Headlamp for vehicle and control method

Abstract

The invention relates to a headlamp for a vehicle and an actuation method. A headlamp for a vehicle includes: a light source unit including a plurality of light source elements for emitting light; an optical unit for imaging the light source element into a plurality of illumination areas, the illumination areas constituting a predetermined light distribution; a control unit for generating a control signal by means of which the light source element can be individually controlled in dependence on an ambient signal; an environment sensor unit for generating an environment signal by means of which an environment parameter in the front area of the vehicle can be determined, the control unit having means for generating a control signal dependent on the environment parameter, in order to actuate only such light source elements (2, 2 ') which are imaged into such a part of the light distribution (5) in which there is a varying illumination intensity on the basis of the light (14) emitted by the external light source (13).

Description

Technical Field

[0001] The present invention relates to a headlamp for a vehicle, comprising: a light source unit including a plurality of light source elements for emitting light; an optical unit for imaging the light source elements into a plurality of illumination areas, and a predetermined light distribution being formed by the illumination areas; a control unit for generating a control signal, by means of which the light source elements can be individually controlled depending on an environmental signal; and an environmental sensor unit for generating an environmental signal, by means of which environmental parameters in the front area of the vehicle can be determined.

[0002] Furthermore, the present invention relates to a method for controlling a headlamp for a vehicle, wherein a plurality of light source elements are individually controlled depending on environmental parameters and imaged into illumination areas of a predetermined light distribution by means of an optical unit. Background Art

[0003] A headlamp for a vehicle is known from DE 10 2020 122 322 A1, which is configured as a high-resolution headlamp including a plurality of light source elements, and the light source elements form a light source unit. The light source elements are configured as LED light-emitting elements, and the LED light-emitting elements are arranged on a common carrier or chip. Furthermore, the headlamp has an optical unit including a lens device, by means of which the light source elements of the light source unit are respectively imaged into illumination areas of a predetermined light distribution. A control unit for generating a control signal is provided, by means of which each light source element can be turned on or off or dimmed. The control unit controls the light source elements in such a way that different partial light distributions are generated, and more precisely different partial light distributions are generated depending on environmental parameters determined by an optical detection unit. When, for example, a pedestrian is recognized at the right edge of the vehicle, a partial light distribution can be generated in this way. If the vehicle is in an urban area, a control signal can be automatically generated, by means of which the light source elements are controlled in such a way that an urban light distribution is generated.

[0004] It is known from DE 10 2022 001 571 A1 to detect and evaluate street lighting, thereby preventing a sudden change in illumination intensity when the street lighting is blocked, for example, by existing trees. However, it is disadvantageous in the known headlamp that the post-regulation of the illumination is effective only when the vehicle drives through the section again. Summary of the Invention

[0005] The object of the present invention is to provide a headlamp for a vehicle and a control method, so that an optimized adaptation can be carried out relatively quickly depending on environmental parameters.

[0006] To solve this task, the present invention is characterized in combination with the preamble of claim 1 in that the control unit has means for generating a control signal dependent on the environmental parameter, such that only those light source elements are controlled which are imaged into such a part of the light distribution in which there is a changed illumination intensity based on the light emitted by an external light source.

[0007] A particular advantage of the present invention is that an optimized adaptation of a predefined light intensity distribution can be made dependent on environmental conditions, such as street lighting or street geometry. According to the invention, only a part of the light source elements is controlled by dimming or switching off or on, which light source elements are imaged in the illumination area by means of an optical unit, in which illumination area the illumination intensity changes based on an external light source. If, for example, an external light source, in particular switched-on street lighting, is recognized by means of a detection unit (camera), the part of the light source elements which are imaged in the part of the light distribution illuminated by the street lighting is dimmed to a minimum light intensity or minimum light flux, such that a reduced illumination intensity is emitted in these illumination areas by means of the headlamp. The illumination intensity generated by the headlamp and the illumination intensity generated by the street lighting (street lamp) are superimposed to the actual illumination intensity perceived by the driver of the vehicle, which illumination intensity is greater than the minimum illumination value and less than the maximum illumination value. Advantageously, in this way, the light distribution can be kept the same or uniform within an illumination intensity range, in which the light intensity of the light source elements can be dimmed or the light source elements can be switched off in an energy-saving manner when sufficient external illumination is present.

