Method for removing glare from objects using a headlight system of a motor vehicle

Abstract

Method for removing glare from objects (O1, O2, O3) by means of a headlight system (2) of a motor vehicle (1), comprising the following measures: a) Determining the positions (P1, P2, P3) of two light (L) from a headlight (3) of the headlight system (2) reflecting objects (8, O1, O2, O3) in a camera image (11) which is generated by a camera (4) of the headlight system (2) directed towards the foreground (V) of the motor vehicle (1), b) Area-by-area dimming of the light (L) emitted by the headlight (3) and illuminating the foreground (V) such that the at least two objects (O1, O2, O3) and an area of ​​the foreground (V), which is represented in the camera image (11) by a connecting image section (13) linking the at least two objects (8, O1, O2, O3), are illuminated with reduced luminous intensity, so that less reflected backlight is produced by them, characterized in that - for each position (P1, P2, P3) of a reflective object (O1, O2, O3) detected in the camera image (11), the distance of which to the headlight (3) of the headlight system (2) is determined, - the reduction of the luminous intensity with which light (L) is emitted from the headlight (3) is carried out in such a way that for objects (O1, O2, O3) at a greater distance from the headlight (3) the luminous intensity is reduced less than for objects (O1, O2, O3) at a shorter distance from the headlight (3).

Description

[0001] The invention relates to a method for removing glare from objects using a headlight system of a motor vehicle. The invention further relates to a motor vehicle with a control / regulating device that is configured / programmed to carry out this method.

[0002] Modern motor vehicles are often equipped with high-performance headlights, which, for example, have light-emitting diodes (LEDs) and therefore emit light with a greater luminous intensity than previously known from headlights of older designs.

[0003] The light emitted by modern headlights is often so intense that it is reflected off objects with reflective surfaces, such as traffic signs or guideposts, and subsequently dazzles the driver. Therefore, it is known in the art to manipulate the light emitted by the headlight in such a way as to at least reduce the reflection of the light emitted by the headlight off the aforementioned reflective object. This procedure is referred to below as "glare reduction" of the respective object.

[0004] For example, DE 10 2012 210 467 A1 describes such a method. In this method, an image of the vehicle's illuminated surroundings is generated, and it is determined whether a traffic sign is present in the vicinity. If so, the position of the traffic sign is determined, and the light emitted by the vehicle's lighting system is adjusted towards the identified position of the traffic sign in such a way as to reduce the reflection of the light emitted by the lighting system from the traffic sign.

[0005] A similar method, in which a high-resolution headlight of a motor vehicle is controlled in such a way that objects detected in the vicinity of the motor vehicle are de-glared, is known from DE 10 2015 016 375 A1.

[0006] From DE 20 2017 102 056 U1, DE 10 2014 216 545 A1 and DE 10 2007 040 042 A1, methods are known in which individual objects in front of a motor vehicle are detected and glare removed.

[0007] US Patent 9,013,058 B2 discloses a method for focusing objects using a vehicle's headlight system. In this method, the positions of two objects reflecting light from a headlight of the headlight system are generated in a camera image of the foreground. The light emitted by the headlight is dimmed in such a way that the two detected objects and a connecting area between the two objects are illuminated with reduced light intensity. This results in less reflected backlighting from these objects.

[0008] It is an object of the present invention to demonstrate new approaches in the development of methods for reducing glare from objects illuminated by a motor vehicle headlight, which generate backlighting through reflection. In particular, an improved method for reducing glare is to be created in which the headlight can be controlled in a simple manner, so that only small amounts of control data need to be transmitted to the headlight for control purposes.

[0009] This problem is solved by the subject matter according to independent claim 1. Preferred embodiments are the subject of dependent claims.

[0010] The basic idea of ​​the invention is therefore to avoid having to separately identify all objects generating backlighting in front of a motor vehicle illuminated by a high-resolution headlight and reduce their illumination by controlling the headlight accordingly, thus reducing the amount of disruptive backlighting. Instead, it is proposed to identify only two objects generating backlighting in a camera image of the area in front of the vehicle by means of image analysis. In a further process step, not only are those two areas of the area in front of the vehicle that correspond to the position of the two identified objects in the camera image masked by controlling the headlight accordingly; according to the invention, an additional area of ​​the area in front of the vehicle that corresponds to a section of the camera image connecting the two previously described image sections is also masked.This image section is subsequently referred to as the "connection image section" or "connection area".

