DE102017209591A1 - Body part for a vehicle and device for detecting a vehicle - Google Patents

Abstract

The invention relates to a body part (1) of a vehicle (F1) comprising a plurality of defined radar reflectors (2) which at least partially reflect back a radar radiation impinging on them in the direction of a radiation source which has emitted the radar radiation, and which in the body part (1). are integrated. Furthermore, the invention relates to a device for detecting a vehicle (F1).

Description

The present invention relates to a body part comprising a plurality of defined radar reflectors. Furthermore, the invention relates to a device for detecting a vehicle.

Radar sensors that radiate radar waves and determine the type of object based on the echo reflected by an object are used to record a vehicle environment. The ability to reflect the radar waves in motor vehicles depends strongly on the outer contour of the vehicles and thus on the design principles of the respective vehicle manufacturer. This leads to a large spread of radar cross sections of motor vehicles. Assistance functions therefore can not detect different vehicles radar-based uniformly well than vehicles. Improvements to the radar-based recognizability of vehicles are usually performed only on the sensor side by the fact that the algorithms and hardware of the sensors are constantly being improved.

The DE 10 2007 060 862 A1 describes an emergency brake assist system in which a radar system can be used to measure a distance between two vehicles or the relative speed of the two vehicles.

The US 3,604,805 A describes an optical detection and ranging system for vehicles. In this case, electromagnetic radiation is emitted by a vehicle driving behind a vehicle in front. The electromagnetic radiation is transmitted in particular in the infrared range. The radiation is then reflected back to the radiation source by optical retroreflectors disposed on the preceding vehicle and the distance to the preceding vehicle is measured from the reflected radiation.

The present invention has for its object to provide a body part and a device by means of which it is possible to improve the radar-based detection of vehicles in a cost effective and space-saving manner.

According to the invention this object is achieved by a body part with the features of claim 1 and a device having the features of claim 13. Advantageous embodiments and further developments emerge from the dependent claims.

The body part according to the invention comprises a plurality of defined radar reflectors, which at least partially reflect back a radar radiation impinging on them in the direction of a radiation source which has emitted the radar radiation, and which are integrated into the body part. The integration of defined radar reflectors in a body part can significantly increase the radar cross-section of a vehicle in which the body part is installed. As a result, the recognizability of a vehicle can be improved by means of a radar sensor. This is particularly advantageous for driver assistance systems which use radar sensors to detect vehicles. The number of integrated radar reflectors is at least two. The body part preferably comprises at least three or more radar reflectors. Furthermore, a stable construction can be provided by the integration of the radar reflectors in the body part.

A defined radar reflector is understood according to the invention to mean a radar reflector which is integrated in the body part specifically for generating a radar reflection.

A body part is understood to mean a component of the vehicle which belongs to the body of a vehicle. The body is composed of a body shell and body parts. The body attachments are attached to the body shell of the vehicle to complete the bodywork. The body shell comprises in particular all supporting cross members, side members, frame parts and the A, B and C pillar of a vehicle. Body attachment parts are, for example, bumpers of the vehicle, trim parts, bumper strips, the glazing, door locks, seat system and interior trim parts of the vehicle. The radar reflectors can therefore be integrated both in a component of the body shell as well as in a body attachment. The radar reflectors can also be integrated in particular only in a component of the body shell or in a body attachment.

Integration of the defined radar reflectors is understood according to the invention that the radar reflectors are firmly connected to the body part.

In one embodiment of the device according to the invention, the defined radar reflectors are integrated in an arrangement in the body part, with which they generate a specific reflection pattern of the radar radiation. Such reflection patterns can be advantageously used by a vehicle of another road user for safety-relevant applications on.

The arrangement of the defined radar reflectors is particularly dependent on the vehicle class of the vehicle in which the body part is arranged. As a result, it is advantageously possible to generate a reflection pattern that is typical for a vehicle class. It can then be transmitted to other road users in a simple and cost-effective manner information, such as size, structure and type of vehicle.

