Lighting system for a motor vehicle and method for adjusting a lighting unit of such a lighting system

Abstract

Lighting system for a motor vehicle, comprising a control unit (26), at least one image acquisition unit (10), and at least one light unit (12) comprising at least one light source (14), wherein the light unit (12) is adjustable by means of at least one adjustment device (15), and wherein the light unit (12) generates a light distribution in the activated state such that adjustment of the light unit (12) by means of the control unit (26) is possible, wherein at least one additional light source (11) is provided by which an additional light object can be generated, characterized in that a time-of-flight measurement unit (11) is provided, and that at least one characteristic point P1 of the light distribution, for example a point of a generated light-dark boundary (16), abbreviated HDG, and an associated pixel position PI1 of the image acquisition unit (10) can be determined by means of the image acquisition unit (10).wherein the control unit (26) is connected to an adjustment device (15) in such a way that a reference displacement of point P1 to a point P, L of the light object or vice versa, point P L and the corresponding pixel position PI L the image acquisition unit (10) can be determined and the reference shift can be evaluated in the control unit (26).

Description

[0001] The invention relates to a lighting system for a motor vehicle, comprising a control unit, at least one image acquisition unit, and at least one lighting unit comprising at least one light source, wherein the lighting unit is adjustable by means of at least one adjustment device, and wherein the lighting unit, in the activated state, generates a light distribution such that adjustment of the lighting unit can be carried out by means of the control unit, wherein at least one additional light source is provided by which an additional light object can be generated. Furthermore, the invention relates to a method for adjusting a lighting unit of such a lighting system.

[0002] Such a lighting system, or a method for adjusting a light unit of such a lighting system, is known, for example, from DE 10 2007 049 619 A1. In this case, the lighting system comprises, in addition to the light unit, a control unit, an image acquisition unit, and an additional light source that briefly and invisibly generates a light object—in this case, a shadow marking—in the traffic area in order to detect the geometry and shape of this shadow marking and subsequently compare it with stored data in order to identify any misalignment and correct it accordingly. Although such a device allows for basic adjustment of a light unit during operation, the lighting system disclosed here, as well as the described method, has the disadvantage that the detection of the shadow marking is subject to a wide variety of boundary conditions in the traffic area, such as...Weather conditions, weather patterns, traffic conditions, etc., can cause deviations from the target conditions stored in the control unit, which can distort the result and lead to incorrect adjustment.

[0003] German patent application DE 10 2010 046 517 A1 discloses a method for calibrating and adjusting a vehicle's lighting unit, in which a specific light distribution is generated by the lighting unit and captured in at least one image by means of at least one image acquisition unit of the vehicle, wherein, based on an evaluation of the image, at least one horizontal light-dark boundary and / or one vertical light-dark boundary is determined and compared with a target value. If the determined light-dark boundary deviates from the target values, the lighting unit is automatically adjusted.

[0004] Document DE 10 2010 048 689 A1 discloses a method for adjusting and / or calibrating at least one headlight of a vehicle, wherein a defined light pattern generated in the vicinity of the vehicle is detected by means of a detection unit and the headlight is calibrated and / or adjusted based on the position of the light pattern relative to the vehicle.The detection unit captures a first reference image of a low beam distribution and a second reference image of a high beam distribution. The first reference image is captured immediately before switching between the low beam and high beam distributions, and the second reference image is captured immediately after switching between them. A common correlation image is generated from these reference images. Based on the contrast ratios between the low beam and high beam distributions in this correlation image, a global position of at least one light-dark boundary forming the light pattern of the low beam distribution is determined. This global position is then compared with a target position, and if a deviation is detected, the headlights are calibrated or adjusted.

[0005] Therefore, the task is to provide a lighting system or a method for adjusting a light unit of such a lighting system, thereby avoiding the aforementioned disadvantage.