[0011] This method exploits the fact that the connecting area between the two identified objects often contains other objects that create backlighting. This is the case, for example, with guideposts and traffic signs that line the side of the road section driven on by a motor vehicle. The same applies to vehicles parked one behind the other at the roadside. In a camera image of the area in front of the vehicle, generated by a camera mounted inside the vehicle, these objects are frequently arranged one after the other along a straight or curved connecting line.

[0012] Therefore, for effective glare reduction using the inventive method, it is sufficient to determine only the positions of the two outer objects arranged on the connecting line by means of image recognition and, as a result of this determination, to control the headlight in such a way that not only the two explicitly determined objects are glare-free in the camera image, but also the aforementioned connecting image section or connecting area between these two objects. A separate control of the headlight to glare-free all (intermediate) objects on the connecting line can thus be omitted. This approach significantly simplifies the control for the area-by-area reduction of the emitted light intensity or light quantity of the headlight.

[0013] In particular, only reduced amounts of data need to be transmitted to control the headlight for area-specific reduction of light intensity or quantity. This allows the use of camera systems and headlights that can be controlled by a vehicle's existing control / regulation unit with a relatively low, upper-limited data transmission rate.

[0014] An inventive method for glare reduction of objects using a headlight system of a motor vehicle comprises two measures a) and b). According to a first measure a), the positions of two objects reflecting light from a headlight of the headlight system are determined in a camera image. The camera image is generated by a camera of the headlight system directed towards the area in front of the motor vehicle and is an image of the area in front. According to a second measure b), the light emitted by the headlight and illuminating the area in front is dimmed, at least in certain areas, such that the two objects and an area of ​​the area in front, which is represented in the camera image by a connecting image section linking the two objects, are illuminated with reduced luminous intensity.As a result, less reflected backlighting is generated by the two objects – and by any objects arranged within the connecting image area. In this way, the desired glare reduction is achieved without having to individually control each object's headlights to reduce glare.

[0015] According to the invention, for each position of an object to be glare-free detected in the camera image, its distance to the headlight is determined. The reduction of the light intensity emitted by the headlight is carried out such that the light intensity is reduced less for objects at a greater distance from the headlight than for objects at a closer distance. In this way, homogeneous glare control is achieved for objects that are positioned at different distances from the headlight at the time it is dimmed.

[0016] According to a preferred embodiment, in measure a), for each position of the two identified objects, a corresponding image section of the camera image is assigned, in which the respective object is positioned in the camera image. Thus, at least a first and a second image section are defined in this way.

[0017] Advantageously, a connecting image section is calculated from the first and second image sections, linking these two sections. This ensures that, in measure b), at least an area in front of the vehicle, corresponding to the two image sections and the connecting image section in the camera image, is illuminated with reduced light intensity. This eliminates the need for the data- and computationally intensive additional determination of further objects requiring glare reduction within the camera image. This significantly simplifies the practical implementation of glare reduction. In particular, the amount of data required for communication between the control unit and the headlight is considerably reduced.

[0018] The two image sections – referred to below as the “first image section” and the “second image section” – each preferably have the geometry of a rectangle. The connecting image section is formed by the two rectangular image sections and by two connecting lines, each linking a corner of the first rectangular image section to a corner of the second rectangular image section.

[0019] According to an advantageous further development, in measure a) the position of at least one third object, preferably several third objects, is additionally determined, which are arranged in the camera image between the first and second objects. In this further development, the connecting image section between the first and second objects is defined such that it contains the at least one third object. In this way, a separate control of the headlight to also glare the at least one third object becomes unnecessary.

[0020] The position of at least two objects can be determined particularly preferably using reflected radar beams. Using said radar beams, the distance determination between the motor vehicle and the object to be glare-free, as described above, can be carried out with exceptional precision.

[0021] According to an advantageous further development, the degree of dimming of the light emitted by the headlight is iteratively varied or adjusted for each object by means of a control loop. In this way, the illumination of the individual objects can be optimized in such a way that, in particular, a camera image with a homogeneous brightness distribution is achieved, and consequently, the area in front of the vehicle is illuminated in such a way that as many objects with reflective properties in the foreground as possible are glare-free.

