Method and driver assistance system for providing visual information about a first vehicle in an environment of a second vehicle, computer program and computer-readable medium

The invention relates to a method for providing visual information about a first vehicle (1) in an environment (4) of a second vehicle (2). The method comprises the step of detecting a reduced visibility of the first vehicle (1) in the environment (4) of the second vehicle (2) and the steps of transmitting an image captured by a camera (7) of the first vehicle (1) to a display device of the second vehicle (2) and of integrating an object (13) representing the first vehicle (1) into the image displayed on the display device of the second vehicle (2). The object (13) is represented in the image (12) at a position which corresponds to the current position of the first vehicle (1) in the environment (4) of the second vehicle (2). The invention further relates to a computer program, a computer-readable medium and a driver assistance system (3).

TECHNICAL FIELD

The invention relates to a method for providing visual information about at least one first vehicle in an environment of a second vehicle. The method comprises the step of detecting a reduced visibility of the at least one first vehicle in the environment of the second vehicle. The invention further relates to a computer program, a computer-readable medium on which the computer program is stored, and a to driver assistance system.

BACKGROUND OF THE INVENTION

Document U.S. Pat. No. 8,983,705 B2 describes a method for detecting bad weather conditions such as fog using laser data provided by a LIDAR unit of a trailing car, i.e. by a car driving behind another car, and by analyzing images captured by a camera of the trailing car. For example, image data may be processed to identify objects in the image. When the objects indicated by the camera image do not agree with the objects indicated by the data from the LIDAR unit, an indication that fog is present can be made.

However, even if the presence of fog is detected by such a method, the preceding car or leading vehicle driving in front of the trailing car is still not well visible for a driver of the trailing car.

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a method, a computer program, a computer-readable medium and a driver assistance system, which allow obtaining an increase in driving safety.

This object is solved by a method having features of claim1.

Advantageous configurations with convenient further developments of the invention are specified in the dependent claims, the description and the drawings.

The method according to the invention for providing visual information about at least one first vehicle in an environment of a second vehicle, comprises the step of detecting a reduced visibility of the at least one first vehicle in the environment of the second vehicle.

The method further comprises the steps of transmitting an image captured by a camera of the at least one first vehicle to a display device of the second vehicle and of integrating an object representing the at least one first vehicle into the image displayed on the display device of the second vehicle. Herein, the object is represented in the image at a position which corresponds to the current position of the at least one first vehicle in the environment of the second vehicle. Thus, by looking at the display device of the second vehicle, a driver of the second vehicle can see the at least one first vehicle as if there was not reduced visibility of the at least one first vehicle. The method therefore allows obtaining an increase in driving safety.

As the image or frame captured by the camera of the at least one first vehicle is received by the second vehicle and then transmitted to the display device of the second vehicle the visibility is increased for the driver of the second vehicle looking at the display device of the second vehicle. Provided that the reduced visibility of the at least one first vehicle is detected, the object which represents the at least one first vehicle is added to the image displayed on the display device. This makes the first vehicle visible to the driver of the second vehicle. And representing or showing the object in the image at the location or position which corresponds to the current position of the first vehicle in the real or actual environment enables the driver of the second vehicle to particularly well estimate a distance between the first vehicle and the second vehicle. The driver can also particularly well estimate a time inter vehicles, i.e. the time which is necessary to cover the distance between the first vehicle and the second vehicle depending on the driving speeds of the two vehicles. The method therefore enables the driver of the second vehicle to drive more safely.

The improved visibility of the at least one first vehicle which is represented by the object added to the image displayed on the display device is particularly helpful during bad weather events such as the presence of fog, strong rain and the like. This is due to the fact, that the driver of the second vehicle looking at the display device of the second vehicle can see the at least one first vehicle as if there was no fog, heavy rain or the like.

