DE102021004693B3 - MODULAR COMBINED RADAR RETROREFLECTORS - Google Patents

Abstract

The invention relates to retroreflector devices for RADAR systems made up of three different basic elements to increase the effective reflecting surface, in particular of vehicles in road traffic or in nautical applications, in the form of functional units that can be assembled in a modular manner according to the respective requirements with the task of transmitting significant RADAR echo signals over as to generate a large horizontal angle range of up to 360 degrees, in order to make small vehicles such as bicycles more clearly recognizable for the driver assistance devices. In addition, functionality and technical effort can be flexibly adapted to the respective requirements. With the possibility of expanding the modular retroreflector devices with additional components such as lighting, Atta array and identification devices, this invention makes a major contribution to increasing traffic safety, particularly in connection with autonomously operated vehicles.

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to retroreflector devices for RADAR systems to increase the effective reflecting surface, in particular of vehicles on the road or in nautical applications.

BACKGROUND OF THE INVENTION

RADAR systems for determining objects are used in nautical science to avoid collisions with other ships in restricted visibility conditions, such as heavy rain or fog.

Innovative driver assistance systems installed in modern motor vehicles use radar modules to increase safety in critical road traffic situations, such as turning off.

For future autonomous driving, RADAR systems installed in the vehicle are irreplaceable components that deliver essential information to the control computer even when optical conditions are insufficient and components such as cameras and lidar systems fail.

In order to ensure that the data determined by the RADAR systems can be evaluated correctly, timely acquisition is necessary because data processing requires computing time before an appropriate reaction, such as triggering a braking process, is initiated.

To ensure that the autonomously controlled vehicle does not brake suddenly when a plastic bag is blown across the street by the wind, the echo signals received by the RADAR system installed in the vehicle must be able to be differentiated as clearly as possible between signals from endangered objects and meaningless interference signals.

For this purpose, different types of retroreflectors are used in shipping, which increase the effective reflecting surface of small sailing boats to such an extent that they can be recognized in good time and clearly by the RADAR systems of large motor ships, although the actual backscattering surface of the sailing boat is so small without these retroreflectors that the weak echo signals can easily be overlooked. Early detection means that any necessary evasive maneuvers can then be initiated in good time.

For the desired autonomous driving of passenger cars in road traffic, adaptive algorithms have been developed for the recognition and behavior of the vehicles involved.

According to the pamphlet DE 11 2019 003 421 T5 with the designation: “Driving support control device for a vehicle, driving support control system for a vehicle, and driving support control method for a vehicle” can be used to record the current vehicle statuses and traffic situations from the time sequence of previously detected radar echoes and the vehicle statuses and traffic situations that are likely to develop from them can be predicted, making the necessary Measures such as swerving or braking can be initiated in good time by the control computer. The prerequisite, however, is the timely recognition of other road users. According to the pamphlet DE 10 2015 001 970 A1 with the designation: "Adaptive distance control for vehicles" there are indications of numerous delay times between the recorded data signals and the subsequent reactions by the control computer of the vehicle, which are referred to there as setting time gap and control time gap.

Also in print DE 10 2019 214 121 A1 with the designation: "Method for operating a driver assistance system" describes a driver assistance method. It is based on a double control algorithm called time gap control, which continuously evaluates relative driving dynamics measured values. Here, too, the timely detection of other road users is absolutely necessary.

In road traffic, cyclists are particularly at risk because their vehicles only have a very small reflective surface, especially if the bicycles are not made of heavy iron but mostly of light composite material. The bicycles are then difficult to distinguish from other irrelevant objects such as garbage cans or plastic bags in good time thanks to the RADAR systems of the autonomous vehicles or vehicles with integrated driver assistance systems.

In order to increase the reflecting surface of vehicles in the nautical sector, there are numerous offers in specialist shops. The embodiments are rod-shaped, angular, barrel-shaped and there are also powered active RADAR retroreflectors.

In order to significantly increase the reflective surface of bicycles, a number of prototypes have been created, all of which are intended for use based on one or two triangular corner reflectors.

A startup company founded on October 9, 2016 in Dallas USA called "iLumaware Shield - Collision Prevention" (Source: MOGRIDGE, Chris: iLumaware Shield TL-Radar technology for bicycle, 12-11-2016, Internet platform: Kickstarter PBC, URL: https://www.kickstarter.com/projects/ilumaware/ilumaware-shield-collisionprevention, [accessed 2021-09-07].) already has a single under-seat mount rear-facing triangular corner reflector with integrated taillight developed and determined through measurements that the distance for recognizing the bicycle by a typical traffic RADAR system can be extended from 75 meters to 198 meters.

