Method for adjusting a headlight projection

Abstract

The invention relates to a method for adjusting a headlight projection, comprising the following steps: a. by means of two headlights, projecting a headlight projection from at least a partial superposition of respective individual projections of the two headlights onto a surface external to the vehicle; b. by means of an optical sensor unit, capturing the headlight projection; c. by means of a control device, determining a projection surface for the headlight projection; d. by means of the control device, adjusting at least one setting parameter of at least one of the headlights to reduce the projection area; and e. Adjust at least one of the headlights based on the adjustment parameters adapted in step d. A method for adjusting headlight projections is proposed, which enables particularly simple and precise focusing of the headlight projection.

Description

[0001] The invention relates to a method for adjusting a headlight projection, a projection device with such a method, and a motor vehicle with such a projection device.

[0002] In industrial practice, headlights are known that project communication information, for example in the form of symbols, pictograms and geometric shapes, onto a surface external to the vehicle, such as a roadway. Such headlights are known, for example, as matrix headlights or digital headlights.

[0003] Higher contrast can be achieved by superimposing the individual projections from both headlights. For the two projections to overlap completely, the headlights must be precisely aligned and the road surface must be as smooth and homogeneous as possible, i.e., without potholes or bumps. Otherwise, the individual projections will only partially overlap, resulting in a blurry, indistinct overall headlight projection.

[0004] DE 10 2018 118 648 A1 discloses a method for compensating double images in the light distribution of a matrix spotlight with a plurality of partially overlapping, at least sectionally, luminous segments generated by a first projection path and a second projection path of the matrix spotlight, wherein a camera image of the light distribution generated by the matrix spotlight is captured by means of a camera and evaluated by a computing device, comprising the steps: extraction of edge elements of the luminous segments from the camera image and generation of an edge image; formation of a plurality of pixel segments in the edge image; calculation of edge elements based on a previously defined error metric relative to each other in the pixel segments; prioritization of pixel segments by an evaluation of the statistical data;Conversion of the mean orthogonal distance and mean orthogonal angle to an image plane of the matrix spotlight and calculation of corrected pixel states; selection and activation of specific luminaire segments of at least one of the two projection paths to generate a substantially, preferably completely, double-image-free light distribution.

[0005] DE 10 2018 116 511 B3 discloses a method for depth perception based on headlights arranged on both sides of a vehicle, in which a characteristic light pattern is projected onto a projection surface by means of the first and second headlights of the vehicle, preferably such that the characteristic light patterns overlap at least partially. After capturing the image of the projection surface by means of an image acquisition unit of the vehicle, a frequency representation of the characteristic light patterns is calculated. Furthermore, an overlap coefficient is calculated, which is correlated with the degree of overlap of the two characteristic light patterns in their overlap area, by evaluating the frequency components in the frequency representation of the characteristic light patterns.If a comparison of the coverage coefficient with a coverage threshold reveals that there is insufficient coverage between the two characteristic light patterns, the two characteristic light patterns are shifted relative to each other.

[0006] Based on this, the present invention aims to overcome, at least partially, the disadvantages known from the prior art. The features of the invention are defined in the independent claims, for which advantageous embodiments are shown in the dependent claims. The features of the claims can be combined in any technically meaningful way, whereby the explanations in the following description and features from the figures, which comprise supplementary embodiments of the invention, can also be used.

[0007] The invention relates to a method for adjusting a headlight projection, comprising the following steps: a. by means of two headlights, projecting a headlight projection from at least a partial superposition of respective individual projections of the two headlights onto a surface external to the vehicle; b. by means of an optical sensor unit, capturing the headlight projection; c. by means of a control device, determining a projection surface for the headlight projection; d. by means of the control device, adjusting at least one setting parameter of at least one of the headlights to reduce the projection area; and e. Adjust at least one of the headlights based on the adjustment parameters adapted in step d.

[0008] Unless explicitly stated otherwise, ordinal numbers used in the preceding and following descriptions serve solely for unambiguous differentiation and do not indicate any order or ranking of the components referred to. An ordinal number greater than one does not necessarily imply the presence of another such component.

[0009] A method for adjusting the headlight projection of a motor vehicle is proposed here. The motor vehicle has at least two headlights suitable for projecting a headlight beam onto an external surface. Examples of such headlights include matrix headlights and / or digital headlights. The headlights feature, for example, multiple light sources, such as LEDs (Light Emitting Diodes), arranged in a matrix, each of which can be controlled separately. The headlights can be configured as rear headlights or front headlights.