Each of the defined radar reflectors has in particular at least two reflecting partial surfaces. These are arranged, for example, at an angle in a range of 70 ° to 120 °, preferably at an angle in a range of 85 ° to 95 ° to each other. In particular, the partial surfaces are arranged at an angle of 90 ° to each other. The defined radar reflectors preferably have at least three partial surfaces, which are arranged at an angle of 90 ° to each other. Thereby, a large effective reflection area of the defined radar reflectors can be provided. The defined radar reflectors are designed in particular as retroreflectors, which largely reflect the incident radar radiation, largely independent of its orientation, back to the radiation source.

The partial areas have, for example, a triangular or quadrangular, in particular square, base area. This allows the forms of radar reflectors, as used in shipping or aviation, reconstruct.

In one embodiment, the subareas of the defined radar reflectors have edges with an edge length in a range of 20 mm to 100 mm. In particular, the edges have an edge length of 30 mm. The small edge length advantageously leads to the fact that the defined Radar reflectors occupy little space and thus can be integrated to save space in the body part.

Furthermore, the partial surfaces may be thin films of an electrically conductive material. By using thin films can be ensured that the defined radar reflectors occupy little space in the body part. In addition, the weight which the radar reflectors occupy can be influenced by the thickness of the films, which is, for example, in a range of 1 μm to 10 mm. The material is selected, for example, from the metals. Furthermore, the radar reflectors can also be made of other electrically conductive materials. For example, the material used is aluminum. Aluminum is a very light electrically conductive material. As a result, a radar reflector is particularly light, so that an installation of multiple radar reflectors in the body part has no negative impact on the fuel consumption of the vehicle or the exhaust emission of the vehicle, in which the body part is arranged.

In particular, the defined radar reflectors are embedded in the material of the body part. This can ensure that, even if the faces are only thin films, they are stably supported in the body part and do not deform during regular driving.

In particular, the body part is a bumper of the vehicle. This may be a front bumper of the vehicle. A bumper of a vehicle typically includes a foam core which is intended to cushion an impact of another vehicle. The integration of radar reflectors in such foam cores is particularly simple and inexpensive. The integration in bumpers is therefore particularly advantageous.

In particular, the body part is attached to the rear of the vehicle. The radar reflectors are then integrated, for example, in the rear bumper of a vehicle. This is particularly advantageous when the rear bumper of the vehicle is used by driver assistance systems of other vehicles for distance measurement for an automatic braking system.

In a further embodiment, an apron made of a material which is permeable to radar radiation is arranged on the body part such that the defined radar reflectors are not visible from the outside. The integration of the radar reflectors then advantageously has no effect on the design of the vehicle in which the body part is arranged.

The body part according to the invention provides, in particular, a measure with which the recognizability of a vehicle in the radar area is not improved on the sensor side, but on the vehicle side.

The invention also relates to a device for detecting a vehicle. The device comprises an emitter unit arranged in the other vehicle, by means of which radar radiation can be emitted. In addition, the device comprises a body part arranged in the vehicle, which comprises a plurality of defined radar reflectors which reflect back at least part of the radar radiation emitted by the emitter unit, which is incident on it, in the direction of the other vehicle, a detection unit arranged in the other vehicle detects the radar radiation reflected back from the defined radar reflectors, and an allocation unit arranged in the other vehicle, which reflects the vehicle in response to the reflected back Detects radar radiation as a vehicle. The device according to the invention comprises in particular a body part according to the invention and therefore has all the advantages of such a body part.

In one embodiment, the defined radar reflectors are integrated in a specific arrangement in the body part, so that the back-reflected electromagnetic radiation is detected by the detection unit as a specific reflection pattern. The allocation unit then recognizes the vehicle class of the vehicle as a function of the detected reflection pattern.

