Method for controlling the lighting function of a vehicle and vehicle with a driver assistance system for carrying out the method

Abstract

Method for controlling the lighting function of a vehicle (40) by means of an evaluation of images (20) of the vehicle environment recorded by means of an image acquisition system using an evaluation unit, wherein, upon detection of a preceding or oncoming vehicle (50), a control signal is generated by the evaluation unit based on the evaluation of the images (20) of the vehicle environment, which is used to control the lighting function of the motor vehicle (40), characterized in that that, based on information about upcoming road sections (30), at least one image area (10, 11, 15) is selected for evaluation which can be illuminated by a preceding or oncoming (50) vehicle, and that during the evaluation of the selected image area (10, 11, 15) the brightness of the selected image area (10, 11, 15) is measured and compared with a known brightness generated by the vehicle's own light output (40) in the selected image area (10, 11, 15), so that when an increase in the measured brightness of the selected image area (10, 11, 15) is registered compared to the brightness generated by the vehicle's own light output (40) in the selected image area (10, 11, 15), an oncoming (50) or preceding vehicle is detected, characterized in that for the evaluation at least one illuminated image area (10) with a first road line area (16) of a detected road line within the vehicle's own light cone (40) and at least one further illuminated image area (11) with a second road line area (18) of a detected road line outside the vehicle's own light cone (40) are selected, that in the evaluation of the selected image areas (10, 11) the second street line area (18) is compared with an extension of the extrapolation (17) of the first street line area (16) and, that if there is a match between the second road line area (18) and an extrapolated extension (17) of the first road line area (16), an oncoming (50) or preceding vehicle is detected.

Description

State of the art

[0001] The present invention relates to a method for controlling the lighting function of a vehicle based on information about road sections ahead and on an evaluation of images of the vehicle's surroundings taken by means of an image recording system.

[0002] The invention also relates to a vehicle with a driver assistance system for carrying out the method.

[0003] Automated lighting control systems for motor vehicles are currently available on the market. These control the headlights' high and low beams, as well as their range and direction, depending on the immediate surroundings. Optical systems are currently used for this task.

[0004] As soon as the driving situation allows, the headlights automatically switch on (high beam), giving the driver maximum visibility. As soon as an oncoming vehicle enters the field of vision, the headlights dim accordingly.

[0005] However, current systems have the problem of being unable to detect early indicators of an oncoming vehicle in order to dim the headlights even earlier and avoid dazzling oncoming traffic.

[0006] From document US 6,343,869 B1, a lighting device for illuminating the driving environment of a vehicle is known, which comprises a detection device for detecting information about the driving environment of the vehicle. The detection device can, by means of a GPS navigation system, provide information about the current route, such as information about the shape of the road to be traveled or about the current position of the vehicle on the road to be traveled. Furthermore, the detection device can have an image recording system for detecting an oncoming or preceding vehicle based on an evaluation of images of the visible surroundings of the vehicle. An oncoming or preceding vehicle can also be detected by means of a photosensor that detects the light incident on its light-sensitive surface.The lighting function of the lighting device is controlled, among other things, depending on the shape of the road to be traveled and on the basis of information as to whether there are other vehicles on the current route in the immediate vicinity of the vehicle.

[0007] The disadvantage is that the detection of an oncoming or preceding vehicle occurs very late in curves at night. With the image recording system presented here, this detection only occurs when the oncoming or preceding vehicle is within the visible vicinity of the (own) vehicle.

[0008] When using a photosensor, this detection only occurs when light from an oncoming or preceding vehicle hits the photosensor's light-sensitive surface. Oblique light from a vehicle cornering and not yet in direct view cannot even reach the photosensor's light-sensitive surface. Early detection of such a vehicle using a photosensor is therefore virtually impossible.

[0009] The driver of such a vehicle, which is not detected early enough, is inadvertently blinded, which can lead to a reduction in road safety.

[0010] The document EP 1 093 966 A2 discloses a method and a device for controlling the light distribution of a headlight arrangement of a vehicle with at least one first light sensor which detects the light emissions acting on a driver of the vehicle from the field of vision in the direction of travel for different areas of the field of vision, a comparison device which compares the intensity of the light emissions for each area with a threshold value and a control device for the light distribution of the headlight arrangement depending on a signal from the comparison device. Disclosure of the invention

[0011] According to the invention, a method is provided for controlling the lighting function of a vehicle based on an evaluation of images of the vehicle's surroundings taken by an image recording system using an evaluation unit. The evaluation unit generates a control signal upon detection of a preceding or oncoming vehicle based on the evaluation of the images of the vehicle's surroundings. The control signal generated by the evaluation unit is used to control the lighting function of the motor vehicle. Furthermore, based on information about upcoming road sections, at least one image area that can be illuminated by a preceding or oncoming vehicle is selected for evaluation. During the evaluation of the selected image area, the brightness of the selected image area is measured and compared with the known brightness generated in the selected image area by the vehicle's own light output.When an increase in the measured brightness of the selected image area is registered compared to the brightness generated by the vehicle's own light output in the selected image area and in particular when there are sections of road ahead without junctions, an oncoming or preceding vehicle is detected.

