Method for controlling the visibility of a vehicle

Abstract

Method for controlling the visibility of a vehicle (1; 101), comprising the steps: - Determining a light distribution comprising a brightness distribution and / or spectral distribution of luminous surfaces (3, 4, ..., 15) on the vehicle (1; 101) and / or in an environment of the vehicle (1; 101), wherein at least the brightness and / or spectral distribution of the luminous surfaces (8, 9, 10, 15) in the environment of the vehicle (1; 101) is determined with the aid of one or more sensing means on the vehicle (1; 101); - determining one or more parameters of one or more of the luminous surfaces (3, 4, ..., 15) and / or between several of the luminous surfaces (3, 4, ..., 15) of the light distribution for a perspective of at least one observation position (2; 401, 501) in the surroundings of the vehicle (1; 101); - Controlling the parameter(s) for the perspective of the at least one observation position (2; 401, 501) as a function of one or more predetermined criteria, wherein the visibility of the vehicle (1; 101) is controlled in such a way that the reflectivity of one or more luminous surfaces (3, 4, ..., 15) of the vehicle (1; 101) is influenced.

Description

The invention relates to a method for controlling the visibility of a vehicle and to a corresponding system for controlling the visibility of a vehicle and to a vehicle comprising such a system.Various methods are known from the prior art which control the light emitted by a vehicle into a specific solid angle. This control can serve for illuminating relevant roadway areas, obstacles and the like. Adaptive vehicle lights are known from the publication DE 10 2005 026 684 A1, which generate a predefined light pattern in the environment of a vehicle, which may be dependent on the traffic situation.U.S. Pat. No. 6,281,806 B1 discloses a system for object detection and illumination for a vehicle. The system comprises one or more sensors with which information about the environment of the vehicle is collected. Furthermore, a processor is provided which, based on the sensor data, determines whether a specific object is located on or in the vicinity of the travel route of the vehicle. If this is the case, the processor outputs a control signal in order to bring about the illumination of the object with a light source of the system.The document DE 103 36 681 A1 describes a motor vehicle having a device for detecting the environment, which comprises a detection means and a means for analyzing the information provided by the detection means for ascertaining an object located in the environment. Furthermore, the motor vehicle contains a lighting device which can be controlled via a control device as a function of the result of the ascertainment in such a way that the ascertained object can be individually illuminated, wherein the means for analysis is designed to ascertain any immovable and movable objects.Methods are also known from the prior art which control the vehicle light as a function of the illumination of the vehicle environment.The document FR 2 907 068 A3 describes a method in which the light intensity in the rear region of a vehicle is measured and the measured light intensity is compared with a predetermined threshold value. If the light intensity is above the threshold value, a lack of visibility of the vehicle is determined and corresponding measures are initiated. In particular, the driver can be warned by a warning light or the headlight of the vehicle can be automatically switched on. Although the visibility of the vehicle is controlled by the method on the basis of the illumination behind the vehicle, the method does not sufficiently take into account the subjective visibility of the vehicle for other road users. This subjective visibility perceived by human eyes depends on the timely perception of the vehicle and thus also the behavior of the road users and the risk of collision. The subjective visibility depends on far more factors than only on the lighting conditions, e.g. on the current driving situation and the situation of the other road users.FIG. 1 is a schematic diagram illustrating factors on which visibility of a vehicle depends. FIG. 1 shows a vehicle 1 in plan view. The two headlights of the vehicle are designated by reference numerals 3 and 4, a lighting surface on the left side mirror by reference numeral 5, a lighting surface on the right side mirror by reference numeral 11, a lighting surface on the left door handle by reference numeral 6 and the left rear headlight by reference numeral 7. Furthermore, a light surface 10 is located to the right next to the vehicle at the height of the headlights and a light surface 15 is located to the left next to the vehicle. Furthermore, in the front region of the vehicle, light surfaces 12 to 14 are characterized which reflect light. A possible position of a further road user, for example of an oncoming vehicle or of a pedestrian on the edge of the road, is denoted by reference symbol 2 in FIG. 1. The amount of light and the light parameters of those light areas that illuminate the position 2 are relevant for the visibility of the road user at the position 2 by the driver of the vehicle 1. These are the luminous surfaces 3 to 10 in FIG. 1, which is also indicated by corresponding solid lines from the luminous surfaces to the position 2. In contrast, for the visibility of the vehicle from position 2, the distribution of the light parameters (light intensity, color, temporal behavior) of the light surfaces 3 to 10 is relevant in particular. These light parameters are decisive for the perception of the contrast ratio between the vehicle and the environment and for the contrasts within the vehicle. Exclusively with the control of the light emitted in the direction of a road user, as is done in methods according to the prior art, the potential for improving the visibility of the vehicle for a road user is not exhausted.It is an object of the invention to provide a method for controlling the visibility of a vehicle, in which the visibility of the vehicle is controlled in a situation-related manner.This object is achieved by the method according to claim 1 or a system according to claim 24 or a vehicle according to claim 26. Further developments of the invention are defined in the dependent claims.The dependent claims also show advantageous embodiments of the method or system or vehicle according to the invention. Various changes and modifications are possible within the scope of the invention without departing from the scope or the scope of the equivalents thereof.In the method according to the invention, a light distribution comprising a brightness distribution and / or spectral distribution of illuminated areas on the vehicle and / or in the environment of the vehicle is determined, wherein at least the brightness and / or spectral distribution of the illuminated areas in the environment of the vehicle is determined with the aid of one or more sensing means on the vehicle. If necessary, the brightness and / or spectral distribution on the vehicle can also be determined using corresponding sensing means or by reading out the values at least partially stored in the vehicle.The term vehicle can be understood to mean, in particular, a motor vehicle, an aircraft or a watercraft. In addition, an autonomous vehicle, e.g., an autonomous user or investigation vehicle and / or a mobile robot, is to be understood as vehicles in the sense of the invention.The ascertained light distribution thus describes a spatial distribution of the illuminated areas according to the invention. The light distribution can be determined and / or further processed as an angle, solid angle or angle ratio between the illuminated surfaces. The ascertainment of the light distribution can relate to the coordinate system of the vehicle or a global coordinate system. The terms "texture", "edge" and "shape" used further below represent a special case of a brightness and / or spectral distribution in the sense of the invention.A lighting surface can be understood to mean both a self-lighting surface and a reflecting, refractive or fluorescent surface. A lighting surface may also be a surface that both illuminates itself and can reflect or refract the light, such as the windshield of a vehicle. A lighting surface may also be a vehicle lamp. The subdivision into light-emitting surfaces can be made, for example, according to geometrical aspects. For example, objects which are located close to one another or parts of which form a luminous surface, while an object arranged at a greater distance or part of which is classified as another luminous surface. It is particularly advantageous to understand and / or process a point set of the light distribution with similar properties as a luminous surface. The luminous surfaces can optionally also be very small non-integral surfaces. The luminous surfaces can have any desired shapes, in particular they can also be curved.According to the invention, one or more parameters of one or more of the light surfaces and / or between a plurality of the light surfaces of the light distribution are determined for a perspective of at least one observation position in the environment of the vehicle. The