Method for locating lane markings in a motor vehicle and motor vehicle

Abstract

The invention relates to a method for locating lane markings (4) in a motor vehicle (1), the motor vehicle (1) having a camera (5), the image data of which are evaluated to generate lane marking data describing the presence and position of the lane markings (4), wherein at least one ground-penetrating radar sensor (8) of the motor vehicle (1) directed toward the surface (2) on which the vehicle is traveling is also used, the radar data of which are evaluated to determine surface data describing the surface structure of the surface (2) on which the vehicle is traveling, a mapping database (12) is used, in which lane marking data and surface data indicating the presence of the lane markings (4) associated with the same recording location are stored in association with one another, in particular in the camera data, at least when a ground covering covering the lane markings (4) is identified, the current surface structure is compared with at least a part of the surface structure of the database by means of the surface data, and in the case of agreement, the lane marking data associated with the surface data of the consistent surface structure are used.

Description

Technical Field

[0001] The invention relates to a method for locating lane markings in a motor vehicle, wherein the motor vehicle has a camera, image data of which are evaluated to generate lane marking data which specify the presence and position of the lane markings. The invention also relates to a motor vehicle. Background Art

[0002] A large number of proposed and implemented vehicle systems in modern motor vehicles can make use of the knowledge of the relative position of lane markings to the motor vehicle. Examples of such vehicle systems include driver assistance systems, which are particularly concerned with the lateral guidance of the motor vehicle, and vehicle systems which are configured to at least partially automatically guide the motor vehicle, in the case of which automated driving interventions, knowledge of the further course of the lane being traveled in the present and / or future is important. For example, lane keeping assistance systems and lane departure warning systems are known in the prior art, which issue a warning when the motor vehicle is about to leave the lane and / or can perform self-correcting driving interventions. Knowledge of the positions of different lanes is also important for driver assistance systems that support lane changes. Many other vehicle systems can also appropriately use data related to lane markings, which are, for example, about the current road being traveled, the number of lanes on the road, the lane in which the motor vehicle is traveling, the width of the lane, etc.

[0003] In order to detect such lane markings in a motor vehicle, it is known to use a camera directed to the area in front of the motor vehicle, to evaluate the image data of the camera regarding the presence and position of the lane markings, wherein the evaluation result can be given, for example, via the lane marking data. The corresponding vehicle system can then use the lane marking data for the corresponding functions of the vehicle system. Problems always arise in such detection when the road markings are difficult or not at all to recognize optically. For example, the lane markings may be covered by snow, mud, dirt, etc. It is also conceivable that over time, the road markings may wear and / or be damaged. The optical sensor system will no longer be able to provide lane marking data. Although this is not very important in the case of a vehicle system in which the driver is still in a "closed loop" (i.e. observing the driving situation himself), because the driver can evaluate the situation himself and react accordingly, this is no longer the case in the case of highly automated driving functions, so that the failure to recognize lane markings may be very serious and may in particular lead to the corresponding vehicle guidance function being discarded.

[0004] DE 10 2016 224 558 A1 relates to a method for determining the position of a vehicle. The vehicle has a navigation system and a ground-penetrating radar system, wherein the ground in the area surrounding the vehicle is scanned by the ground-penetrating radar. The ground-penetrating radar system position data is determined by comparison with ground reference data, and the current vehicle position is determined from both the navigation system position data and the ground-penetrating radar system position data. This should enable a more precise position determination.

[0005] DE 10 2018 132 366 A1 relates to wireless charging of vehicles. Here, a receiving coil on the vehicle is aligned with a charging coil using ground-penetrating radar data. The system thus does not require visual recognition of ground objects and / or lane markings in order to align the receiving coil of the receiver with the charging coil of the transmitter. The system is particularly suitable for many outdoor environmental conditions, in particular in scenarios where there are no ground objects and / or no road markings, road markings are worn or weathered and / or markings are covered by leaves, snow, dirt or other debris.