The device according to the invention can be used in particular by a driver assistance system for accident prevention. Characterized in that the reflection pattern provide information about the vehicle in which the body part is installed, the driver assistance system can initiate appropriate actions of the vehicle based on this information. For example, in an unavoidable collision, a driver assistance system can steer the vehicle so that the risk of injury to the vehicle occupants is as low as possible during the collision.

The invention further relates to a vehicle with a body part according to the invention. The recognizability of the vehicle according to the invention in the radar range can thereby be improved in a cost-effective and space-saving manner.

• 1 zeigt ein Fahrzeug mit einem erfindungsgemäßen Karosserieteil,
• die 2a bis 2c zeigen Ausführungsbeispiele für die Ausgestaltung der Radarreflektoren,
• 3 zeigt ein Beispiel für ein Radarreflexionsmuster wie es von einem Fahrzeug mit einem erfindungsgemäßem Karosserieteil erzeugt wird,
• die 4a bis 4c zeigen weitere Beispiele für Anordnungen von Radarreflektoren in einem erfindungsgemäßen Karosserieteil,
• die 5a bis 5c zeigen die zu den Anordnungen aus den 4a bis 4c gehörigen Reflexionsmuster,
• 6 zeigt ein Diagramm, bei dem die effektive Reflexionsfläche gegen die Kantenlänge der Radarreflektoren aufgetragen ist, und
• 7 zeigt ein Ausführungsbeispiel für eine erfindungsgemäße Vorrichtung.

The invention will now be explained by means of embodiments with reference to the drawings.

• 1 shows a vehicle with a body part according to the invention,
• the 2a to 2c show exemplary embodiments of the design of the radar reflectors,
• 3 shows an example of a radar reflection pattern as produced by a vehicle with a body part according to the invention,
• the 4a to 4c show further examples of arrangements of radar reflectors in a body part according to the invention,
• the 5a to 5c show the to the arrangements of the 4a to 4c associated reflection pattern,
• 6 shows a diagram in which the effective reflection surface is plotted against the edge length of the radar reflectors, and
• 7 shows an embodiment of a device according to the invention.

Related to the 1 becomes a vehicle according to the invention F1 with a body part according to the invention 1 explained.

The vehicle F1 is in 1 shown from behind. The body part 1 is at the back of the vehicle F1 arranged and is in the present embodiment, a body attachment, namely the rear bumper of the vehicle F1 ,

In the rear bumper 1 are several defined radar reflectors 2 integrated.

Generally, a bumper is made from a skirt and an underlying crush body. The crushable body is deformable in an impact such that the energy released during the impact can be absorbed by the crushed body. Such a crushed body is usually made of a semi-rigid foam.

The integration of the defined radar reflectors 2 in the rear bumper 1 takes place in particular by the fact that the radar reflectors 2 in the foam of the rear bumper 1 be embedded.

Related to the 2a to 2c become possible forms for the defined radar reflectors 2 explained. Here are the radar reflectors 2 designed in particular as retroreflectors.

In 2a is an angle reflector with two reflective surfaces 2.1 and 2.2 shown. The partial surfaces 2.1 and 2.2 are arranged at an angle of 90 ° to each other and have a square shape. To ensure a satisfactory retroreflection, it is advantageous if the faces 2.1 and 2.2 perpendicular to the plane of incident radar radiation in the bumper 1 be embedded. Each partial surface forms 2.1 and 2.2 in particular an angle of 45 ° with the longitudinal axis of the vehicle F1 , In 2 B is an example of an embodiment of a radar reflector 2 shown which three faces 2.1 ' . 2.2 ' and 2.3 ' having. The three subareas 2.1 ' . 2.2 ' and 2.3 ' are also arranged in a 90 ° -Wnkel to each other and have a triangular base. The effective retroreflective surface σ of such a triangular reflector is calculated according to: $$\mathrm{\sigma \; =}\left(4\mathrm{\pi }{\text{a}}^4\right)\text{/}\left(3{\mathrm{\lambda }}^2\right)=\left(4\mathrm{\pi }{\text{a}}^4\right)\text{/}\left(3{\left(\text{c / f}\right)}^2\right)$$

Where a is the length of the touching edges of the faces 2.1 ' . 2.2 ' and 2.3 ' and λ is the wavelength of the incident radar radiation. The wavelength λ in turn can be over the Speed of light c divided by the frequency f expressing the incident radar radiation.