parameters relate in particular to the parameters of the emitted and / or reflected light from the luminous surfaces of the vehicle. Subsequently, the parameter or parameters of the light-emitting surfaces or between the light-emitting surfaces for the perspective of the at least one observation position are controlled as a function of one or more predefined criteria, wherein the visibility of the vehicle is controlled in such a way that the reflectivity is influenced by one or more light-emitting surfaces of the vehicle. The reflectivity can be influenced in particular in that at least one reflective and / or at least partially transparent surface of the vehicle contains a coating which changes its optical properties, for example in the event of the influence of an electric field applied by means of means of the vehicle. The change in the light transmission and reflectivity of surfaces is also possible by means of a layer of liquid crystals or other electrochemical methods.The invention is based primarily on the realization that parameters of or between light surfaces of the light distribution for a relevant spatial part, which is specified by a perspective of at least one observation position in the environment of the vehicle, enable a situation-related control of the visibility of the vehicle as a function of different observation positions.In a particularly preferred embodiment of the invention, parameters of one or more light emitting surfaces and / or between a plurality of light emitting surfaces are controlled at least partially, which are located laterally, in particular to less than 90° relative to the direction of travel of the vehicle, next to the vehicle and / or closer to the at least one observation position than the vehicle. This embodiment is based on the realization that illuminated areas at the aforementioned locations have particularly great relevance for road users in front of the vehicle with respect to the visibility of the vehicle. For example, a green vehicle is more visible and thus requires little energy to radiate if blue light areas, e.g. of another vehicle, are located laterally next to this vehicle than if green light areas are located laterally next to the vehicle. The light surfaces that are located closer to the observation position than the vehicle can also decisively influence its visibility and the parameters necessary for controlling the visibility according to the invention. These light areas can cause a local glare of a road user in the observation position. In particular, these light emitting surfaces influence the visual perception of the spatial part in which the vehicle is located relative to the observation position and thus the visibility of the vehicle.In a particularly preferred embodiment of the invention, the parameters of or between illuminated areas represent one or more contrast conditions for the perspective of the at least one observation position in the environment of the vehicle. The contrast ratio is understood here to mean a measure of the difference between the brightness distributions or spectral distributions of illuminated areas.The contrast ratio can optionally also be determined via a function which describes the respective spatial profiles of the brightness or spectral distribution of the individual luminous surfaces, optionally the dependence on the solid angle of the observation position or the distance to the observation position. The contrast ratio can thus also represent the difference between the averaged brightnesses or averaged spectral distributions of two luminous areas, wherein the brightness or spectral distribution is averaged over the extent of the respective luminous area. In particular, a contrast ratio between the vehicle and the environment of the vehicle is determined as the contrast ratio. In particular, the contrast ratio between the light surfaces of the vehicle, which identify the geometric limits or the dimensions of the vehicle, and the light surfaces of the environment, in particular the light surfaces not covered by the vehicle, can be determined. It is particularly advantageous to control the contrast ratio between the luminous surfaces which form the geometric boundaries of the vehicle with respect to specific observation positions and the luminous surfaces from the environment which are visible at a substantially adjacent solid angle to the geometric boundaries of the vehicle.In a particularly preferred embodiment of the method according to the invention, the respective value of one or more contrast ratios is thereby essentially kept at a predefined setpoint value. The setpoint value corresponds in particular to a setpoint contrast ratio which corresponds to adequate visibility of the vehicle in the corresponding traffic situation.In a preferred embodiment of the invention, the respective value of one or more of the parameters is changed according to the predetermined criteria as a function of a visibility measure of the vehicle for the perspective of the at least one observation position in the environment of the vehicle.The visibility measure represents in particular the recognizability of the vehicle and / or its outer boundaries and / or the spatial orientation of the vehicle for the human visual system with or without aids. The auxiliary means can be an infrared camera, for example. Furthermore, the visibility measure can also take into account the distinguishability of the vehicle from other vehicles or other objects. The visibility measure can be expressed in the form of the probability with which the vehicle is seen or overseeed, in particular, by a statistical, human or animal vision system. The visibility measure can also represent a visibility measure for artificial object recognition methods.Advantageously, the visibility measure of the vehicle can also be further evaluated and controlled depending on the respective traffic situation. In some traffic situations, such as parking and maneuvering, it is extremely important whether the shapes of the vehicle boundaries, e.g., curvatures of the bumper, height of lateral convex surfaces, are visible to both an observer in the at least one observation position and the driver himself. When the vehicle is moving on an expressway, such shapes are again relatively unimportant, but the dimensions, the lights and the direction of movement of the vehicle must be clearly recognizable. The value of the visibility measure can thus be automatically determined and / or changed depending on the situation.In a further embodiment of the invention, the visibility measure is determined from a plurality of partial visibility measures of individual vehicle parts. The partial visibility measures can be controlled individually, in particular in such a way that the perceptibility of the vehicle is changed. In particular, the visibility and / or visibility is changed based on a combination of the partial visibility measures.Particularly preferably, the perceptibility of the vehicle for different classes of perceptibility can be determined by controlling the partial visibility dimensions of individual light-emitting surfaces and / or light-emitting surface groups of the vehicle. Such classes of perceptibility may be, for example:"Perceptibility of the presence of the vehicle as an object";"Perceptibility which permits the recognition of the vehicle as a vehicle, in particular a vehicle of a specific type, for example a car, truck, motorcycle";"Perceptibility of the external dimensions and orientation of the vehicle";"Perceptibility of the shape of the surfaces of the vehicle".Depending on the traffic situation, different perceptivities can be sought in the different classes of perceptibility. Thus, for example, unnecessary energy consumption can be dispensed with.Particularly preferably, at least one measure for the visual effect of the vehicle, in particular for its aesthetic effect, can also be determined from the combination of the partial visibility dimensions of the light surfaces or light surface groups of the vehicle. The light surfaces or light surface groups of the vehicle can be design elements, decorative strips, edges and curvatures of the vehicle illuminated or backlit by the light sources of the vehicle, elements of a signal light, etc. An objective measure for the interaction of different shape and light elements with respect to the visual effect of the entire vehicle is thus determined, in particular as a function of boundary conditions discussed above, and / or is controlled, for example, by controlling the luminous surfaces of the vehicle. Thus, it is automatically determined, with respect to a specific observation position and, for example, depending on the traffic situation, brightness, color and textures of the environment, how the visual effect of the vehicle is. In particular, the visual effect of the vehicle and / or its individual design elements can be determined with reference to predefined formulae and dependencies which characterize a measure of the visual effect of the vehicle. The predetermined formulas and dependency can be created on the basis of the design specifications, e.g. according to generally known circumstances of the harmonic effect of the shapes or the color jig. These formulas and dependencies can also