Radar-reflective road marking

Abstract

The present invention relates to a road marking (10) for a road (12), wherein the road marking (10) comprises at least one radar reflection layer (30) provided on the road (12). Furthermore, the present invention relates to a road marking system and to a method for producing a road marking (10).

Description

[0001] RWTH Aachen University, RWTH Ref.: 2798 abbreviated RWTH Aachen, public corporation SRLTG Ref.: 69233P DE

[0002] Radar-reflective road markings

[0003] Technical field

[0004] The present disclosure relates to a road marking. Furthermore, the disclosure relates to a road marking system and a method for producing a road marking.

[0005] State of the art

[0006] Road markings serve to coordinate traffic flow on roads and to inform drivers and other road users. For example, road markings act as traffic signs and delineate lanes, carriageways, parking spaces, hard shoulders, and other traffic areas. Vehicles with automated or autonomous driving functions also process information from road markings. For this to work, a sensor system in the vehicle must detect and interpret the road markings. This information is typically captured using only optical sensors, such as a camera and / or a LiDAR sensor. However, optical detection is hampered by adverse lighting conditions, precipitation, and other environmental factors.

[0007] Conventional radar reflectors, due to their size and small radar cross-section at shallow angles of incidence, are suitable for vertical signs and guideposts. However, they are unsuitable as road markings because they can obstruct the roadway and are easily damaged or worn down by vehicles driving over them.

[0008] EP 3 276 748 A1 describes a radar reflection band. This reflection band features individual radar-reflecting antennas spaced apart from one another in a band. The reflection band is complex and expensive to manufacture. RWTH Aachen University, Ref.: 2798 (abbreviated RWTH Aachen)

[0009] Public corporation SRLTG Ref.: 69233P DE

[0010] Description of the invention

[0011] A first aspect concerns road markings. Road markings can provide information for traffic guidance and / or traffic control. For example, they can define the edge of the roadway. Road markings can be designed as lane markings. They can delineate a hard shoulder, a parking area, and / or different lanes. Road markings can also serve as traffic signs, indicating speed limits, pedestrian crossings, navigation information, and warnings. The road itself can be a highway, motorway, parking area, or other type of traffic surface. The road surface can be made of asphalt, concrete, or paving stones. Road markings can be applied directly or indirectly to the road surface.Road markings can be designed as essentially two-dimensional markings. They can form an additional layer in a section of the road, for example, applied to the top surface of a road pavement. Road markings can also be integrated as horizontal markings on a traffic surface.

[0012] The road marking has at least one radar-reflective layer, which can be arranged or is already present on the road. This radar-reflective layer can be designed to be detected by a radar sensor. The radar sensor can operate, for example, in the millimeter-wave range (30-300 GHz) common for automotive radars. The radar-reflective layer can be distinguished from other road surfaces, such as asphalt, by the radar sensor. Thus, the radar sensor can detect, for example, the shape of the road marking or at least the presence of the radar-reflective layer in a specific area of ​​the road. Alternatively or additionally, the radar sensor can also detect other factors, such as the orientation and type of radar-reflective layer, thereby providing additional information about the road marking.The reflective layer can be completely or partially replaced by other components of the Rheinisch-Westfälische Technische Hochschule Aachen, RWTH-Ref.: 2798 abbreviated RWTH Aachen,.

[0013] Public corporation SRLTG Ref.: 69233P DE

[0014] The road marking may be covered. The road marking can, for example, be designed as a radar marking. The road marking may only be detectable by a radar sensor. However, the road marking can also function as other types of marking, such as optical or acoustic markings. In this case, the road marking may also be detectable by the human eye or by other sensors, such as an optical sensor. The reflective layer can have a planar extent. The reflective layer can be formed by a single element, such as a metal foil. The reflective layer can also be formed by several elements, which may be adjacent to each other or spaced apart. The multiple elements can have different or identical spatial configurations.The reflective layer can be provided along the entire length of the road marking or only in a partial area.

