Method for controlling a matrix headlight system and matrix headlight system

Abstract

Method for controlling a matrix headlight system of a motor vehicle with a plurality of individually controllable lighting elements, wherein objects (2) to be glare-free are detected in a light distribution (1) during operation of the matrix headlight system by means of at least one camera device and a glare-free zone (3) is calculated for each of the objects (2) to be glare-free, wherein the lighting elements are controlled such that for each of the objects (2) to be glare-free, the corresponding glare-free zone (3) is generated in the light distribution (1) by reducing the light intensities of those lighting elements emitting in the direction of the glare-free zone (3), wherein a distance d to the motor vehicle is determined for each of the objects (2) to be glare-free and each of the glare-free zones (3) is calculated and generated such that it has a central glare-free area (32) with a glare-free area width b0,which corresponds to the width of the object (2), and has a first glare-free safety area (30) with a first width b1 and a second glare-free safety area (31) with a second width b2 to the side of the central glare-free area (32), characterized in that the sum of the widths b1 + b2 of the two safety areas (30, 31) is determined by means of a scaling factor S(d) dependent on the distance d of the object (2) and the width b0 of the central glare-free area, and in that a total width B of the glare-free zone (3) is kept constant for different distances d of the object (2) by increasing the widths b1, b2 of the safety areas (30, 31) with increasing distance d and decreasing the width b0 of the central glare-free area accordingly, wherein the following applies to the total width B of the glare-free zone (3): , B = b 0 + b 1 + b 2 = b 0 + S ( d ) ⋅ b 0.

Description

[0001] The present invention relates to a method for controlling a matrix headlight system of a motor vehicle with a plurality of individually controllable lighting elements according to the preamble of claim 1. Furthermore, the invention relates to a matrix headlight system.

[0002] Matrix headlight systems in various configurations are known from the prior art. These systems feature a multitude of lighting elements, particularly a multitude of LED lighting elements, arranged in a segmented matrix. The lighting elements can be individually controlled, allowing pixels to be generated in a defined manner within the light distribution of the matrix headlight system to illuminate different spatial angles in front of the vehicle. Such matrix headlight systems, which now often have tens of thousands of pixels, can be adaptively adjusted to different driving and environmental conditions. Specific objects in front of the vehicle equipped with the matrix headlight system can be selectively deactivated or dimmed in a defined manner to minimize glare.The adaptive light distributions of matrix headlight systems are often controlled in a camera-based manner by using at least one camera system of the vehicle.

[0003] The vehicle's camera system, at least at least one of its cameras, becomes less accurate in determining the position of objects at greater distances, especially to vehicles ahead or approaching from the opposite direction. At close range, object recognition accuracy is high. Conversely, increasing distances reduce recognition accuracy. This results in the problem that objects in front of the vehicle, particularly vehicles ahead or approaching from the opposite direction, may be blinded by the glare.

[0004] DE 10 2011 006 554 A1 discloses a method for adjusting a headlight of a motor vehicle, wherein a distance to another motor vehicle is detected by a camera system and a sensor. The distance detected by the camera system is validated by the data from the sensor.

[0005] From DE 10 2011 088 136 A1 a method for controlling the light emission of at least one headlight is known, wherein an area not to be illuminated around a foreign vehicle is determined taking into account the course of a road and position information regarding the foreign vehicle located in the course of the road, wherein a safety distance between the light emitted by the headlight and the foreign vehicle is set based on the area.

[0006] DE 10 2015 214 760 A1 describes a method for controlling the light distribution of a headlight, wherein, in the case of an uncertain distance determination of an object, the glare area of ​​the headlight is reduced in such a way that all objects are at least in a safe zone.

[0007] A method for controlling a matrix headlight system of a motor vehicle with a large number of individually controllable lighting elements of the type mentioned above is known from DE 10 2017 202 466 A1.

[0008] The present invention aims to provide a method for controlling a matrix headlight system of the type mentioned above, as well as a matrix headlight system, which makes it possible to easily compensate for inaccuracies in the camera-based detection of objects in front of the motor vehicle and thus also to ensure the safe glare control of these objects.