be determined and / or controlled depending on user operating actions. For the user of the vehicle, the effect of the design of the vehicle in different traffic situations represents a great value. This value may be both an aesthetic value and a distinctive feature or expression of remaining features of the vehicle, e.g. particular design elements. Design elements can be, for example, the arrangement of concave and convex surfaces, edges and curvatures. By automatically controlling the visual effect, for example also from certain perspectives, the degree of utilization or the effect of these design elements, which are usually very costable, increases. It is particularly advantageous to determine and / or control a plurality of measures for the visual effect, which e.g. characterize different aspects of the effect.In a further embodiment of the invention, the visibility measure is determined from a plurality of partial visibility measures of individual vehicle parts. Specific combinations of these individual partial visibility measures may be sufficient-for example despite a value which is relatively low per se-for recognizing the vehicle as such.In a further embodiment of the method according to the invention, the parameters of or between light surfaces are controlled in such a way that a predefined visibility measure for the at least one observation position is substantially achieved.In a preferred variant, the respective value of one or more parameters is changed in such a way that the visibility measure of the vehicle, in particular the visibility measure in relation to the energy used for generating the luminous surfaces, is increased, in particular maximized, for the perspective of the at least one observation position. In this way, the visibility is optimized to the extent of the energy to be applied for this purpose. Consequently, energy in the vehicle can be saved.In a particularly preferred embodiment of the method according to the invention, the parameter or parameters between a plurality of the light surfaces on the vehicle and the environment of the vehicle are determined, wherein the parameters are controlled in particular in such a way that at least parts of the contour of the vehicle, with respect to a specific observation position, are emphasized. These contours can be obscured, for example, in the presence of strongly illuminated light surfaces in the background of the vehicle. In particular, at least those parts of the contour which are visible from the at least one observation position are emphasized. In this case, it is taken into account that contours of the vehicle viewed from different observation positions can be very different. Therefore, contour control depending on the respective observation position is advantageous.As can be seen from the above explanations, the actual recognition of a road user at the at least one observation position is not required in the method according to the invention. This offers a significant advantage, since methods for automatically detecting road users are usually complex and often not sufficiently reliable. For the method according to the invention, the assumption of a "virtual" observer at the observation position is sufficient, for the perspective of which the parameters of or between the luminous surfaces are determined and controlled. The observation position is preferably selected such that it can be assumed that a road user is highly likely to be located at this observation position. For example, the observation position can lie on a predicted trajectory of the vehicle, where the stay of another road user is associated with high collision risks. The observation position may be assumed in an extended portion of the roadway for a certain length, e.g., on an opposite lane.In a further preferred embodiment of the invention, the contrast ratio or ratios are psycho-optical contrast ratios. Psychooptic contrast ratios and their influence variables are known per se to the person skilled in the art. A psycho-optical contrast ratio is based on the known specific properties of the vision system of humans or of an animal, i.e. on the ability of this vision system to recognize differences between differently illuminated spatial parts, color profiles, intensity profiles, textures and edges of an object, inter alia on the basis of the spatial and temporal gradients of different light parameters.In a preferred embodiment of the method according to the invention, the psychooptic contrast conditions additionally include the adaptation properties of the vision system of humans or animals. The determination of resulting contrast ratios can be carried out according to the invention by means of a simulation of the eye state of a real or assumed observer in the at least one observation position. In this case, the environment and / or history of the lighting conditions to which the virtual observer is exposed and / or was exposed in the near past can be taken into account. In a preferred variant, the psychooptic contrast ratio is determined on the basis of a simulation of the visual system of an e.g. statistical driver of an oncoming vehicle at the location of the at least one observation position. In this case, a series of influencing variables which act (would) on the (possibly virtual) observer of this situation can be taken into account, for example the influence of a windshield in front of his eyes. The method according to the invention can be applied analogously with respect to the visual system of animals. Since the visual system of the animals has properties which in some cases differ significantly from the human visual system, in particular with regard to color sensations, spatial frequency sensations, adaptation properties, etc., the psychooptic contrast ratio can also be determined and controlled for a specific species. Thus, for example, the visibility of a vehicle for a hire can be controlled.In a further embodiment of the method according to the invention, textures and / or shapes on the vehicle and / or in the environment of the vehicle are taken into account in the determination of the contrast ratio or ratios. It is known in particular to the person skilled in the art to make the visibility and in particular the recognizability of objects dependent not only on the average illumination and color, but also on the textures, edges and shapes of the object. The texture depends on, for example, the structural nature of a surface, the distribution of the LEDs of a luminaire, and the like. For example, if the average brightness or color of the object under consideration corresponds or resembles the average brightness or color of the background, the differentiation of the occurring textures and / or shapes of the object and the background by the vision system is important for the visibility. By incorporating textures according to the invention for determining and controlling the visibility of the vehicle, the visibility of the vehicle can thus be controlled and in particular increased in a suitable manner even with similar brightness and color of the vehicle and of the background.Textures on the vehicle are formed in particular by light arrangements, e.g. headlight arrangements, arrangements of LEDs, OLEDs, incandescent lamps or other lighting means and the corresponding diffusing screens, such as brake or parking lights. Mathematically, a texture can be understood as a synthesis of various so-called spatial frequencies. Further textures are formed by reflection plates, such as occur on the vehicle or road boundaries, and other reflection surfaces, for example the radiator of an engine or by design elements. A corresponding texture contrast ratio takes into account both the contrast ratio within a luminaire (e.g. a large-area headlight) based on the brightness or spectral distribution and the structural condition and shape resulting from the arrangement of a plurality of luminaires. In the case of the texture contrast ratio, the arrangement of the individual lighting means, for example within a lighting surface, is important, in particular, whether the arrangement has transitions of light / dark, colored / color-neutral or different-colored regions with a specific regularity.With regard to the visual perception of humans and certain animals, the texture contrast ratio and / or shape contrast ratio acts in addition to the contrast ratio which results from the illumination differences between the total luminous intensities of two illuminated areas. Thus, in one embodiment of the method according to the invention, the texture contrast ratio is also taken into account, which serves for a very advantageous precise control of the visibility. Even in the case of light conditions in the environment of the vehicle in which light reflected by the vehicle is substantially equal on average to the light in the environment in terms of brightness and spectral distribution, in one embodiment of the method according to the invention a contrast ratio for a specific observation position can be determined and controlled from the distribution of the luminous surfaces and their textures.In a further embodiment of the method according to the invention, during the control of the parameter or parameters, the light distribution, in particular