[0010] Furthermore, the motor vehicle includes an optical sensor unit and a control unit for adjusting the headlights. The proposed method comprises at least steps a. to e., preferably in the order mentioned, which are explained below.

[0011] In step a., a headlight projection is created using two headlights and projected onto a surface external to the vehicle. Each headlight emits an individual projection, which are superimposed to form the overall headlight projection. Whether intentionally or unintentionally, the individual projections may only partially overlap, for example, due to uneven road surfaces, timing discrepancies of the headlights, inclined surfaces, or similar factors.

[0012] Such partial overlapping, in other words an offset or deviation, for example size deviation, between the individual projections, leads to a reduced contrast or a blurring in the headlight projection.

[0013] The surface external to the vehicle is, for example, a road surface.

[0014] In step b., the headlight projection is captured using a sensor unit. Preferably, the outlines of the headlight projection, i.e., the overall projection from both individual projections, are captured.

[0015] In step c, the control unit determines the projection area of ​​the headlight projection based on the outlines of the headlight projection captured in step b. For example, the area is determined using a grid comparison, integration over the captured outlines, artificial intelligence, and / or based on the geometry of the outlines.

[0016] In step d., at least one setting parameter of at least one of the two headlights is adjusted, i.e., changed, by means of the control unit. This at least one setting parameter is changed with the aim of reducing the area of ​​the projection surface and thus improving the superposition of the individual projections, which leads to improved contrast and sharpness of the headlight projection. Preferably, the individual projection of the corresponding headlight is shifted relative to the vehicle and the other individual projection on the external surface by adjusting the setting parameter. For example, the individual projections are first shifted relative to each other along a surface direction, such as in the transverse or longitudinal direction of the vehicle. Preferably, the longitudinal direction of the vehicle is arranged parallel to the direction of travel of the vehicle when driving straight ahead.Preferably, the vehicle transverse direction is arranged transversely, and especially preferably orthogonally, to the vehicle longitudinal direction.

[0017] In step e. the headlight is adjusted based on at least one setting parameter adapted in step d., for example by means of a digital control of the individual light sources of the headlights.

[0018] The resulting altered headlight projection is captured according to step b, and the process is then executed, for example, in a loop. For instance, the area of ​​the headlight projection is iteratively reduced.

[0019] Thus, a particularly easy-to-implement method for adjusting a sharp headlight projection from several individual projections is proposed.

[0020] In a further advantageous embodiment of the method, it is proposed that a minimization problem for the projection area is solved by means of the control device in order to determine the adapted setting parameters.

[0021] In step b., or by an iterative loop of steps b. to e., the setting parameters are adjusted until a minimum, possibly within predefined boundary conditions, is set for the projection area, i.e., the area of ​​the spotlight projection. Preferably, the minimum projection area, or the target area to which the projection area is optimized, is as large as the respective areas of the individual projections.

[0022] For example, one of the following algorithms and methods is used to solve the minimization problem: - a gradient descent method: for example, an iterative optimization algorithm that uses the gradient of the objective function to determine the nearest point that minimizes the function value, and / or a stochastic gradient descent, in which the gradient descent is performed on a random subset of the data to speed up the calculations. - a Newton method: for example, a Newton-Raphson method, which uses the second derivative of the objective function to speed up the convergence of the minimization function, and / or a quasi-Newton method, which approximates the second derivative of the objective function to simplify the calculations. - a linear programming approach: for example, a simplex algorithm and / or an interior-point method, which solves linear and non-linear optimization problems by remaining within the feasible range of the solution. - non-linear programming: for example, Sequential Quadratic Programming (SQP), which solves non-linear optimization problems by solving a series of quadratic subproblems, and / or trust region methods, which approximate the objective function within a bounded region and iteratively adjust the region. - an evolutionary and heuristic algorithm; - a convex optimization; - Interior point methods; and / or - Barrier methods.

[0023] In a further advantageous embodiment of the method, it is proposed that the projection area is iteratively reduced by means of the control device.

[0024] According to this embodiment, the control device is now iteratively reduced or minimized, for example by iteratively adjusting the setting parameters using the control device, for example by performing steps b. to e. in a loop, as explained above.