In particular, offering such a better visibility of the first vehicle to the driver of the second vehicle enables the so called vacuum effect to be diminished or avoided. The vacuum effect, which can be responsible for accidents when the visibility is reduced or impaired due to fog, heavy rain or the like, describes the situation in which the second vehicle is driving behind the first vehicle. In order not to lose sight of the rearward lights of the first vehicle in front of the second vehicle, the driver of the second vehicle tends to increase his driving speed. At the same time, a driver of the first vehicle, who sees the second vehicle approaching from behind, tends to accelerate. This can result from a fear of the driver of the first vehicle to be hit by the second vehicle or from a unpleasant feeling of the driver of the first vehicle when the distance between the two vehicles decreases. Thus, instead of slowing down the driving speed of both vehicles increases.

This so called vacuum effect can, in particular in combination with not respecting safety distances, cause an accident of at least one of the vehicles. The reason is that the drivers of the first vehicle and the second vehicle, respectively, travel at a speed which is not adapted to the reduced visibility conditions caused by for example fog, rain or the like. However, by showing the image with the object added to the image on the display device of the second vehicle to the driver of the second vehicle, the vacuum effect can be avoided or at least reduced.

Preferably, a view representing at least a section of an area ahead of the at least one first vehicle is transmitted as the image displayed on the display device of the second vehicle. The view can in particular be captured by a front camera of the at least one first vehicle. As the view representing at least the section of the area ahead of at least one first vehicle is shown on the display device of the second vehicle, the visibility of the environment is improved for the driver of the second vehicle looking at the display device of the second vehicle. This is due to the fact that the camera of the first vehicle which is travelling in front of the second vehicle can capture more details of the surroundings of the first vehicle than it is the case for a driver or for a camera of the second vehicle, having the first vehicle in his or its field of view. Therefore, utilizing the view representing at least the section of the area ahead of the first vehicle as the image displayed on the display device leads to an improved visibility of the environment for the driver of the second vehicle.

Preferably, a view captured by the camera of the at least one first vehicle before reaching its current position is displayed as the image on the display device of the second vehicle. In other words, the camera of the first vehicle captures a view before the vehicle reaches the current position. Thus, the view captured by the camera of the first vehicle corresponds to the situation when the first vehicle is located or situated at a previous position. And preferably this view captured at the previous position is transmitted or transferred as the image to the second vehicle. This has several advantages.

For one thing, the view captured by the camera of the first vehicle before reaching its current position corresponds to a view taken when the first vehicle is less far away from the second vehicle than in the situation in which the first vehicle has reached its current position. Consequently, the risk of fog or the like impairing the visibility in an area between the second vehicle and the first vehicle is decreased.

On the other hand, a zone in which there is no fog or the like around the object representing the at least one first vehicle in the image is larger than in a situation in which a view captured by the camera of the first vehicle having reached its current position would be utilized as the image. Therefore, the object representing the at least one first vehicle can be particularly well recognized or distinguished by the driver of the second vehicle looking at the display device of the second vehicle.

The camera of the at least one first vehicle can for example be a video camera which captures images with a given frequency, i.e. a predetermined number of images per second. The view captured by the camera of the first vehicle before reaching the current position of the first vehicle can in particular be the image or frame captured immediately before the image or frame captured at the current position of the first vehicle. However, it is also possible to utilize another one of the images taken by the camera before the first vehicle has reached its current position, as long as the image corresponds to a situation in which the first vehicle is located ahead of the second vehicle at its current position.

Preferably, as the object representing the at least one first vehicle a three-dimensional model of the at least one first vehicle is displayed on the display device of the second vehicle. By adding the three-dimensional model of the first vehicle to the image displayed on the display device of the second vehicle, a particularly realistic image of the first vehicle is shown to the driver of the second vehicle looking at the display device of the second vehicle. Therefore, the driver of the second vehicle can assess the traffic situation in a particularly realistic manner.

Preferably, data defining the three-dimensional model are transmitted from a communication device of the at least one first vehicle to a communication device of the second vehicle. In other words the two vehicles can be connected to each other over a wireless communication line or communication link established between the communication devices such that a car-to-car or vehicle-to-vehicle communication is enabled. Such a vehicle-to-vehicle communication between the at least one first vehicle and the second vehicle makes it particularly simple to present to the driver of the second vehicle a realistic three-dimensional model of the first vehicle on the display device of the second vehicle. Further, less storage space for storing three-dimensional models in a storage device of the second vehicle is necessary. Thus, the effort and the expenses for presenting the three-dimensional model of the first vehicle on the display device of the second vehicle are reduced.

