Detection of headlight misalignment during lane illumination

Abstract

In various embodiments, a method for detecting a headlight misalignment of a vehicle (1) is provided, comprising: detecting at least one road marking (4); detecting an edge (7) of a light projection (5) generated on the road surface (3) by means of the vehicle's headlight; comparing the position of the at least one road marking (4) with the detected edge (7) of the light projection (5) generated on the road surface (3); detecting the headlight misalignment based on the comparison performed.

Description

[0001] The present invention relates to a detection of headlight misalignment during lane brightening.

[0002] In high-resolution headlight systems (e.g., HD matrix LED headlights), a lateral mechanical basic adjustment is crucial for correctly displaying various projection functions such as lane lighting or construction and narrow-area lighting. Mechanical influences can lead to misaligned headlights, which also prevent the projection functions from being executed correctly. For example, the projection functions of lane lighting or construction and narrow-area lighting can result in incorrect display in the form of a laterally offset light field that deviates from the correct projection when the vehicle was delivered from the factory. Such incorrect display can pose a safety risk for the driver, who relies on correct light projection from these assistance systems.

[0003] From document DE 10 2008031159 A1, a method for detecting misalignment of a vehicle headlight using a camera system is known. In this method, the light distribution pattern of the headlight is captured using a camera system of the vehicle. Based on this, a comparison of the actual light distribution pattern with the desired light distribution pattern is performed in order to detect a possible misalignment of the headlight. A similar method is known from document DE 10 2020000292 A1.

[0004] Document DE 10 2017117594 A1 describes a method for the automated detection of headlight misalignment using a calibrated camera.

[0005] The object of the present invention can be seen in providing a further method by means of which a misalignment of the headlights, in particular a lateral misalignment of the headlights, can be detected.

[0006] This object is achieved by the subject matter of the independent patent claim. Further preferred embodiments can be found in the dependent patent claims.

[0007] The invention is based on the basic idea of ​​detecting road markings and a light projection generated by the vehicle's headlights, e.g. a brightened area of ​​the road on which the vehicle is moving, using a vehicle camera. Their position relative to one another is then evaluated, in particular the course of at least one edge of the generated light projection with the course of at least one road marking (e.g. median reservation or road edge). The generated light projection on the road can correspond to lane brightening or construction site or bottleneck light and can be detected in the image from the vehicle camera via its edges, i.e. light-dark transitions. If a deviation between the actual position of the light projection on the road and its target position (taking into account a tolerance range) relative to at least one road marking is detected, it can be concluded that the headlight in question is incorrectly positioned.This can then be compensated or corrected by shifting the corresponding texture on the headlight's LED matrix and / or by changing the headlight's alignment. Based on a quantification of the deviation of the actual position from the target position of the generated light projection, the control unit can apply a corresponding correction factor in the form of a lateral offset to the light texture and / or adjust the position / alignment of the headlight in question. The correction factor and / or the extent of the adjustment can be taken from an implementation table or determined using a formula stored by the vehicle manufacturer in the headlight control unit.

[0008] In this description, lane lighting refers to a lighting function that serves to better illuminate one's own lane and has a carpet of light projected onto one's own lane, whereby the lane between the lane markings is significantly illuminated compared to adjacent areas of the road, which are usually also illuminated but with a lower light intensity. Narrow-area and construction site lighting is related to this lighting function and can be understood as a special type of lane lighting in which a strip of light is projected onto the road in front of the vehicle with a width that corresponds to the width of the vehicle, thus providing greater safety in narrow passages in the dark. The vehicle width is stored in the control unit. With construction site and narrow-area lighting, the edges of the illuminated area therefore do not lie above or below the lane markings.Not on the lane markings, but ideally at a predetermined distance from them, which depends on the final width of the narrowed lane. Consequently, it is expected that the width of the generated light projection for narrow and construction zone lighting will be smaller than the width of the light projection for lane illumination.