[0008] According to a preferred embodiment of the present invention, the light distribution is formed by a plurality of distance zones, wherein the distance zones are distinguished from one another by the illumination of different distance regions. Each distance zone includes a certain number of illumination areas, which illumination areas are formed by a corresponding number of imaged light source elements. The size and / or dimensions of the distance zone depend on the foreseeable and / or calculable environmental conditions or environmental influences. For example, the distance zone can correspond to a distance region in the front area of the vehicle, which distance region corresponds to the illumination area of a street lamp. Advantageously, in this way, a defined distance zone can be dimmed, switched off, or dimmed, switched on or switched off.

[0009] According to a further configuration of the present invention, at least one intermediate distance zone is provided, which intermediate distance zone covers a part of the lane of the vehicle. External distance zones for illuminating adjacent lanes or side edges are provided on the left and right of the intermediate distance zone. Advantageously, it is possible to switch or adjust only three different regions defined by the distance zones in the horizontal plane of the light distribution, such that the desired illumination intensity distribution enters into the horizontal plane. Thereby, the control or adjustment effort is defined.

[0010] According to a further configuration of the invention, the light source elements of the right headlight and the left headlight of the vehicle can be controlled differently, such that the brightness gradient in the boundary space between adjacent distance zones is smaller compared to the same control of the same light source elements of the left and right headlights. Advantageously, the horizontal offset of the left and right headlights can be utilized to cause a smoother transition with respect to the lighting intensity distribution in the boundary region between two adjacent distance zones.

[0011] To solve this task, the invention has the features of method claim 10.

[0012] A particular advantage of the method according to the invention is that when the measured and / or calculated lighting intensity values in a part of the front area of the vehicle exceed a predetermined upper threshold or fall below a predetermined lower threshold, the light source elements are controlled with a corresponding drive power for such a long time and to such an extent that the current lighting intensity in the corresponding part of the front area of the vehicle is less than the predetermined upper threshold and greater than the predetermined lower threshold. The current lighting intensity or lighting intensity distribution in the said part of the front area of the vehicle consists of the lighting intensity of the headlight and an external light source, such as streetlight light. Advantageously, a relatively rapid adaptation to different light conditions in the front area of the vehicle can be carried out thereby. Advantageously, the light of an external light source can be utilized in particular for reducing the light power of the headlight in an energy-saving manner. Description of the Drawings

[0013] The embodiments of the invention are further explained with the aid of the drawings.

[0014] Wherein:

[0015] Figure 1 A block diagram of a headlight according to the invention is shown;

[0016] Figure 2 A diagram of the light distribution according to the invention including a plurality of distance zones in the front area of the vehicle is shown and

[0017] Figure 3 A lighting intensity diagram in a distance zone illuminated by an external light source is shown and

[0018] Figure 4 A flow chart of the said control is shown. Detailed Description of the Invention

[0019] The headlight for a vehicle is arranged in the front area of the vehicle. The headlight has a light source unit 1 including a plurality of light source elements 2 arranged in an array, and the light source elements are preferably arranged on a common chip. The light source elements 2 are preferably configured as LED light sources.

[0020] Furthermore, the headlamp has an optical unit 3 which has at least one lens for imaging a light source element 2 in the front area 4 of the vehicle, wherein the light source element 2 is imaged into an illumination area of a predetermined light distribution 5 respectively.

[0021] The light distribution 5 can be formed, for example, as an urban light distribution as shown in Figure 2 .

[0022] Furthermore, the headlamp has a control unit 6 by means of which a control signal 7 is generated for controlling the light source unit 1 or the individually controllable light source elements 2 respectively. The light source element 2 can be controlled such that the light source element is switched on or off or operates in a dimming state, wherein the light intensity or luminous flux of the respective light source element 2 can be adjusted in a range between zero and a maximum value.

[0023] The light source unit 1, the optical unit 3 and the control unit 6 are arranged in a common housing. The control unit 6 is preferably arranged on the same circuit board as the light source unit 1. The optical unit 3 is arranged in front of the light source unit 1 along the main emission direction of the headlamp.

[0024] Furthermore, the headlamp has an ambient sensor unit 8 which is preferably arranged remotely. The ambient sensor unit can be formed, for example, as a camera for detecting an image of the front area 4 of the vehicle. The ambient sensor unit 8 provides image data 9 for the control unit 6, and the image data is evaluated in the control unit 6 for determining the current illumination intensity in different areas of the front area 4 of the vehicle.