[0022] According to a further advantageous embodiment, the headlight has at least one high-resolution and at least one low-resolution light-emitting area. For cost reasons, many headlights installed in motor vehicles are designed such that not all light-emitting areas are high-resolution. Since the method presented here can only be implemented by controlling a high-resolution light-emitting area, this embodiment proposes limiting the inventive dimming of the light emitted by the headlight to its at least one high-resolution area.

[0023] For the purposes of this document, a "high-resolution headlight" is understood to mean any headlight that has at least one high-resolution light-generating area.

[0024] Advantageously, at least one object can be a road user, preferably another vehicle or motor vehicle, or a traffic sign or a guidepost or a reflector, preferably on road edges, most preferably on guardrails.

[0025] The invention further relates to a motor vehicle with a headlight system comprising at least one high-resolution headlight for illuminating the area in front of the vehicle and a camera for capturing the area in front. The motor vehicle also includes a control / regulating device that interacts with the headlight system and is configured / programmed to carry out the inventive method described above. The advantages of the inventive method described above are therefore also transferred to the inventive motor vehicle.

[0026] Further important features and advantages of the invention will become apparent from the dependent claims, the drawings and the associated description of the figures based on the drawings.

[0027] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0028] Preferred embodiments of the invention are shown in the drawings and are explained in more detail in the following description, wherein identical reference numerals refer to identical or similar or functionally identical components.

[0029] They show, schematically: Fig. 1 in a side view an example of a motor vehicle according to the invention with a backlight-generating object in the form of a guidepost, Fig. 2a an example of a camera image produced in the course of the inventive method, in which several objects in the form of guideposts, each generating backlighting, can be seen, Fig. 2b an abstract representation of the camera image of the Fig. 2a, in which in Fig. The objects shown in 2a are greatly simplified and depicted as rectangular image sections. Fig. 3a an application example of the method according to the invention, in which vehicles parked one behind the other along a curved trajectory are de-glared, Fig. 3b an application example of the method according to the invention, in which vehicles parked one behind the other along a straight trajectory are de-glared.

[0030] Fig. Figure 1 illustrates an exemplary motor vehicle 1 according to the invention. The motor vehicle 1 comprises a headlight system 2, which has at least one headlight 3 for illuminating a foreground V of the motor vehicle 1 and a camera 4 for capturing this foreground V. Furthermore, the motor vehicle 1 comprises a control / regulation device 5 that interacts with the camera 4 and is configured / programmed to carry out the method according to the invention. For this purpose, the invention communicates with both the headlight 3 and the camera 4 via a fieldbus 6, for example, a CAN or LIN bus. The headlight 3 is a high-resolution headlight, which, for example, has at least 5000 pixels that can be controlled separately or at least partially independently of one another by the control / regulation device 5.This is necessary in order to carry out the method according to the invention, which is explained below using an example.

[0031] The method according to the invention serves to eliminate glare from objects 8 using the headlight system 2. The object to be eliminated can, in particular, be another road user, preferably another (motor) vehicle. However, a traffic sign or a guidepost can also be suitable as the object. The object to be eliminated can, in particular, be a reflector provided on road boundaries such as guardrails or guideposts. In the course of carrying out the method, two or more objects are eliminated, whereby different types of objects can also be eliminated.

[0032] The procedure executed by the control / regulating device 5 comprises two measures a) and b). According to a first measure a), in a Fig. The camera image 11 shown in Figure 2a, generated by camera 4 directed at the area in front of the vehicle 1 (V), detects the two positions P1 and P2 of two objects O1 and O2 that reflect light L from the headlight 3, thus creating backlighting. This backlighting can be perceived as disturbing or at least unpleasant by the driver of the vehicle 1 when observing the area in front of the vehicle (V). In extreme cases, the backlighting can even dazzle the driver, impairing their ability to safely control the vehicle 1.

[0033] In the example of the Fig. 2a In section 2a, the two objects O1 and O2 are guideposts L1 and L2, each of which has a light-reflecting reflector R1 and R2, respectively. Object O1 and guidepost L1 are referred to below as the "first object" and "first guidepost" L1, respectively. Object O2 and guidepost L2 are referred to below as the "second object" and "second guidepost," respectively.

[0034] How Fig. As illustrated in 2a, in measure a) the positions P3 of several third objects O3, which generate backlighting, are additionally determined. In the example of the Fig. 2a These objects O3 are also guideposts L3 with respective reflectors R3. These guideposts L3 are arranged as part of the road boundary between the two guideposts L1 and L2 and are therefore also present in camera image 11 between the first and second guideposts L1, L2, i.e., between the first and second objects O1, O2. In the course of the procedure, a connecting image section 13 is now defined in camera image 11 between the first and second objects O1, O2, in which the third objects O3 are also included.