[0015] The radar reflection layer can be designed to reflect radar beams back to the radar sensor more strongly than other surfaces and / or road markings without the radar reflection layer. This applies particularly to radar beams emitted by a vehicle's radar sensor on the road, which therefore arrive at a greater distance and at a shallow angle. Other explanations regarding radar reflection also apply to this situation, where applicable. The radar reflection layer can be optimized for detection by one or more specific radar systems or for a specific wavelength range. The radar reflection layer can be designed as a radar reflection enhancement layer. The radar reflection layer can form a radar-readable or radar-detectable component of the road marking.

[0016] The radar reflective layer can be integrated into conventional road markings. This layer can be a continuous piece, for example, a film or metal plate. This allows for cost-effective production and application of the road marking. Furthermore, its traffic resistance can be comparable to that of conventional road markings without a radar reflective layer, making the road marking robust and durable. (Rheinisch-Westfälische Technische Hochschule Aachen, RWTH-Ref.: 2798 abbreviated RWTH Aachen)

[0017] Public corporation SRLTG Ref.: 69233P DE

[0018] Road markings, such as optical, acoustic, or haptic markings, can be replaced or supplemented by radar-readable properties. The radar-reflective layer allows the marking to be equipped with radar-readable properties in addition to its optical, acoustic, and / or haptic properties, as well as its grip characteristics, without compromising the durability of the marking or its optical, acoustic, and / or haptic properties compared to conventional road markings. This road marking can significantly improve the reliability of road marking detection by vehicles with automated or autonomous driving functions. Furthermore, it enables the use of radar sensors in vehicles for detecting road markings even under challenging conditions and provides redundancy for optical detection.Sensor fusion for detecting road markings can significantly improve functional safety and detection quality. This ensures that automated vehicles are reliably provided with all necessary information from an infrastructure perspective.

[0019] The road marking can be designed to retain its radar readability under the stress of tire contact. Furthermore, the road marking can be designed to prevent a greater loss of its optical properties under the stress of tire contact than is the case with a marking system without a radar-reflective layer.

[0020] In one embodiment of the road marking, the radar reflector layer may have a profile. This profile can be formed by a spatial deviation of the radar reflector layer in its extent, for example, by deviations in a vertical direction. The vertical direction can be defined as orthogonal to a road surface or by a vertical direction. For example, the radar reflector layer may be positioned higher or lower in the road marking in certain areas. The radar reflector layer may also be thicker or thinner in certain areas. The reflector layer may have peaks and valleys. It may also have elevations and depressions. One profile shape can be used for enhanced reflection of radar beams. (RWTH Aachen University, Ref.: 2798, abbreviated RWTH Aachen)

[0021] The radar cross-section may be designed by a public corporation (SRLTG Ref.: 69233P DE). For example, the profile shape may be tailored to one or more typical wavelengths of vehicle radar sensors and / or to a typical beam angle range of vehicle radar sensors. For example, the protrusions and recesses may be designed such that radar beams incident at a shallow angle onto the radar cross-section are reflected back to the transmitter and thus to the radar sensor to a particularly large extent. For example, the radar cross-section may have an effective reflecting area (radar cross-section) that is more than 20, 30, 40, or even 50 times larger than an area perpendicular to the radar beam.

[0022] For example, the radar reflective layer can have a height of up to 7 mm, in particular up to 4 mm or 3 mm. The thickness of the radar reflective layer can, for example, be up to 2 mm, in particular up to 1 mm, 0.1 mm, or even only up to 0.05 mm. The desired reflection behavior can still be achieved. The road marking can have a total thickness and / or height of, for example, at least 4 mm, in particular at least 5 mm, with additional layers. The total thickness and / or height of the road marking can, for example, be from 5 mm to 10 mm. For example, the thickness of the road marking can be 7 mm or 10 mm, with conventional road markings also typically being 7 mm thick, or 10 mm if the road marking has special acoustic properties.Despite the radar-reflective coating having a profile, the road marking can have a substantially flat top and / or bottom surface. Alternatively, the road marking can have a textured top and / or bottom surface whose structure differs substantially from that of the radar-reflective coating profile. This can, for example, provide acoustic and / or tactile guidance or increase skid resistance. The bottom surface can face the road and be bonded to it. The top surface can face away from the road and form the outer surface of the road marking. Additional layers can be provided for the flat top and / or bottom surface. Layers on the top surface can have high radar transmittance, allowing for good reflection from the radar-reflective coating profile. RWTH Aachen University, Ref.: 2798.