The working group for accident mechanics Zurich has carried out a project called: "Development of a radar reflector for two-wheelers" and in the final report of 21.01.2019 (URL: https://www.stiftung-praevention.ch/pdfs/Schlussbericht-Radarreflektor.pdf [accessed on 2021-11-04]) presented a detailed documentation on the problem with the focus on the primary use of the reflectors in the inner-city environment. Individual triangular corner reflectors and a combination of two triangular corner reflectors in the frequency range 24 GHz to 26 GHz and in the range 77 GHz to 81 GHz were measured and examined.

In the previously known devices, it was possible to demonstrate a significant improvement in the effective reflecting surface, but this only applies in a very limited angular range. This means that the echo signals are not increased when the bicycles are driven through tight bends. In particular, bicycles entering the detection range of the radar signals from the side, as is typically the case at intersections, were detected too late.

STATE OF THE ART

Furthermore, various radar retroreflectors are known, in particular for applications in road traffic, which define the state of the art for the invention disclosed here.

The pamphlet DE 10 2018 111 691 A1 with the designation: "Reflector for electromagnetic waves and method for producing the same" describes retroreflectors based on Perkin-Elmer pyramid structures, which are modified in such a way that they function as retroreflectors for electromagnetic waves in the microwave range with wavelengths in the range of 5 mm , for electromagnetic waves in the range of visible light, i.e. for wavelengths in the range of about 0.0005 mm, but reflect additional circular scattered light cones with a large opening angle. This special behavior is generated by the fact that the reflector for radar beams acts like a conventional trihedral retroreflector for microwaves due to mirror surfaces that are sufficiently large for microwaves, but for the light rays with their significantly lower wavelengths it acts as a retroreflector to a degree that depends on the dimensioning of the geometric modification and in addition that incident light is reflected as circular scattered light. While conventional Perkin-Elmer structures have pointed planar planes in the area where the mirror structures meet, the modified mirror structures have conical roundings. As a result, part of the incoming light is scattered back by these conical roundings in the shape of a circular ring.

The radar system for the vehicle's driver assistance system is usually located below the driver's eye level, e.g. B. in the area of the headlights. Due to the modified Perkin-Elmer pyramid structures, the radar beams are largely completely retro-reflected and, at the same time, a sufficient amount of non-dazzling scattered light from the headlights reaches the driver's eyes with the same reflector.

Reflectors of this type are suitable for marking objects and people and serve to improve visibility both for driver assistance systems and for the respective vehicle driver.

The document published on May 14, 2015 is considered to be the closest prior art US 2015/0130651 A1 with the designation "Passive Radar Activated Anti-Collision Apparatus". It describes an arrangement that consists of a polyhedron acting as a retroreflector, called "polyhedron" there, which is firmly connected to a bracket that allows it to be mounted on an object whose radar cross-section is to be enlarged. This can be, for example, a walking stick, a wheelchair or a bicycle. As an exemplary embodiment, a trihedral corner reflector, consisting of three square conductive surfaces, is used as the polyhedron in this publication, which is mounted on the left rear side of a bicycle with the aid of a bracket. It is explained in detail that a retroreflector mounted in this way significantly increases traffic safety in that the cyclist can be more reliably recognized by the driver assistance system in comparison to other road user objects due to the echo signal strength that is increased in this way.

However, other meaningful forms of possible polyhedra are not mentioned. A retroreflector structure that acts predominantly horizontally or a structure with a significantly larger horizontal opening angle than is typically the case with trihedral retroreflectors of around +/- 20 degrees is also not even touched upon. An all-round 360-degree marking of a traffic sign mast, for example, would also require a larger number of such reflector units on a fixed mounting bracket because of the shading by the mast, regardless of the shape of the polyhedron.

DISCLOSURE OF THE INVENTION

• - Erzeugung eines signifikanten Echosignals über einen möglichst großen horizontalen Winkelbereich,
• - anwendungsspezifische modulare Ausbaumöglichkeit der Retroreflektor-Vorrichtungen bis hin zu einem vollständigen Winkelbereich von 360 Grad,
• - Möglichkeit der Erweiterung der modularen Retroreflektor-Vorrichtungen mit zusätzlichen Komponenten wie Beleuchtung, Atta-Array und Identifikations-Vorrichtungen.
• - sichere Erzeugung von Echosignalen auch bei vollständigem Stromausfall.