[0006] DE 10 2018 202 267 A1 relates to a method for illuminating a lane while supplementing lane markings. In order to increase the amount of information for the driver of a motor vehicle when illuminating the lane, the direction of at least one lane marking in the surrounding area of ​​the motor vehicle is at least partially determined, and the light distribution is calculated so that the direction of the lane marking is at least partially supplemented by the brightness distribution emitted onto the road. In this case, for example, the direction of the lane marking can be detected with the help of map data and / or by a camera of the motor vehicle. Missing markings are determined by interpolating, extrapolating and / or smoothing the detected lane markings. In areas where there are no lane markings or where the lane markings are obscured, the obscured areas can be extrapolated or interpolated. In addition, the lane markings can be compared with lane markings determined with the help of a digital map in order to supplement the missing areas by comparison. Summary of the invention

[0007] The object of the present invention is to localize lane markings as robustly and accurately as possible even for optical lane markings that are covered and / or not recognizable in other ways.

[0008] To achieve this object, according to the invention, in a method of the type mentioned at the outset, provision is made for at least one ground-penetrating radar sensor of the motor vehicle directed toward the surface / surface layer on which travel is being made, radar data of the ground-penetrating radar sensor being evaluated to determine surface data / surface layer data (underground data) describing the surface structure / surface layer structure (structure below the ground) of the surface on which travel is being made, wherein lane marking data and surface data indicating the presence or absence of lane markings associated with the same recording location / detection location are stored in the mapping database in association with each other, wherein, in particular in the camera data, at least when a ground covering covering the lane markings is identified, the current surface structure is compared with at least a portion of the surface structure of the database with the aid of the surface data, and in the event of agreement, the lane marking data associated with the surface data of the consistent surface structure are used.

[0009] The ground covering that covers the lane markings may include, for example, snow, mud, leaves and / or other dirt. This can be detected, for example, in the image data of the camera, wherein, if necessary in a specific embodiment of the invention, other surrounding sensors of the motor vehicle, such as radar sensors or the like, can also be used—in particular in addition—in order to be able to determine lane markings that are not recognizable optically. In this case, a comparison with digital map data can also be carried out in particular expediently, after which, for example, it can be determined whether lane markings are possibly present.

[0010] Although the method according to the invention is particularly advantageous for covered lane markings, a corresponding comparison of the surface structure is also suitable, since the robustness of the determination of the lane markings can be increased and / or a plausibility check can be performed. In principle, a comparison is always possible, in particular if information about the current recording location is already available in the mapping database.

[0011] Since the relative installation positions of the camera and the ground-penetrating radar sensor are fixed and possibly even known, the surface structure is clearly associated with the lane marking and the surface structure is associated with the position of the lane marking. In particular, it can be provided within the scope of the invention that, in the case of identical surface structures that are laterally offset from one another, this offset is used to correct the position of the lane marking in the associated lane marking data. In other words, it can be determined whether the motor vehicle can pass the surface structure with a slight lateral offset, so that the position of the lane marking data that is usually stored in the lane marking data relative to the motor vehicle can also be adjusted accordingly, so that the relative position of the lane marking relative to the motor vehicle is correctly recognized.

[0012] A ground penetrating radar sensor (GPR) is understood to be a radar sensor whose radar signal penetrates the ground surface and can characterize the reflection patterns present in the ground at different depths. For example, the radar data can be classified and evaluated layer by layer based on reflections from different ground layers.

