DE102018109766A1 - Method for operating a lighting device of a motor vehicle and lighting device - Google Patents

Abstract

A method is provided for operating a lighting device of a motor vehicle, comprising: determining (102) an image stream, wherein the image stream comprises successive individual images of a vehicle-oriented vehicle apron in the direction of travel; Recognizing (104) at least one traffic sign as a function of the images of the image stream; Determining (106) a driving situation of the motor vehicle; Selecting (108) the at least one traffic sign as a function of the driving situation; and emitting (110) a light distribution in the direction of travel of the motor vehicle, wherein the light distribution in a solid angle, which at least partially covers the selected traffic sign, highlights the selected traffic sign.

Description

The invention relates to a method for operating a lighting device of a motor vehicle and to a lighting device of a motor vehicle.

Light modules are known from the prior art, which have a plurality of separately controllable light-emitting diodes for emitting electromagnetic radiation. Such light modules generate, for example, a marking light, which serves for the targeted and spatially limited illumination of an object detected in front of the vehicle. Exemplary is on the DE 10 2010 006 097 U1 directed.

A particular driving situation requires the driver to react to the regulations or instructions given by traffic signs. This is necessary to ensure traffic safety.

The object of the invention is therefore to assist the driver situationally with the aid of the vehicle headlamp in the guidance of the vehicle.

To achieve this object, a method for operating a lighting device of a motor vehicle is provided, wherein the lighting device comprises a headlight, a camera and a control unit. The method comprises: determining an image stream, wherein the image stream comprises successive frames of a vehicle-oriented vehicle apron in the direction of travel; Detecting at least one traffic sign as a function of the images of the image stream; Determining a driving situation of the motor vehicle; Selecting the at least one traffic sign as a function of the driving situation; and emitting a light distribution in the direction of travel of the motor vehicle, wherein the light distribution in a solid angle, which at least partially covers the selected traffic sign, highlights the selected traffic sign.

Advantageously, the at least one traffic sign determined to be relevant for the driving situation is emphasized by the provided method. This highlighting of the traffic sign can be carried out at any ambient light intensity - including during the day - to assist the driver of the motor vehicle in the respective driving situation. For example, the driver can be supported in the prescribed compliance with a speed limit or depending on the navigation situation and context certain traffic signs - such as diversion signs and turn signals - highlighted on the selected route or no parking and parking signs after reaching the destination. In addition, a display on the head-up display or on the dashboard can either be omitted or supported. Consequently, the driver is supported by better readability of the traffic sign and the increased attention and can respond more quickly in the event of danger, which improves overall road safety.

The methods presented in this description are advantageous, in particular when using a matrix headlamp with high pixel resolution, since the highlighted traffic sign can already be selected by illumination technology at a great distance due to the increased pixel resolution. In conjunction with a matrix headlight, the recognition of the highlighted traffic sign by the driver is thus improved. Consequently, the use of a matrix headlamp in conjunction with the described methods contributes to increasing traffic safety.

In an advantageous embodiment, the method comprises: determining a relevance of the recognized traffic sign for the determined driving situation; and selecting the recognized traffic sign as a function of the ascertained relevance.

The selection of the traffic sign as a function of its relevance makes it possible to highlight only those traffic signs that are important to the driver in the respective driving situation for the driver. For example, at a vehicle speed of 50 km / h in a Tempo 30 zone, it does not matter whether the navigation context indicates that the driver is looking for a parking space. Rather, in this situation it is advisable to remind the driver of compliance with the maximum speed by highlighting the Tempo 30 signs. After reaching the maximum speed of 30 km / h recognized parking signs are classified as relevant and highlighted highlighted.

In an advantageous embodiment, the method comprises: selecting the recognized traffic sign if the assigned relevance exceeds a threshold value.

By a threshold operation, the selection of the recognized traffic sign can be performed in a simple manner. Advantageously, by setting the threshold, the number of highlights can be influenced. For example, the threshold is increased in operation when many other vehicles are in the area to reduce interference to the other road users by highlighting traffic signs. On the other hand the threshold is lowered as the vehicle density in the environment decreases. For example, it is provided that the maximum number of highlighted traffic signs is limited to a number of one or two, or that the number is adjustable by the driver.