[0012] The method according to the invention enables the detection of early indicators of an oncoming or preceding vehicle in curves at night. For this reason, image areas that are or would be directly illuminated by an oncoming or preceding vehicle are evaluated.

[0013] If the road sections ahead are known and there are no merging roads, the image areas that are or would be directly illuminated by an oncoming or preceding vehicle can be easily selected for analysis. Information about road sections ahead can be provided in particular using a GPS navigation system. If a large increase in brightness is registered in the image areas selected for analysis, which is above the "own capability", and if the navigation environment (GPS) does not show any merging roads, it can be assumed that an oncoming or preceding vehicle is approaching. If a preceding or oncoming vehicle is detected early, the headlights will be dimmed in good time.

[0014] If, however, no significant increase in brightness is registered in the selected image areas compared to the brightness generated by the vehicle's own light output, it can be assumed that the road is clear and that driving with the high beam is still suitable.

[0015] Early detection of other road users is extremely important for the automatic control of lighting functions, especially for deactivating the high beam function in good time. On long straight stretches, oncoming or preceding vehicles can be detected early. However, in very winding roads, this is very difficult, as there is no direct line of sight to the oncoming or preceding vehicle.

[0016] The method according to the invention uses a brightness measurement in at least one selected image area to detect an oncoming or preceding vehicle in curves at night. The selection of the image area to be evaluated and the measurement of its brightness are carried out without significant computational effort.

[0017] Advantageously, in particular an image area is selected and evaluated which is an illuminated area of ​​a route section, e.g. a road, of the vehicle's surroundings.

[0018] The method according to the invention can also be applied to recognized road lines. In particular, the selected image area comprises at least a first road line area of ​​a recognized road line. If the lines in the vehicle's own light cone are brighter than would be possible based on its own luminous intensity, it can be concluded that a preceding or oncoming vehicle is present. In the invention, areas of recognized road lines are selected and evaluated, as these are particularly easy to recognize and identify due to their light color.

[0019] According to the invention, a selected image area can be located inside or outside the vehicle's own light cone.

[0020] According to the invention, at least one illuminated image area with a first road line area of ​​a detected road line within the vehicle's own light cone and at least one further illuminated image area with a second road line area of ​​a detected road line outside the vehicle's own light cone are selected for the evaluation. During the evaluation of the selected image areas, the second road line area is compared with an extrapolated extension of the first road line area. If there is a match between the second road line area and the extrapolated extension of the first road line area, an oncoming or preceding vehicle is detected.

[0021] In very dark conditions, road lines outside your own light cone may not be visible because they are not visible. However, at even greater distances, especially in the case of oncoming traffic, a section of the road line may become visible again. If this section lies on the extrapolated extension of your own perceived line, this is also an indicator of oncoming traffic.

[0022] This makes it possible according to the invention to detect a preceding or oncoming vehicle very easily and at an early stage, even in very dark conditions.

[0023] Advantageously, a vehicle is provided with a driver assistance system for implementing the method according to the invention, in which the driver assistance system comprises a system for providing information about upcoming route sections, an image recording system, an evaluation unit for evaluating images captured by the image recording system, and a control unit for controlling the vehicle's lighting function. In particular, the system for providing information about upcoming route sections is a GPS navigation system.

[0024] The evaluation unit is designed to select at least one image area based on information about route sections ahead, to detect a preceding or oncoming vehicle based on information about route sections ahead and based on at least one measurement of the brightness in the at least one selected image area and to generate a control signal when a preceding or oncoming vehicle is detected.

[0025] Furthermore, the control unit is designed to control the lighting function of the vehicle based on a control signal generated by the evaluation unit.

[0026] A vehicle with a vehicle assistance system does not require any relevant additional modules with high computing power to implement the method according to the invention. Since a typical vehicle assistance system includes a GPS navigation system, an image acquisition system with an evaluation unit, and a control unit for evaluating control signals from the evaluation unit, no additional systems are required to implement the method according to the invention, nor are any relevant changes to the existing systems required.

[0027] Advantageously, the evaluation unit is designed to detect a preceding or oncoming vehicle by measuring the brightness of at least one illuminated area of ​​a route section, e.g. a road, in an image of the vehicle surroundings recorded by the image recording system.

[0028] In particular, the evaluation unit according to the invention is designed to detect a preceding or oncoming vehicle by measuring the brightness profile, in particular the brightness profile generated by the vehicle's own light output, in the vehicle environment based on an evaluation of the images recorded by the image recording system.

[0029] In a particularly preferred embodiment of the invention, the evaluation unit is designed to detect a preceding or oncoming vehicle by using predetermined, stored data on the brightness profile in the vehicle environment generated by the vehicle's own light output.