the light characteristics generated by the lighting system of the vehicle, is adapted to scattering and / or transmission properties of a medium between the vehicle and the at least one observation position in such a way that the parameter or parameters for the perspective of the at least one observation position are held substantially at a setpoint value. The scattering and / or transmission properties of the medium can be determined or estimated here, for example, on the basis of information about the weather conditions in the environment of the vehicle. In road vehicles and in air traffic, the light scattering properties of the medium are dependent above all on the weather conditions or local properties. Rain and fog can have very different and locally different properties with respect to light scattering. Advantageously, the local position and the properties of the fog and / or cloud velocities can also be taken into account. Thus, in one embodiment of the method according to the invention, the influence of spatially non-uniform fog which frequently occurs in road traffic is taken into account.The scattering properties of the medium have a very great influence on the visibility and in particular on the visibility of textures or the recognizability of shapes or further properties of surfaces and objects. Although the penetration of the majority of the total amount of light emitted by a vehicle to the at least one observation position would enable the detection of the presence of an object that is located in a specific direction, this does not necessarily mean that the detectability of the object as a predetermined object, for example as a vehicle, is also possible. The same applies to the assessment of the object speed. Binocular spatial vision of humans is severely impaired by light scattering, since the directions from which an image comes to both eyes can no longer be differentiated from one another. Thus, the distance, e.g. to an obstacle in the fog, can be estimated only with great difficulty by the vision system.In one embodiment of the invention, the reduced transmission of the air (e.g. due to mist, exhaust gases, mist) can be taken into account in the control of the parameters of or between lighting surfaces. In this case, in particular the influence of the scattering properties with respect to the specific calculated light distributions and / or contrasts is taken into account. The contrast ratios affected by the scattering properties of the medium, which are perceived by the human visual system, are different depending on the specific observation position. If the visibility of the vehicle from a specific observation position is based, for example, mainly on the brightness contrasts or color contrasts with the vehicle environment visible from the same observation position, then this visibility is reduced, for example by a fog, far less than the visibility based on the texture contrasts, in particular on the texture contrasts formed mainly by high spatial frequencies. Different spatial frequencies therefore have different visibilitys both as a function of the observation angle and as a function of the distance from the observer. This dependence is clearly influenced, in particular amplified, by the influence of the scattering properties. Thus, in the control of the parameters of or between light surfaces, the influence of the scattering and / or transmission properties of the medium on the visibility of the vehicle, which may be very different as discussed above, with respect to specific traffic situations, can be taken into account.The influence of the scattering and / or transmission properties can advantageously be taken into account by means of one or more multiplying coefficients of a matrix or by means of an additional matrix in the determination of the parameters of or between luminous surfaces of a visibility measure. Thus, the scattering properties of fog or rain can be expressed mathematically in the form of a multiplying matrix that takes into account the influence of the parameters, in particular in the current situation. The transmission and / or scattering properties of the medium can be determined using known methods, for example by means of the automatic measurement of a light beam emitted by the vehicle, for example a laser beam.In one embodiment, the scattering properties of the medium can be calculated from information about the prevailing weather conditions. The weather conditions can be taken from wirelessly available information, such as RDS data from radio transmitters. Alternatively or additionally, a rain-light sensor on the vehicle can likewise provide usable information about the prevailing weather conditions.In a further embodiment of the method according to the invention, the visibility of a vehicle is controlled, which comprises at least one luminous part as a part of the body, wherein the at least one luminous part is illuminated by lighting means of the vehicle. In this case, the at least one luminous part represents a luminous surface within the meaning of Claim 1, for which parameters are controlled. Advantageously, the contrast ratio calculated for the at least one observation position can be effected by changing the illumination of the vehicle body parts. For this purpose, both already existing points of its surface illuminated by the vehicle itself, such as, for example, the vehicle body parts illuminated by the front field illumination and by the license plate illumination, and new lamps and / or projection means specifically provided for this purpose, can be adaptively controlled.Preferably, those parts of the vehicle are taken into account in the control of the parameters which can be identified immediately by other road users as specific parts of the vehicle and thus provide the road user with a better spatial idea about the dimensions, alignments and / or type of the vehicle. For example, rims or door handle depressions, the grid of the radiator or curvature points of the own vehicle can be illuminated or illuminated with LEDs. This does not have to be a permanent illumination of these parts. The additional illumination can be designed as electronically controlled or regulated merely as required and with regard to its parameters.If a road user approaches the vehicle dangerously, for example, it is less expedient from an energy point of view to add his front headlights or to increase their power. The road user could also be unnecessarily blinded in this way. Instead, for example, for better orientation or collision avoidance, the road user must recognize that this is a vehicle having specific dimensions. For a better orientation, the road user must be able to spatially perceive or present the vehicle, including its orientation and boundaries. If, according to the invention, for example, a front field illumination or license plate illumination, which is perceived particularly well from a relevant spatial region, is used for controlling the contrast ratio, the energy for permanent light generation for all directions can be saved. For example, it is very difficult for a road user to maneuver between parked vehicles in darkness, even if they have switched on their parking lights. Even if these are well recognizable as vehicles, the exact position of the bumper or the lateral areas can only be roughly estimated. Advantageously, when a road user approaches the vehicle, a part of the latter or of its environment can be illuminated in a targeted manner. For example, its front-end lighting is automatically turned on. Thus, a sufficient number of bright / dark contrasts and / or color contrasts are created so that the contours of the vehicle can be clearly recognized by the road user. In comparison with the known parking lights, this is a very advantageous energy-saving variant which additionally also emphasizes the geometric shape of the vehicle and offers a certain aesthetic advantage.In a preferred variant of the invention, the visibility of a vehicle is controlled, which comprises at least one illuminated part as at least one partially transparent surface of the vehicle, which is backlit by lighting means of the vehicle. Again, the at least one luminous part represents a luminous surface in the sense of claim 1, for which parameters are controlled. Advantageously, the contrast ratio can thus also be controlled by backlighting partially transparent surfaces of the vehicle. Since large parts of the vehicle body are currently made of plastic, this can preferably be an internally illuminated translucent surface of the vehicle body. In particular, a decorative strip, a part of the bumper or pillars of the vehicle (preferably A and C pillars of a passenger car), can be backlit, for example by means of a plurality of LEDs or OLEDs.Luminous surfaces in the sense of claim 1 can also be parts of the body with several incorporated lighting means, e.g. LEDs or OLEDs. For example, visible textures can be generated by driving the lighting means individually or in groups and thus generating a corresponding light distribution. The lighting means can be incorporated into a grid-like or honeycomb-like structure made of metal and / or plastic, whereby both sufficient mechanical properties, e.g. energy absorption capacity in the event of a