[0009] This problem is solved by a method for controlling a matrix headlight system of the type mentioned above, comprising the features of the characterizing part of claim 1, and by a matrix headlight system comprising the features of the characterizing part of claim 8. The dependent claims relate to advantageous embodiments of the invention.

[0010] The invention provides a method for controlling a matrix headlight system of a motor vehicle with a plurality of individually controllable lighting elements, wherein objects to be glare-free are detected in a light distribution during operation of the matrix headlight system by means of at least one camera device and a glare-free zone is calculated for each of the objects to be glare-free, wherein the lighting elements are controlled such that for each of the objects to be glare-free the corresponding glare-free zone is generated in the light distribution by reducing the light intensities of those lighting elements that emit in the direction of the respective glare-free zone, wherein a distance d to the motor vehicle is determined for each of the objects to be glare-free and each of the glare-free zones is calculated and generated such that it has a central glare-free area with a glare-free area width b0.which corresponds to the width of the object, and has a first glare-free safety area with a first width b1 and a second glare-free safety area with a second width b2 to the side of the central glare-free area.

[0011] According to the invention, it is proposed that the sum of the widths b1 + b2 of the two safety areas is determined by means of a scaling factor S(d) dependent on the distance d of the object and the width b0 of the central glare reduction area, and that a total width B of the glare reduction zone is kept constant for different distances d of the object by increasing the widths b1, b2 of the safety areas with increasing distance d and decreasing the width b0 of the central glare reduction area accordingly, wherein the following applies to the total width B of the glare reduction zone: B=b0+b1+b2=b0+S(d)⋅b0.

[0012] The method according to the invention advantageously makes it possible to compensate for inaccuracies in the camera-based detection of objects in front of the vehicle and thus ensure the reliable glare control of these objects. This is achieved by not only controlling the glare of the objects themselves, but also by controlling the first and second safety zones to the left and right of the central glare control area assigned to one of the objects to be controlled. For glare control, the luminous intensity of the lighting elements of the matrix headlight system that shine towards the respective glare control zone is reduced to a specific threshold by dimming. It is also possible to completely deactivate at least some of the relevant lighting elements so that they no longer emit light during the glare control phase of one or more objects.In the method presented here, the sum of the first width of the first glare-free safety area and the second width of the second glare-free safety area is multiplied by the central glare-free area width b0, which corresponds to the width of the object to be glare-free, by the scaling factor S(d) which depends on the distance d of the object, so that scaling takes place in a defined manner.

[0013] In one embodiment, it is possible that the first width b1 of the first safety area and the second width b2 of the second safety area are set to be of different sizes.

[0014] In an alternative embodiment, it is provided that the first width b1 of the first safety area and the second width b2 of the second safety area are set so that they are the same size.

[0015] In one embodiment, it is proposed that a scaling factor S(d) be used, which is represented by a linear characteristic curve.

[0016] In an alternative embodiment, it is possible to use a scaling factor S(d) which is represented by a non-linear characteristic curve.

[0017] In a preferred embodiment, it is proposed that the distances d of the objects to be glare-free are determined by means of the camera images captured by the at least one camera device. The camera images are preferably evaluated by the control unit of the matrix headlight system in such a way that not only the presence of the objects to be glare-free is detected in the camera images, but also the distances d of the detected objects to the motor vehicle equipped with the matrix headlight system are determined by means of a distance determination algorithm.

[0018] In a further embodiment, the distances d of the objects to be de-glare-free can be determined by means of at least one non-camera-based sensor device, in particular a radar sensor device and / or a lidar sensor device. The data from the at least one non-camera-based sensor device, in particular the radar sensor device and / or the lidar sensor device, are also evaluated by the control device. The at least one non-camera-based sensor device can be used alternatively or additionally to the at least one camera device for determining the distances d, with the latter embodiment advantageously enabling mutual plausibility checks.

[0019] According to claim 8, a matrix headlight system for a motor vehicle is provided with a plurality of lighting elements and with a control device configured to individually control the light intensity of each of the lighting elements, wherein the control device is configured to perform a method according to one of claims 1 to 7.