The object of the invention is to improve the state of the art in at least one of the following aspects:

• - Generation of a significant echo signal over the largest possible horizontal angular range,
• - application-specific modular expansion option of the retroreflector devices up to a full angle range of 360 degrees,
• - Possibility of expanding the modular retroreflector devices with additional components such as lighting, Atta array and identification devices.
• - Safe generation of echo signals even in the event of a complete power failure.

• Es können, je nach Bedarf und Anwendungsfall, die nur drei einzelnen Komponenten der modularen Retroreflektor-Vorrichtung so kombiniert werden, dass Retroreflektoren gebildet werden, die nur nach vorne oder nur nach hinten oder zusätzlich auch seitlich oder rundherum Echosignale an eine RADAR-Anlage liefern. Zusätzlich können Leuchtmittel oder zusätzliche optisch wirkende Reflektor-Scheiben ergänzt werden. Es können zusätzlich stromgespeiste elektronische Mikrowellenkomponenten integriert werden, die beispielsweise Identifikationssignale generieren, die telemetrisch gelesen werden können.

The invention is defined in the claims. In particular, it allows solutions as follows:

• Depending on requirements and the application, the only three individual components of the modular retroreflector device can be combined in such a way that retroreflectors are formed which only deliver echo signals to the front or only to the rear or additionally to the side or all around to a RADAR system. In addition, lamps or additional optically effective reflector panes can be added. In addition, current-fed electronic microwave components can be integrated, which, for example, generate identification signals that can be read telemetrically.

Further details and advantages of the invention result from the following, purely exemplary and non-limiting description in connection with the respective figures.

character list

• 1 shows schematically a trihedral corner reflector, consisting of three triangular discs made of metallic conductive material, which are each at right angles to each other and which can be used as a retroreflector for RADAR rays. Such retroreflectors have been known for a long time and correspond to the state of the art.
• 2 shows schematically a dihedral corner reflector, consisting of two rectangular flat discs made of metallic conductive material, which are each at right angles to each other and which can be used as a retroreflector for RADAR beams. Such retroreflectors have been known for a long time and correspond to the state of the art.
• 3 shows schematically a triangular disc made of metallic conductive material, which can be used as a reflector for RADAR beams. Such reflectors have been known for a long time and correspond to the state of the art.
• 4 shows schematically the modular element X (1) used to build the modular retroreflector device as a front view with the respective corner points A to G.
• 5 shows schematically the modular element X (1) used to construct the modular retroreflector device with the respective vertices A to G from a side perspective.
• 6 shows schematically the modular element Y (2) used to build the modular retroreflector device with the vertices H to M from a side perspective.
• 7 shows schematically the modular element Z (3) used to construct the modular retroreflector device with the vertices N to P from a side perspective.
• 8th shows schematically an embodiment of a modular retroreflector device in the front view, consisting of a total of five modular elements, namely a modular element X (1), two modular elements Y (2) and two modular elements Z (3).
• 9 shows schematically an embodiment of a modular retroreflector device in top view, consisting of a total of five modular elements, namely a modular element X (1), two modular elements Y (2) and two modular elements Z (3).
• 10 shows schematically an embodiment of a modular retroreflector device in front view, consisting of a total of seven modular elements, namely two modular elements X (1), three modular elements Y (2) and two modular elements Z (3).
• 11 shows schematically an embodiment of a modular retroreflector device in top view, consisting of a total of seven modular elements, namely two modular elements X (1), three modular elements Y (2) and two modular elements Z (3).
• 12 shows schematically an embodiment of a modular retroreflector device in front view, consisting of a total of nine modular elements, namely two modular elements X (1), four modular elements Y (2) and three modular elements Z (3).
• 13 shows schematically an embodiment of a modular retroreflector device in top view, consisting of a total of nine modular elements, namely two modular elements X (1), four modular elements Y (2) and three modular elements Z (3).
• 14 shows schematically an alternative embodiment of a modular retroreflector device in front view, consisting of a total of nine modular elements, namely two modular elements X (1), three modular elements Y (2) and four modular elements Z (3).
• 15 shows schematically an alternative embodiment of a modular retroreflector device in top view, consisting of a total of nine modular elements, namely two modular elements X (1), three modular elements Y (2) and four modular elements Z (3).
• 16 shows a schematic plan view of an embodiment of a modular retroreflector device, consisting of a total of eight modular elements, namely four modular elements X(1), four modular elements Y(2).
• 17 shows schematically an embodiment of a modular retroreflector device in top view, consisting of a total of sixteen modular elements, namely eight modular elements X(1), eight modular elements Y(2).
• 18 shows schematically an alternative embodiment of a modular retroreflector device in front view, having additional mounted optical reflectors (4).
• 19 shows schematically an alternative exemplary embodiment of a modular retroreflector device in a front view, this having additional mounted electrically operated lighting means (5).
• 20 shows schematically an alternative exemplary embodiment of a modular retroreflector device in the front view, with this having additional mounted interaction elements (6) for radio-based data transmission.
• 21 shows schematically an alternative embodiment of a modular retroreflector device in front view, this having additional mounted interaction elements in the form of planar Atta arrays (7).
• 22 shows a schematic example of an embodiment of a planar Atta array, which has electronic circuitry that enables radio-based data transmission.