[0025] As can be seen from Figure 2 , the light distribution 5 jointly has different parts or distance zones Z0, Z 1M , Z 1R , Z2, Z 2R , Z 2L . The basic distance zone Z0 extends relative to the vehicle in the range of 0 m to 20 m over the entire horizontal width of the light distribution 5. A first distance zone in the distance range between 20 m and 40 m from the vehicle is formed by a first intermediate distance zone Z 1M , a first right-hand distance zone Z 1R which is adjacent to the first intermediate distance zone on the right and a first left-hand distance zone Z 1M which extends to the left relative to the intermediate distance zone Z 1L . The first intermediate distance zone Z 1M extends on the lane 10 of the vehicle. The first right-hand distance zone Z 1R extends on the right next to the lane 10 in the side area 11. The first left-hand distance zone Z 1L extends on the oncoming traffic lane 12 which adjoins the first intermediate distance zone Z1M On the left side.

[0026] Includes a second intermediate distance zone Z 2M , a second right distance zone Z adjacent to the right on the second intermediate distance zone 2R And in the intermediate distance zone Z 2M The second left distance zone Z extending to the left 2L The second distance zone of extends in another distance area at a distance between 40m and 60m from the vehicle. The second intermediate distance zone Z 2M Like the first intermediate distance zone Z 1M Covers lane 10 of the vehicle. The second right distance zone Z 2R Extends in the side area 11. The second left distance zone Z 2L Extends in the area of lane 12 of oncoming traffic.

[0027] See step 100 in Figure 4 In the initial operating state of the urban light distribution, the light source element 2 is controlled in such a way that a predetermined light distribution 5 is generated. The corresponding light source element 2' emits light, so that there is an illumination intensity B2 in the distance zone Z 1M .

[0028] If it is determined during driving by means of the environmental sensor unit 8 that light 14 is emitted by an external light source 13, preferably a street lamp, onto the front area 4 of the vehicle, in this embodiment onto the first intermediate distance zone Z 1M - which is indicated by hatching in Figure 2 - then a correction of the control of the light source unit 1 is carried out. If the detection occurs at the first moment, then in the first intermediate distance zone Z 1M , as the superposition of the light flux of the external light source 13 and the light source element 2' controlled for this distance zone Z 1M The illumination intensity is above the maximum threshold S MAX . This comparison is continuously carried out in the evaluation device of the control unit 6. If - as can be seen in step 101 according to Figure 4 - it is determined that the illumination intensity B ZM1 And the external illumination intensity B EXT Is greater than the maximum threshold S MAX , then the control signal 7 is changed in such a way that the corresponding light source element 2' is dimmed and controlled in such a way that the sum of the current illumination intensity B ZM1 And the illumination intensity B of the external source EXT Corresponds to the illumination intensity B2 that existed in the first intermediate distance zone Z in the initial state of the light distribution 5 1M . The emitted light flux of the light source element 2' results in a reduced illumination intensity B1.

[0029] If the illumination intensity in the intermediate distance range Z 1M is reduced so much that the sum of the illumination intensity B1 of the headlamp and the illumination intensity B EXT of the external light source 13 is less than the minimum threshold S MIN , then the light source element 2' is brightened again to the initial state, so that the light source element 2' forms an illuminated area with the illumination intensity B2, see the steps 102, 103 and 100 in Figure 4 . The control according to step 100 remains effective for such a long time until the maximum threshold S MAX is exceeded.

[0030] In Figure 4 , the control routine shown is applicable when the illumination intensity released by the headlamp in the corresponding distance range exceeds the upper threshold S MAX . In the same way, a reverse control can be carried out when it is below the lower threshold S MIN .

[0031] For the sake of simplicity, only two thresholds, namely the upper threshold S MAX and the lower threshold S MIN , are given in this embodiment. In an alternative embodiment form of the present invention not shown, multiple thresholds can also be considered, so that a smoother transition with a smaller illumination intensity difference can be carried out at smaller time intervals. In this embodiment, it is determined at the second moment that the illumination intensity of the external light source 13 is reduced so much that the light source element 2' in the first intermediate distance range Z 1M has to be brightened again to the light intensity in the initial state 100 of the light distribution.