In an advantageous embodiment, the method comprises determining the relevance as a function of a value from a look-up table, whereby a respective value is assigned to the respective driving situation in the look-up table.

The use of a lookup table provides an easy-to-implement way to deposit the relevance of traffic signs for occurring driving situations.

In an advantageous embodiment, the method comprises determining the relevance as a function of a variable parameter and / or measured value over time.

The consideration of a variable parameter and / or measured value makes it possible to carry out a weighting in determining the relevance. Thus, for example, blatant transgressions of the speed given by the recognized traffic sign go hand in hand with a high weighting of the relevance of the recognized traffic sign in order to exceed the threshold value which leads to the selection of the traffic sign and the corresponding highlighting of the traffic sign.

In an advantageous embodiment, the method comprises: detecting a first number of traffic signs in response to the images of the image stream; Determining a respective relevance of the recognized first number of traffic signs for the determined driving situation; Selecting a second number as a subset of the first number of recognized traffic signs depending on their respective relevance; and emitting the light distribution in the direction of travel of the motor vehicle, wherein the light distribution in a number of solid angles, which covers the respective selected traffic sign at least in sections, have a respective selected traffic sign highlighting light intensity.

Advantageously, several traffic signs are highlighted, which are relevant to the particular driving situation. A third number of traffic signs, which are included in the first number but not in the second number, are not highlighted, so come back in the visual perception of the driver.

In an advantageous embodiment, the method comprises: emitting a detection light distribution in the direction of travel of the motor vehicle; and detecting the at least one traffic sign, which is illuminated by the detection light distribution, in dependence on the images of the image stream.

Advantageously, the recognition of the respective traffic sign is improved by the light, which can happen for example in a flash like a flare. Thus, there is an iterative improvement of the recognition accuracy of the respective traffic sign. The detection light distribution includes, for example, non-visible light for humans, e.g. As infrared light, so that the other road users are not disturbed.

In an advantageous embodiment, the highlighting of the at least one traffic sign comprises an increase in the light intensity in the associated solid angle of the emitted light distribution with respect to a region around the solid angle.

Increasing the light intensity in the solid angle directs the driver's attention to the illuminated and reflective traffic sign. The area around the solid angle includes a reduced light intensity to visually clearly demarcate the traffic sign.

In an advantageous embodiment, the method comprises: a vehicle speed; and / or rain sensor information; and / or navigation context information. The driving situation is determined, for example, as a function of the aforementioned information.

Another aspect of this description relates to a control unit of a lighting device of a motor vehicle, which is designed to carry out the method according to one of the preceding aspects.

A further aspect of this description relates to a lighting device of a motor vehicle, wherein the lighting device comprises a headlight, a camera and a control unit, and wherein the lighting device is designed to: determine a picture stream, wherein the picture stream comprises successive individual images of a vehicle front-oriented in the direction of travel; to determine at least one traffic sign as a function of the images of the image stream; to determine a driving situation of the motor vehicle; to select the at least one traffic sign depending on the driving situation; and to emit a light distribution in the direction of travel of the motor vehicle, the light distribution in a solid angle, which at least partially covers the selected traffic sign, highlights the selected traffic sign.

• 1 ein schematisches Ablaufdiagramm;
• 2 ein Blockdiagramm eines Kraftfahrzeugs;
• 3-5 einen schematisch dargestellten Messschirm mit einer beispielhaften Straßendarstellung; und
• 6 eine Ausführungsform eines Blocks aus 2.

Further features and advantages will become apparent from the following description of exemplary embodiments of the drawing. In the drawing show:

• 1 a schematic flow diagram;
• 2 a block diagram of a motor vehicle;
• 3-5 a schematically illustrated measuring screen with an exemplary road representation; and
• 6 an embodiment of a block 2 ,

1 shows a schematic flow diagram for operating a lighting device of a motor vehicle. A picture stream becomes in one step 102 determined, wherein the image stream comprises successive individual images, which depict an oriented in the direction of travel vehicle apron. In one step 104 At least one traffic sign is detected as a function of the images of the image stream. In one step 106 a driving situation of the motor vehicle is determined. Depending on the determined driving situation becomes in a step 108 that selects at least one traffic sign. In one step 110 a light distribution is radiated in the direction of travel of the motor vehicle. The light distribution highlights the selected traffic sign in a solid angle, which covers the selected traffic sign at least in sections.