DESCRIPTION OF PREFERRED EMBODIMENTS

It shows the 1 a schematic representation of a trihedral corner reflector, which is constructed from three triangular discs consisting of metallically conductive material and which can be used as a retroreflector for RADAR rays. Such retroreflectors have been known for a long time and correspond to the state of the art. The electrically conductive surfaces are at an angle of 90 degrees to each other. A hollow cube with square sides of edge length a, in which the trihedral corner reflector is embedded, serves as an aid to the construction. The diagonal of the respective square cube faces then has the length b and is equal to the edge length a multiplied by the square root of the number two.

Incoming RADAR beams are reflected back in a typical angular range of about 40 degrees based on a 3 dB power limit by three reflections on the metallic surfaces in exactly the direction from which the RADAR beam hits the corner reflector. The angle of incidence in relation to the axis of symmetry of the trihedral angle reflector, the latter resulting when the spatial diagonal is extended from the corner point of the imaginary hollow cube through the diagonal surface perpendicular thereto, is known as the opening angle. Accordingly, an opening angle of 40 degrees that an angular deviation from the axis of symmetry of both 20 degrees to one side and 20 degrees to the exactly opposite side reflects up to half of the incident energy.

It shows the 2 schematically shows a dihedral corner reflector, consisting of two rectangular flat discs made of metallic conductive material, which can be used as a retroreflector for RADAR beams. Such retroreflectors have been known for a long time and correspond to the state of the art. The electrically conductive surfaces are at an angle of 90 degrees to each other. The respective depths of the plane slices have as in the 2 shown a length a whereby the distance between the two outer edges, which can have any length c, then have the length b as a geometric diagonal, which is then equal to the edge length a multiplied by the square root of the number two.

It shows the 3 schematically shows a triangular disc made of metallic conductive material, which can be used as a reflector for RADAR beams. Such reflectors have been known for a long time and correspond to the state of the art. The disk forms an isosceles right-angled triangle with side lengths a and base length b and is therefore equal to the side length a multiplied by the square root of the number two.

For the retroreflector devices described below by way of example, formed from three different modular elements, namely from the modular elements X (1), Y (2) and Z (3), which serve as basic building blocks for the construction of modular combined RADAR reflectors as functional units , it is stipulated that the respective lengths a used in the previously described figures are the same for all described modular elements X (1), Y (2) and Z (3) within a functional unit and thus those derived from them and described in the previous ones The respective lengths b used in the figures then also have the same values for all modular elements. This is the only way that the modular elements can be put together to form suitable functional units.

Are more complex functional units such as in connection with the 17 will be explained, is made up of modular elements which are stacked on top of one another, for example in the manner of a tower, the lengths a and thus also b for the differently constructed functional units can, however, deviate from those of other functional units. However, they are always of the same size within a respective individual functional unit.

The verbal description of the arrangement of the modular elements X (1), Y (2) and Z (3) used, which serve to construct the respective retroreflector devices, requires a detailed specification of connection points by naming the respective corner points, where the respective modular elements X (1), Y (2) and Z (3) are connected to each other. The connections of the corresponding edges of the modular elements X (1), Y (2) and Z (3) then result inevitably from the geometric shapes of the modular elements X (1), Y (2) and Z (3).

It shows the 4 Schematically the modular element X (1) used to build the modular retroreflector device as a front view with the respective corner points A to G.

It shows the 5 1 schematically shows the same modular element X(1) used to construct the modular retroreflector device, with the respective vertices A to G, but from a side perspective for better understanding.