[0035] According to a second measure b), the light L emitted by the spotlight 2 is dimmed in certain areas such that the two objects O1, O2 or guideposts L1, L2 and an area X of the foreground V, which is represented in the camera image 11 as connecting image section 13, are illuminated with reduced light intensity. Thus, less reflected backlight is generated by both the two objects O1, O2 or the two guideposts L1, L2, as well as by the objects O3 or guidepost L3.

[0036] According to Fig. 2b, as part of measure a), for each position P1, P2 of the two identified reflective objects O1, O2, a corresponding image section 14a or 14b of the camera image 11 is defined, in which the respective object O1, O2 is positioned in the camera image 11. In this way, the first image section 14a and the second image section 14b are defined. Fig. 2b, starting from the first and second image sections 14a, 14b, a connecting image section 13 is also calculated or determined, linking these two image sections 14a, 14b.

[0037] In the example of the Fig. 2a, Fig. In 2b, the two image sections 14a and 14b each have the geometry of a rectangle with corners 21c (image section 14a) and 21b (image section 14b), respectively. As the Fig. 2a, Fig. As illustrated in 2b, the connecting image section 13 is bounded by the two rectangular image sections 14a, 14b and by two connecting lines 21c, 21d, each connecting a corner 21a of the first rectangular image section 14a with a corner 21b of the second rectangular image section 14b.

[0038] For the purpose of glare reduction, at least one area V1 (see measure b) is used. Fig. 2a, Fig. 2b) of the area in front of the motor vehicle V, which corresponds to the two image sections 14a, 14b and the connecting image section 13 in camera image 22, is illuminated with reduced light intensity.

[0039] For each position P1, P2, P3 of a reflective object O1, O2, O3 detected in camera image 11, its distance to the illuminator 3 is determined. This results in a distance-dependent reduction of the luminous intensity L of the light emitted by the illuminator 3 and striking the respective object O1, O2, O3. For objects O1, O2, O3 at a greater distance from the illuminator 3, the luminous intensity L is reduced less than for objects O1, O2, O3 at a closer distance; this is because the glare effect caused by reflection is greater for objects at a closer distance, thus requiring a stronger glare reduction than for objects at a greater distance.

[0040] The method described above can be applied not only to objects O1, O2, O3 in the form of guideposts L1, L2, L3, but also to other types of objects such as traffic signs. It is also conceivable to apply the method to objects in the form of other road users, such as other motor vehicles. This is advantageous because the bodywork of motor vehicles can exhibit high reflectivity.

[0041] In the Fig. 3a, and Fig. 3b shows two possible application variants of the method to other motor vehicles that generate backlighting 22. For example, it is conceivable that - as in Fig. Figure 3a shows several such motor vehicles 22 parked one behind the other along a curved trajectory 23a. If the parked vehicles 22 are located in the area V in front of the motor vehicle 1, the area V1 of the area V containing the motor vehicles 22 can be glare-free using the method according to the invention.

[0042] The Fig. 3b shows a variant of the example of Fig. 3a. The example of the Fig. 3b differs from that of the Fig. 3a in that in the example of the Fig. 3b the motor vehicles 22 are parked one behind the other not along a curved trajectory 23a, but along a straight trajectory 23b.

[0043] In another variant, which can be combined with all the examples described above, the position of the objects O1, O2, O3 to be de-glare-free is determined not using the camera image 11, but by means of reflected radar beams. For this purpose, a radar system known to those skilled in the art as "LI DAR" can be used, for example.

[0044] Particularly good glare reduction is achieved when the degree of dimming of the light L emitted by the headlight 3 is controlled for each object O1, O2, O3 by means of a control loop. Such a control loop can be processed iteratively by the control unit 5.

[0045] In practice, vehicles are often fitted with headlights 3 as standard equipment, which are not entirely high-resolution, but only have high-resolution sections. Such a headlight 3 therefore has at least one high-resolution light-emitting area and at least one light-emitting area with a lower resolution than the high-resolution area – this lower-resolution area will be referred to as the "low-resolution area" in the following. Such a headlight 3 is less expensive to manufacture than a headlight that has only high-resolution areas. The high-resolution area differs from the low-resolution area in that it has a higher number of pixels per unit area.