Another example of an embodiment of a radar reflector is shown in FIG 2c shown. This radar reflector 2 also has three faces 2.1 " . 2.2 " and 2.3 " on. Also these subareas 2.1 " . 2.2 " and 2.3 " are arranged at a 90 ° angle to each other, but have a square base. This embodiment is therefore similar to a cube with a missing cube corner. The effective retroreflective surface σ of such a square reflector is calculated according to: $$\mathrm{\sigma \; =}\left(\mathrm{twelve}\mathrm{\pi }{\text{a}}^4\right)\text{/}{\mathrm{<figure-callout\; id="2"\; label="\lambda "\; filenames="DE102017209591A1\_0003.png,DE102017209591A1\_0004.png"\; state="\{\{state\}\}">\lambda </figure-callout>}}^2=\left(\mathrm{twelve}\mathrm{\pi }{\text{a}}^4\right)\text{/}{\left(\text{c / f}\right)}^2$$

Again, a is the length of the touching edges of the faces 2.1 " . 2.2 " and 2.3 " and λ is the wavelength of the incident radar radiation.

Unlike a retroreflector with two faces, as in 2a are shown, the embodiments of the 2 B and 2c location independent. This means that an exact alignment perpendicular to the plane of the incident radar radiation is not necessary in order to obtain a satisfactory back reflection.

The edge lengths a of the radar reflectors 2 lie in a range of 20 mm to 100 mm. In order to determine the used edge lengths a, a compromise between the available construction space and the desired effective retroreflective surface must be found.

Frequently used frequencies of radar sensors in the automotive sector are 24 GHz and frequencies in a range of 75 to 77 GHz. At these frequencies, the atmospheric attenuation of radar radiation is utilized, which reaches its maximum at a frequency of about 76 GHz. When using radar radiation with a frequency in this frequency range, a mass use of radar equipment is possible. A mutual interference is prevented by the then occurring attenuation by the molecular scattering. However, while radar sensors operating at a frequency of 24 GHz are relatively short-sighted, the use of radar sensors with a frequency of approximately 75 GHz to 77 GHz in addition to the determination of short distances and the distance determination for medium and longer distances is possible ,

In 6 are two curves 8th and 9 which shows the effective retroreflective surface σ plotted against the edge length a at 76 GHz. Curve 8th In doing so, it represents the effective reflection surface σ for the square reflector 2c dar. The curve 9 In doing so, it represents the effective reflection surface σ for the triangular reflector 2 B represents.

It can be seen from the curves that, for example, an edge length of 30 mm for the triangular reflector 2 out 2 B the effective return surface σ to about 0.2 m ² and for the square reflector off 2c to about 2 m ² results. For both reflector shapes this is a satisfactory effective retroreflective surface σ. At the same time is a radar reflector 2 with such edge sounds a small enough to fit even in a body part 1 to be integrated, which provides little space.

Furthermore, the faces 2.1 and 2.2 . 2.1 ' . 2.2 ' and 2.3 ' or 2.1 " . 2.2 " and 2.3 " made of a thin layer of electrically conductive material. Such a material is selected from the metals and is in particular aluminum. Alternatively, the material may also be carbon fiber. This choice of material can ensure that the radar reflectors are very light and thus hardly to the total weight of the vehicle F1 contribute. The installation of a body part according to the invention 1 thus also has no negative impact on the fuel consumption or exhaust emission of the vehicle F1 ,

The use of a thin film of material is also possible because the radar reflectors 2 in the foam of the bumper 1 be embedded. As a result, for example, the use of a film, for example in the form of an aluminum foil, which is generally unstable and not self-supporting, possible. The thickness of the film is in particular in a range of 1 .mu.m to 1 mm.