collision, are achieved and the possibility is provided of generating and controlling light distributions.The backlighting of translucent parts can also be illuminated in a spatially variable manner, for example, in order to generate a visible texture which contrasts sufficiently with the environment. It is also possible to use a self-illuminating and / or reflecting and / or fluorescent layer based on nanotechnology, which can be combined with a lacquer layer, for example.Preferably, the illuminated parts of the vehicle are thus controlled in accordance with the remaining lights of the vehicle in order to produce a sufficient amount of contrast for specific spatial parts from which the vehicle may not otherwise be easily seen. That is, the control of the parameters can be carried out in such a way that a contrast ratio generated for a specific observation position is controlled from the cooperation of all lamps of the vehicle.In a preferred embodiment, the method according to the invention generates a certain degree of visibility and maintains this degree. Both too small and too large contrast ratios are avoided. Thus, the vehicle and its orientation in space will not be oversighted. At the same time, it is avoided that an unnecessary light power is emitted which is not economically, ethically or legally acceptable. Depending on the situation, the emission of high powers can also be counterproductive, for example if the background of the vehicle illuminates brightly.In a variant of the method according to the invention, on the other hand, the contrast ratio can also be changed by selectively switching off or respectively attenuating specific luminous surfaces and / or reducing their reflectivity. This is advantageous, for example, in order to recognize the contours of the vehicle when it is located in strong counter light, as viewed from the at least one observation position. Alternatively or additionally, the vehicle may illuminate a portion of the background visible from the relevant space portion to provide or enhance contrast between the vehicle and the environment. This can be a color and / or time-variable illumination.Advantageously, a contrast ratio, in particular a texture contrast ratio, can be controlled in that the parameters of the light surfaces in their surroundings are changed by means of the vehicle in such a way that the difference between the textures of the vehicle and the textures of the surroundings, in particular with respect to a specific observation position, is changed. According to the invention, this can be done by projecting shapes and textures into the surroundings of the vehicle. For example, in the event that insufficient visibility of the vehicle is detected, the near field illumination of the vehicle may project the textures or shapes (e.g., grid structures, circles, hexagon) onto the roadway in the immediate vicinity of the vehicle. Thus, the contours and shapes of the vehicle in the dark are securely distinguishable from the surrounding roadway. The contrast ratio may also be varied by projecting textures and / or shapes and / or edges in the direction that is substantially in the opposite direction to the direction in which an observer is located. The application of the method to a stationary vehicle is particularly advantageous since it is thus possible to dispense with permanent light emission in all directions from a vehicle that is parked, for example, or this light emission can be greatly reduced.In the case of a determined visibility or perception in a class of perception, which does not correspond, for example, to the visibility or perception in the class of perception desired or required for a location of the vehicle, the parameters of the light surfaces of the vehicle, in particular their distribution, are changed in that textures in the form of intensity and / or color transitions are generated, for example, on a backlit decorative strip of the vehicle, and specifically in such a way that the visibility or perceptibility in the class of perception of the vehicle is changed from the observer position.In a further embodiment of the method according to the invention, the at least one observation position is selected such that one or more road users are located in the at least one observation position with a probability above a predefined threshold value. The at least one observation position can furthermore be selected as a function of the spatial profile of a roadway and / or a lane and / or a crosswalk, wherein in this case the at least one observation position is preferably substantially at the height of a vehicle windshield and / or at the eye height of pedestrians. The course of roads, lanes and, for example, zebra strip courses can be read out from the navigation map in the vehicle, for example. In contrast to already known methods, in which a specific solid angle is illuminated with a weakened or changed light, the observation position is a three-dimensional structure or a three-dimensional location in space. For the contrast ratio, in particular for the psycho-optical contrast ratio, at this observation position, the distance from the luminous surfaces of the light distribution is important.As explained above, the at least one observation position is, for example, a spatial part in which a road user has been detected and / or where, on the basis of statistical calculations or the prevailing traffic situation, a road user is located with an above-average probability. However, a detection or accurate localization of a road user is not absolutely necessary for this invention.If a plurality of observation positions are relevant for controlling the parameters of or between light surfaces, however, the required contrast ratio cannot be set equally for these observation positions, the contrast ratio can be controlled by means of an algorithm, for example according to an automatically determined priority-in particular one after the other-or on the basis of a predefined sequence or sequence. The priority can be determined automatically, for example, according to legal regulations, for example, a minimum visibility to be ensured, and / or according to the probability of a road user or his eyes being present in the corresponding room part.Advantageously, a time-sequential control of the required contrast ratio can take place for different spatial parts. When creating a respectively predetermined contrast ratio for specific room parts sequentially or group by group, it can be ensured that a possible observer from each of these room parts often has enough chance to see the vehicle so that the vehicle is not overlooked. The time intervals in which a specific contrast ratio is to be generated can be selected here, for example, as a function of the distance from the observation position and / or as a function of speed.In a further embodiment of the method according to the invention, the above-described setpoint value of the contrast ratio is calculated as a function of the emission characteristics of the luminous surfaces on the vehicle and / or in the environment of the vehicle. The setpoint value, i.e. the setpoint contrast ratio and in particular the contrast ratio required for adequate visibility in the corresponding traffic situation, is thus calculated for the vehicle or in particular for the delimitations of the vehicle in a specific illumination situation in order to ensure the visibility from the at least one observation position by detecting the emission characteristics of the luminaires, which can likewise be seen from the at least one observation position.Illumination or emission characteristics of the background are understood here to be at least the illumination intensity, the distribution and parameters of the luminous surfaces of the vehicle or laterally next to the vehicle or in front of the vehicle or on the roadway, namely seen in each case from the perspective of the at least one observation position. The determination of the parameters of the light surfaces can be limited to those spatial parts which can be seen from the at least one observation position, i.e. which are not covered by the vehicle.In a further embodiment of the method according to the invention, the control of the parameters is achieved by redistribution of the brightness and / or spectral distribution between the luminous surfaces of the vehicle. In particular, the desired contrast ratio can be set by redistribution of the light emission between the luminous parts of the vehicle. In this case, the entire light emitted into the at least one observation position and its parameters can remain largely constant or can be controlled, for example, in accordance with the specifications of a system for reducing glare effects. Redistribution may also be configured as an alternating process. For example, light waves of variable light can be generated on the large-area headlights of a vehicle or the light intensity can be shifted from one headlight to the other. Redistribution of the brightness and / or spectral distribution may be performed for any illuminating parts of the vehicle.The term "redistribution of the light emission" means that such a change in the emission characteristics emitted from different luminaires or luminous parts is achieved that the