[0023] Public corporation SRLTG Ref.: 69233P DE

[0024] The profile of the radar reflection layer can have a periodic pattern. A periodic spacing and / or amplitude or height of the profile can be adapted to the radar beams, for example, their wavelength. This allows a large radar cross-section to be achieved even at small angles of incidence.

[0025] In one embodiment of the road marking, the profile may be rectangular, sinusoidal, triangular, cylindrical, or trapezoidal. For example, the radar reflection layer may have a sinusoidal height profile along its extent within the road marking. The overall extent of the radar reflection layer may be parallel to the road surface. These shapes may be particularly suitable for reflecting radar beams back to vehicles. Only a small vertical extent of the radar reflection layer may be required. For example, the overall height of the road marking may correspond to the typical height of conventional road markings.

[0026] In one embodiment of the road marking, the radar reflective layer may have a first section and a second section with different profiles. The radar reflective layer can have multiple sections with different profiles. This allows the radar reflective layer to be adapted to different radar sensors and / or different angles of incidence. For example, one section may be optimized for reflecting radar beams of one wavelength, and another section for reflecting radar beams of a different wavelength. For instance, the road marking may delineate a hard shoulder, with one section optimized for reflecting radar beams from more distant vehicles and another section optimized for reflecting radar beams from vehicles located nearby.The radar beams then strike the plane of the road from different angles, and the various sections can be aligned accordingly. For example, in this case, the radar reflection layer can have a first strip running lengthwise along the shoulder boundary, which essentially reflects radar beams from the longitudinal direction back towards the origin. A second strip, parallel to this or arranged in series, can essentially reflect radar beams from the Rheinisch-Westfälische Technische Hochschule Aachen, RWTH-Ref.: 2798 abbreviated RWTH Aachen.

[0027] Public corporation SRLTG-Ref.: 69233P DE reflects orthogonally to the longitudinal direction back to the origin. This ensures good detection even with different relative positions of the vehicle to the road marking.

[0028] In one embodiment of the road marking, the profile of the first section may be oriented differently from the profile of the second section. For example, a sinusoidal shape of the reflective layer in a first section may run parallel to the longitudinal extent of the road marking in the road plane, and in a second section transversely, and in particular orthogonally, to the longitudinal extent of the road marking in the road plane. This ensures good reflection even with different incident directions of radar beams in the road plane. The road plane may be defined by the surface of the road.

[0029] In one embodiment of the road marking, the profile of the first section may be designed to reflect a first type of radar beam, and the profile of the second section may be designed to reflect a second type of radar beam, which differs from the first type, for example, by its frequency spectrum. The type of radar beam may differ, for example, by its wavelength, wavelength dispersion, and / or power. The profile may be adapted accordingly, for example, in its shape, periodicity, and / or spacing of peaks and valleys.

[0030] In one embodiment of the road marking, the radar reflective layer may be made of an electrically conductive material with high electrical permittivity, such as aluminum. Alternatively or additionally, the radar reflective layer may be made of a metallic material. In particular, the radar reflective layer may consist of an electrically conductive material with high electrical permittivity and / or a metallic material. The radar reflective layer may have a smooth surface on its upper and / or lower sides. The radar reflective layer may have a high density. The radar reflective layer may, for example, be solid. This can result in particularly good reflection of radar beams. RWTH Aachen University, Ref.: 2798 (abbreviated RWTH Aachen), a public corporation, SRLTG Ref.: 69233P DE

[0031] In one embodiment of the road marking, the road marking may include a bonding layer located between the radar-reflective layer and the road surface. This bonding layer may be located on the underside of the radar-reflective layer. It may be an adhesive layer, for example, made of a two-component adhesive. The bonding layer may connect the road marking to the road surface. It may also support the radar-reflective layer from below, for example, by embedding the underside of the radar-reflective layer within the bonding layer. The bonding layer may, for example, fill a structure on the underside of the radar-reflective layer's profile. It may prevent or reduce permanent deformation of the radar-reflective layer caused by vehicles driving over it.The bonding layer allows for easy and particularly robust application of the road markings. This layer can extend laterally beyond the radar-reflective layer, for example, by at least 15 mm or 20 mm. This ensures a highly reliable bond between the radar-reflective layer and the road surface, and also reliably prevents the lateral penetration of foreign objects and liquids, such as stones or water, beneath the radar-reflective layer. The bonding layer can consist of one or more layers and components. The road markings themselves can be free of any additional layers between the road and the radar-reflective layer. The road markings can be incorporated into the road surface during construction or applied to the surface.