[0032] In Figure 3 , the control state according to step 102 is shown. It can be seen that through the superposition of the light fluxes of the external light source 13 and the headlamp in the first intermediate distance range Z 1M , there is the same illumination intensity B2 as at least in the edge regions of the adjacent first right distance range Z 1R and the adjacent first left distance range Z 1L .

[0033] Preferably, the optical unit 3 is designed such that the boundary edge 15 showing the formation of adjacent distance ranges is softened, that is, the illumination intensity on the boundary edge 15 of the adjacent distance ranges does not drop suddenly but decreases continuously. The corresponding distance ranges Z 1M , Z 1R , Z 1L ; Z 2M , Z 2R , Z 2L have a relatively small slope of the brightness gradient on their boundary edge 15.

[0034] According to an alternative embodiment of the invention, the horizontal misalignment of the identically configured right and left headlamps of the vehicle can be used to design the brightness gradient at the boundary edge 15. The brightness gradient has a small slope at the boundary edge 15 in the distance zones Z 1M Z 1R Z 1L ; Z 2M Z 2R Z 2L .

[0035] Alternatively or additionally, according to another embodiment of the invention, when the first intermediate distance zone Z 1M is illuminated relatively brightly by the external light source 13, the light source element 2 is controlled such that the second intermediate distance zone Z 2M is illuminated with an increased illumination intensity compared to the initial state 100. Thereby, the contrast between the intermediate first distance zone Z 1M and the second distance zone Z 2M is reduced, which makes the light distribution more uniform overall.

[0036] According to an alternative embodiment of the invention, the number of thresholds, i.e., the maximum threshold S MAX and the minimum threshold S MIN , can be increased in order to adjust the illumination intensity values in the corresponding distance zones to a predetermined initial value B2 or theoretical value. For example, a PID controller can be used to adapt the luminous intensity or luminous flux of the light source element 2 such that the target illumination intensity in the corresponding distance zone is formed dynamically, i.e., in a relatively short time.

[0037] List of reference numerals

[0038] 1 Light source unit

[0039] 2, 2' Light source element

[0040] 3 Optical unit

[0041] 4 Front area of the vehicle

[0042] 5 Light distribution

[0043] 6 Control unit

[0044] 7 Control signal

[0045] 8 Environmental sensor unit

[0046] 9 Image data

[0047] 10 Lane

[0048] 11 Side area[[ID=QQQ]] [[ID=QQQ]]

[0049] 12 Lane

[0050] 13 External light source

[0051] 14 Light

[0052] 15 Boundary edge

[0053] Z… Distance area

[0054] B EXT , B ZM1 , B2, B1 Illumination intensity

[0055] S MAX Maximum threshold

[0056] S MIN Minimum threshold

[0057] Step

Claims

1. Headlamp for a vehicle, comprising: - a light source unit (1) comprising a plurality of light source elements (2, 2') for emitting light, - an optical unit (3) for imaging the light source elements (2, 2') into a plurality of illumination areas, the plurality of illumination areas forming a predetermined light distribution (5), - a control unit (6) for generating a control signal (7), by means of which the light source elements (2, 2') can be individually controlled depending on an environmental signal, - an environmental sensor unit (8) for generating an environmental signal, by means of which environmental parameters in the front area (4) of the vehicle can be determined, characterized in that the control unit (6) has means for generating a control signal (7) depending on the environmental parameters, such that only the light source elements (2, 2') imaged into the following part of the light distribution (5) are controlled, in which part there is a changed illumination intensity based on light (14) emitted by an external light source (13).

2. The headlamp according to claim 1, characterized in that, The part of the light distribution (5) has a plurality of illumination areas of the light source elements (2, 2') imaged respectively, and the light source elements can be controlled such that the part of the light distribution (5) is formed by the superposition of the light emitted by the light source elements (2, 2') and the light (14) emitted by the external light source (13), wherein the synthesized illumination values in this part of the light distribution (5) form between a predetermined maximum threshold (S MAX ) and a predetermined minimum threshold (S MIN ).

3. The headlamp according to claim 1 or 2, characterized in that, Light source elements (2, 2') can be jointly controlled by means of the same control signal (7), the imaged illumination areas of which are in a common distance zone of the light distribution (5), where the distance zone is differentiated by different distances relative to the vehicle, and at least two distance zones are provided, the at least two distance zones being independently switchable on and off or having dimmable illumination areas respectively, and the illumination areas being arranged side by side in the horizontal direction.

