172. Of all these vehicles 12 to 17, the distance and the angular position relative to the vehicle 9 are now correspondingly detected in a manner known per se via the environment sensor system 10 of the vehicle 9. The two headlights 1 of the vehicle 9 are now controlled in such a way that these vehicles 12 to 17 are not dimmed when the partial high-beam light is switched on, so that a so-called high-beam gap 19 is therefore realized in the partial high-beam light distribution 18 calculated by a dimming algorithm in the region of the respective vehicle 12 to 17.In the illustration of FIG. 6, such a partial high-beam light distribution 18 is indicated accordingly. An oncoming vehicle, for example the vehicle 15, is correspondingly drawn to the left of a vertical center line. In the light control unit 6 or a higher-order control unit, which correspondingly controls the light control units 6 of the two headlights 1, a so-called high beam gap 19 is now calculated via a dimming algorithm in order to dim the vehicle 15, i.e., not to transmit a high beam into the area of this vehicle 15. This high beam gap 19 can be seen in the illustration of FIG. 6. The light distribution of the partial remote light 18 thus takes the oncoming vehicle 15 out, so that this vehicle or its driver or its environment sensor system is not dimmed in the case of an autonomous driving system. This is fundamentally known to the extent from the prior art.Due to the special structure of the headlights 1 with several pixel light sources 2.1, 2.2, 2.3, 2.4 illuminating adjacent areas of the environment U or the roadway 8, it is however now the case that the size of the high beam gap 19, and here in particular its horizontal width b, cannot always be kept to a minimum, as desired in principle, in order to illuminate as much area of the environment U as possible. If the position of the high beam gap 19 is now such that it falls into one of the transition regions 7 between the pixel light sources 2.1, 2.2, 2.3, 2.4 with respect to the illumination to be suppressed, then a reduced quality of the imaging of the light onto the roadway 8 is present in this region. There is then the risk that, in the case of a very narrowly dimensioned size or width b of the high beam gap 19, as is desired in principle, glare will be produced in the edge regions as a result of the blurring. In order to compensate for this, the masking algorithm can now select a somewhat larger high beam gap, in particular to increase the high beam gap 19 with respect to its horizontal width b, in particular in the case where the high beam gap 19 is assigned to one of the transition regions 7, so that safe and reliable masking of the oncoming vehicle 15 is ensured in the example of FIG. 6 despite the possibly non-optimum imaging quality of the pixel light sources 2.1, 2.2, 2.3, 2.4 in its transition region 7.In addition, it is possible to take into account the distance of the vehicle 15 to be deblended that is already determined by the environment sensor system 10, since when positioned at a distance from the focus of the light distribution, the latter increasingly loses sharpness, so that this also requires a larger size, and here in particular a larger horizontal width b of the high beam gap 9, at a correspondingly larger distance.In practice, it is the case that in particular a location matrix 20 can be provided, which is stored accordingly, for example, in the area of the light control units 6, or else at another location of the electronic control of the vehicle 9. The correction factors are then assigned to each individual pixel and thus to each two-dimensional location on the adjacent pixel light sources 2.1, 2.2, 2.3, 2.4, to which a high beam gap 19 or the edges of such a high beam gap 19 can be assigned. The correction factor can describe in particular the required variable of the high beam gap in degrees, i.e. contains a corresponding angle indication. The masking algorithm can now take this correction factor into account accordingly for determining the high beam gap, and here in particular its size and in particular its horizontal width b, and preferably, as described above, the distance of the vehicle 15 to be masked from the vehicle 9 in order to determine the optimum size of the high beam gap and to implement it via the light control units 6 of the headlights 1. This makes it possible to always ensure reliable masking, in this case of the oncoming vehicle 15 or other objects to be masked, and nevertheless to get as much light as possible into the environment U or onto the roadway 8, in order to ensure the best possible visibility for the driver of the vehicle 9, even in darkness, which is a decisive safety advantage.

Claims

Method for generating a high-beam distribution (18) having at least one high-beam gap (19) by means of at least one headlight (1) which has at least two high-resolution pixel light sources (2.1, 2.2, 2.3, 2.4) which illuminate adjacent regions on a roadway (8), and which comprises at least one controllable imager (4), wherein a size (b) of the high-beam gap (19) is adapted as a function of its position with respect to the surface of the pixel light sources (2.1, 2.2, 2.3, 2.4), characterized in that the high-beam gap (19) is predefined to be greater at a transition (7) between two of the high-resolution pixel light sources (2.1, 2.2, 2.3, 2.4) in the case of its position than for the case of its position in the center of one of the pixel light sources (2.1, 2.2, 2.3, 2.4).Method according to Claim 1, characterized in that the size (b) of the high-beam gap (19) is additionally adapted as a function of the distance of the object (12, 13, 14, 15, 16, 17) to be dimmed by the high-beam gap (19).Method according to Claim 1 or 2, characterized in that tolerances and optical errors in the transition region (7) of the adjacently arranged pixel light sources (2.1, 2.2, 2.3, 2.4) are stored in a location matrix (20) as system-dependent correction factors.Method according to Claim 3, characterized in that the correction factors describe the required variable (b) of the high beam gap (19) in degrees.Method according to Claim 3 or 4, characterized in that a masking algorithm takes into account the correction factor, and in particular the distance of the object (12, 13, 14, 15, 16, 17) to be masked, in the determination of the size (b) of the high-beam gap (19).Method according to Claim 3, 4 or 5, characterized in that the location matrix (20) is based on a sequential or parallel luminance measurement of the respective headlight (1).Method according to one of Claims 1 to 6, characterized in that the size of the high-beam gap (19) is determined by its horizontal width (b).Method according to one of Claims 1 to 7, characterized in that adjacent regions of a common controllable image generator (4) are illuminated by the at least two pixel light sources (2.1, 2.2, 2.3, 2.4).Computer program having program code means for executing the method according to one of Claims 1 to 8 by a computer system (6) when the program is executed by the computer system (6).Computer program product having program code means which are stored in a computer-readable medium in order to carry out the method according to one of Claims 1 to 8 when the computer program product is executed on a computer system (6).

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