total intensity and / or spectral distribution of the light emitted into the at least one observation position remains substantially constant. The method according to the invention can be configured such that the illumination of the spatial part in which the at least one observation position is located caused by the vehicle remains substantially constant at least in the perception of the driver of the vehicle. This is particularly advantageous if no real road user is present in the at least one observation position. This means that for the relevant observation positions, there are no visible shadows or areas with modified light for the driver, which could disturb him.In the sense of the invention, the increase in the contrast ratio for the at least one observation position can also be achieved by attenuating the intensity of a luminous part of the vehicle.In a particularly preferred embodiment of the invention, the control of the contrast ratio takes place on the basis of a control process. In this case, the setpoint value is a predefined contrast ratio and the actuating value is the current value of the contrast ratio or ratios.In a further embodiment of the method according to the invention, for controlling the contrast ratio or ratios, the composition of the textures or spatial frequencies which characterize them is changed within illuminated areas of the vehicle and / or between illuminated parts of the vehicle, in particular substantially continuously. In particular, the ratio of the spatial frequencies generated by the illumination system is changed. It is known from psycho-optics that the perception or visibility of specific spatial frequencies depends on the distance of the light source from the observation position and on the properties of the medium between light source and observation position. For each distance, viewing angle and weather condition, there is an optimum composition of the spatial frequencies. Advantageously, the parameters of the light emitting surfaces can be controlled in such a way that the composition of the spatial frequencies within the light emitting surface and / or of the spatial frequencies formed by a plurality of light emitting surfaces is changed. For example, the lighting means can be controlled for a specific selection of refractive or light-conducting parts of the vehicle light in such a way that a composition of spatial frequencies required according to a criterion results. Grids of individual parts (e.g. LEDs) with different intensities can also be produced for influencing the spatial frequencies. The spatial frequencies shown can be changed almost continuously. The vehicle light system can also be designed in such a way that a specific pattern or basic pattern of spatial frequencies is always present, wherein the controller according to the invention only switches on depending on the situation and brings about a change in the composition of the spatial frequencies, for example an increase in the proportion of specific spatial frequencies.According to the invention, the visibility can thus be optimized for a specific observation position. This can be effected, for example, in such a way that, for a far-away virtual observer (for example for an assumed road user), for example in poor weather, every second luminous segment (for example in the form of a light strip) of a vehicle lamp lights up more strongly, while the remaining luminous segments light up or cancel out or change their reflectivity locally. In contrast, in the case of a road user traveling immediately behind, higher spatial frequencies (as many lines as possible with a small distance between them) are activated. The method according to the invention can be used for any signal lights or signaling lights generated in another way (indicators, projections of light symbols, etc.). It is also possible that the method is also applied to non-directly visible light, such as infrared light. In this case, the method can enable or improve, for example, the automatic recognition of the vehicle by road users and / or by infrastructure devices. In particular, the visibility of the vehicle with respect to the vision can also be controlled with specific aids, such as a so-called night vision system (near infrared or thermal imaging camera). If necessary, the method can also reduce the visibility of a vehicle. For example, the visibility can be kept at a certain level without auxiliary means, while the visibility in the infrared spectrum is intentionally reduced, or vice versa.In addition to the method described above, the invention also comprises a system for controlling the visibility of a vehicle, which is designed such that any variant of the method according to the invention can be carried out using the system. The invention furthermore relates to a vehicle which comprises such a system.Exemplary embodiments of the invention are described in detail below with reference to the attached figures.The following are shown: FIG. 1 shows a schematic illustration of the environment of a vehicle for illustrating the factors influencing the visibility of the vehicle; FIG. 2 is a schematic diagram for describing control of contrast ratios according to an embodiment of the present invention; and FIG. 3 is a perspective view of a vehicle lamp for illustrating the spatial frequencies generated by the lamps.FIG. 1, which has already been described in the introduction to the description, illustrates the factors which determine the visibility of a road user from the observation position of the driver of the vehicle 1 (with or without assistance by the driver or by camera systems) and the visibility of the vehicle for another road user. Position 2 corresponds to the observation position of a (virtual) observer, and reference numerals 3 to 15 denote illuminated areas on or in the environment of vehicle 1. These light emitting surfaces 3 to 7 and 11 are specific light sources on the vehicle, and the light emitting surfaces 8 to 10 and 15 are light sources in the vicinity of the vehicle. The light surfaces 12 to 14 are located on the vehicle and do not actively light but rather reflect the light of the light sources in the environment of the vehicle, e.g. the light of the light source 15. For the visibility of an object in the observation position 2 by the driver of the vehicle 1, in particular light parameters of the light surfaces 3 to 10 are relevant. For the visibility of the vehicle 1 from the position 2, moreover, and above all, the distribution of the parameters to these light-emitting surfaces, in particular the contrast conditions formed by these light-emitting surfaces, is relevant for the perspective of the observation position 2.The visibility of the vehicle is determined by means of the following method steps. The light distribution of the illuminated areas 3 to 7 and 11 is determined from the geometric position, the emission characteristics and the operating state of these light sources by the computing unit of the vehicle. The brightness and / or spectral distributions of the luminous surfaces 8 to 10 and 15 are determined using sensing means of the vehicle. The parameters of the luminous surfaces for the observation position 2 are determined from the previously determined light distributions or brightness and / or spectral distributions of the luminous surfaces. In this case, the luminaires which form or influence a perceptible contrast ratio are first of all selected on the basis of geometric criteria. In the scenario of FIG. 1, the light surface 11 has no influence on the visibility of the vehicle from the observation position 2, since this is concealed and itself does not cause any illumination of the background of the vehicle that can be perceived from the position 2. The tire of the vehicle (luminous surface 14), which in itself has insufficient reflectivity to be seen from the observation position 2, is however taken into account in the embodiment of the method according to the invention described here, since this luminous surface plays an important role in the determination of the contrast ratio between the luminous surfaces 12 and 14. It also plays a role in the class of perceptibility of the vehicle as a vehicle.The contrast conditions between the luminous surfaces inside the vehicle 1 and between the luminous surfaces inside and outside the vehicle 1 are determined.For example, it is taken into account that the luminous surface 15 influences the perception of the contrast conditions between the luminous surfaces 3, 12 and 14 from the observation position 2. By determining psycho-optical contrast ratios, it is also taken into account whether the eyes of the observer can distinguish the color contrasts, for example, in the present situation. The perception of color contrasts is very greatly reduced or impossible, for example, during night vision, which is taken into account by the determination of the psycho-optical contrast ratio. In an analogous manner, the textures, not shown in FIG. 1, which are formed by illuminated areas of the vehicle and the environment, are determined and taken into account in the determination of the contrast conditions.When determining and controlling or regulating the visibility of the vehicle, different classes of perceptibility are