It is through the in the 4 and 5 illustrated arrangement of two trihedral corner reflectors defines the modular element X (1). Both trihedral angle reflectors only touch at the common corner point G. The metallically conductive surfaces spanned by the planes of the corner points A, B and C and by the corner points D, E and F are parallel to one another. The two axes of symmetry of the respective trihedral corner reflectors point laterally into the plane that is defined by the line bisectors of the line AB and DE. The symmetry axis of the trihedral retroreflector defined by vertices A,B,C and G is oriented 45 degrees upwards and the symmetry axis of the trihedral retroreflector defined by vertices D,E,F and G is oriented 45 degrees downwards

It shows the 6 Schematically the modular element Y (2) used to build the modular retroreflector device with the vertices H to M from a side perspective. The modular element Y (2) is a dihedral corner reflector which, however, only reflects the incident RADAR rays back towards the source when the latter is at right angles to the path formed by vertices K and J or parallels thereto becomes. As a single construction element, the modular element Y (2) is therefore less suitable for constructing a retroreflector. Only through the targeted arrangement of further modular elements does the modular element Y (2) become an important modular component components for the structure of the respective functional unit.

It shows the 7 schematically shows the modular element Z (3) used to construct the modular retroreflector device with the vertices N to P from a side perspective. The modular element Z (3) is a simple metallic conductive plate, which, however, only reflects the incident RADAR beams back towards the source when it is exactly at right angles to the plane passing through the vertices N, O and P is formed. With regard to the RADAR rays, this modular element Z (3) behaves similarly to a planar mirror in the optical area. As a single construction element, the modular element Z (3) is therefore even less suitable for constructing a retroreflector. This modular element Z (3) also becomes an important modular component for the construction of the respective functional unit only through the targeted arrangement of further modular elements.

However, the inventive arrangement of the individual modular elements X (1), Y (2) and Z (3) lead to highly effective modular retroreflector devices with almost any large horizontal opening angles, which only depend on the combination of the respective modular elements X (1), Y (2) and Z (3) depend and can thus be constructed as required.

It shows the 8th schematically a first embodiment of a modular retroreflector device in the front view, consisting of a total of five modular elements, namely a modular element X (1), two modular elements Y (2) and two modular elements Z (3).

Already in the front view it can be seen that the arrangement shown here of the modular elements Z (3) in combination with the modular elements Y (2) to the right and left of the modular element X (1) in turn form a trihedral corner reflector. The axes of symmetry of the trihedral corner reflectors formed from the respective modular elements Z (3) in combination with the modular elements Y (2) both point exactly in the frontal direction. This results in a particularly intense echo signal over a wide horizontal and vertical angle range in the case of frontal irradiation.

It shows the 9 schematically shows an embodiment of a modular retroreflector device according to FIG 8th in top view, consisting of a total of five modular elements, namely a modular element X (1), two modular elements Y (2) and two modular elements Z (3). In this depiction it is easy to see that the upper and the lower planes each result in a common closed area. The respective sides are also closed by metallically conductive walls. As a result, a modular retroreflector device constructed in this way can be realized as a compact part or as a compact component and can be used, for example, as an improved RADAR retroreflector or with additional elements as a combination, for example with lighting elements, as a retroreflective rear light for a bicycle.

It shows the 10 schematically another embodiment of a modular retroreflector device in the front view, consisting of a total of seven modular elements, namely two modular elements X (1), three modular elements Y (2) and two modular elements Z (3).

This modular retroreflector device is particularly suitable for retroreflection when irradiated from the side by RADAR rays. Together with an electrically operated lamp (5) according to 19 this exemplary embodiment is excellently suited for realizing, for example, a front light or rear light for a bicycle.

It shows the 11 schematically an embodiment of a modular retroreflector device in plan, consisting of a total of seven modular elements, namely two modular elements X (1), three modular elements Y (2) and two modular elements Z (3) according to 10 . In this depiction it is easy to see that the upper and the lower planes each result in a common closed area. The respective backs are also sealed by metallically conductive walls. As a result, a modular retroreflector device constructed in this way can be realized as a compact part or as a compact component if, for example, the front and side surfaces are covered by optically acting reflectors (4), as is the case in FIG 18 is shown as an example.

It shows the 12 schematically an embodiment of a modular retroreflector device in the front view, consisting of a total of nine modular elements, namely two modular elements X (1), four modular elements Y (2) and three modular elements Z (3). In contrast to the similar realization according to 10 , which only has a dihedral retroreflector in the frontal area, now has two additional trihedral ones by attaching a modular element Z (3) in the middle of the modular element Y (2). Retroreflectors with significantly larger opening angles. This example shows the variety of RADAR retroreflectors that can be implemented for different applications with this modular retroreflector device according to the invention.

It shows the 13 schematically shows an embodiment of a modular retroreflector device according to FIG 12 in top view, consisting of a total of nine modular elements, namely two modular elements X (1), four modular elements Y (2) and three modular elements Z (3).