[0020] According to another aspect, a motor vehicle is provided which includes a matrix headlight system according to claim 8.

[0021] According to yet another aspect, a computer program product is provided which includes machine-readable instructions which, when the program is executed by the control device, cause it to execute a method according to one of claims 1 to 7.

[0022] Further features and advantages of the present invention will become clear from the following description of a preferred embodiment with reference to the accompanying figures. Fig. 1. A camera image from a camera system of a motor vehicle showing an object located a short distance from the motor vehicle in front of it. Fig. 2. A camera image from the vehicle's camera system showing an object which is in a position that is in comparison to Fig. 1 greater distance to the motor vehicle in its forecourt, Fig. 3 a graphical representation of a distance-dependent scaling factor for calculating an extended glare reduction zone for an object in front of the motor vehicle, Fig. 4 A schematically simplified representation of a glare reduction zone in a light distribution of the matrix headlight system for an object located at a short distance in front of the vehicle, Fig. 5 A highly simplified schematic representation of a glare reduction zone in the light distribution of the matrix headlight system for an object which, in comparison to Fig. 4 is located at a greater distance from the motor vehicle in its forecourt.

[0023] A high-resolution matrix headlight system, not shown in detail here, whose basic technical structure is known from the prior art, comprises a multitude of lighting elements, in particular a multitude of LED lighting elements, which are arranged segmented in a matrix. For example, the matrix headlight system can comprise several tens of thousands of such lighting elements. These lighting elements can be individually controlled by a control unit of the matrix headlight system, so that a light distribution 1 of the matrix headlight system can be generated in a defined manner with a multitude of pixels in order to illuminate different solid angle areas in front of the vehicle equipped with the matrix headlight system. This makes it possible to adaptively adjust the light distribution 1 of the matrix headlight system to different driving and environmental conditions.A motor vehicle lighting system equipped with such a matrix headlight system is often also referred to as an "Adaptive Frontlighting System".

[0024] Examples of special light distributions that can be generated using the matrix headlight system include city light (for example, up to a speed of about 50 km / h), country road light (for example, from a speed of about 50 km / h and up to a speed of about 100 km / h), motorway light (for example, from a speed of more than 100 km / h) and bad weather light.

[0025] Because the lighting elements of the matrix headlight system can be individually controlled by the control unit, it is advantageously possible to selectively dim objects 2 in front of the vehicle equipped with the matrix headlight system. The objects 2 to be dimmed can be, for example, vehicles ahead or approaching, but also traffic signs or people.

[0026] For this purpose, the control unit of the matrix headlight system continuously receives camera images 4 from one or more camera systems of the vehicle and, if applicable, additional sensor data from further, non-camera-based sensor systems of the vehicle. These non-camera-based sensor systems may be, in particular, radar sensors and / or lidar sensors designed to detect objects 2 in front of the vehicle.

[0027] If one or more objects 2 are detected in front of the vehicle, this information is used to determine the position, size, and shape of one or more glare reduction zones 3 assigned to the detected object(s) 2 in front of the vehicle. In particular, the distance d of the object 2 to the vehicle can also be determined.

[0028] The lighting elements of the matrix headlight system are then controlled by the control unit in such a way that, depending on the number of detected objects 2, one or more glare reduction zones 3 are created. For glare reduction, the luminous intensity of the lighting elements of the matrix headlight system shining towards the respective glare reduction zone 3 is reduced to a specific threshold by dimming. It is also possible that at least some of the relevant lighting elements are completely deactivated so that they no longer emit light during the glare reduction phase for the object 2.

[0029] Currently used camera systems in motor vehicles exhibit greater inaccuracies in determining the position of objects 2 at larger distances, particularly to vehicles ahead and oncoming vehicles. This will be explained below with reference to Fig. 1 and Fig. 2 will be explained in more detail. Both figures show a camera image 4 with an object 2 contained therein. A grid 40, also shown, schematically and not to scale represents the image resolution in the form of image pixels. Fig. Figure 1 shows the situation in which object 2, which in this case is a vehicle driving ahead, is closer to the vehicle equipped with the matrix headlight system than in Fig. 2. It becomes clear that the detection quality of object 2 decreases at short distances ( Fig. 1) is higher than with a larger distance ( Fig. 2) This lower recognition quality at greater distances results in the problem that the glare reduction of the detected object 2 may not be sufficient.