[0009] According to the invention, a method for detecting a headlight misalignment of a vehicle is provided. The method comprises detecting at least one lane marking and detecting an edge of a light projection generated on the roadway by the vehicle's headlight. Both processes can take place in parallel and be carried out using a vehicle camera, in particular the vehicle's driver assistance camera. For this purpose, the images captured by the vehicle camera can be processed using a suitably configured image recognition algorithm. The light projection generated on the roadway can be a light projection that is carried out as part of lane lighting or narrow-area and construction site lighting. Of course, both edges of the generated light projection can also be detected, wherein each of the edges is generated by the headlight arranged on the corresponding side.is correlated with this.

[0010] The method according to the invention further comprises comparing the position of the at least one lane marking with the detected edge of the light projection generated on the lane. This can particularly refer to a comparison of a target position of the edge of the generated light projection with its actual position relative to the lane marking. The target position of the generated light projection can be calculated based on the known position of the vehicle in its lane.

[0011] The method according to the invention then comprises detecting the headlight misalignment from the comparison carried out.

[0012] According to further embodiments of the method according to the invention, at least one lane marking may be a lane boundary. The lane marking may therefore, in particular, comprise a dashed line or a solid line.

[0013] According to further embodiments of the method according to the invention, the light projection can be a region of the road that is brighter than the rest of the illuminated roadway when the vehicle's headlights are on. The brightened region can be square or rectangular in shape with a width that, depending on the lighting function implemented, essentially corresponds either to the width of the lane or to the width of the vehicle.

[0014] According to further embodiments of the method according to the invention, this may further comprise detecting both edges of the light projection generated on the roadway.

[0015] According to further embodiments of the method according to the invention, this method can further comprise performing a correction of the headlight projection based on the detected headlight misalignment. For this purpose, the light texture can be shifted laterally on the LED matrix by a value dependent on the misalignment of the corresponding headlight (or the misalignment of both headlights). Alternatively or additionally, the corresponding headlight can be adjusted using actuators to eliminate or at least reduce the misalignment.

[0016] According to further embodiments of the method according to the invention, it may further comprise issuing a warning if the headlight misalignment exceeds a limit value. The warning may prompt the driver of the vehicle to visit a workshop to have the at least one headlight readjusted.

[0017] According to further embodiments of the method according to the invention, the left edge of the generated light projection can be generated by a left headlight and the right edge by a right headlight.

[0018] According to further embodiments of the method according to the invention, the generated light projection can be one that runs substantially parallel to the at least one detected lane marking. The generated light projection can, for example, have a rectangular shape, which has a trapezoidal shape in the image from the vehicle camera due to perspective distortion.

[0019] In the case of construction and bottleneck lighting, the edges of the generated light projection can be arranged at a distance from the lane markings of the lane in which the vehicle is moving.

[0020] According to further embodiments of the method according to the invention, the headlight misalignment can be determined on the basis of an angle between the detected edge of the generated light projection and the position of the at least one road marking.

[0021] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0022] Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

[0023] In Fig. 1 shows a driving situation with correctly adjusted headlights and lane lighting switched on.

[0024] In Fig. 2 shows a driving situation with adjusted headlights and lane lighting switched on.

[0025] In the Fig. 1 and Fig. Figure 2 illustrates an embodiment of the method according to the invention based on lane illumination. Vehicle 1 is positioned in its lane 2, which is part of a roadway 3. Lanes 2 are separated from one another by lane markings 4, which comprise solid and broken lines, as is common in road traffic. The lane illumination lighting function is activated in vehicle 1, in which vehicle 1 generates a brighter light area 5 on lane 2. The generated light projection 5 comprises a brightened rectangular light area with a width corresponding to the width of lane 2.

[0026] The scene is recorded by means of the vehicle camera provided in the vehicle 1 (not explicitly shown), and both the lane markings 4, which delimit the lane 2 of the vehicle 1 and are identified as recognized objects in the camera image with the reference symbol 6, as well as the generated light projection 5 and in particular its edge or edges 7 are recognized.