At the beginning of the emphasis, d. H. Milliseconds before and / or at the beginning of the highlighting, an audible signal is generated in the vehicle interior, in order to additionally inform the driver of the highlighting that takes place for him. Further, the end of the highlighting is brought to the attention of the driver by another acoustic signal.

2 shows the motor vehicle 202 in a schematic block diagram. The lighting device comprises a headlight 204 , a camera 206 and a control unit 208 , The control unit 208 comprises a microprocessor and a memory element, on which a computer program is stored, which is designed to carry out the method steps illustrated in this description. The control unit 208 For example, it includes a number of controllers or a single controller. The camera 206 is arranged by way of example in the front region of the motor vehicle, is arranged in another embodiment at another location, for example in the region of a windshield of the motor vehicle.

The camera 206 is in the direction of travel x of the motor vehicle 202 so aligned to the vehicle apron and generates a stream of images stre. A block 212 detects traffic signs in the stream of images stre. The block 212 is therefore adapted to allocate areas in frames previously known traffic signs and these areas in subsequent frames in the form of coordinates 214 pursue. Will one or more traffic signs 216 through the block 212 recognized in the stream stre, so this is at least one traffic sign met to a block 218 to hand over.

A rain sensor 220 generates a rain sensor signal r , A speed sensor 226 for example, is near a wheel 228 of the motor vehicle and generates a speed signal v.

A GPS receiver 222 generates a time signal t. The time signal t is used in such a way that traffic signs which are valid only at certain times are only evaluated with high relevance if the time signal t indicates that the time period indicated on the traffic sign is present. In another example, signs for a railroad crossing are only rated with high relevance if a train is expected at the respective railroad crossing in the present period. For this purpose, for example, train schedules and / or Zugdurchfahrzeiten for the respective railroad crossing with the time signal t connected.

A navigation unit 224 is adapted, upon input by the driver, to navigate the driver to the entered destination. Here is the navigation unit 224 a navigation context N which, for example, the search of the driver for a parking lot, a highway ride, a cross-country drive or another, the driving situations S comprising information characterizing the vehicle. If, for example, a road is blocked and the navigation takes place along a detour route, diversion information signs are evaluated with a high relevance for the driving situation, with the result that they can be highlighted. In another example, the navigation context N Before that, a departure from the highway should be taken and the corresponding signs are rated with high relevance, to emphasize this for the driver by targeted illumination.

In an example, not shown, billboards are recognized and highlighted at the edge of the road. In another example, not shown, the motor vehicle comprises a Temperature sensor, the temperature signal of which is evaluated so that snow or Eisglätte traffic signs can be evaluated and highlighted with high relevance. Another example, not shown, evaluates a sensor signal from a tank sensor and rates petrol station signage as highly relevant to alert the driver to the low fuel stock.

The rain sensor signal r , the time signal t , the navigation context N , the speed signal v and more the driving situation S characterizing signals become the block 218 supplied and characterize individually and in any combination with each other, the current driving situation S of the motor vehicle.

The block 218 determines a relevance R depending on the at least one traffic sign trafS and the present driving situations S , In one embodiment, the block is 218 executed as a lookup table, wherein the respective driving situation in the lookup table a respective value of relevance R assigned. Alternatively or in addition to the lookup table becomes the relevance R depending on a time varying parameter such as the time signal t or the navigation context N or a time varying measurement such as the rain sensor signal r or the speed signal v determined.

A block 230 selects the traffic sign TRAF depending on the determined relevance R and forwards the selected traffic sign trafS_sel to a block 232 further. For example, a threshold operation can be used for the selection. Thus, the recognized traffic sign trafS then as a selected traffic sign trafS_sel selected if the assigned relevance R exceeds a threshold. This threshold can be fixed. In another example, the threshold value is set as a function of threshold parameters such as, for example, the number of vehicles traveling in the direction of travel in the surroundings, wherein the number of vehicles can be determined via a local radio interface (not shown).