[0030] To remedy this problem, the method presented here proposes to generate two additional, also glare-free safety zones 30, 31 within at least one glare-free zone 3 of the light distribution 1 in a defined manner depending on the distance of the object 2 detected in front of the motor vehicle, in order to compensate for the inaccuracy of the camera device and to ensure corresponding glare relief of the detected object 2.

[0031] In Fig. 3 is a scaling factor S(d) for generating safety zones 30, 31 within the at least one glare reduction zone 3 as a function of the distance of the object 2 from the motor vehicle, represented in the form of a characteristic curve 5. In the embodiment shown here, the characteristic curve 5 has a linear profile. This results, for example, in a scaling of approximately two for an object distance of about 400 m. The slope of the characteristic curve 5 is shown in the diagram below. Fig. The characteristic curve 5 shown in Figure 2 is intended to be understood as merely an example. Furthermore, there are also conceivable embodiments in which the characteristic curve 5 exhibits a non-linear profile.

[0032] The in Fig. The characteristic curve 5 of the distance-dependent scaling factor S(d) shown in Figure 3 can be used by the control unit to calculate the total width of the two safety zones 30, 31 depending on the distance of object 2, in particular a vehicle traveling ahead and / or approaching from the opposite direction, and to modify this width by appropriately controlling the lighting elements of the matrix headlight system. This will be described below with reference to Fig. 4 and Fig. 5 will be explained in more detail.

[0033] Fig. Figure 4 shows the glare reduction zone 3 of the light distribution 1 for a detected object 2, which is at a small distance d from the motor vehicle. Fig. Figure 5 shows the glare reduction zone 3 of the light distribution 1 for a detected object 2, which has a glare compared to Fig. 4 greater distance d to the motor vehicle.

[0034] In one embodiment, the distances d of the objects 2 to be de-glared can be determined using the camera images 4 captured by the at least one camera device. The camera images 4 are evaluated by the control unit of the matrix headlight system in such a way that not only is the presence of the objects 1 to be de-glared detected in the camera images 4, but also the distances d of the detected objects 2 to the motor vehicle equipped with the matrix headlight system are determined by means of a distance determination algorithm.

[0035] It is also possible that the distances d of the objects 2 to be de-glare-free are determined by means of at least one non-camera-based sensor device, in particular by means of the radar sensor device and / or the lidar sensor device. The data from the at least one non-camera-based sensor device, in particular the radar sensor device and / or the lidar sensor device, are also evaluated by means of the control device. The at least one non-camera-based sensor device can be used alternatively or additionally to the at least one camera device to determine the distances d, whereby in the latter embodiment a mutual plausibility check is advantageously possible.

[0036] Using a control algorithm executed by the control unit, the position, size, and shape of the glare reduction zone 3 are calculated in real time, and the lighting elements of the matrix headlight system are controlled accordingly. The glare reduction zone 3 has a central glare reduction area 32 that corresponds to the detected object 2. This central glare reduction area 32 has a central glare reduction area width b0, which is calculated from the width of the object 2 detected in the camera image 4.

[0037] The width of object 2 in camera image 4 is - as in Fig. 1 and Fig. 2. The glare reduction area is larger at shorter distances than at longer distances. By applying the distance-dependent scaling factor S(d), two additional safety zones 30 and 31 are calculated to the sides of the central glare reduction area 32. Glare reduction also occurs in these zones and is generated by appropriately controlling the lighting elements of the matrix headlight system. A first safety zone 30 to the left of the central glare reduction area 32 has a first width b1. A second safety zone 31 to the right of the central glare reduction area 32 has a second width b2.