[0013] According to the present invention, it is now specifically proposed to create a mapping database that can associate a surface structure with determined lane markings present at the corresponding locations, so that even if the lane markings cannot be detected optically, for example because they are covered, it is possible to infer whether the lane markings are present and the positions of the lane markings from the surface structure, and thus to infer a suitable lane marking data set. It can be specifically provided that, in order to generate the database, surface data and lane marking data are determined by means of the motor vehicle and / or at least one identically designed motor vehicle during at least one trip, and lane marking data and surface data indicating the presence of lane markings associated with the same recording location are stored in the mapping database in association with each other. That is, whenever a motor vehicle or motor vehicles of identical design with respect to the relative arrangement and orientation of the ground-penetrating radar sensor and the camera pass through a road section, along which both surface data and lane marking data based on the detectability of lane markings can be recorded, the lane marking data are stored in a mapping database in association with the corresponding surface data, which can also be recorded over a period of time, so that when the corresponding surface structure described by the surface data is detected again, the lane marking data can be obtained even if the lane markings cannot be detected optically. In other words, the mapping database is generated by combining the surface structure detected by means of the ground-penetrating radar sensor and the optically determined lane marking data, which enables a comparison with the currently measured surface structure, from which the correct, associated lane marking data can be derived. The comparison of the surface structure thus essentially corresponds to the positioning of the motor vehicle in a surface map / surface layer map of the mapping database, which also contains the locations of the lane markings.

[0014] Thus, when driving on the ground, that is, in particular on a roadway, the ground-penetrating radar sensor senses the ground structure and compares the current ground structure, which can be understood as a map part, with the ground structure stored in the mapping database, which can be understood as an overall map. By comparing the ground structure currently sensed using the ground-penetrating radar with the ground structure stored in the system, lane markings that are covered by snow, for example, can still be recognized.

[0015] This is based on the knowledge that the surface structure does not or hardly changes over time or due to weather influences, thus providing a robustly detectable reference that provides optically undetectable lane markings. The lane markings are therefore detected indirectly by comparison with a mapping database.

[0016] In this way, the method according to the invention enables safe driving when lane markings are covered due to snow, dirt, aging, etc. The surface structure forms a reliable map for "matching". Even in automated driving, this solution enables reliable driving when lane markings are covered. While optical sensors cannot determine lane marking data when lane markings are covered, ground-penetrating radar is technically capable of penetrating covering layers, such as snow or dirt, and determining lane marking data despite the covering. Therefore, despite the covering of lane markings, functions related to lane markings, in particular driver assistance functions, can still be performed. Although lane markings are not optically recognizable, the driver can, for example, still be able to visualize lane markings; the driver can be warned when leaving the current lane; automatic lane changes can be performed despite covered lane markings; detected objects can be correctly associated with the lane in order to recognize dangerous scenes in time and avoid collisions; the individual trajectories can be correctly calculated without direct optical sensing of lane markings; motor vehicles or other detected traffic participants can be positioned in the lane despite covered lane markings; the entry of motor vehicles into the lane can be automatically controlled, and much more.

[0017] In an advantageous refinement of the invention, the ground-penetrating radar sensor may have a penetration depth of at least 0.5 m. For example, it is conceivable to consider at least 20 layers of different depths, for example 25 layers of different depths, during the evaluation. In this way, a sufficient amount of information for describing the structure of the surface is generated. In addition, the ground-penetrating radar sensor may be operated at a carrier frequency between 1 MHz and 1 GHz and / or at a frequency bandwidth of at least 250 MHz, in particular at least 500 MHz. In order to provide a determined penetration depth in the surface, a determined frequency range must be used. Therefore, a ground-penetrating radar sensor in the range of 1 MHz to 1 GHz carrier frequency provides the feasibility of being able to penetrate the surface. For this purpose, preferably, a specific frequency bandwidth is used that can achieve the desired distance resolution. If the penetration depth is small, a higher frequency bandwidth, for example 500 MHz, can be used to analyze the layers of the surface in a distance-resolved manner (at a small distance, for example about 20 cm). In a specific design of the present invention, it can be provided, for example, that when the distance resolution is in a range of less than 2 cm, the ground surface is scanned in layers at a distance of 2 cm until a penetration depth of 0.5 m, that is, 25 layers under the track are scanned, which enables high-resolution mapping of the ground surface.