It can be clearly seen that only a small modification to the in 10 shown embodiment leads to a significantly different reflection behavior. Because the modular element Z (3) was placed in the middle of the modular element Y (2), the retroreflector is now also able to reflect laterally offset, frontally incident RADAR beams back into the direction of incidence.

It shows the 14 schematically another alternative embodiment of a modular retroreflector device in the front view, also consisting of a total of nine modular elements, namely two modular elements X (1), three modular elements Y (2) and four modular elements Z (3) . It is the same basic configuration as in each case 10 , 11 , 12 and 13 has been used. This time too, only modular elements Z(3) are placed at selected locations, as a result of which the reflection behavior of the modular retroreflector device changes significantly. Due to the fact that two modular elements Z (3) were not placed in the middle of the modular element Y (2), but rather on the right and left at the ends of the modular element Y (2), the retroreflector is now also capable of laterally offset frontal incident to reflect RADAR rays back in the direction of incidence. It is also easily possible with this configuration, an electrically operated light source (5) according to 19 to integrate.

It shows the 15 schematically this alternative embodiment of a modular retroreflector device in top view, consisting of a total of nine modular elements, namely two modular elements X (1), three modular elements Y (2) and four modular elements Z (3). The staggered arrangement of the modular elements Z (3) can be easily recognized in the top view.

It shows the 16 schematically an embodiment of a modular retroreflector device in plan, consisting of a total of eight modular elements, namely four modular elements X (1), four modular elements Y (2). Only the view from above is given because the front view is very similar to the front view according to FIG 10 without clarifying the facts in more detail.

In the top view, on the other hand, it can be clearly seen that this is a modular retroreflector device with a horizontal opening angle of almost 360 degrees. This retroreflector reflects horizontally in all directions all around. By adding further modular elements Z (3), as in connection with the 10 until 15 has been shown, any preferred directions for the angle covers can be constructed depending on the application. In this exemplary embodiment, only the basic configuration with the modular elements X(1) and Y(2) is shown. By adding further modular elements Z (3), as is done in the previously discussed figures and explained there, the dihedral corner reflectors Y (2) can easily be converted into trihedral corner reflectors, which then provide significantly larger opening angles overall place.

It shows the 17 schematically an embodiment of a modular retroreflector device in plan, consisting of a total of sixteen modular elements, namely eight modular elements X (1), eight modular elements Y (2). This multitude of modular elements comes about because two of the in 16 illustrated embodiments have been stacked like a tower. where is in 17 the lower part of the modular retroreflector assembly has been rotated 45 degrees. In addition, the respective edge lengths a and b have been modified there in such a way that the respective modified modular elements without projections or shoulder edges as in FIG 17 shown can be connected to each other.

For example, the edge length of the dihedral retroreflector previously denoted c, ie the edge length of the upper modular element Y (2), is equal to the diagonal length, which was previously denoted b for the trihedral retroreflector.

The edge lengths of dihedral and trihedral retroreflectors must therefore be swapped over in the different planes of the tower-shaped modular retroreflector device thus formed, as in FIG 17 has been presented. Of course, all the embodiments shown above can be stacked in this way in a tower to at for example, to increase the respective opening angles or to increase the total amount of high-frequency power reflected.

The large number of configuration options enables the construction of modular retroreflector devices for almost any application to be implemented.

The 18 shows schematically an alternative embodiment of a modular retroreflector device in front view, having additional mounted optical reflectors (4).

Optical retroreflectors are used, for example, as reflectors in order to reflect the incident light from a light source, such as that of a car headlight, to the driver of the vehicle so that he can react to the existing traffic situation early on. These optical retroreflectors (4) are usually made of specially shaped plastic material, which has little effect on RADAR rays. Thus, the two different retroreflectors, namely the one for optical light sources and the one for RADAR rays, can be combined with one another in a very simple and space-saving manner by simply mounting the optical reflector (4) in front of the modular retroreflector device. The 18 shows an example of such an assembly.

The 19 shows schematically an alternative exemplary embodiment of a modular retroreflector device in a front view, this having additional mounted electrically operated lighting means (5).

A light source powered by a battery or by a bicycle dynamo can be fixed very easily on a face of a modular element Y (2). For example, high-performance, two-dimensionally shaped light-emitting diodes are suitable for this, which have a high degree of efficiency with regard to the current-dependent light output and a very long service life. Although a simple metallic surface is sufficient for the retroreflection, if the modular retroreflector device is implemented as a front light, for example for bicycles, the high-gloss mirror coating of the surface of the modular element Y (2) is recommended.