[0038] The total width B of the glare reduction zone 3 is as follows: B=b0+b1+b2=b0+S(d)⋅b0

[0039] In the embodiment shown here, the safety zones 30, 31 have identical widths b1 = b2, so that: b1=b2=S(d)⋅b02

[0040] However, it is also possible that the widths b1 and b2 of the safety zones 30, 31 are chosen differently.

[0041] The representations in Fig. 4 and Fig. Figure 5 illustrates that the total width B of the glare reduction zone 3 is identical regardless of the distance of the object 2 to be glare-reduced in front of the vehicle. At a small distance d of the object 2, the safety zones 30, 31 are narrower due to the smaller scaling factor S(d) than at a larger distance d, where the safety zones 30, 31 become wider. The widening of the safety zones 30, 31 with increasing distance d of the object 2 ensures that the object 2 is reliably glare-reduced despite the reduced detection quality of the camera system. Reference symbol list 1 Light distribution 2 objects 3 Glare reduction zone 4 camera images 5 Characteristic curve of the scaling factor 30 first glare-free safety area 31 second glare-free safety area 32 central glare reduction area 40 grid B Total width of the glare reduction zone b0 Width of the central glare reduction area b1 Width of the first safety zone b2 Width of the second safety zone d distance to the object S(d) distance-dependent scaling factor

Claims

[1] Method for controlling a matrix headlight system of a motor vehicle with a plurality of individually controllable lighting elements, wherein objects (2) to be glare-free are detected in a light distribution (1) during the operation of the matrix headlight system by means of at least one camera device and a glare-free zone (3) is calculated for each of the objects (2) to be glare-free, wherein the lighting elements are controlled such that for each of the objects (2) to be glare-free the associated glare-free zone (3) is generated in the light distribution (1) by reducing the light intensities of those lighting elements that emit in the direction of the glare-free zone (3) in question, wherein a distance d to the motor vehicle is determined for each of the objects (2) to be glare-free and each of the glare-free zones (3) is calculated and generated such that it has a central glare-free area (32) with a glare-free area width b0,which corresponds to the width of the object (2), and has a first glare-free safety area (30) with a first width b1 and a second glare-free safety area (31) with a second width b2, , next to the central glare-free area (32), characterized by , that the sum of the widths b1 + b2 of the two safety areas (30, 31) is determined by means of a scaling factor S(d) dependent on the distance d of the object (2) and the width b0 of the central glare control area, and that a total width B of the glare control zone (3) is kept constant for different distances d of the object (2) by increasing the widths b1, b2 of the safety areas (30, 31) with increasing distance d and decreasing the width b0 of the central glare control area accordingly, wherein the following applies to the total width B of the glare control zone (3): B=b0+b1+b2=b0+S(d)⋅b0. [2] Method according to claim 1, characterized by, that the first width b1 of the first safety area (30) and the second width b2 of the second safety area (31) are set so that they are of different sizes. [3] Method according to claim 1, characterized by , that the first width b1 of the first safety area (30) and the second width b2 of the second safety area (31) are set so that they are equal in size. [4] Method according to any one of claims 1 to 3, characterized by , that a scaling factor S(d) is used, which is represented by a linear progression of a characteristic curve (5). [5] Method according to any one of claims 1 to 3, characterized by , that a scaling factor S(d) is used, which is represented by a non-linear characteristic curve (5). [6] Method according to any one of claims 1 to 5, characterized by, that the distances d of the objects to be de-glared (2) are determined by means of the camera images captured by the at least one camera device. [7] Method according to any one of claims 1 to 6, characterized by , that the distances d of the objects to be de-glared (2) are determined by means of at least one non-camera-based sensor device, in particular by means of a radar sensor device and / or a lidar sensor device. [8] Matrix headlight system for a motor vehicle comprising a plurality of lighting elements and a control device designed to control the light intensity of each of the lighting elements individually, characterized by that the control device is configured to execute a method according to one of claims 1 to 7. [9] Motor vehicle comprising a matrix headlight system according to claim 8. [10] Computer program product comprising machine-readable instructions which, when the program is executed by a control device, cause the control device to execute a method according to any one of claims 1 to 7.

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