[0025] In an advantageous embodiment of the method, it is further proposed that the adjustment of at least one setting parameter is carried out for a fixed longitudinal distance of the headlight projection from the motor vehicle along a longitudinal direction of the vehicle and / or for a fixed transverse position of the headlight projection along a transverse direction of the vehicle.

[0026] According to a first embodiment of this design, at least one setting parameter is adjusted for a defined longitudinal distance of the headlight projection to the vehicle along the vehicle's longitudinal direction. For example, the longitudinal distance is the distance from a leading edge of the vehicle to a vehicle-side end or a center point of the headlight projection. Alternatively or additionally, the setting parameters are adjusted for a defined lateral position along the vehicle's transverse direction.

[0027] In a further advantageous embodiment of the method, it is proposed that the headlight projection includes communication information or is a reference symbol.

[0028] According to one embodiment of this design, the headlight projection displays communication information. This communication information allows the driver and / or other road users to receive information, such as warnings. In other words, the headlight projection includes a textual representation, a pictogram, an image, and / or a symbol; preferably, the headlight projection consists of the textual representation, the pictogram, the image, and / or the symbol.

[0029] Alternatively or additionally, the spotlight projection can be used as a reference symbol. Such a reference symbol is preferably displayed separately from the communication information. For example, the reference symbol could be used exclusively for adjusting the spotlights and evaluating the spotlight projection. The shape or geometry of the reference symbol is designed to detect and determine deviations between individual projections with particular precision and accuracy. For example, the reference symbol could be a cross or a triangle, enabling a simple, direction-dependent determination of the deviation between the individual projections.

[0030] In a further advantageous embodiment of the method, it is proposed that the projection surface is reduced in its dimensions along at least one spatial direction by means of the control device.

[0031] According to this embodiment, the projection area is reduced by reducing the dimensions of the headlight projection along at least one spatial direction. Preferably, the dimensions of the headlight projection are reduced separately along several different spatial directions. For example, the spatial directions are the longitudinal direction and the transverse direction of the vehicle.

[0032] According to another aspect, a projection device for carrying out a method according to an embodiment as described above is proposed, comprising at least the following components: - a control device; - an optical sensor unit; and - at least two headlights.

[0033] A projection device for carrying out a method according to the preceding description is disclosed here. The projection device comprises at least one control unit, one optical sensor unit, and at least two headlights.

[0034] The control unit communicates with the optical sensor unit and the at least two headlights. The two headlights can be controlled via the control unit. Furthermore, the projection area can be determined by the sensor unit based on the headlight projection detected by the optical sensor unit. Additionally, setting parameters for the at least two headlights can be determined or adjusted via the control unit in order to reduce the projection area.

[0035] The control unit comprises at least one processor and one data storage device. The control unit is located, for example, wholly or partially within the motor vehicle or a stationary backend.

[0036] The optical sensor unit is designed to capture the headlight projection. For example, the optical sensor unit is a camera.

[0037] The headlights are designed to project a beam onto a surface external to the vehicle. Examples of such headlights include matrix headlights and / or digital headlights. For instance, headlights feature multiple light sources, such as LEDs (Light Emitting Diodes), arranged in a matrix, each of which can be controlled separately. These headlights can be configured as rear headlights or front headlights.

[0038] According to another aspect, a motor vehicle is proposed, comprising a projection device according to an embodiment as described above.

[0039] Such a motor vehicle, in addition to the projection device, has at least one drive wheel and a drive motor. The drive motor is designed to provide drive torque and transmits torque, for example by means of a clutch, a gearbox and / or a differential, to which at least one drive wheel is connected.

[0040] Preferably, the motor vehicle has four wheels, two or four of which are designed as drive wheels. The drive engine is, for example, an internal combustion engine and / or an electric drive engine.

[0041] The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, although it should be noted that the drawings are not dimensionally accurate and are not suitable for defining size relationships. It is illustrated in Fig. 1: a motor vehicle with a projection device in a schematic top view; Fig. 2: a spotlight projection after Fig. 1 in a schematic detail view; Fig. 3: a spotlight projection with partially overlapping individual projections in a schematic view; Fig. 4: the headlight projection according to Fig. 3 in a schematic view; Fig. 5: the headlight projection according to Fig. 3 with congruent individual projections; and Fig. 6: a flowchart of a procedure for adjusting a headlight projection.