[0006] This task is solved by a lighting system for a motor vehicle by providing a time-of-flight measuring unit and by enabling the determination of at least one characteristic point P1 of the light distribution, for example a point of a generated light-dark boundary, abbreviated HDG, and an associated pixel position PI1 of the image acquisition unit, wherein the control unit is connected to an adjustment device in such a way that a reference shift of point P1 to a point P L of the light object or vice versa, point P L and the corresponding pixel position PI LThe image acquisition unit can determine the reference shift, and the control unit can evaluate the resulting reference shift. This allows for automatic or manual adjustment of the vehicle's lighting system during operation, for example, when stationary (such as at a traffic light or in a traffic jam), or while driving. The lighting system can thus be individually adapted to the specific conditions of each operating situation. This adjustment, tailored to the traffic environment in every situation, is achieved simply by generating and evaluating a light point and by capturing at least one point of the characteristic light distribution, such as a high-beam distribution (HDD), and superimposing these two points.

[0007] It has proven particularly advantageous that the control unit stores the calculation operation g = m × m + m0 for the vector to the additional light object originating from a coordinate origin, where m is known via the time-of-flight measurement of the time-of-flight measuring unit, m is the direction vector of the light object originating from the additional light source, and where m0 describes the mounting position of the additional light source originating from the coordinate origin, where for a target point P 1Soll A geometric relationship to the light object originating from the image acquisition unit is stored in the control unit, such that a misalignment of the light unit can be determined by comparing a target travel path with an actual travel path.

[0008] In this case, the lighting unit can have a positioning motor assigned to the respective light source, acting as an adjustment device. The incorrect position can then advantageously be determined using a minimum value problem approach.

[0009] It is also possible that the light source is designed as an LED unit with a matrix beam, with the adjustment device being a pixel switching device.

[0010] The additional light source is advantageously designed as a laser, and the additional light object is a laser point.

[0011] From an assembly engineering perspective, it is advantageous if the adjustment device is formed by the adjustment device.

[0012] Furthermore, the task is solved by a method for adjusting a light unit of such a lighting system, wherein in a first step a characteristic light distribution, for example in the form of a HDG, is mapped in the traffic area, in a second step the pixel position of at least one first point P1 of the HDG is determined, and in a third step a light object with a light point P is created by the additional light source. L It is broadcast that in a fourth step the pixel position of the light point P L It is determined that in a fifth step, point P1 and the light point P Lby means of the adjusting device, whereby the travel path of the adjusting device is determined, that in a sixth step the misalignment data are calculated in the control unit with reference to the target point P1 and that in a seventh step, if a calculated deviation is found, the light unit is adjusted by means of the adjusting device.

[0013] It is particularly advantageous that in the sixth step, the misalignment data is calculated using a rotation matrix multiplication, and the deviation is solved by applying the minimum value problem approach. Alternatively, in the sixth step, the misalignment data can be calculated via pixel switching, and the deviation can be calculated by the control unit. This creates a method that can be used regardless of distance, the nature of the traffic area, or the orientation of the image acquisition unit, the additional light source, and the lighting unit relative to the surface onto which the HDG and the light object are projected.

[0014] The invention is explained in more detail below with reference to a drawing, which shows: Fig. 1 A schematic view of a vehicle in operation, in which an adjustment of a light unit of a lighting system is being carried out, Fig. 2a, Fig. 2b a schematic representation of the functioning of rotation matrix multiplication, and Fig. 3 A block diagram for adjusting a lighting unit of the lighting system.

[0015] Fig. Figure 1 shows a vehicle 2 in operation, for example, stationary, such as at a traffic light or in a traffic jam, or parked against a garage front 4. However, the method for adjusting a light unit 12 is also possible in driving situations. The vehicle 2 has a lighting system 6 which, in the present embodiment, is a Fig. 3. A control unit 26, shown schematically, an image acquisition unit 10 arranged in the front of the vehicle 8, preferably the windshield, and two light units 12, each comprising headlights 14 known per se with integrated conventional adjustment devices 15 designed as actuators, as light sources. In addition, an additional light source 11, for example a laser, is also provided, which projects a light object in the form of a point P. L depicted on the garage front. It should be clear that, for the sake of simplicity, this exemplary embodiment assumes only one light source 11 with a headlight. Furthermore, the following description only concerns the adjustment of one light unit 12.