[0027] In the Fig. 1, it can be assumed that the vehicle's headlights are correctly adjusted, since the (on the Fig. 1) upper and lower lane markings 4 each correspond to one of the edges 7 of the generated light projection 5 of the lane illumination. It should be mentioned here that the generated light projection 5 can be integrated into a basic light function such as a low beam, so that in particular the area (towards the Fig. 1) above and below the generated light projection can also be illuminated, but with a lower light intensity.

[0028] In the Fig. In the scenario shown in Figure 2, however, the generated light projection 5 for lane illumination is distorted compared to its intended shape. The left lane marking 6 detected in the image of the vehicle camera, which in Fig. 2 of the upper lane marking does not coincide with the corresponding edge 7 of the generated light projection 5 of the lane illumination. In other words, the ( Fig. 2), the upper edge 7 of the generated light projection 5 is arranged at an angle α relative to the detected left lane marking 6 of lane 2. Therefore, there is no parallelism between these two, so that it can be concluded that the left headlight of vehicle 1 is incorrectly positioned. The right headlight of vehicle 1, on the other hand, produces an edge 7 of the generated light projection 5 that is arranged parallel to and substantially above the right lane marking 4 of lane 2. Based on the lane markings 4 on the lane 3 detected in the image of the vehicle camera, vehicle 1 knows how it is positioned relative to its lane 2.

[0029] Of course, it may also be the case that both edges 7 of the generated light projection 5 are arranged obliquely or not parallel to the road markings 4. In this case, each of the two edges 7 of the generated light projection 5 can be aligned at a different angle to the road markings 4 (assumed to be parallel).

[0030] A similar scenario would arise in the case of a generated light projection 5, which is set up as a narrow and construction site light. For explanation, the same reference numerals are used as in the Fig. 1 and Fig.2, which denote the same elements. The only modification would be that, in the case of properly adjusted narrow-area and construction site lights, the light projection 5 would lie within lane 2, with each of the two edges 7 running parallel to the lane markings 4. In the case of an adjusted headlight, the corresponding or correlated edge 7 of the generated light projection 5 would also be oblique and would run at an angle α to the lane markings 4.

[0031] In the present invention, the road markings 4 are used as calibration markings, so to speak, with the aid of which it can be checked whether the headlights are correctly adjusted when the lane lighting or the construction and bottleneck lights are activated.

Claims

[1] Method for detecting a headlight misalignment of a vehicle (1), comprising: Detecting at least one lane marking (4) on a lane (3); Detecting an edge (7) of a light projection (5) generated on the roadway (3) by means of the vehicle's headlight; Comparing the position of the at least one road marking (4) with the detected edge (7) of the light projection (5) generated on the road (3); Detection of headlight misalignment based on the comparison performed. [2] Method according to claim 1, wherein the at least one road marking (4) is a boundary of a lane (2). [3] Method according to claim 1 or 2, wherein the light projection (5) is a region of the roadway (3) which is brightened in the headlight operation of the vehicle (1) compared to the rest of the illuminated roadway (3). [4] Method according to one of claims 1 to 3, further comprising: Detecting both edges (7) of the light projection (5) generated on the roadway (3). [5] Method according to one of claims 1 to 4, further comprising: Perform a correction of the headlight projection based on the detected headlight misalignment. [6] Method according to one of claims 1 to 5, further comprising: Issue a warning when the headlight misalignment exceeds a limit. [7] Method according to one of claims 1 to 6, wherein the left edge (7) of the generated light projection (5) is generated by a left headlight and the right edge (7) is generated by a right headlight. [8] Method according to one of claims 1 to 7, wherein the generated light projection (5) is one which runs substantially parallel to the at least one road marking (4). [9] Method according to one of claims 1 to 8, wherein the headlight misalignment is determined on the basis of an angle between the edge (7) of the generated light projection (5) and the position of the at least one road marking (4).

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