[0042] In Fig. Figure 1 shows a motor vehicle 11 with a projection device 12 in a schematic top view. The motor vehicle 11 comprises a projection device 12 which projects a headlight projection 1 onto an external surface 7. The projection device 12 comprises a left headlight 2, which produces a left single projection 5, and a right headlight 3, which produces a right single projection 6 (compare Figure 1). Fig. 2) The individual projections 5 partially overlap and together form a spotlight projection 1.

[0043] The vehicle-external surface 7 is depicted as a roadway. The projection device 12 further comprises a control unit 9, by means of which the headlight projection 1 can be controlled and the superposition 4 of the individual projections 5, 6 can be optimized. The control unit 9 is connected to an optical sensor unit 8, by means of which the outlines 13 of the headlight projection 1 can be detected.

[0044] The headlight projection 1 has a projection surface 10 which is arranged parallel to a vehicle longitudinal direction 14 and vehicle transverse direction 16.

[0045] The control unit 9 is designed to reduce the projection area 10 of the headlight projection 1 by adjusting the setting parameters of the headlights 2, 3 and thus repositioning the headlights. For example, the projection area 10 can be iteratively reduced to produce a sharp and high-contrast headlight projection 1.

[0046] The projection device 12 also includes a sensor unit 8, implemented here as a camera, by means of which the headlight projection 1 and its outlines 13 can be detected. Thus, the projection area 10 of the headlight projection 1 can be detected by means of the control device 9 based on the detected outlines 13, for example to evaluate whether it has been reduced by adjusting the setting parameters of the headlights 2, 3.

[0047] The motor vehicle 11 further comprises, as shown, two drive wheels 15 and a drive motor 17, which, as shown, is connected to the drive wheel 15 by means of a transmission 18 to transmit torque.

[0048] In Fig. 2 is a headlight projection 1 after Fig. Figure 1 is shown in a schematic detail view. As depicted, the headlight projection 1 is a symbol, here an arrow.

[0049] The two individual projections 5 and 6 are also represented by arrows. Ideally, the individual projections 5 and 6 overlap completely, so that they are exactly congruent and thus form a sharp contrast. However, as shown, the individual projections 5 and 6 only partially overlap and thus form a spotlight projection 1 with a projection area 10 that is larger than the areas of the respective individual projections 5 and 6. Therefore, the spotlight projection 1 is not sharp and lacks contrast.

[0050] By means of the control unit 9 (compare Fig. 1), which is connected to the optical sensor unit 8, the outlines 13 of the headlight projection 1 can be detected, the projection area 10 can be determined, and the setting parameters of the headlights 2, 3 can be adjusted to reduce the projection area 10. By reducing the projection area 10, the superposition 4 of the individual projections 5, 6 is increased. With complete superposition 4, i.e., perfect alignment, the projection area 10 then corresponds to the area of ​​the respective individual projections 5, 6. The headlight projection 1 then exhibits high sharpness or high contrast.

[0051] In Fig. Figure 3 shows a schematic view of a spotlight projection 1 with partially overlapping individual projections 5 and 6. The spotlight projection 1 shown is, for example, an alternative to the spotlight projection 1 according to [reference missing]. Fig. 2.

[0052] The headlight projection 1 is shown to be a cross. A longitudinal bar of the cross is arranged parallel to the vehicle's longitudinal direction 14 and a transverse bar of the cross is arranged parallel to the vehicle's transverse direction 16.

[0053] For example, the control unit 9 is designed to separately reduce the dimensions of the headlight projection 1 along different spatial directions. Here, for example, a projection length 20 of the headlight projection 1 can first be reduced (compare Fig. 4) and subsequently a projection width of 19 (compare Fig. 5) If the spotlight projection 1 contains communication information or has such communication information, the projection width 19 or projection length 20 of the entire spotlight projection 1 is preferably taken, i.e. the greatest extent of the spotlight projection 1 along the respective spatial direction.

[0054] A cross, as shown here, can be used, for example, as a defined reference symbol and projected in addition to the actual spotlight projection 1. In such a case, the projection width 19 or projection length 20 can be taken from the defined bars of the cross, as shown here.

[0055] In Fig. 4 is the headlight projection 1 after Fig. Figure 3 shows a schematic view. The headlight projection 1 along the vehicle's longitudinal direction 14 has been minimized so that the individual projections 5 and 6 of the crosses now completely overlap along the longitudinal direction. This is particularly evident in the illustration by the reduced projection width 19 of the cross's longitudinal bar.