A vehicle in which no inventive body part 1 with defined radar reflectors 2 is built, generates a nonspecific radar reflection pattern. Radar radiation is reflected in such vehicles mainly from the body shell, and in particular from a rear cross member. Driver assistance systems of other vehicles can not unambiguously assign these nonspecific reflection patterns. It may even come so far that a vehicle radar-based is not recognized as such. This makes it difficult for a driver assistance system which works radar-based to initiate suitable responses to different traffic situations.

3 shows a reflection pattern M1 which from the rear bumper 2 out 1 is produced. That of the radar reflectors 2 out 1 generated reflection pattern M1 it allows the vehicle F1 can actually be recognized as a vehicle. In particular, the radar reflectors 2 in a particular arrangement in the rear bumper 1 integrated, so that a subsequent vehicle vehicle according to the invention F1 not only as a vehicle per se, but also the vehicle class, which belongs to the vehicle can recognize. The reflection pattern M1 indicates, for example, a vehicle of the compact class.

The 4a to 4c show further examples of possible arrangements of the radar reflectors 2 in the rear bumper. The 5a to 5c show those of the arrangements of radar reflectors from the 4a to 4c generated reflection pattern M2 to M4 , The arrangement of the radar reflectors 2 out 4a generates the reflection pattern M2 , the arrangement of radar reflectors 2 out 4b generates the reflection pattern M3 and the arrangement of the radar reflectors 4c generates the reflection pattern M4 , The reflection pattern M2 characterizes a vehicle from the middle class, the reflection pattern M3 identifies the vehicle as a small car and the reflection pattern M4 identifies the vehicle as an off-road vehicle.

The arrangements of the radar reflectors shown 2 are merely examples and can be made for any vehicle class and any other way. Furthermore, of course, special arrangements not only for the mentioned vehicle classes, but for all vehicle classes possible. Furthermore, a distinction can be made between vehicle subclasses. The arrangement of the radar reflectors 2 can thus code the vehicle class or the vehicle type.

In reference to 6 an embodiment of a device according to the invention will be explained.

The device is partially in the vehicle F1 and partly in the other vehicle F2 arranged.

The device initially comprises the body part according to the invention 1 , which is the rear bumper of the vehicle F1 is.

The device also includes one in the other vehicle F2 arranged emitter unit 5 , which emits electromagnetic radiation in the frequency range of radar radiation. For example, the emitter unit emits 5 electromagnetic radiation R1 with a frequency of 76 GHz in the direction of the vehicle F1 ,

Furthermore, in the other vehicle F2 a detection unit 4 arranged. This can be the one from the radar reflectors 2 which in the vehicle F1 are arranged, reflected back radiation R2 detect. In particular, the detection unit detects 5 one of the radar reflectors 2 generated reflection pattern M1 to M4 ,

Furthermore, the device according to the invention comprises an allocation unit 6 , The allocation unit 6 may be dependent on the detected reflection pattern M1 to M4 the vehicle F1 Assign to a vehicle class.

The vehicle can F2 radiate the radar continuously.

Alternatively, the device may be one in the other vehicle F2 arranged detection unit 3 include. The registration unit 3 can be configured as a camera that is capable of that in front of the vehicle F2 moving vehicle F1 in a conventional manner. For example, the vehicle F1 detected by a pattern recognition. The radar radiation is in this case only sent out when the camera 3 a vehicle F2 has recorded.

The device according to the invention is used in particular for a driver assistance system. The driver assistance system is, for example, an automatic braking system, which is used for collision avoidance.

A driver assistance system of a following vehicle may in particular depend on the detected pattern M1 to M4 initiate a coordinated response. The information obtained from the reflection patterns, such as size and type of the preceding vehicle, can be taken into account in the reaction of the driver assistance system. In particular, in the event of an unavoidable accident, the driver assistance system may use the information that the risk of injury to vehicle occupants is as low as possible during the impending impact.