[0016] The term "adjustment device" is to be understood here as encompassing both a mechanical actuator and an electronic pixel control.

[0017] With the headlights 14 of the motor vehicle 2 switched on, the light-dark boundary 16, shown in solid lines, appears on the projection surface 4. This light-dark boundary includes point P1. A further light-dark boundary 18 is shown in dashed lines, which corresponds to the target light-dark boundary stored in a control unit 26 at point P 1Soll describes. Another characteristic point could also be indicated. The deviation between point P1 and P 1Soll describes the misalignment, characterized by the angles α and β.

[0018] The laser now projects a point of light P. L to the projection surface. In control unit 26, the calculation operation for the vector to the additional light point P is... LStarting from a coordinate origin g = m × m + m0, where m is known from the time-of-flight measurement of the time-of-flight measuring unit provided in the housing of the laser 11. m is the direction vector of the light point P. L Starting from laser 11 and m0, the mounting position of laser 11 is described relative to the origin of the coordinate system. This is determined by measuring the distance m of the laser and iteratively moving point P1 to the laser point P. L The misalignment of the headlight can be determined by measuring horizontal and vertical angles or by switching the pixels in a pixel headlight.

[0019] The adjusting device 15 can then adjust the light unit 14. This can be done, for example, using the arithmetic operation (rotary matrix multiplication) based on the Fig. 2a and Fig. 2b is shown.

[0020] Here, a reference shift will be demonstrated using the example of moving point a to point e. First, a rotation by angle φ1 towards point b is performed, followed by a rotation by angle φ1 towards point c. Then, a rotation by angle ψ2 towards point d is performed, and finally, a rotation φ2 towards point P. 1' The starting vector to point a is denoted by x1 and the target vector to point e by x. 1' The target vector x 1' So, x 1' = D φ2 × D ψ2 × D φ1 × D ψ1 × x1. It should be clear that this is merely an example of a reference shift. Other reference shifts are of course possible. Using rotation matrix multiplication, the light unit 14 can therefore be adjusted in a particularly simple way by means of an actuator (not shown).

[0021] Based on the in Fig. 3 block diagram shown, using the following Fig.Section 1 will now explain the procedure for adjusting the lighting unit 12 in more detail. In a first step, the HDGs 16 are projected onto a projection surface 4 located in the traffic area 19. This is done by activating the headlights 14, represented by arrow 20. In a second step, a point P1 of the HDG 16 is determined by the image acquisition unit 10, represented by arrow 22. Arrow 24 shows the transmission of this image data from P1 for a pixel position PI1 to the control unit 26. The control unit 26 is also connected to the headlight 14, and thus to the adjustment device 15, which also serves as the adjustment mechanism, as shown by arrow 30.

[0022] In a third step, a light point P is created by the additional light source 11. L emitted and, in a fourth step, the pixel position of the light point P Lis determined (double arrow 36). In a fifth step, point P1 and the light point P are determined. L The adjustment device 15 is superimposed (arrow 20), whereby the travel distance of the adjustment device 15 is determined (arrow 30), so that in a sixth step the misalignment data is calculated in the control unit 26 with reference to the target point P1, and that in a seventh step, if a deviation is calculated, the light unit 14 is adjusted by means of the adjustment device 15, as represented by the information block 28 and the arrow 31. The information about the magnitude of the misalignment α, β is transmitted to the headlight via the arrow 31.

[0023] Whether through the use of the low beam of the headlights 14 or through special functions such as tracking, masking, or marking, as represented by block 32 and arrow 34, optimal light distribution is now ensured. It should be clear that the headlight adjustment does not need to be permanent. Furthermore, arrow 60 indicates the possibility that the misalignment of the headlight 14 is transmitted to the image acquisition unit 10, creating an optical coupling between the image acquisition unit 10 and the headlights 14. The image acquisition unit then takes the misalignment into account when illuminating the traffic area 19. With a pixel headlight, adjustment can also be made by switching individual pixels on or off.In this case, the adjustment device 15 is no longer designed by a classic mechanical actuator or adjustment device, but by an electronic control for switching pixels on and off. It is also conceivable that the actual travel distance is carried out and recorded by means of the laser 11.