[0056] In Fig. 5 is the headlight projection 1 after Fig. Figure 3 shows a schematic view. The headlight projection 1 along the vehicle's transverse direction 16 has been minimized so that the individual projections 5, 6 of the crosses now completely overlap along the vehicle's transverse direction 16 and the vehicle's longitudinal direction 14, i.e., in all spatial directions. This is particularly evident in the illustration by the reduced projection length 20 of the cross's crossbar.

[0057] In Fig. Figure 6 shows a flowchart of a procedure for adjusting a headlight projection 1.

[0058] The flowchart shows the steps of a method for adjusting a headlight projection 1 using a projection device 12, preferably according to Fig. 1 and the preceding description.

[0059] In a first step a., a headlight projection 1 is projected onto the vehicle's external surface 7 using the two headlights 2, 3. The individual projections of the two headlights 2, 3 partially overlap to form the headlight projection 1.

[0060] In a second step b., the headlight projection 1 is detected by means of the optical sensor unit 8. Preferably, the outlines 13 of the headlight projection 1 are detected.

[0061] In a third step c., the projection area 10 of the headlight projection 1 is determined using the control unit 9. For example, the area of ​​the projection area 10 is determined by means of a grid comparison, by integration over the captured outlines 13, by means of artificial intelligence and / or on the basis of the geometry of the outlines 13.

[0062] In a fourth step d., at least one setting parameter of at least one of the two headlights 2, 3 is adjusted by means of the control device 9 in order to reduce the projection area 10. Preferably, the individual projection 5, 6 of the corresponding headlight 2, 3 on the vehicle-external surface 7 is shifted relative to the vehicle 11 and the other individual projection 5, 6.

[0063] In a fifth step e. the headlight is adjusted based on the adapted setting parameter, for example by means of a digital control of the individual light sources of the headlights 2,3.

[0064] The procedure is preferably performed iteratively to further reduce the projection area 10 of the spotlight projection 1 and thus produce a sharp and high-contrast spotlight projection 1. For example, steps b. to e. are executed in a loop. In other words, after adjusting the parameters, the modified spotlight projection 1 is recorded, and it is determined whether the projection area 10 has decreased. If the projection area 10 has decreased, the corresponding parameter is adjusted, for example, in the same direction as before. If the projection area 10 increases, the corresponding parameter is adjusted, for example, in the opposite direction.

[0065] If the projection area 10 remains unchanged or increases after a previous decrease, this is, for example, a termination criterion for the loop. Terminating the loop is represented here by step f. Alternatively or additionally, the loop can be restarted, for example, after a pause. Such a pause is defined, for example, by fixed time intervals, changing driving situations, road conditions, gradients, and / or headlight projection 1.

[0066] A method for adjusting headlight projections is proposed, which enables particularly simple and precise focusing of the headlight projection.

Claims

[1] Method for adjusting a headlight projection (1) comprising the following steps: a. by means of two headlights (2,3), projecting a headlight projection (1) from at least a partial superposition (4) of respective individual projections (5,6) of the two headlights (2,3) onto a vehicle-external surface (7); b. by means of an optical sensor unit (8), detecting the headlight projection (1); c. by means of a control device (9), determining a projection surface (10) of the headlight projection (1); d. by means of the control device (9), adjusting at least one setting parameter of at least one of the headlights (2, 3) to reduce the projection area (10); and e. Adjust at least one of the headlights (2,3) based on the adjustment parameters adapted in step d. [2] Method according to claim 1, wherein a minimization problem for the projection surface (10) is solved by means of the control device (9) to determine the adapted setting parameters. [3] Method according to claim 1 or claim 2, wherein the projection area (10) is iteratively reduced by means of the control device (9). [4] Method according to one of the preceding claims, wherein the adjustment of the at least one setting parameter is carried out for a defined longitudinal distance of the headlight projection (1) from the motor vehicle (11) along a vehicle longitudinal direction (14) and / or for a defined transverse position of the headlight projection (1) along a vehicle transverse direction (16). [5] Method according to any of the preceding claims, wherein the headlight projection (1) includes communication information or is a reference symbol. [6] Method according to one of the preceding claims, wherein by means of the control device (9) the projection surface (10) is reduced in its dimensions along at least one spatial direction. [7] Projection device (12) for carrying out a method according to one of the preceding claims, comprising at least the following components: - a control device (9); - an optical sensor unit (8); and - at least two headlights (2,3). [8] Motor vehicle (11) comprising a projection device (12) according to claim 7.

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