The current position of the at least one first vehicle in the environment of the second vehicle can be determined by at least one sensor device of the second vehicle. The sensor device can be configured as or comprise a camera and/or a laser device such as a laser scanner. In particular by utilizing a laser scanner the current position of the at least one first vehicle can be detected with a high accuracy, even if the first vehicle cannot or can hardly be detected by a camera of the second vehicle. However, when data obtained by a camera of the second vehicle and a laser device such as a laser scanner of the second vehicle are both analyzed, the reliability of the determination of the current position of the first vehicle can be particularly high.

Alternatively or additionally position data indicating the current position of the at least one first vehicle in the environment of the second vehicle can be transmitted to the second vehicle. For example, the first vehicle can be equipped with a position sensor such as a GPS receiver (GPS=global positioning system) or the like. Consequently, particularly accurate position data of the at least one first vehicle, which indicate the current position of the first vehicle, can be provided to the second vehicle. Therefore, the effort for 20 determining the current position of the at least one first vehicle in the environment of the second vehicle can at least be reduced.

The image comprising the object representing the at least one first vehicle can be superimposed on least one further image captured by a camera of the second vehicle. Herein, the least one further image is displayed on a screen of the second vehicle. In such a configuration it is sufficient if the driver of the second vehicle takes a short look at the screen in order to perceive the object representing the at least one first vehicle in the environment of the second vehicle. This is particularly simple to be implemented, if the second vehicle has such a screen for displaying images captured by a camera, in particular by a front video camera of the second vehicle. The screen can in particular be integrated into an instrument panel of the second vehicle.

Preferably, a view representing at least a section of the environment of the second vehicle is displayed on the screen as the least one further image, wherein the section is situated ahead of the second vehicle. In this configuration the image comprising the object is merely added to the further images captured by the camera, in particular front camera, of the second vehicle. The driver can thus easily recognize the environment ahead of the second vehicle as if the driver was looking through a windshield of the second vehicle, when the driver is looking at the screen.

Alternatively or additionally the image comprising the object representing the at least one first vehicle can be displayed on a head-up display of the second vehicle. Displaying the image on the head-up display is particularly user-friendly and therefore particularly comfortable for the driver of the second vehicle, as the driver does not need to look away from a windshield of the second vehicle. Rather, the driver of the second vehicle can stay concentrated on the road ahead of him by looking through the windshield of the second vehicle. And the image comprising the object is displayed directly in the field of view of the driver by utilizing the head-up display.

Preferably, a viewing direction of the eyes of a driver of the second vehicle is tracked when the image is displayed on the head-up display. Tracking the viewing direction of the eyes of the user can be done by means of a driver monitoring system comprising a camera installed inside a cabin of the second vehicle. Therefore the image comprising the object can be displayed exactly at the correct position for the driver looking through the windshield of the second vehicle.

Preferably, in the image comprising the object representing the at least one first vehicle at least one rearward light of the at least one first vehicle is displayed on the display device of the second vehicle. Herein, the visibility of the at least one rearward light is increased with respect to the visibility of the at least one rearward light in the environment of the second vehicle. In other words the at least one rearward light of the at least one first vehicle is highlighted with respect to its visibility in the real environment, for example by increasing the brightness and/or the intensity of pixels representing the at least one rearward light in the image. By doing so, the driver of the second vehicle can particularly well recognize the at least one rearward light of the first vehicle.

Displaying the at least one rearward light in the image with the increased visibility can indicate to the driver of the second vehicle that the first vehicle is braking or performing a lane change, for example. In these cases rearward lights such as braking lights or a direction indicator light can be represented in the image displayed on the display device of the second vehicle. Consequently, by looking at the display device the driver of the second vehicle can realistically judge the traffic situation comprising the at least two vehicles, as if the rearward lights of the at least one first vehicle were perfectly visible. And as the driver of the second vehicle can adapt his driving mode to the maneuvers performed by the first vehicle, the driving safety is further increased.