[0032] In one embodiment of the road marking, the road marking may have a top layer arranged on the side of the radar reflective layer facing away from the road. The top layer may be arranged on the upper surface of the radar reflective layer. For example, the top layer may form the upper surface of the road marking. The top layer may have one or more layers. The top layer may have multiple components. The road marking may be free of any further layers above the radar reflective layer. The road marking may be free of any further layers on the surface of the road marking. (Rheinisch-Westfälische Technische Hochschule Aachen, RWTH-Ref.: 2798 abbreviated RWTH Aachen)

[0033] Public corporation SRLTG-Ref.: 69233P DE on the side of the radar reflective layer facing away from the road. The radar reflective layer can alternatively also form the uppermost layer of the road marking. For example, the road marking can consist of the bonding layer, radar reflective layer and surface layer. Alternatively, the road marking can consist only of the radar reflective layer or of the radar reflective layer and either the bonding layer or the surface layer.

[0034] The surface layer can also serve an optical, grippy, acoustic, and / or haptic road marking function. For this purpose, reflective beads and / or grip agents can be embedded in the surface layer. The surface layer can, for example, have a textured surface. The surface layer can contain grip agents to improve tire adhesion. The surface layer can, for example, produce a humming or whistling sound when tires roll over it. The surface layer can also cause a vibration in a passing vehicle. The surface layer can have a substantially smooth and / or flat surface. The surface layer can protect the radar reflector layer from damage caused by passing vehicles. For example, the radar reflector layer can be embedded in the surface layer.The top layer can, for example, fill a surface structure within the profile of the radar reflector layer. The top layer can prevent or reduce permanent deformation of the radar reflector layer caused by vehicles rolling over it or by the edges of snowplows.

[0035] The surface layer can extend laterally beyond the radar reflection layer, for example by at least 15 mm or 20 mm. This allows the radar reflection layer to be particularly reliably protected from the stresses of traffic and winter maintenance and to be reliably encapsulated in other layers. The surface layer can, for example, be essentially transparent to radar beams. The surface layer can, for example, reflect and / or absorb radar beams to a significantly lesser extent than the radar reflection layer and / or the road. For example, the reflection of radar beams by the radar reflection layer can be one magnitude greater than by the surface layer. The surface layer can, for example, be made of the same material and be the same as the surface layer. (Rheinisch-Westfälische Technische Hochschule Aachen, RWTH-Ref.: 2798 abbreviated RWTH Aachen)

[0036] Public corporation SRLTG-Ref.: 69233P DE have the same structure as the top layer of a conventional road marking.

[0037] A second aspect concerns a road marking system. This road marking system features the road marking described in the first aspect. Further features, embodiments, and advantages are described in the first aspect. Conversely, features, embodiments, and advantages of the second aspect also represent features, embodiments, and advantages of the first aspect.

[0038] The road marking system can include the road itself, on which the road markings are applied. The road may, for example, have a top layer of asphalt, concrete, or paving stones with which road users come into contact and to which the road markings are attached, for example, by adhesive bonding.

[0039] Alternatively or additionally, the road marking system can include a vehicle radar sensor designed to detect radar beams reflected by the radar reflective coating. The radar sensor can be configured to distinguish between the road and the road marking. The radar beams can be emitted by a radar system of the vehicle that incorporates the radar sensor.

[0040] A third aspect concerns a method for producing a road marking, in particular a road marking according to the first aspect or as part of the second aspect. Further features, embodiments, and advantages of each aspect are described in the first and second aspects. Conversely, features, embodiments, and advantages of the third aspect also represent features, embodiments, and advantages of the first and second aspects, respectively.

[0041] The process includes a step involving the application of a radar-reflective coating to a road surface. The application of the radar-reflective coating can also be part of a step involving the application of road markings. The application can be carried out, for example, by Rheinisch-Westfälische Technische Hochschule Aachen, RWTH-Ref.: 2798, abbreviated RWTH Aachen.