4. The headlamp according to any one of claims 1 to 3, characterized in that, Set at least one distance zone, the distance zone having an intermediate distance zone (Z 1M 、Z 2M ), a left distance zone (Z 1L 、Z 2L ), and a right distance zone (Z 1R 、Z 2R ), the left distance zone adjoining on a first side of the intermediate distance zone (Z 1M 、Z 2M ), and the right distance zone adjoining on a second side of the intermediate distance zone (Z 1M 、Z 2M ) that is disposed opposite to the first side of the intermediate distance zone (Z 1M 、Z 2M ).

5. The headlamp according to any one of claims 1 to 4, characterized in that, The light distribution (5) is configured as an urban light distribution, where - The intermediate distance area (Z 1M , Z 2M ) illuminates the lane (10) of the vehicle, - the left distance zone (Z 1L , Z 2L ) illuminates another lane (12) of the carriageway or the side edge of the carriageway, - The right distance zone (Z 1R , Z 2R ) illuminates additional lanes of the carriageway or the lateral edge of the carriageway.

6. The headlamp according to any one of claims 1 to 5, characterized in that, The optical unit (3) is configured such that the luminance gradient on the boundary edge (15) between two adjacent distance zones (Z 1M 、Z 1R 、Z 1L ;Z 2M 、Z 2R 、Z 2L ) has a small slope, such that the illumination intensity distributions of the adjacent distance zones (Z 1M 、Z 1R 、Z 1L ;Z 2M 、Z 2R 、Z 2L ) are superimposed.

7. The headlamp according to any one of claims 1 to 6, characterized in that, The light source elements (2, 2') of the right headlight and the left headlight of the vehicle can be controlled differently such that the distribution of the brightness gradient in the region of the boundary edge (15) between two adjacent distance zones (Z 1M 、Z 1R 、Z 1L ; Z 2M 、Z 2R 、Z 2L ) has a smaller slope compared to when the light source elements (2, 2') of the left headlight and the right headlight are controlled identically.

8. The headlamp according to any one of claims 1 to 7, characterized in that, The light source elements (2, 2') are arranged on the chip such that the light source elements are imaged respectively into illumination areas by means of the optical unit (3), and by means of the illumination areas, distance zones (Z 1M 、Z 1R 、Z 1L ;Z 2M 、Z 2R 、Z 2L ) are formed in the light distribution (5).

9. The headlamp according to any one of claims 1 to 8, characterized in that, It is possible to control the light source elements (2, 2') such that starting from the minimum distance from the vehicle, a plurality of distance zones (Z 1M Z 1R Z 1L ; Z 2M Z 2R Z 2L ) can be formed in different shapes and / or sizes and arranged side by side in the horizontal direction.

10. A method for controlling a headlight for a vehicle, wherein, The illumination areas of the light distribution (5) generated in the front area (4) of the vehicle, in which a plurality of light source elements (2, 2') are individually controlled depending on environmental parameters and imaged by means of an optical unit (3) into the predetermined light distribution (5), are characterized in that the illumination intensity values of the illumination areas are determined, and when a predetermined deviation from the determined illumination intensity value and the predetermined illumination intensity value generated by the imaging of the corresponding light source element (2, 2') is exceeded, the corresponding light source element (2') is dimmed such that the determined illumination intensity value is within the predetermined deviation.

11. The method according to claim 10, characterized in that, When the measured and / or calculated illumination intensity values of the light distribution (5) in the front area (4) of the vehicle exceed a predetermined upper threshold (S MAX ) as a deviation and / or fall below a lower threshold (S MIN ) as a deviation, the light source elements (2, 2') imaging in these illumination areas are controlled such that the measured and / or calculated illumination intensity values are below the upper threshold (S MAX ) and / or above the lower threshold (S MIN ).

12. The method according to claim 10 or 11, characterized in that, Determine the measured and / or calculated illumination intensity values in groups for different distance zones (Z 1M 、Z 1R 、Z 1L ; Z 2M 、Z 2R 、Z 2L ).

13. The method according to any one of claims 10 to 12, characterized in that The illumination intensity value in the front area (4) of the vehicle is determined by evaluating the image data of a camera.

14. The method according to any one of claims 10 to 13, characterized in that, The illumination intensity value is calculated by identifying the position data of the external light source (13), where the illumination intensity value is obtained as the superposition of the light generated by the corresponding light source element (2, 2') and the light (14) emitted by the external light source (13).

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