Preferably, an intensity with which the at least one rearward light is displayed on the display device is set in dependence on a distance between the first vehicle and the second vehicle. Consequently, if the second vehicle approaches the first vehicle, the intensity of the pixels representing the at least one rearward light of the first vehicle is increased. This shows to the driver of the second vehicle a decreasing distance between the second vehicle and the first vehicle. Further, if a lateral distance between rear position lamps and/or braking lights of the first vehicle increases, the driver of the second vehicle can also conclude that the distance between the second vehicle and the first vehicle is decreasing. This also helps the driver of the second vehicle to adapt his driving mode in order to drive safely.

Preferably, an information indicating an at least intended activation of the at least one rearward light of the first vehicle is communicated to the second vehicle. This information is taken into consideration in displaying the at least one rearward light on the display device of the second vehicle. In such a configuration the first vehicle, in particular the preceding car, and the second vehicle, in particular the ego car or trailing car, are connected by means of a car-to-car or vehicle-to-vehicle communication system.

By communicating this information to the second vehicle a particularly reliably information at least on the intended lighting status of the at least on rearward light of the first vehicle can be taken into account by, for example, a control unit of the second vehicle. Even if a rearward light of the first vehicle has a failure, the first vehicle can communicate to the second vehicle that this rearward light should have been activated but is not working. But also if the rearward light is working but not visible for a camera of the second vehicle, the information on the at least intended activation status of this rearward light of the first vehicle is helpful for realistically displaying the rearward light on the display device of the second vehicle, in particular with the increased intensity.

Preferably, a plurality of images captured by respective cameras of a plurality of first vehicles are transmitted to the display device of the second vehicle. Herein, respective objects representing the respective first vehicle are integrated into the respective images. In other words the method can be also very helpful for the driver of the second vehicle, if a plurality of first vehicles are travelling in front of the second vehicle, but a visibility of these vehicles is reduced due to weather conditions, in particular fog or heavy rain.

The invention also relates to a computer program comprising instructions which, when the program is executed by a computer cause the computer to carry out the steps of the method according to the invention and preferably at least one of its embodiments.

Further, the invention also relates to a computer-readable medium, on which the computer program according to the invention is stored.

The advantages described with regard to the method according to the invention and its embodiments also apply to the computer program and the computer-readable medium and vice versa.

Moreover, the invention relates to a driver assistance system for providing visual information about at least one first vehicle in an environment of a second vehicle. Herein, the driver assistance system comprises a control unit which is configured to detect a reduced visibility of the at least one first vehicle in the environment of the second vehicle. The driver assistance system is further configured to receive an image captured by a camera of the at least one first vehicle and to transmit the image to a display device of the second vehicle. Still further, the driver assistance system is configured to integrate an object representing the at least one first vehicle into the image displayed on the display device of the second vehicle. Herein, the object is represented in the image at a position corresponding to the current position of the at least one first vehicle in the environment of the second vehicle. Thus, in a situation in which the reduced visibility of the at least one first vehicle in the environment of the second vehicle is detected, transmitting the image to the display device of the second vehicle and integrating the object into the image renders the at least one first vehicle particularly well visible for the driver of the second vehicle looking at the display device. Consequently, the driver assistance system, which is configured to carry out the method according to the invention and preferably at least one of its embodiments allows obtaining an increase in driving safety.

The advantages described with regard to the method according to the invention and its embodiments also apply to the driver assistance system and vice versa.

Further features of the invention are apparent from the claims, the figures and the description of figures. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of figures and/or shown in the figures alone are usable not only in the respectively specified combination, but also in other combinations without departing from the scope of the invention. Thus, implementations are also to be considered as encompassed and disclosed by the invention, which are not explicitly shown in the figures and explained, but arise from and can be generated by separated feature combinations from the explained implementations. Implementations and feature combinations are also to be considered as disclosed, which thus do not have all of the features of an originally formulated independent claim. Moreover, implementations and feature combinations are to be considered as disclosed, in particular by the implementations set out above, which extend beyond or deviate from the feature combinations set out in the relations of the claims.