The block 232 generates a control signal 234 for a light module 236 of the headlight 204 , The light module 236 comprises a number of light sources arranged in a matrix, which are provided for example by a micromirror arrangement or individual semiconductor light sources. In the determination of the control signal 234 become the current coordinates 214 of the selected traffic sign trafS_sel taken into account as being that of the light module 236 in response to the control signal 234 generated light distribution L the solid angle Ω1 in which the traffic sign is currently located, relative to adjacent solid angles Ω2 and Ω3 highlights. The emphasis in the area of the solid angle Ω1 can be reinforced by the fact that in a region, not shown, around the solid angle Ω1 a targeted darkening takes place.

The light distribution L includes visible to humans light that the driver of the motor vehicle to a possible danger situation in front of the vehicle by lighting the selected traffic sign trafS_sel draws attention to visible light. This dangerous situation is indicated for example by excessive speed or minus degrees of ambient temperature. The attention of the driver can be further enhanced by the fact that this is on the selected traffic sign trafsS_sel directed light in the solid angle Ω1 flashes (for example, alternating switching on and off or increasing and decreasing the brightness or the brightness (so-called dimming)). For example, a brief flashing of the traffic sign in the form of a flash can be used to improve the recognition of the traffic sign. In addition, the brightness in the solid angle can be determined by the brightness value or reflectance of the illuminated traffic sign Ω1 be adjusted, since the reflectance of traffic signs depending on the weather and aging of the traffic sign and the distance between the vehicle 202 and traffic signs trafS_sel varies greatly. Or the light is alternatively or additionally in a certain, preferably the light color of the rest, of the in the solid angles Ω2 or Ω3 at least temporarily different color varies. As colors, all colors permitted in the ECE color space are conceivable, for example from bluish white to yellowish white. In addition, one around the Solid angle Ω1 arranged solid angle range with respect to the solid angle Ω1 reduced luminosity can be generated to prevent glare from other reflective objects surrounding the selected traffic sign trafS_sel can be arranged around, to avoid.

3 shows the light distribution L on a front of the vehicle at a distance to the headlight arranged screen. The light distribution L is in the area of the solid angle Ω1 in the form of a marker light 10 exemplified. On the screen are a vertical W and a horizontal HH located. A roadway on which the vehicle drives includes a roadside edge 11 on the own traffic side as well as a roadside edge 12 on the oncoming traffic side (here for right traffic, in reverse traffic accordingly reversed). Between the roadway on the own traffic side as well as the roadway on the Oncoming traffic page is a marker line 13 located. The marker light 10 can, for example, by electrically switching LEDs of an LED array of the light module in the direction of arrows 14 horizontal and in the direction of arrows 15 be moved vertically to selectively illuminate different areas in front of the vehicle can. Of course, the size of the marker light 10 and thus the solid angle Ω1 the light distribution L be varied. Important for the position of the marker light 10 is that a selected traffic sign brighter than normal or brighter than the environment of the selected traffic sign is illuminated, and so the attention of the driver of the vehicle is directed to the selected traffic sign.

4 indicates by analogy 3 a single picture 402 of the image stream stre 2 in schematic form. There are two road signs located at the edge of the road trafS_1 and trafS_2 shown. The first traffic sign trafS_1 means congestion hazard. The second traffic sign trafS_2 specifies a speed limit of 60 km / h in wet conditions. These traffic signs are using the block 212 out 2 recognized.

5 shows another single picture 502 , which temporally after the frame 402 from the 4 was determined. For example, the vehicle drives at a speed of 80 km / h and it rains. The blocks 218 and 230 out 2 arrange this driving situation so that both traffic signs trafS_1 and trafS_2 selected and subsequently with a respective marker light in the solid angles Ω1a and Ω1b be illuminated the light distribution. With decreasing distance to the respective traffic sign trafS1 . trafS2 the illuminance is in the respective solid angle Ω1a and Ω1b reduced to avoid dazzling the driver of the vehicle. The distance is either determined from a corresponding sensor signal of a distance sensor or determined in the context of image processing and sign recognition from the image stream.