[0018] Ground-penetrating radar sensors can be operated as pulse radars or continuous wave radars to record radar data. In general, ground-penetrating radar sensors are intended to function monostatically, that is, to send and receive radar signals via a common antenna assembly. Ground-penetrating radar sensors known today and therefore readily available are conventionally based on pulse technology, wherein at least one transmitting antenna element of the antenna assembly of the ground-penetrating radar sensor sends out a series of radar pulses, wherein at least one receiving antenna element of the antenna assembly of the ground-penetrating radar sensor detects the radar pulses reflected from the ground surface. The time between transmission and reception enables distance measurement or positioning of the individual reflections. Pulse radar technology is particularly commonly used here, since Doppler measurements (speed of movement of detected objects) do not play any role in the analysis of the ground surface.

[0019] In contrast, the use of continuous wave radar technology (Frequency Modulated Continuous Wave “FMCW”) offers the possibility of performing spectrum analysis in order to generate additional information from the spectrum. In other words, an advantageous development of the invention provides that when operating as a continuous wave radar, spectrum analysis is performed, in particular for detecting and eliminating ambiguities. This makes it easier to distinguish between different targets.

[0020] It can be particularly advantageous to provide that the ground-penetrating radar sensor is operated as a radar with a synthetic aperture, in particular when the ground-penetrating radar sensor is oriented perpendicular to the direction of travel. Thus, the generally given orthogonality (90°) between the direction of movement of the motor vehicle and the emission direction of the ground-penetrating radar sensor (forward or downward) allows the use of high-resolution SAR radar concepts (synthetic aperture radar) in order to significantly improve the angular resolution performance in the analysis of the surface. The principle of synthetic aperture is to replace the snapshot of a large antenna assembly with the recording of many small, moving antenna assemblies. Because during this movement, each reflecting object in the target area is illuminated with a changing perspective and recorded accordingly. If the path of the antenna assembly is known with sufficient accuracy and the scene - as in the case of the surface - is stationary, a larger aperture of the antenna assembly can be synthesized from the intensity and phase of the received radar signal, so that a high azimuth resolution can be achieved in the direction of movement of the antenna assembly.

[0021] In another particularly preferred embodiment of the invention, absolute, in particular geodetic and / or digital map-related position information is also assigned to the mutually associated surface data and lane marking data in the mapping database. This makes it possible to first at least roughly locate the motor vehicle itself in the mapping database so that a robust adaptation of the surface structure that can be performed in real time can be carried out. In other words, it can be provided that, based on the current position information of the motor vehicle, in particular determined by a position sensor (for example a GPS sensor), the amount of data from the database that can be used for comparison is limited to an area around the position specified by the current position information of the motor vehicle. The position sensor can in particular be a sensor of a global navigation satellite system, in particular a GPS sensor. In this way, it can be said that possible surface structures are preselected in order to significantly reduce the amount to be compared and thus obtain reliable results more quickly. In this case, the size of the area can be fixedly predetermined, but it is also conceivable to adjust the size of the area according to the error value associated with the position information, for example, a larger area is selected when the uncertainty of the position information is relatively small than in the case where the position information is known very accurately.

[0022] In this context, it may also be expedient to store a mapping database representing a large amount of data outside the motor vehicle, if necessary, and to download only the mapping data currently required (at least the surface structure data and the associated lane marking data) into the motor vehicle. In other words, it may be provided that, for a mapping database stored outside the motor vehicle, mapping data describing the area and / or describing the region including the area are retrieved as a local database for comparison. This can be done in particular via a cellular network and / or the Internet.

[0023] In this context, it should also be noted that in principle a centrally managed mapping database can be used expediently, for example on a backend device, since in this case various motor vehicles which are identical in structure at least with regard to ground-penetrating radar sensors and cameras can contribute to the construction of a mapping database which thus achieves a high degree of coverage and a high degree of accuracy. In particular, information can also be obtained for the motor vehicle itself if it has not yet passed through a road section. In the case of a preferred abstraction of the surface structure, even slightly different data can be combined without problems due to deviations in the measuring conditions.