differentiated. Depending on the individual contrast conditions determined, for example between the illuminated areas 7 and 8 and 4 and 10, a measure is determined for the visibility of geometric boundaries of the vehicle and for the perceptibility of this vehicle as such, for example in the case of fog or smog. In the case of a perception in a class of perceptibility of the vehicle that is not sufficient for the present traffic situation, the contrast conditions or partial contrast conditions within and / or between the light surfaces of the vehicle and / or the environment are controlled in a targeted manner.The contrast ratios are controlled, for example, by generating textures which generate a specific contrast ratio from the observation position 2 to the textures of the environment. Alternatively or additionally, the light distribution of the light surfaces and of the projection means of the vehicle in the environment of the vehicle is controlled in such a way that specific partial contrast conditions are changed. The textures are controlled by controlling the spatial frequencies, the orientation of the textures, continuously or in fine steps. For example, parts of the environment which form the background of the vehicle relative to the observation position 2 are illuminated with light of a specific brightness and spectral distribution. The parameters of the light surfaces in the environment of the vehicle are thus changed in such a way that the measure for the visibility of the vehicle and / or for the perceptibility of the vehicle satisfies predefined criteria in one or more classes of perceptibility.The partial contrast ratios and thus also the perceptivities for different classes of perceptibility of the vehicle and / or the visual, in particular aesthetic effect of the vehicle are changed e.g. by the projection of light patterns, which in particular represent color profiles and / or textures, onto light surfaces of the vehicle or in the environment of the vehicle. The control of the visibility, perceptibility and visual effect of the vehicle can take place permanently, at specific times or as a function of predetermined events.FIG. 2 schematically shows a traffic situation, on the basis of which a temporal priority-controlled or sequential control of the contrast ratio for specific spatial parts is explained. According to FIG. 2, a vehicle 101 approaches an intersection at which a further vehicle 201 is located. Moreover, a cyclist 301 moves next to the vehicle 101. In the embodiment described herein, the contrast ratio of the vehicle 101 is controlled appropriately for the two observation positions 401 and 501. It is thereby made clear which light sources on the vehicle in the observation positions 401 or 501 are relevant for the visibility of the vehicle at these positions. This is reproduced by corresponding arrows from the respective observation positions toward the light sources of the vehicle. In the embodiment of FIG. 2, the contrast ratio at which the vehicle is viewed from the space parts 401 and 501 is sequentially controlled. That is, successively, at certain time intervals, the contrast ratio is set for the space part 401 and then for the space part 501. In this case, in particular a predefined desired contrast ratio is set for the respective spatial parts. The sequence or priority with which the desired contrast ratio is generated in the two spatial parts 401 or 501 is controlled by the estimated or determined probability of the traffic participants in these spatial parts. The time intervals are selected in such a way that a road user possibly located in these spatial parts can see the vehicle sufficiently frequently, in particular in such a way that collision risks are avoided. In the scenario of FIG. 2, the two spatial parts 401 and 501 are selected in such a way that they correspond to the presumed future position of the vehicle 201 (spatial part 501) or the presumed future position of the cyclist 301 (spatial part 401).FIG. 3 shows a modern rear lamp of a motor vehicle. The rear lamp is designated here by reference numeral 700. The region of the red-lighting rear headlight is denoted by 701, for example, and the yellow-lighting turn signal is denoted by 702. The luminaire 700 comprises a plurality of internally illuminated refractive bodies, whereby the corresponding luminous areas are generated with different textures (luminous gratings) which are more visible to other road users than an area of the luminaire illuminated with a corresponding average value.The composition of the spatial frequencies of the luminaire 700 can be controlled according to the invention as a function of the current and locally detected air properties in the environment of the luminaire. In clear weather and for road users who are close to the vehicle, high spatial frequencies (relatively dense arrangement of lighter and darker areas) are advantageous. High spatial frequencies offer a high partial visibility within the luminaire in relation to the energy consumption. In contrast, in the case of fog, smog and / or road users at a great distance, the texture changes toward the lower spatial frequencies. In this case, the contrast ratio between relatively widely arranged parts of the luminaire is increased, while the high spatial frequencies are suppressed. Low spatial frequencies are also visible from longer distances or in the case of smog or fog. The control according to the invention of the corresponding light distributions, which are composed of the brightness and spectral distributions of the luminaire, can be effected in a luminaire which contains a plurality of lighting means (e.g. LEDs or OLEDs) in that the lighting means are controlled individually or in groups, namely in such a way that a change in the light distributions can take place almost continuously or in fine steps.Further surfaces of the vehicle, for example a decorative strip which is extended laterally on the vehicle in the direction of travel, are backlit with such a light distribution by the control of a plurality of lighting means, for example an OLED layer incorporated into the decorative strip, that brightness and color profiles visible to the outside are produced. The parameters of the corresponding light distribution visible from the outside are selected according to the invention such that the contrast ratio between the decorative strip (which can simultaneously characterize the geometric limits of the vehicle) and the respective light surfaces located in their immediate vicinity is set or maximized on the basis of a predefined value.The light surfaces of the vehicle thus adapt a brightness and / or color profile and / or the textures formed therefrom to the objects in the immediate vicinity of these light surfaces. Partial visibilitys, for example between a geometric boundary of the vehicle and other objects, can thus be controlled according to specifications. In particular, the light surfaces of the vehicle can form textures whose spatial frequencies have a specific difference from the spatial frequencies of the light surfaces in the environment of the vehicle. The difference can also relate to the orientation of the textures, e.g. horizontal and vertical color or brightness gratings contrast strongly with one another.If an increase in the partial visibility is required, spectral distributions can also be generated which correspond essentially in each case to a predefined color assignment, for example based on mutually complementary colors. For example, the visibility of a decorative strip at the locations where it comes close to a blue object may illuminate with yellowish light, while it produces a purple hue at another location that is close to a green object. In both cases, a very high visibility and the interactive effect of the decorative strip are produced even with a very low luminous intensity and with a very low energy consumption. The sensing means of the vehicle can also be provided on the decorative strip in this case. Such a configuration of the method offers a very great advantage with regard to the control of the visibility, perceptibility or visual effect of parked vehicles, since this requires very little energy.The method according to the invention has the advantage, among other things, that it can also be used without an object recognition system. Object detection systems have the disadvantage that they cannot provide absolute certainty for correct object detection in all situations and are often expensive or are not available in each vehicle or are not effective in each direction of the vehicle. According to the invention, the relevant observation positions are preferably selected or updated in such a way that they can wholly or partly contain particularly critical spatial parts (exits, intersections and the like) in terms of traffic. As relevant observation positions, spatial parts with an increased probability of traffic participants being present are also used, if appropriate. In this case, the road users are assigned speeds or speed bandwidths which can occur (with high probability) in the known or automatically detected course of the roads. The course of the roads, the traffic volume or the traffic statistics can be taken from a navigation system of the vehicle, for example.