In the FIG. same elements or elements having the same function are indicated by the same reference signs.

DETAILED DESCRIPTION OF THE INVENTION

FIG.1schematically shows a situation in which a first vehicle1, for example a passenger car, is driving in front of a second vehicle2. The second vehicle2, which is exemplarily shown to be also a passenger car, has a driver assistance system3which is only very schematically illustrated inFIG.1. Components of the second vehicle2and the driver assistance system3can more easily be recognized inFIG.2which shows an enlarged, schematic view of the second vehicle2. The second vehicle2, in particular the driver assistance system3of the second vehicle2has detection means for detecting objects in an environment4of the second vehicle2. In the case exemplarily shown inFIG.2these detection means comprise for one thing a camera5and on the other hand a distance sensor device which is preferably configured as a laser scanner6. The positions of the camera5and the laser scanner6of the second vehicle2with respect to other components of the second vehicle2are only shown exemplarily and these detection means can be located at any appropriate position within and/or on the second vehicle2.

The second vehicle2or ego car in the situation exemplarily shown inFIG.1is following the first vehicle1or preceding car. In a like manner as the second vehicle2, the first vehicle1is also equipped with a camera7in a form of a frontal camera. The cameras5,7, in particular video cameras, of the vehicles1,2are therefore adapted to capture images in respective areas ahead of each one of the two vehicles1,2. Both vehicles1,2are further connected to each other via a wireless communication link enabling a vehicle-to-vehicle communication. Consequently, the first vehicle1comprises a communication device8which is able to transmit data to the second vehicle2and to receive data from the second vehicle2. In a like manner the second vehicle2, in particular the driver assistance system3, comprises a communication device9which is configured to receive data from the first vehicle1and to transmit data to the first vehicle1.

InFIG.1a situation is exemplarily shown in which the first vehicle1is not well visible for a driver of the second vehicle2. This can be due to the presence of fog10ahead and around the second vehicle2. Due to the fog10not only the driver of the second vehicle2can hardly perceive the first vehicle1. Rather, the situation can be such that also the camera5of the second vehicle2can hardly detect the first vehicle1. In other words it can be difficult to detect the presence of the first vehicle1in the environment4of the second vehicle2by analyzing images captured by the camera5of the second vehicle2. Other low visibility situations can comprise the presence of rain, in particular heavy rain in the environment4of the second vehicle2. In such situations the connectivity between the two vehicles1,2which can be established by utilizing the communication devices8,9is taken advantage of. The goal of this is to make the first vehicle1visible to the driver of the second vehicle2, even though in reality the first vehicle1is more or less hidden in the fog10. The driver of the second vehicle2is therefore enabled to see the hidden first vehicle1as if there was no fog10, heavy rain or the like. This shall be explained with reference toFIG.3andFIG.4in particular.

InFIG.1the situation is shown in which the second vehicle2or ego car or trailing car and a first vehicle1or preceding car or leading car are both located at their current positions.FIG.3shows a situation in which the second vehicle2is still at its current position. However, the first vehicle1is shown at a previous position. In other words, before reaching the current position shown inFIG.1the first vehicle1was located or situated at the position shown inFIG.3. The camera7of the first vehicle1captures an image of an area11situated ahead of the first vehicle1.FIG.6shows a corresponding image12which is captured by the camera7of the first vehicle1situated at the previous position according toFIG.3. As this image12is taken ahead of the first vehicle1, the image12represents a view of the environment4as if a driver of the second vehicle2was looking through a windshield of the first vehicle1situated at the previous position according toFIG.3. Consequently, in the image12a portion of the fog10has disappeared. In other words, the visibility in the fog10for the driver of the second vehicle2can be increased, as the image12is shown or presented to the driver of the second vehicle2.