[0024] In general, it is also particularly advantageous within the scope of the invention if, in order to determine the surface data, the surface structure described by the radar data is abstracted, in particular in a manner that reduces the amount of data, in particular a surface map is determined. For example, it can be specifically provided that only reflecting objects that meet a relevance criterion are included in the surface data, wherein the relevance criterion in particular requires a minimum size and / or a minimum reflectivity, and / or in particular the included reflecting objects are assigned to an object class by classification, in particular a crack class and / or at least one inclusion object class. In particular, the orientation of cracks in the surface, the position of air pockets in the surface and / or the position of other inclusion objects in the ground are an excellent basis for a surface map, in particular when restricted to the area around the current position of the motor vehicle, in which surface structures can be easily found by comparison, in particular by description from a local surface map, which is derived from the currently recorded radar data. In order to further appropriately reduce the amount of data, a minimum size and / or a minimum reflectivity of reflecting objects, in particular cracks and / or inclusions, can also be required.

[0025] Regardless of whether the lane marking data are determined by a camera or from a mapping database, the lane marking data can be used as is basically known in the prior art. Thus, for example, it is conceivable to evaluate the current lane marking data for determining the lane width and / or lane width and / or number of lanes and / or lane assignment of the motor vehicle and / or at least one other traffic participant. Furthermore, the lane marking data can be evaluated by and / or for at least one vehicle system, in particular a driver assistance system and / or a vehicle system that is configured to be at least partially automatically guided. With regard to the advantages of the invention, corresponding examples have already been described in more detail.

[0026] In addition to the method, the invention also relates to a motor vehicle having a camera, at least one ground-penetrating radar sensor and a control device set up to implement the method according to the invention. All embodiments of the method according to the invention can be applied analogously to the motor vehicle according to the invention, whereby the advantages already mentioned can also be achieved by the motor vehicle according to the invention. The control device can be in particular a controller, in particular a controller assigned to at least one vehicle system, for example a driver assistance system. The controller can in particular be the controller of a so-called central driver assistance system, in which the functions of several driver assistance systems are combined. The control device can have: at least one processor, which implements functional units suitable for implementing the method according to the invention; and / or storage means, in particular for a mapping database and / or a local database. Furthermore, within the scope of the invention, the term camera is to be understood in a broad sense as an imaging optical sensor, so that in particular an imaging lidar sensor can also be used as a camera. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Further advantages and details of the invention emerge from the exemplary embodiments described below and with reference to the drawings.

[0028] in:

[0029] Figure 1 shows a schematic diagram of a motor vehicle according to the invention on a surface on which it is travelling,

[0030] Figure 2 A schematic diagram showing the working mode of the method according to the invention, and

[0031] Figure 3 A schematic diagram of a motor vehicle according to the invention is shown. DETAILED DESCRIPTION

[0032] Figure 1 The schematic diagram of a motor vehicle 1 according to the invention is shown, which is driven on a surface 2, here a roadway 3. The motor vehicle is located in a lane marked by lane markings 4. To detect the lane markings 4, the motor vehicle 1 has a camera 5 as an imaging optical sensor device, which is directed toward the front area of ​​the motor vehicle and can be mounted, for example, behind a windshield 6 of the motor vehicle 1.

[0033] In the present case, at least one of lane markings 4 is covered by a layer 7 , for example a layer of snow, dirt or leaves, so that the lane marking cannot be detected in the image data of camera 5 .

[0034] For this case, the motor vehicle 1 in this case also has two ground-penetrating radar sensors 8, whose detection range 9 points vertically downward. In this case, each of the ground-penetrating radar sensors 8 is operated at a carrier frequency in the range of 1 MHz to 1 GHz at a frequency bandwidth of 500 MHz so that a penetration depth of 0.5 m is obtained. In addition, due to the high frequency bandwidth, a very high distance resolution is also achieved, in particular less than 2 cm. In the case of the ground-penetrating radar sensor 8 pointing downward and therefore perpendicular to the direction of movement of the motor vehicle 1 (which is usually forward, but in any case horizontal), the principle of synthetic aperture is also used to increase the angular resolution, that is, the radar signals of the continuously recorded reflecting objects can be taken into account together to generate an enlarged virtual aperture.