[0042] Public corporation SRLTG-Ref.: 69233P DE through a nozzle. During application, the radar reflective coating can, for example, be unrolled from a roll. The same equipment and vehicles used for applying conventional road markings without a radar reflective coating can be used for application, provided that these devices and vehicles have been adapted for applying the radar reflective coating, if necessary.

[0043] In one embodiment of the method, the process includes a step of applying a bonding layer between the radar-reflective coating and the road surface. The bonding layer can be applied simultaneously with the radar-reflective coating. Alternatively, the bonding layer can be applied before the radar-reflective coating. For example, the bonding layer can be applied as a viscous mass and cured only after the radar-reflective coating has been applied. The bonding layer can be partially cured before the radar-reflective coating is applied, or curing can begin only after the coating has been applied.

[0044] In one embodiment of the method, a step is provided for applying a top layer to the side of the radar reflective layer facing away from the road. The top layer can be applied simultaneously with the radar reflective layer. The top layer can also be applied after the radar reflective layer. For example, the top layer can be applied as a viscous mass and applied and / or cured only after the bonding layer has cured. The top layer can also be cured together with the bonding layer. The top layer and the bonding layer can also be applied as films or form another type of finished layer upon application. For example, the road marking can be provided as a prefabricated layer package, which is bonded to the road, for example, by pressing it onto the road surface.

[0045] Brief description of the characters: Rheinisch-Westfälische Technische Hochschule Aachen, RWTH-Ref.: 2798 abbreviated RWTH Aachen,

[0046] Public corporation SRLTG Ref.: 69233P DE

[0047] Fig. 1 illustrates a road marking system in a schematic top view.

[0048] Fig. 2 schematically illustrates a road marking in a sectional view.

[0049] Fig. 3 schematically illustrates a method for producing the

[0050] Road marking.

[0051] Fig. 4 schematically illustrates in a top view the profile of a radar reflection layer of the road marking.

[0052] Detailed description of embodiments

[0053] Fig. 1 schematically illustrates a road marking system in a top view. The road marking system comprises several road markings 10, which define a carriageway or lane on a road 12. In one embodiment, the road 12 also forms part of the road marking system. The road 12 with one of the road markings applied to it is illustrated in a sectional view in Fig. 2.

[0054] A motor vehicle 14 is traveling on road 12. The motor vehicle 14 has a radar sensor 16 which emits radar beams 18 from its front. The emitted radar beams 18 strike road 12 and the road markings 10 at a small angle of incidence 22. Nevertheless, the emitted radar beams 18 are reflected at least partially back to the radar sensor 16 by the road markings 10. The reflection to the radar sensor 16 occurs to an extent necessary for detection. Road 12 does not reflect the emitted radar beams 18, or only to a comparatively very small extent. The radar sensor 16 is designed to receive the reflected radar beams 20 and thus detect the road markings 10 against the background of road 12. The motor vehicle 14 has a control device 24 which is designed to control the motor vehicle 14 depending on the detected road markings 10.For example, the control device 24 is designed to automatically or autonomously follow the roadway marked by the road markings 10 while driving. Optionally, the motor vehicle 10 has one or more optical detection devices, which are also designed to detect the road markings 10. The reliability of the automated or autonomous control can then be increased by sensor fusion. In one embodiment, the radar sensor 16 or even the entire motor vehicle 14 also forms part of the road marking system.

[0055] A layered structure of the road marking 10, designed to be detectable from the road 12 by the radar sensor 16, is illustrated in Fig. 2. The road marking 10 has a radar reflective layer 30. The radar reflective layer 30 is formed by an electrically conductive metallic material with high electrical permittivity, such as aluminum. Furthermore, the radar reflective layer 30 has a profile for enhanced reflection of the emitted radar beams 18. The profile is sinusoidal here, but in other embodiments it can also be rectangular, triangular, cylindrical, or trapezoidal. The profile has, for example, a periodic pattern as shown here. Thus, despite the small angle of incidence 22, the emitted radar beams 18 are reflected back to the emitting radar sensor 16 to a high degree, as schematically illustrated in Fig. 2.