By the body part according to the invention 1 In particular, the ability to detect by means of radar sensors can not be improved on the sensor side, but on the vehicle side.

LIST OF REFERENCE NUMBERS

1

Body part; rear shock absorber

2

radar reflector

2.1, 2.2

subareas

2.1 'to 2.3'

subareas

2.1 "to 2.3"

subareas

3

acquisition unit

4

detection unit

5

emitter unit

6

allocation unit

8th

graph

9

graph

M1 to M4

reflection pattern

R1

emitted radar beams

R2

reflected radar beams

F1

vehicle

F2

another vehicle

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007060862 A1 [0003]
• US 3604805 A [0004]

Claims (15)

Body part (1) for a vehicle (F1) comprising a plurality of defined radar reflectors (2) which at least partially reflect back a radar radiation incident thereon in the direction of a radiation source which emitted the radar radiation and which are integrated into the body part (1). Body part (1) after Claim 1 , characterized in that the defined Radarreflektoren (2) are integrated in an arrangement in the body part, with which they produce a certain reflection pattern (M1 to M4) of the radar radiation. Body part (1) after Claim 2 , characterized in that the arrangement of the defined radar reflectors (2) is dependent on the vehicle class of the vehicle (F1), in which the body part (2) is arranged. Body part (1) according to one of the preceding claims, characterized in that each of the defined radar reflectors (2) has at least two reflecting partial surfaces (2.1, 2.2, 2.1 'to 2.3', 2.1 "to 2.3"). Body part (1) after Claim 4 , characterized in that the partial surfaces (2.1, 2.2, 2.1 'to 2.3', 2.1 "to 2.3") are arranged at an angle in a range of 70 ° to 120 ° to each other. Body part (1) after Claim 4 or 5 , characterized in that the partial surfaces (2.1, 2.2, 2.1 'to 2.3', 2.1 "to 2.3") of the defined radar reflectors (2) have edges with an edge length in a range of 20 mm to 100 mm. Body part (1) according to one of Claims 4 to 6 , characterized in that the partial surfaces (2.1, 2.2, 2.1 'to 2.3', 2.1 "to 2.3") are thin films of an electrically conductive material. Body part (1) after Claim 7 , characterized in that the thickness of the films is in a range of 1 micron to 1 mm. Bodywork part (1) according to one of the preceding claims, characterized in that the defined radar reflectors (2) are embedded in the material of the bodywork part (1). Body part (1) according to one of the preceding claims, characterized in that on the body part (1) an apron of material which is transparent to radar radiation, is arranged such that the defined Radarreflektoren (2) are not visible from the outside. Body part (1) according to one of the preceding claims, characterized in that the body part (1) is a bumper of the vehicle (F1). Body part (1) according to one of the preceding claims, characterized in that the body part (1) is attached to the rear of the vehicle (F1). Device for recognizing a vehicle (F1), comprising an emitter unit (4) arranged in the other vehicle (F2), by means of which radar radiation (R1) can be emitted, a body part (1) which is arranged in the vehicle (F1) and which comprises a plurality of defined radar reflectors (2) which at least partly illuminate the part of the radar radiation (R1) emitted by the emitter unit (4) which strikes it, in the direction of the other vehicle Reflect (F2), a detection unit (5) arranged in the other vehicle (F2), which detects the radar radiation (R2) reflected back from the defined radar reflectors (2), and an allocation unit (6) arranged in the other vehicle (F2) which recognizes the vehicle (F1) as a vehicle as a function of the back-reflected radar radiation (R2). Device after Claim 13 , characterized in that the defined radar reflectors (2) are arranged in a specific arrangement in the body part (1), so that the back-reflected radar radiation (R2) is detected by the detection unit (5) as a specific reflection pattern (M1 to M4) Allocation unit (6) in response to the detected reflection pattern (M1 to M4) detects the vehicle class of the vehicle (F1). Vehicle (F1) with a body part (1) according to one of Claims 1 to twelve ,

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