[0046] If such a headlight 3 with at least one high-resolution area and at least one low-resolution area is used, the method according to the invention is advantageously applied only if the desired glare reduction of the area in front of the headlight V takes place in an area V1 of the area in front of the headlight V that is illuminated by the high-resolution area. Otherwise, i.e., if illumination of area V1 is only possible by means of the low-resolution area, the required resolution cannot be achieved to glare reduction of area V1 in the desired manner. Advantageously, the dimming, i.e., the reduction of the luminous intensity or amount of light L emitted by the headlight 3, is limited to the high-resolution area of ​​the headlight 3. This also applies, of course, to headlights with two or more high-resolution light-generating areas as well as—alternatively or additionally—with two or more low-resolution light-generating areas.

Claims

[1] Method for glare reduction of objects (O1, O2, O3) by means of a headlight system (2) of a motor vehicle (1), comprising the following measures: a) Determining the positions (P1, P2, P3) of two light (L) from a headlight (3) of the headlight system (2) reflecting objects (8, O1, O2, O3) in a camera image (11) which is generated by a camera (4) of the headlight system (2) directed towards the foreground (V) of the motor vehicle (1), b) Area-by-area dimming of the light (L) emitted by the headlight (3) and illuminating the foreground (V) such that the at least two objects (O1, O2, O3) and an area of ​​the foreground (V), which is represented in the camera image (11) by a connecting image section (13) connecting the at least two objects (8, O1, O2, O3), are illuminated with reduced light intensity, so that less reflected backlight is produced by them, characterized by , that - for each position (P1, P2, P3) of a reflective object (O1, O2, O3) detected in the camera image (11), the distance of which to the headlight (3) of the headlight system (2) is determined, - the reduction of the luminous intensity with which light (L) is emitted from the headlight (3) is carried out in such a way that for objects (O1, O2, O3) at a greater distance from the headlight (3) the luminous intensity is reduced less than for objects (O1, O2, O3) at a shorter distance from the headlight (3). [2] Method according to claim 1, characterized by , that in the course of measure a) for each position (P1, P2) of the at least two identified reflective objects (O1, O2) a section of the image (14a, 14b) of the camera image (11) belonging to the respective object (O1, O2) is assigned, in which the object in question (O1, O2) is arranged in the camera image (11), so that in this way at least a first and a second section of the image (14a, 14b) are determined. [3] Method according to claim 2, characterized by , that starting from the first and second image sections (14a, 14b) a connecting image section (13) linking these two image sections (14a 14b) is determined, so that in measure b) at least an area of ​​the foreground (V) of the motor vehicle (1), which corresponds in the camera image to the two image sections (14a, 14b) and the connecting image section (13), is illuminated with reduced light intensity. [4] Method according to any one of claims 1 to 3, characterized by , that - in measure a) additionally the position (P3) of at least one third, preferably several third, object(s) (O3) is determined, which are arranged in the camera image (11) between the first and second object(s) (O1, O2), - the connecting image section (13) between the first and the second object (O1, O2) is defined such that it contains at least one third object (O3). [5] Method according to any one of the preceding claims, characterized by that the position (P1, P2, P3) of at least two objects (O1, O2, O3) is determined by means of reflecting radar beams. [6] Method according to any one of the preceding claims, characterized by , that a degree of dimming of the light (L) emitted by the headlight (2) is iteratively controlled for each object (O1, O2, O3) by means of a control loop. [7] Method according to any one of the preceding claims, characterized by , that - the headlight (3) has at least one high-resolution and at least one low-resolution light-emitting area, - the dimming of the light (L) emitted by the headlight (3) is limited to at least one high-resolution range. [8] Method according to any one of the preceding claims, characterized by, that at least one object (O1, O2, O3) is a road user, preferably another vehicle or motor vehicle (22), or a traffic sign or guidepost (L1, L2, L3) or a reflector (R1, R2, R3) provided preferably on road boundaries, most preferably on guardrails. [9] Motor vehicle (1), - with a headlight system (2) comprising at least one high-resolution headlight (3) for illuminating the area in front of the motor vehicle (1) and a camera (4) for capturing the area in front (V), - with a control or regulating device (5) cooperating with the headlight system (2), which is set up or programmed to carry out the method according to one of the preceding claims.

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