6 shows an exemplary section of an embodiment of the block 218 out 2 , The driving situation S is defined by the speed signal v and the rain sensor signal r, where for r equal to zero no rain and for r 1 rain is signaled. The individual traffic signs trafS_1 to trafS_3 will be relevant values for relevance R specified in the sense of the lookup table. The example in the 4 and 5 explained driving situation, so r equal to 1 and v equals 80, resulting in values for the relevance of 20 and 15. Assuming a threshold value for the relevance of 10, the two recognized traffic signs are located trafS_1 and trafS_2 with the assigned relevance R above and are selected for emphasis.

For the third traffic sign trafS_3 On the other hand, there is a high relevance of 12, for example, if the speed v in the range of 30 km / h. The third traffic sign trafS_3 is a signpost and is divided into different areas B1 to D3 , Depending on the route or destination specified by the navigation system, one of the areas becomes B1 to B3 a high relevance R assigned to select this one area and emphasize targeted.

In an example, not shown, the input variables such as the speed v taken into account in determining the relevance, as being a weighting depending on the value of the speed v he follows. The speed limit is 120 km / h and shows the rain sensor signal r Rain on, that's the speed signal v for example linked to a larger multiplier than in the case of a dry roadway. If the permissible maximum speed is 80 km / h, the relevance of the associated traffic sign results, for example, as a function of the second power of the speed signal v ,

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102010006097 U1 [0002]

Claims (11)

A method of operating a lighting device of a motor vehicle, the lighting device comprising a headlight (204), a camera (206) and a control unit (208), the method comprising: - determining (102) an image stream, the image stream comprising successive individual images of a vehicle-oriented vehicle front-end in the direction of travel; - recognizing (104) at least one traffic sign as a function of the images of the image stream; - determining (106) a driving situation of the motor vehicle; - selecting (108) the at least one traffic sign as a function of the driving situation; and - emitting (110) a light distribution in the direction of travel of the motor vehicle, wherein the light distribution in a solid angle, which at least partially covers the selected traffic sign, highlights the selected traffic sign. The procedure according to Claim 1 the method comprising: determining a relevance of the recognized traffic sign for the determined driving situation; - Select the recognized traffic sign depending on the determined relevance. The procedure after the Claim 2 wherein the method comprises: - selecting the recognized traffic sign if the assigned relevance exceeds a threshold. The procedure after the Claim 2 or 3 wherein the method comprises: determining the relevance as a function of a value from a look-up table, a respective value being assigned to a respective driving situation in the look-up table. The method according to one of Claims 2 to 4 wherein the method comprises: determining the relevance as a function of a time-variable parameter and / or measured value. The method of any one of the preceding claims, wherein the method comprises: - detecting a first number of traffic signs in response to the images of the image stream; Determining a respective relevance of the recognized first number of traffic signs for the determined driving situation; - selecting a second number as a subset of the first number of detected traffic signs depending on their respective relevance; and - Radiating the light distribution in the direction of travel of the motor vehicle, wherein the light distribution in a number of solid angles, which covers the respective selected traffic sign at least partially, have a respective selected traffic sign highlighting light intensity. The method of any one of the preceding claims, wherein the method comprises: - emitting a detection light distribution in the direction of travel of the motor vehicle; and - Detecting the at least one traffic sign, which is illuminated by the detection light distribution, depending on the images of the image stream. The method of any one of the preceding claims, wherein highlighting the at least one traffic sign comprises increasing the light intensity in the associated solid angle of the radiated light distribution from a region around the solid angle. The method according to one of the preceding claims, wherein the ascertained driving situation at least comprises: a vehicle speed; and or a rain sensor information; and or - a navigation context information. A control unit of a lighting device of a motor vehicle, which is designed to carry out the method according to one of the preceding claims. An illumination device of a motor vehicle, wherein the illumination device comprises a headlight (204), a camera (206) and a control unit (208), and wherein the illumination device is designed to: - To determine a picture stream, wherein the image stream comprises successive frames of a vehicle-oriented in the direction of travel apron; to determine at least one traffic sign as a function of the images of the image stream; to determine a driving situation of the motor vehicle; - to select the at least one traffic sign depending on the driving situation; and - To emit a light distribution in the direction of travel of the motor vehicle, the light distribution in a solid angle, which at least partially covers the selected traffic sign, highlights the selected traffic sign.

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