[0024] Misalignments made during a specific setting can be saved and integrated into the adjustment procedure for future settings. It is also conceivable that multiple reference displacement runs can be performed for multiple points of the HDG's 16.

[0025] Furthermore, it should be clear that the rotation matrix multiplication is defined with respect to the headlight center point. If, as is usually the case, the image acquisition unit deviates from the headlight center point, the captured image data must be scaled to the headlight center point to be set using appropriate calculations.

Claims

[1] Lighting system for a motor vehicle, comprising a control unit (26), at least one image acquisition unit (10), at least one light unit (12) comprising at least one light source (14), wherein the light unit (12) is adjustable by means of at least one adjustment device (15) and wherein the light unit (12) in the activated state produces a light distribution such that adjustment of the light unit (12) by means of the control unit (26) is possible, wherein at least one additional light source (11) is provided by which an additional light object can be produced, characterized by, that a time-of-flight measurement unit (11) is provided and that at least one characteristic point P1 of the light distribution, for example a point of a generated light-dark boundary (16), abbreviated HDG, and an associated pixel position PI1 of the image acquisition unit (10) can be determined by means of the image acquisition unit (10), wherein the control unit (26) is connected to an adjustment device (15) in such a way that a reference displacement of point P1 to a point P L of the light object or vice versa, point P L and the corresponding pixel position PI L the image acquisition unit (10) can be determined and the reference shift can be evaluated in the control unit (26). [2] Lighting system according to claim 1, characterized by, that in the control unit (26) the calculation operation for the vector to the additional light object originating from a coordinate origin g = m × m + m0 is stored, where m is known via the time-of-flight measurement of the time-of-flight measuring unit, m is the direction vector of the light object originating from the additional light source (11) and where m0 describes the mounting position of the additional light source (11) originating from the coordinate origin, where for a target point P 1Soll a geometric relationship to the light object originating from the image acquisition unit (10) is stored in the control unit (26) such that a misalignment of the light unit (12) can be determined via a time-of-flight measurement m by a laser and by the travel path (horizontal, vertical) of a characteristic point of the light-dark boundary into the laser. [3] Lighting system according to claim 1 or 2, characterized by, that the light unit (12) as an adjustment device (15) has a stepping motor assigned to the respective light source (14). [4] Lighting system according to claim 2, characterized by that the misalignment can be determined using a minimum value problem approach. [5] Lighting system according to claim 1 or 2, characterized by , that the light source (14) is designed as an LED unit with a matrix beam, wherein the adjustment device (15) is designed by a pixel switching device. [6] Lighting system according to one of claims 1-5, characterized by that the additional light source (11) is designed as a laser and the additional light object is a laser point P L is. [7] Lighting system according to one of claims 1-6, characterized by , that the adjustment device is formed by the adjustment device (15). [8] Method for adjusting a light unit (12) of a lighting system (6) according to one of the preceding claims, characterized by , that in a first step a characteristic light distribution in the form of an HDG (16) is mapped in the traffic space (4), that in a second step the pixel position of at least one first point P1 of the HDG (16) is determined, that in a third step a light object with a light point P is created by the additional light source (11) L It is broadcast that in a fourth step the pixel position of the light point P L It is determined that in a fifth step, point P1 and the light point P L by means of the adjusting device, whereby the travel path of the adjusting device is determined, that in a sixth step the misalignment data are calculated in the control unit (26) with reference to the target point P1, and that in a seventh step, if a calculated deviation is found, the light unit (12) is adjusted by means of the adjusting device (15). [9] Method for adjusting a light unit (12) of a lighting system (6) according to claim 8, characterized by , that in the sixth step the calculation of the misalignment data is carried out by a rotation matrix multiplication and the deviation is solved by applying the minimum value problem approach. [10] Method for adjusting a light unit of a lighting system (6) according to claim 8, characterized by , that in the sixth step the calculation of the misalignment data is carried out via a pixel switching and the deviation is calculated by the control unit (26).

Images