The 20 shows schematically an alternative exemplary embodiment of a modular retroreflector device in the front view, this having additional mounted interaction elements for radio-based data transmission.

Such an additional device for generating stored digital numerical information (6) would be a conceivable useful supplement and could be realized by installing, for example, a soundboard that has different waveguides that have natural resonances in the frequency range of the RADAR radiation, whose absorption spectrum can be read by a suitable reading device can be recorded and evaluated telemetrically. In this way, for example, a type of electronically remotely readable number plate for bicycles can be implemented.

The 21 Fig. 12 shows schematically an alternative embodiment of a modular retroreflector device in front view, having additional mounted interaction elements in the form of planar Atta arrays. These planar Atta arrays are antennas that are specially interconnected by cables and are also able to function as retroreflectors. In the case of a purely passive realization, however, their efficiency is lower than in the case of trihedral retroreflectors. Broadband amplifiers for the microwave frequency range in question are therefore often connected to the antenna lines, as a result of which the retroreflection properties of the Atta arrays are significantly increased. However, if amplifiers are installed anyway, additional functions such as wireless data transmission can also be implemented.

The 22 shows schematically an embodiment of a planar Atta array, which has an electronic circuitry that enables radio-based data transmission. A minimally simple arrangement of four planar antennas (8) to (11) with two microwave broadband amplifiers (12) and (13) is shown here as an example.

The electrical length of the line from a first receiving antenna (8) via a first microwave broadband amplifier (12) to a first transmitting antenna (11) and the electrical length of the line from a second receiving antenna (9) via a second broadband amplifier (13) up to a second transmitting antenna (10) are the same. As a result, this Atta array shown as an example reflects an incident RADAR beam back in the direction of incidence. Due to the planar arrangement of the antennas, preferably on a metal plane, they are not coupled to one another, which enables an amplification factor of the microwave broadband amplifiers (12) and (13) of around 20 dB each without any problems.

The two microwave broadband amplifiers (12) and (13) are fed by a voltage source (U), which also supplies an electronic switching device (14) with electrical operating energy, which cyclically continuously an electronic switching device (14) between the Voltage source (U) and the two microwave broadband amplifiers (12) and (13) operated. In this case, such a switching rhythm is continuously selected that is capable of serially transmitting, for example, a coded identification number. The RADAR beam reflected by the switched Atta array then contains a coding according to the Morse alphabet or the Miller code and an identification number, for example, can be recognized and evaluated by the RADAR device modified accordingly for this purpose.

Reference List

1

Modular Element X

2

Modular Element Y

3

Modular element Z

4

Optical reflector

5

Electrically operated illuminant

6

Devices for generating stored digital information

7

Atta array

8th

First receiving antenna

9

Second receiving antenna

10

Second transmitting antenna

11

First transmission antenna

12

First microwave broadband amplifier

13

Second microwave broadband amplifier

14

Electronic switching device

Claims (6)