[0030] In particular, the driver's own field of vision can be determined quickly and easily while driving without traffic or oncoming traffic by evaluating the illuminated area on the road in the image. This can be achieved, for example, using a corresponding gradient method with a defined tolerance threshold or local histograms. The pixels in each image where the driver's own light cone has an effect are then known. Furthermore, the decreasing brightness with distance can be determined. Both pieces of information can also be available as a lookup table and applied in advance. This enables quick access to the values ​​of the brightness generated by the vehicle's own light output in the selected image areas. Short description of the drawings

[0031] Embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawings: Fig. 1 shows an image area selected for evaluation according to a first embodiment of the invention, which is illuminated by a moving and an oncoming vehicle, Fig. 2 shows an area of ​​the road selected for evaluation in an image of the vehicle surroundings according to a second embodiment of the invention, which area is illuminated by a moving and an oncoming vehicle, Fig. 3 shows an image area selected for evaluation according to a third embodiment of the invention, which includes a first road line area of ​​a recognized road line, which is illuminated by a moving and an oncoming vehicle, and Fig. 4 shows two image areas selected for evaluation according to a fourth embodiment of the invention, wherein an illuminated image area with a first road line area of ​​a recognized road line lies within the own light cone of a moving vehicle and an illuminated image area with a second road line area of ​​a recognized road line lies outside the own light cone of the moving vehicle and within the light cone of an oncoming vehicle. Embodiments of the invention

[0032] Fig. 1 shows an image area 10 selected for evaluation according to a first embodiment of the invention, which is illuminated by a moving vehicle (not shown) and an oncoming vehicle (not shown).

[0033] According to the invention, based on the knowledge of upcoming route sections 30, image areas 10 are selected that are of interest for a corresponding evaluation. The knowledge of upcoming route sections 30 is provided in particular by a GPS navigation system (not shown).

[0034] In the Fig. 1, the selected image area 10 is the one illuminated by a vehicle (not shown) in a curve, which travels on the route 30 ahead in the opposite direction to its own motion.

[0035] In the case of curves, the oncoming vehicle not only illuminates the section of road ahead, but also neighbouring architecture, buildings (posts, guard rails, signs, etc.), vegetation and the like.

Claims

[1] Method for controlling the lighting function of a vehicle (40) based on an evaluation of images (20) of the vehicle surroundings taken by means of an image recording system by means of an evaluation unit, wherein upon detection of a preceding or oncoming (50) vehicle based on the evaluation of the images (20) of the vehicle surroundings, a control signal is generated by the evaluation unit, which is used to control the lighting function of the motor vehicle (40), characterized by , that, based on information about the route sections (30) ahead, at least one image area (10, 11, 15) is selected for evaluation, which area can be illuminated by a preceding or oncoming (50) vehicle, and that during the evaluation of the selected image area (10, 11, 15), the brightness of the selected image area (10, 11, 15) is measured and compared with a known brightness in the selected image area (10, 11, 15) generated by the vehicle's own light output, so that when registering an increase in the measured brightness of the selected image area (10, 11, 15) compared to the brightness generated by the vehicle's own light output (40) in the selected image area (10, 11, 15), an oncoming (50) or preceding vehicle is detected, characterized bythat for the evaluation, at least one illuminated image area (10) with a first road line area (16) of a recognized road line within the vehicle's own light cone (40) and at least one further illuminated image area (11) with a second road line area (18) of a recognized road line outside the vehicle's own light cone (40) are selected, that when evaluating the selected image areas (10, 11), the second road line area (18) is compared with an extension of the extrapolation (17) of the first road line area (16) and, that if there is a match between the second road line area (18) and an extrapolated extension (17) of the first road line area (16), an oncoming (50) or preceding vehicle is detected. [2] Vehicle (40) with a driver assistance system which is designed to carry out the method according to claim 1 to carry out, wherein the driver assistance system comprises a system for providing information about upcoming route sections (30), an image recording system, an evaluation unit for evaluating images (20) recorded by the image recording system, and a control unit for controlling the lighting function of the vehicle (40), wherein the evaluation unit is designed to select at least one image area (10, 11, 15) based on information about upcoming route sections (30), to detect a preceding or oncoming (50) vehicle based on information about upcoming route sections (30) and based on at least one measurement of the brightness of the at least one selected image area (10, 11, 15), and to generate a control signal upon detection of a preceding or oncoming (50) vehicle,and the control unit is designed to control the lighting function of the vehicle (40) based on a control signal generated by the evaluation unit and, for the evaluation, at least one illuminated image area (10) with a first road line area (16) of a recognized road line within the vehicle's own light cone (40) and at least one further illuminated image area (11) with a second road line area (18) of a recognized road line outside the vehicle's own light cone (40) are selected, that when evaluating the selected image areas (10, 11), the second road line area (18) is compared with an extension of the extrapolation (17) of the first road line area (16) and, that if there is a match between the second road line area (18) and an extrapolated extension (17) of the first road line area (16), an oncoming (50) or preceding vehicle is detected.

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