Claims

Method for controlling the visibility of a vehicle (1; 101), comprising the steps of: - determining a light distribution comprising a brightness distribution and / or spectral distribution of light areas (3, 4,..., 15) on the vehicle (1; 101) and / or in a vicinity of the vehicle (1; 101), wherein at least the brightness and / or spectral distribution of the light areas (8, 9, 10, 15) in the vicinity of the vehicle (1; 101) is determined with the aid of one or more sensing means on the vehicle (1; 101); - determining one or more parameters of one or more of the light areas (3, 4,..., 15) and / or between more of the light areas (3, 4,..., 15) of the light distribution for a perspective of at least one observation position (2; 401, 501) in the vicinity of the vehicle (1; 101); controlling the parameter or parameters for the perspective of the at least one observation position (2; 401, 501) as a function of one or more predefined criteria, wherein the visibility of the vehicle (1; 101) is controlled such that the reflectivity is influenced by one or more light-emitting surfaces (3, 4,..., 15) of the vehicle (1; 101).Method according to claim 1, characterized in that at least partially parameters are controlled by one or more light emitting surfaces (3, 4,..., 15) and / or between a plurality of light emitting surfaces (3, 4,..., 15) which are located laterally next to the vehicle (1; 101) and / or closer to the at least one observation position (2; 401, 501) than the vehicle (1; 101).Method according to Claim 1 or 2, characterized in that the parameter or parameters are one or more contrast conditions for the perspective of the at least one observation position (2; 401, 501) in the environment of the vehicle (1; 101).Method according to claim 3, characterized in that according to the predetermined criteria the respective value of one or more of the contrast ratios is maintained substantially at a predetermined set value.Method according to one of the preceding claims, characterized in that, according to the predetermined criteria, the respective value of one or more of the parameters is changed as a function of a visibility measure of the vehicle (1; 101) for the perspective of the at least one observation position (2; 401, 501) in the environment of the vehicle (1; 101).Method according to Claim 5, characterized in that the perceptibility of the vehicle (1; 101) for one or more classes of perceptibility and / or at least one measure for the visual effect of the vehicle (1; 101) is determined for the at least one observation position (2; 401, 501) and is modified by controlling partial visibility measures of individual light-emitting surfaces (3, 4,..., 15) and / or light-emitting surface groups of the vehicle (1; 101).Method according to Claim 3 or 4 or according to Claim 5 or 6 in combination with Claim 3, characterized in that the parameters of the luminous surfaces (3, 4,..., 15) in the environment of the vehicle (1; 101), in particular of the luminous surfaces (3, 4,..., 15) which are located in front of or behind the vehicle (1; 101) from the perspective of a specific observation position (2; 401, 501), are changed by means of means of the vehicle (1; 101) in such a way that a partial contrast ratio between the luminous surfaces (3, 4,..., 15) of the vehicle (1; 101) and the changed luminous surfaces (3, 4,..., 15) in the environment of the vehicle (1; 101) is changed.Method according to claim 5 or 6 or according to claim 7 in combination with claim 5 or 6, characterised in that the parameter or parameters are controlled in such a way that a predetermined visibility measure and / or a predetermined perceptibility of the vehicle (1; 101) for one or more classes of perceptibility and / or a predetermined visual effect of the vehicle (1; 101) for the at least one observation position (2; 401, 501) is substantially achieved.Method according to Claim 5 or 6 or 8 or according to Claim 7 in combination with Claim 5 or 6, characterized in that the respective value of one or more of the parameters is changed in such a way that the visibility measure of the vehicle (1; 101), in particular the visibility measure in relation to the energy used for generating the luminous surfaces (3, 4,..., 15), is increased, in particular maximized, for the perspective of the at least one observation position.Method according to one of the preceding claims, characterized in that the parameter or parameters between a plurality of the luminous surfaces (3, 4,..., 15) on the vehicle (1; 101) and in the environment of the vehicle (1; 101) are determined, wherein the parameters are in particular controlled in such a way that at least parts of the contour of the vehicle (1; 101) are emphasized.Method according to claim 3 or 4 or according to claim 5 or 6 in combination with claim 3 or according to claim 7 or according to any one of claims 8 to 10 in combination with claim 3, characterised in that the contrast ratio or ratios are psycho-optical contrast ratios and take into account in particular adaptation properties of the vision system of the human or an animal.Method according to Claim 11, characterized in that one or more light distributions at earlier points in time are taken into account in the determination of the psycho-optical contrast ratio.Method according to Claim 3 or 4 or according to Claim 5 or 6 in combination with Claim 3 or according to Claim 7 or according to one of Claims 8 to 10 in combination with Claim 3 or according to Claim 11 or 12, characterized in that textures and / or shapes on the vehicle (1; 101) and in the environment of the vehicle (1; 101) are taken into account in the determination of the contrast ratio or ratios.Method according to one of the preceding claims, characterized in that, during the control of the parameter or parameters, the light distribution, in particular the light characteristics generated by the lighting system of the vehicle (1; 101), are adapted to scattering and / or transmission properties of a medium between the vehicle (1; 101) and the at least one observation position (2; 401, 501) in such a way that the parameter or parameters for the perspective of the at least one observation position (2; 401, 501) are held substantially at a setpoint value.Method according to one of the preceding claims, characterized in that the visibility of a vehicle (1; 101) is controlled, which comprises at least one luminous part as a part of the body, wherein the at least one luminous part is illuminated by lighting means of the vehicle (1; 101), wherein the at least one luminous part is a lighting surface (3, 4,..., 15) for which parameters are controlled.Method according to one of the preceding claims, characterized in that the visibility of a vehicle (1; 101) is controlled, which comprises at least one luminous part as at least one partially transparent surface of the vehicle (1; 101), which is backlit by lighting means of the vehicle (1; 101), wherein the at least one luminous part is a luminous surface (3, 4,..., 15) for which parameters are controlled.Method according to one of the preceding claims, characterized in that the at least one observation position (2; 401, 501) is selected such that one or more road users (201, 301) are located in the at least one observation position (2; 401, 501) with a probability above a predefined threshold value.Method according to one of the preceding claims, characterized in that the at least one observation position (2; 401, 501) is selected as a function of the spatial profile of a roadway and / or of a lane and / or of a pedestrian path.Method according to Claim 18, characterized in that the at least one observation position (2; 401, 501) lies substantially at the height of a vehicle windshield and / or at the eye height of pedestrians.Method according to Claim 4 or according to one of Claims 5 to 19 in combination with Claim 4, characterized in that the setpoint value is calculated as a function of the emission characteristics of the luminous surfaces (3, 4,..., 15) on the vehicle (1; 101) and / or in the environment of the vehicle (1; 101).Method according to one of the preceding claims, characterized in that the control of the parameter or parameters is effected by means of redistribution of the brightness and / or spectral distribution between the luminous surfaces (3, 4,..., 15) of the vehicle (1; 101).Method according to claim 4 or according to any one of claims 5 to 19 in combination with claim 4 or according to claim 20 or according to claim 21 in combination with claim 4, characterised in that the respective value of one or more of the contrast ratios is controlled, wherein the setpoint value is a predefined contrast ratio and the control value is the current value of the contrast ratio or ratios.Method according to claim 3 or 4 or according to claim 5 or 6 in combination with claim 3 or according to claim 7 or according to any one of claims 8 to 10 in combination with claim 3 or according to claim 11 or 12 or 13 or according to any one of claims 14 to 19 in combination with claim 3 or according to claim 20 or according to claim 21 in combination with claim 3 or according to claim 22, characterised in that, in order to control the contrast ratio or ratios, the composition of the spatial frequencies is changed within illuminating parts of the vehicle (1; 101) and / or between illuminating parts of the vehicle (1; 101), in particular substantially continuously.System for controlling the visibility of a vehicle (1; 101), comprising one or more sensing means on the vehicle (1; 101) and a computing unit, wherein the computing unit performs the following steps during operation: - determining a light distribution comprising a brightness distribution and / or spectral distribution of the luminous surfaces (3, 4,..., 15) on the vehicle (1; 101) and / or in a vicinity of the vehicle (1; 101), wherein at least the brightness and / or spectral distribution of the luminous surfaces (8, 9, 10, 15) in the vicinity of the vehicle (1; 101) is determined with the aid of the sensing means or means on the vehicle (1; 101); - determining one or more parameters of one or more of the luminous surfaces (3, 4,..., 15) and / or between more of the luminous surfaces (3, 4,..., 15) of the light distribution for a perspective of at least one observation position (2; 401, 501) in the environment of the vehicle (1; 101); controlling the parameter or parameters for the perspective of the at least one observation position (2; 401, 501) as a function of one or more predefined criteria, wherein the visibility of the vehicle (1; 101) is controlled such that the reflectivity is influenced by one or more light emitting surfaces (3, 4,..., 15) of the vehicle (1; 101).System according to claim 24, which is designed such that a method according to one of claims 1 to 23 can be carried out with the system.A vehicle comprising a system according to claim 24 or 25.

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