[0056] In the example shown, the profile of the radar reflective layer 30 extends along the roadway. The peaks and valleys of the profile thus follow one another in the direction of travel. The radar reflective layer 30 extends uniformly in the transverse direction to the direction of travel on the roadway. This is schematically illustrated in Fig. 4, which shows a top view of the road marking 10. The solid lines represent the low points, and thus the vertices, of the valleys in the profile, and the dashed lines represent the high points, and thus the vertices, of the peaks in the profile. In the example shown, these extend as straight lines, for instance, perpendicular to one direction of travel on the roadway of the road 10.

[0057] In further embodiments, the radar reflection layer 30 has a first section and a second section with differently shaped profiles. RWTH Aachen University, Ref.: 2798 (abbreviated RWTH Aachen)

[0058] Public corporation SRLTG Ref.: 69233P DE

[0059] For example, the first section points in the described direction, and the second section is rotated by 45° or 90° on road 12, causing the profiles in the two sections to differ in their orientation. This allows the first section to effectively reflect radar beams from a more distant radar sensor 16, which then strike the radar reflection layer 30 in the direction of travel. The second section can effectively reflect radar beams from a radar sensor 16 located closer in the direction of travel, which then strike the radar reflection layer 30 perpendicular to the direction of travel. Thus, the profile can be aligned with a specific direction of radar beam incidence. The first and second sections can be connected or formed by separate parts.

[0060] Alternatively or additionally, the two sections can have different profile shapes. For example, the first section can be sinusoidal, as shown, and the second section can have a rectangular profile. Alternatively or additionally, the distance between the high and low points of the profile can differ between the two sections. The profile of the first section can thus be designed to reflect a first type of radar beam, and the profile of the second section to reflect a second type of radar beam, which differs from the first type in its frequency spectrum.

[0061] The radar reflective layer 30 is connected to the road 12 via a bonding layer 32 of the road marking 10. The bonding layer 32 is designed as a two-component adhesive. The bonding layer 32 is positioned between the radar reflective layer 30 and the road 12. The bonding layer 32 thus supports the radar reflective layer 30 from below, completely or almost completely filling any raised and recessed areas of the profile on the side facing the road 12. This prevents permanent deformation of the radar reflective layer 30 by vehicles driving over it and reduces elastic deformation.

[0062] The road marking 10 also has a surface layer 34. The surface layer 34 is located on the side of the radar reflection layer 30 facing away from the road 12. The surface layer 34 forms a surface facing away from the road 12 and thus the outermost [Rhenish-Westphalian Technical University of Aachen, RWTH-Ref.: 2798 abbreviated RWTH Aachen, public corporation SRLTG-Ref.: 69233P DE]

[0063] The surface of the road marking 10 is shown. In the illustrated embodiment, the top layer 34 is white and thus also provides an optical road marking function similar to conventional road markings. The top layer also includes reflective beads and / or anti-slip agents. The radar reflection layer 30 is embedded in the top layer 34, as in the bonding layer 32. The radar reflection layer 30 completely or almost completely fills the respective protrusions and depressions of the profile on the side facing away from the road 12. The top layer 34 protects the radar reflection layer 30 from damage caused by vehicles driving over it. The top layer 34 is essentially transparent to the emitted radar beams 18.

[0064] As indicated in Fig. 4, the radar reflection layer 30 extends only to approximately 20 mm in front of an edge of the road marking 10 in the plane of the road 12. Accordingly, the top layer 34 and the bonding layer 32 are in direct contact with each other in an edge region of the road marking 10 that is free of the radar reflection layer, as shown in Fig. 2. The radar reflection layer 30 is thus completely encapsulated.

[0065] Fig. 3 illustrates a method for producing the road marking 10. In step 50, the bonding layer 32 is applied to the road 12, so that the bonding layer 32 of the finished road marking 10 is located between the radar reflective layer 30 and the road 12. In step 52, the radar reflective layer 30 is applied to one side of the bonding layer 32 facing away from the road 12. In step 54, the top layer 34 is applied to the other side of the radar reflective layer 30 facing away from the road.