However, the purpose in the context of the present disclosure is not to make the first vehicle1disappear for the driver of the second vehicle2. Rather, an object representing the first vehicle1, in particular a three-dimensional model13(seeFIG.4) of the first vehicle1, is integrated into the image12. This model13is located in the image12at a position, which corresponds to the current position of the first vehicle1in the real environment4according toFIG.1. The three-dimensional model13which is integrated into the image12, for example by superimposing the three-dimensional model13on the image12captured by the first vehicle1, is also shown inFIG.7. The approach detailed above, which comprises the presentation of the image12together with the model13to the driver of the second vehicle2, allows the driver of the second vehicle2to see the first vehicle1as if there was no fog10or the like ahead of the second vehicle2. This situation is shown inFIG.4. In reality, however, the first vehicle1is at least partially hidden by the fog10in the environment4of the second vehicle2.

As can be seen fromFIG.7, it is advantageous to utilize the image12for representing the three-dimensional model13to the driver of the second vehicle2, namely the image12which has been captured by the first vehicle1before the first vehicle1has reached its current position. For one thing, and according to the situation shown inFIG.3, a distance14between the second vehicle2at its current position and the first vehicle1at its previous position is smaller than a distance15between the two vehicles1,2, when both vehicles1,2are at their current positions (seeFIG.1). Therefore the surface area of the image12displayed to the driver of the second vehicle2is larger than if the first vehicle1had already reached its current position and the image captured at the current position of the first vehicle1was utilized as the image displayed to the driver of the second vehicle2.

In addition, the probability that the first vehicle1disappears in the fog10ahead of the second vehicle2is reduced, as the image12captured when the first vehicle1was situated at its previous position is utilized for displaying the image12to the driver of the second vehicle2. The relatively large surface area of the image12is also helpful in allowing the driver of the second vehicle2to see the three-dimensional model13integrated into the image12in a particularly clear manner.

In order to determine the current position of the first vehicle1, at which the three-dimensional model13is represented in the image12, at least one sensor device of the second vehicle2can be utilized. In other words, even if the first vehicle1is not or not very well visible to the naked eye, by means of at least one sensor device such as the camera5and in particular the laser scanner6of the second vehicle2the presence of the first vehicle1at its current position in the environment4of the second vehicle2can be readily detected. It is also possible to transmit position data of the first vehicle1to the second vehicle2by utilizing the vehicle-to-vehicle communication link that can be established between the communication devices8,9.

However, even in a situation represented inFIG.5, in which the first vehicle1is hardly visible to with the eyes of the driver of the second vehicle2, it might be possible that the presence of the first vehicle1in the environment4of the second vehicle2can be detected by analyzing images or frames captured or taken by the camera5of the second vehicle2. To analyze these images the driver assistance system3of the second vehicle2can comprise a control unit16, in particular an electronic control unit. This control unit is also configured to analyze the data obtained by the laser scanner6. Therefore, by analyzing the images or pictures captured by the camera5and/or by analyzing the data obtained by the laser scanner6, the current position of the first vehicle1in the environment4can be detected by the driver assistance system3of the second vehicle2.

In the situation with low visibility, which is for example due to the presence of the fog10, rain or the like in the environment4of the second vehicle2, the second vehicle2recovers a video stream in the form of the images captured by the camera7of the first vehicle1situated in front of the second vehicle2. For one thing this helps in better visualizing the surrounding environment4to the driver of the second vehicle2. And as the driver of the second vehicle2has a better view of the road ahead, the distance of vision is augmented for the driver of the second vehicle2. This can be done by presenting to the driver of the second vehicle2the image12as shown inFIG.6.

Further, by reproducing virtually the first vehicle1in the form of the three-dimensional model13within the image12, the current position of the first vehicle1can be indicated to the driver of the second vehicle2. To present or show the image12comprising the object in the form of the three-dimensional model13to the driver of the second vehicle2, different display devices of the second vehicle2can be utilized.

For example, the second vehicle2can be equipped with a screen17which can be integrated into an instrument panel of the second vehicle2. On this screen17images18captured by the camera5of the second vehicle2can be displayed to the driver of the second vehicle2. One example of such an image18is shown inFIG.7. Therefore, the view shown inFIG.7can either be a view of the driver of the second vehicle2through a windshield19of the second vehicle2(seeFIG.2) or the image18displayed on the screen17. In the latter case the image12comprising the object in form of the three-dimensional model13is superimposed on the further image18captured by the camera5of the second vehicle2.