[0035] Here, at a penetration depth of 0.5 m, a division into 50 2 cm layers can be performed, in which the ground surface 2 can be mapped, which is indicated by the dotted mapping area 10. By classifying and abstracting the reflective objects with relevant criteria, in particular the smallest size and / or the lowest reflectivity, the radar data of the ground-penetrating radar sensor 8 can be evaluated to form surface data describing the surface structure of the ground surface 2. In the end, a newly recorded local surface map is thus created.

[0036] The ground penetrating radar sensor 8 can be operated as a pulse radar or a continuous wave radar. The use of pulse radar is common for ground penetrating radar sensors 8 and takes advantage of the fact that Doppler information on velocity is not required. However, the use of continuous wave radar technology enables spectral analysis, which can resolve ambiguities and provide additional information if necessary.

[0037] The surface structure data can now be used in motor vehicle 1 to determine the presence and relative position of lane markings 4 , either for a plausibility check and / or to increase robustness in the case of lane markings 4 that are optically recognizable anyway, or for determining the presence and position of lane markings 4 even if they are not optically recognizable, for example due to layer 7 .

[0038] For this purpose, a mapping database stored in or outside the motor vehicle 1 is accessed, which contains mutually associated terrain structure data and lane marking data together with the respective assigned position information, here the geodetic position. In other words, the mapping database mainly includes a surface map with a wide coverage as an overall map. If now, based on the position information of the motor vehicle 1 determined by means of the position sensor 11 of the motor vehicle 1, a relevant local area is selected from the mapping database (this can be achieved based on the position information of the ground), then the currently measured surface structure, that is, the local surface map as a map part in particular, can be compared with the surface structure of the area, that is, the larger surface map, so that the motor vehicle 1 can be positioned within the larger surface map and the correct lane marking data can be obtained as lane marking data associated with a consistent surface structure. Obviously, lateral offsets can also be taken into account here.

[0039] In this case, the mapping database can be determined by the motor vehicle 1, more precisely by a motor vehicle of identical construction with respect to the camera 5 and the ground-penetrating radar sensor 8, when previously driving over the lane 3, wherein the lane markings 4 can be optically detected at this point in time. In particular, a fleet of motor vehicles can be used to generate a mapping database, which can then be compiled on an external backend device, wherein the mapping data of at least the region of the area can be transmitted as a local database to the motor vehicle 1. Due to the abstraction of the surface structure and the limitation to the surrounding area of ​​the current position of the motor vehicle, a relatively small amount of data is obtained.

[0040] Figure 2 The idea underlying the invention is explained in a simple schematic diagram. A mapping database 12 is provided so that a comparison with current surface data 14, in particular a local surface map, in step 13 can find consistent surface structures from the mapping database 12. Correct, associated current lane marking data 15 are then derived from this.

[0041] As is known, the lane marking data 15 can be further evaluated, for example, in order to determine a lane width, a lane width, the number of lanes and / or at least one lane assignment. The corresponding information can be evaluated, for example, by a corresponding vehicle system, in particular a driver assistance system and / or a vehicle system configured to at least partially automatically guide the motor vehicle 1.

[0042] in this regard, Figure 3 The functional principle diagram of a motor vehicle 1 according to the invention is shown. In addition to the camera 5, the ground-penetrating radar sensor 8 and the position sensor 11, the motor vehicle 1 also has a control device 17 designed as a controller 16, which is designed to carry out the method according to the invention, namely in particular to compare currently determined surface data 14 with the surface structure in the mapping database 12 in order to determine corresponding lane marking data 15, in particular when lane markings 4 cannot be detected optically by the camera 5. The lane marking data can then be provided to further vehicle systems 18, in particular at least one driver assistance system 19 and / or at least one vehicle system 20 designed to guide the motor vehicle 1 fully automatically.