[0066] The various layers 30, 32, 34 can be provided as a pre-assembled layer package before being applied to road 12, for example, on a roll. Layers 30, 32, 34 are thus applied together, while steps 50, 52, 54 are carried out before application to road 12 and / or simultaneously. The road marking 10 is then, for example, simply affixed to road 12 by pressing it down. The underside of the layer package or road 12 can be bonded, for example, with an adhesive, primer, and / or other bonding material. (RWTH Aachen University, Ref.: 2798, abbreviated RWTH Aachen)

[0067] Public corporation SRLTG-Ref.: 69233P DE. Alternatively, for example, a material of the bonding layer 32 can first be applied as a viscous mass. The radar reflection layer 30 is then pressed onto it. Curing then takes place, forming the finished bonding layer 32 and holding the radar reflection layer 30 in place. The top layer 34 can be applied before, after, or during the curing of the bonding layer 32. The top layer can, for example, also be applied as a viscous mass, with the finished top layer 34 being formed by subsequent curing.

[0068] RWTH Aachen University, Ref.: 2798, abbreviated RWTH Aachen

[0069] Public corporation SRLTG Ref.: 69233P DE

[0070] Reference sign

[0071] 10 road markings

[0072] 12th Street

[0073] 14 Motor vehicle

[0074] 16 radar sensor

[0075] 18 emitted radar beams

[0076] 20 reflected radar beams

[0077] 22 small angle of incidence

[0078] 24 Control device

[0079] 30 Radar reflection layer

[0080] 32 Compound layer

[0081] 34 Top layer

[0082] Step 50: Applying the connection layer

[0083] Step 52: Applying the reflective layer

[0084] Step 54: Applying the top coat

Claims

RWTH Aachen University, Ref.: 2798, abbreviated RWTH Aachen Public corporation SRLTG Ref.: 69233P DE Patent claims 1. Road marking (10) for a road (12), wherein the road marking (10) has at least one radar reflective layer (30) arranged on the road (12).

2. Road marking (10) according to claim 1, the radar reflection layer (30) having a profile, in particular wherein a shape of the profile is designed for enhanced reflection of radar beams (18).

3. Road marking (10) according to claim 2, wherein the profile is rectangular, sinusoidal, triangular, cylindrical or trapezoidal.

4. Road marking (10) according to claim 2 or 3, wherein the radar reflection layer (30) has a first section and a second section whose profile is configured differently, in particular wherein the profile of the first section is oriented differently from the profile of the second section and / or wherein the profile of the first section is designed to reflect a first type of radar beams (18) and the profile of the second section is designed to reflect a second type of radar beams (18) which differs from the first type of radar beams (18).

5. Road marking (10) according to one of the preceding claims, wherein the radar reflection layer (30) is formed from an electrically conductive material with high electrical permittivity, such as aluminium and / or wherein the radar reflection layer (30) is formed from a metallic material. RWTH Aachen University, Ref.: 2798, abbreviated RWTH Aachen Public corporation SRLTG Ref.: 69233P DE 6. Road marking (10) according to one of the preceding claims, wherein the road marking (10) has a connecting layer (32) which is arranged between the radar reflection layer (30) and the road (12), in particular wherein the connecting layer (32) connects the road marking (10) to the road (12) and / or wherein the connecting layer (32) supports the radar reflection layer (30) from below.

7. Road marking (10) according to one of the preceding claims, wherein the road marking (10) has a cover layer (34) which is arranged on a side of the radar reflection layer (30) facing away from the road (12), in particular wherein the cover layer (34) provides an optical, acoustic and / or haptic road marking function and / or wherein the cover layer (34) protects the radar reflection layer (30) from damage caused by vehicles driving over it.

8. Road marking system comprising a road marking (10) according to one of the preceding claims and a road (12) on which the road marking (10) is applied, and / or a radar sensor of a vehicle (14) which is designed to detect radar beams (20) reflected by the radar reflection layer (30).

9. Method for producing a road marking (10), in particular a road marking (10) according to any one of claims 1 to 7, wherein the method comprises the following step: - Applications (52) of a radar reflective layer (30) to a road (12).

10. The method of claim 9, wherein the method further comprises at least one of the following steps: RWTH Aachen University, Ref.: 2798, abbreviated RWTH Aachen Public corporation SRLTG Ref.: 69233P DE - Orders (50) of a connection layer (32) between the radar reflective layer (30) and the road (12); and - Applications (54) of a surface layer (34) on one side facing away from the road (12) Side of the radar reflection layer (30).

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