However, the second vehicle2can alternatively or additionally be equipped with a head-up display20as display device (seeFIG.2). In this case, the image12comprising the object in form of the three-dimensional model13can be displayed on the head-up display of the second vehicle2. In this situation the driver of the second vehicle2does not need to look at the screen17located in particular below the windshield19in order to see the image12comprising the model13. Rather, the driver of the second vehicle2can continue looking through the windshield19, and the image12comprising the three-dimensional model13is projected in the field of view of the driver of the second vehicle2.

If the head-up display20is particularly large, a particularly big part of the windshield19, in particular the whole windshield19of the second vehicle2can be utilized for displaying the image12on the head-up display20. In both cases, i.e. when the screen17or the head-up display20is utilized, the three-dimensional model13of the first vehicle1is displayed at its current position in the environment4of the second vehicle2.

In order to integrate the three-dimensional model13into the image12, one of the images or frames captured by the camera7of the first vehicle1before the first vehicle1has reached its current position is preferably utilized. InFIG.6a situation is shown in which a fusion of the images or frames captured by the camera5of the second vehicle2and of the images or frames captured by the camera7of the first vehicle1, i.e. the preceding car, has taken place. And inFIG.7the integration of the three-dimensional model13into these images is illustrated.

A further implementation of the method shall be explained with reference toFIG.7and toFIG.8. As can be seen fromFIG.7, the three-dimensional model13of the first vehicle1has rearward lights for example in the form of position lamps21,22. Further rearward lights of the three-dimensional model13can be braking lights of the first vehicle1, direction indicator lights or blinkers or the like.

Preferably, these rearward lights, exemplarily shown inFIG.8as the position lamps21,22, are not only represented in the image12. Rather, a visibility of these rearward lights is increased with respect to the visibility of these rearward lights in the real environment4of the second vehicle2. In other words, pixels representing the position lamps21,22and/or other such rearward lights of the first vehicle1are amplified or intensified with respect to their visibility. Thus, the driver of the second vehicle2looking at the screen17and/or at the head-up display20will perceive the rearward lights of the first vehicle1more easily. This is due to the fact that these rearward lights, in the example chosen the position lamps21,22, are presented with the increased intensity.

As the driver assistance system3effects this representation of the rearward lights with the increased intensity the driver of the second vehicle2can be alerted if for example the driver of the first vehicle1decelerates. In this case the braking lights of the first vehicle1are shown with an increased intensity in the three-dimensional model13contained within the image12. In the same manner the driver of the second vehicle2can be alerted that a lane change of the first vehicle1will take place by representing a rearward light configured as a, in particular blinking, direction indicator light of the first vehicle1in the three-dimensional model13. The driver of the second vehicle2can therefore perceive the rearward lights of the first vehicle1as if there was perfect visibility. To achieve this, the driver of the second vehicle2merely needs to look at the screen17or at the display device in form of the head-up display20, i.e. keep on looking through the windshield19of the second vehicle2.

FIG.9illustrates a situation in which a plurality of first vehicles1are present in the environment4of the second vehicle2. In other words a multiplicity of first vehicles1are preceding the ego car or second vehicle2. Also in this situation the respective images12captured by the respective cameras7of the first vehicles1are displayed on the display device of the second vehicle2(seeFIG.10), i.e. on the screen17and/or on the head-up display20. Each one of the images12preferably comprises the three-dimensional model13representing the respective first vehicle1at its current position in the fog10.

FIG.10further shows that the rearward lights, for example the position lamps21,22of the plurality of first vehicles1, are represented with an increased intensity in the respective three-dimensional model13.

The examples show how in cases of a detected low visibility in the environment4of the second vehicle2presenting a virtual image12of the leading vehicle or first vehicle1on the display device of the second vehicle2can increase the driving safety for the driver of the second vehicle2.