Modular combined RADAR retroreflectors, characterized in that these using a discrete number of three different modular elements that serve as building blocks for the construction of modular combined RADAR retroreflectors as functional units, namely • a first modular element X (1), • a second modular element Y (2) and • a third modular element Z (3) are each built up to form retroreflective functional units, the horizontal angle of aperture of which is determined by the number and arrangement of the modular elements used to build up the functional units, with all modular elements ( 1) to (3) of a respective functional unit have at least two geometric lengths (a) and (b) in common, the length (a) depending on the frequency of the RADAR signal to be reflected and at least equal to or greater than the wavelength of the to be reflected RADAR signal must be and up to tenfold world length or greater and where length (b) is the diagonally dependent value of length (a) multiplied by the square root of two and where the first modular element X (1) of two is joined together at the vertex ( G) converging trihedral triangular retro angle reflectors, each having three metallically conductive flat surfaces and being assembled in such a way that a lower angle reflector has three metallically conductive triangular planes, each of which is at right angles to one another, the lower plane passing through the vertices (A), (B) and (C), the lower right lateral plane through vertices (C), (B) and (G) and the lower left plane through vertices (A), (C) and (G) is determined, whereby the segments determined by the vertices (A) and (C), (C) and (B) as well as (C) and (G) each have the lengths (a) and the segments determined by the vertices ( A) and (B), (A) u nd (G) as well as (B) and (G) each have the lengths (b) and that an upper corner reflector has three metallically conductive, triangular planes, which are each at right angles to one another, the upper plane passing through the vertices (D) , (E) and (F), the upper right lateral plane is determined by the vertices (F), (E) and (G) and the upper left plane by the vertices (D), (F) and (G), where the segments determined by the vertices (D) and (F), (E) and (F) and (F) and (G) each have the lengths (a) and the segments determined by the vertices (D) and (E), (D) and (G) and (E) and (G) each have the lengths (b) and the through the vertices (A), (B) and (C) determined lower metallically conductive level and the determined by the corner points (D), (E) and (F) upper metallic conductive plane running parallel to each other in two different planes and the determined by the corner points (A), (G) and (C) lower The left metallically conductive plane and the upper left metallically conductive plane determined by the vertices (D), (G) and (F) lie parallel to one another in a common plane and the surfaces defined by the vertices (G), (B) and (C ) determinate lower right metallically conductive plane and the upper right metallically conductive plane determined by the corner points (G), (E) and (F) lie parallel to each other in a common plane and where the corner points (C) and (G ) and (G) and (F) determinate paths lie on a common straight line, the second modular element Y (2) is constructed as a dihedral retro-angle reflector, this retro-angle reflector having two flat, metallically conductive surfaces and being composed in such a way that a lower metallically conductive one , rectangular Level, this level being determined by the corner points (H), (I), (J) and (K) and an upper metallically conductive, rectangular level, this level being defined by the corner points (K), (J), (L ) and (M) is determined and these two planes are mounted perpendicular to each other in such a way that the common vertices (K) and (J) coincide, with the lines determined by the vertices (H) and (K), (K) and (L), (I) and (J) and (J) and (M) each have the lengths (a) and the distances determined by the vertices (H) and (I), (K) and (J) and (L) and (M) each have a length (c), this length (c) having any value depending on the intended design of the particular modular combined RADAR reflector, and the third modular element Z (3) of a planar reflector is constructed, which has a metallically conductive flat surface and is realized in such a way that a planar metallically conductive, dr egg-shaped plane is formed, this plane being determined by the vertices (N), (O) and (P), the distances determined by the vertices (N) and (O) and (O) and (P) each being the have lengths (a) and the respective retroreflective functional units are formed in that the modular elements X (1) and the modular elements Y (2) are laterally connected to one another in an alternating sequence in such a way that the respective outer corner points (A) and ( D) or (B) and (E) of the modular element X (1) and the outer vertices (I) and (M) or (H) and (L) of the modular element Y (2) common points of the modular in this way form a composite functional unit, with the respective opening angles of the individual modular elements (1) and (2) always being directed outwards, i.e. from the metallically conductive planes in the direction of the free space, and with the modular elements Z (3) being attached to any from the intended ten design of the respective modular combined RADAR reflector dependent points of the modular element Y (2), are positioned in such a way that the corner point (N) is on the edge determined by the corner points (H) and (I), the corner point (Q) on the edge determined by vertices (K) and (J) and vertex (P) is on the edge determined by vertices (L) and (M). Modular combined RADAR retroreflectors after Claim 1 , characterized in that in front of the modularly combined RADAR retroreflectors, i.e. in the area of the respective opening angle of the retroreflective functional units, colored or uncolored dielectric, non-conductive and low-attenuation optical reflectors (4) in the area of the respective RADAR frequencies are arranged, which tend to reflect in the same direction as the modularly combined RADAR retroreflectors positioned behind them. Modular combined RADAR retroreflectors after Claim 1 and 2 , characterized in that in selected retro-reflective functional units of the modularly combined RADAR retro-reflectors, electrically operated lamps (5) are mounted, which can be switched on or off as required. Modular combined RADAR retroreflectors according to one of the preceding patent claims, characterized in that devices for the transmission of stored digital numerical information (6) are mounted in respectively selected retroreflective functional units of the modular combined RADAR retroreflectors in such a way that this digital numerical information is remotely positioned suitable reading devices can be read out wirelessly. Modular combined RADAR retroreflectors according to one of the preceding patent claims, characterized in that there are additional planar antenna fields below, above or both above and below the retroreflective functional units of the modularly combined RADAR retroreflectors, each of which has retroreflective so-called Van Atta arrays (7) form, whose reflected electromagnetic energy can be modulated by means of a modulation device with digital numerical information, so that by means of remotely positioned suitable readers this information can be read wirelessly. Modular combined RADAR retroreflectors according to one of the preceding patent claims, characterized in that retroreflective functional units of the same or similar construction are stacked one on top of the other in a tower-like manner in order to thereby further increase the opening angle and to increase the overall effective RADAR cross-sectional area.

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