Claims

1. A method for locating lane markings (4) in a motor vehicle (1), wherein: The motor vehicle (1) has a camera (5), the image data of which are evaluated to form lane marking data which specify the presence and position of lane markings (4). It is characterized in that Also using at least one ground-penetrating radar sensor (8) of the motor vehicle (1) directed toward the surface (2) on which the vehicle is traveling, radar data of the ground-penetrating radar sensor are evaluated to determine surface data describing the surface structure of the surface (2) on which the vehicle is traveling, wherein lane marking data and surface data associated with the same recording location indicating the presence of lane markings (4) are stored in association with one another in the mapping database, wherein at least when a ground covering covering the lane markings (4) is identified, the current surface structure is compared with at least a portion of the surface structure of the database with the aid of the surface data, and in the event of a match, the lane marking data associated with the surface data of the matching surface structure are used, In order to determine the surface data, the surface structure described by the radar data is abstracted to determine a surface map.

2. The method according to claim 1, characterized in that A ground covering that obscures the lane markings (4) is detected in the camera data.

3. The method according to claim 1, characterized in that The ground-penetrating radar sensor (8) has a penetration depth of at least 0.5 m and / or is operated with a carrier frequency between 1 MHz and 1 GHz and / or with a frequency bandwidth of at least 250 MHz.

4. The method according to claim 1, characterized in that: The ground penetrating radar sensor (8) operates at a frequency bandwidth of 500 MHz.

5. The method according to any one of claims 1 to 4, characterized in that The ground-penetrating radar sensor (8) is operated as a pulse radar or a continuous wave radar to record the radar data.

6. The method according to any one of claims 1 to 4, characterized in that When the ground-penetrating radar sensor (8) is oriented perpendicularly to the direction of travel, the ground-penetrating radar sensor (8) is operated as a radar with a synthetic aperture.

7. The method according to any one of claims 1 to 4, characterized in that In the mapping database (12), absolute position information and / or position information related to a digital map are assigned to the mutually associated surface data and lane marking data.

8. The method according to claim 7, characterized in that Based on current position information of the motor vehicle (1), the amount of data from the database used for the comparison is limited to a region around the position specified by the current position information, which is determined by a position sensor (11) of the motor vehicle (1).

9. The method according to claim 8, characterized in that For a mapping database (12) stored outside the motor vehicle, mapping data describing the area and / or a region including the area are retrieved as a local database for comparison.

10. The method according to any one of claims 1 to 4, characterized in that: The surface structure described by the radar data is abstracted in such a way as to reduce the amount of data.

11. The method according to claim 10, characterized in that Only reflective objects that meet relevance criteria are included into the surface data, wherein the relevance criteria are requiring a minimum size and / or a minimum reflectivity, and / or by assigning object classes to the included reflective objects through classification, wherein the object classes are fracture classes and / or inclusion object classes.

12. The method according to any one of claims 1 to 4, characterized in that The current lane marking data are evaluated to determine a lane width and / or a lane width and / or a number of lanes and / or a lane assignment for the motor vehicle (1) itself and / or for at least one other road user.

13. The method according to any one of claims 1 to 4, characterized in that The lane marking data are evaluated by and / or for at least one vehicle system (18), the at least one vehicle system being a driver assistance system (19) and / or a vehicle system (20) designed to be at least partially automatically guided.

14. The method according to any one of claims 1 to 4, characterized in that In order to generate a mapping database (12), surface data and lane marking data are determined during at least one trip using the motor vehicle and / or at least one motor vehicle (1) of identical construction, and lane marking data and surface data indicating the presence of lane markings (4) associated with the same recording location are stored in the mapping database (12) in association with each other.

15. A motor vehicle (1) having a camera (5), at least one ground-penetrating radar sensor (8) and a control device (17) designed to carry out the method according to any one of claims 1 to 14.

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