Housing structure for a vehicle radar device and radar device

Abstract

The invention relates to a housing structure (1) for a radar device for a vehicle, the housing structure (1) having a radiation window (2) which is at least partially or partially formed from a plastic material, the material permittivity and permittivity of the plastic material of the radiation window (2) are selected such that electromagnetic waves emitted and / or received by the radar device can pass through the radiation window (2), preferably at least approximately without attenuation, in particular with an attenuation of a maximum of 6 dB when passing through the radiation window (2), and wherein the housing structure (1) has a frame region (3) surrounding the radiation window (2), a heating device (4) is integrated in the frame region, and wherein a filler that increases the thermal conductivity of the plastic material of the radiation window (2) is embedded in the plastic material of the radiation window (2).

Description

[0001] The present invention relates to a radar device for a vehicle, the radar device having at least one antenna element and a housing structure with a radiation window, wherein the radiation window is configured to allow electromagnetic waves emitted and / or received by the radar device to pass through.

[0002] The radar device is in particular a front radar sensor as part of a driver assistance system for enabling higher comfort, safety and driving functions for autonomous driving.

[0003] Especially during autonomous driving, the vehicle must always be able to reliably detect objects and pedestrians and react to them. In particular, the corresponding radar device configured as a front radar device can achieve precise, fast and stable object detection and object tracking by virtue of a large range, a wide viewing angle, a high angular resolution and optionally its own Chirp sequence modulation (Chirp-Sequenz-Modulation), so that the radar device is particularly suitable for complex traffic situations.

[0004] Generally, a radar device is used in a vehicle as a detection system to determine the distance, angle or speed of an object in the vehicle's surroundings relative to the radar device. The radar device typically has: at least one transmitter that generates electromagnetic waves in the radio wave or microwave range; at least one transmitting antenna; at least one receiving antenna; a receiver and a processor. The radio waves emitted by the radar device are reflected by objects in the vehicle's environment. The return signal, i.e., the reflected radio wave, is received by the radar device and gives information about the position and speed of the object.

[0005] The term "radar" is an abbreviation that stands for radio detection and ranging.

[0006] Radar devices, especially front radar devices, are usually affected by weather conditions (such as snow, ice or rain / moisture), which affects the object image resolution of the radar signal. In addition, it is also known that weather conditions can affect the radar signal characteristics, which may lead to false information about the area in front of the vehicle / sampling area in the context of downstream dynamic image analysis. Therefore, there are weather conditions that are unfavorable for radar sensing detection and thus for object recognition, such as in the case of freezing rain. However, even under these weather conditions, reliable vehicle operation is required.

[0007] Therefore, it is particularly necessary to ensure that the radiation window of the radar device housing (through which the electromagnetic waves emitted and / or received by the radar device pass) is as completely protected as possible from moisture and ice.

[0008] To this end, as is known, for example, from publication DE 10 2013 214 286 A1, warm air for defrosting or de-icing the radiation window of a radar sensor is guided to the edge region of the radiation window via an exhaust nozzle which is connected to a vehicle air-conditioning system via an exhaust hose.

[0009] However, such a solution for defrosting and / or de-icing the radiation window of a radar sensor results in relatively high additional manufacturing and assembly costs. In addition, the vehicle has to be configured accordingly so that the additional exhaust hose, which also requires additional design space, can be accommodated.

[0010] Another problem to be considered when using a radar device in a vehicle is that in a relatively hot environment (for example, during midsummer), the temperature inside the radar device housing can rise significantly, which also has an adverse effect on object detection and object recognition achievable in the forward driving area.

[0011] In order to avoid excessive heating of the radar device, especially its electronic components, it is known to provide corresponding ventilation openings in the radar device housing so that an air flow can circulate through the housing, thereby preventing the housing from overheating.

[0012] However, the disadvantage of providing such ventilation openings in the housing is that dirty particles and / or moisture can also enter the housing through the ventilation openings, which again has a negative impact on the operating ability of the radar device.

[0013] Therefore, based on the above problems, the basic object of the present invention is to provide a solution by which the radiation window of the housing structure of a radar device can be reliably defrosted and / or de-iced in an easy-to-implement but still effective manner, while ensuring cooling during summer operation and preventing dirt or moisture from entering the interior of the housing structure of the radar device.

[0014] This object is achieved in particular by a housing structure for a vehicle radar device according to patent independent claim 1, wherein advantageous refinements of the present invention are given in the corresponding dependent claims.

[0015] Therefore, the present invention particularly relates to a housing structure for a vehicle radar device, wherein the housing structure has a radiation window which is at least partially or locally formed of a plastic material.

[0016] The housing structure particularly forms a cover element which is configured such that electromagnetic waves emitted and / or received by at least one antenna (receiving antenna and / or transmitting antenna) of the radar device pass through the radiation window. Thus, at least the radiation window of the housing structure is at least substantially invisible to the electromagnetic waves emitted and / or received by the radar device.

[0017] The housing structure, especially the area of the housing structure that forms the radiation window, is usually arranged upstream of the antenna of the radar device. Therefore, this area can be referred to as a radome or an antenna cover.

[0018] In particular, the material permittivity and dielectric constant of the plastic material of the radiation window are selected such that the electromagnetic waves emitted and / or received by the radar device can preferably pass through the radiation window with at least near-zero attenuation.

[0019] In this regard, "near-zero attenuation" especially means that the electromagnetic waves emitted and / or received by the radar device can pass through the radiation window with an attenuation of at most 6 dB during a single pass.

[0020] In addition to the radiation window, the housing structure also has other parts, especially also made of plastic. Obviously, it is also conceivable that other parts of the housing structure are made of other materials, such as metal. In particular, the housing structure has a frame area that surrounds the radiation window, and a heating device is integrated in this frame area.

[0021] The heating device is especially an electrically operated or electrically operable heating device.

[0022] In order to enable at least part or locally, especially as large an area as possible, of the thermal energy released by the heating device as needed to be transferred to the radiation window of the housing structure, according to the present invention, it is especially proposed that fillers that increase the thermal conductivity of the plastic material of the radiation window are embedded in the plastic material of the radiation window.

[0023] In this case, the dielectric constant of the fillers embedded in the plastic material of the radiation window, which improve / increase the thermal conductivity of the plastic material of the radiation window, is selected such that these fillers are at least substantially transparent to the electromagnetic waves emitted and / or received by the radar device.

[0024] Fillers made of boron nitride (especially hexagonal boron nitride), fillers made of magnesium oxide, fillers made of aluminum oxide, fillers made of aluminum nitride, fillers made of aluminum silicate, and / or fillers made of zinc sulfite have proven to be particularly suitable as fillers for embedding in the plastic material of the radiation window.

[0025] The above-mentioned fillers are outstanding in that these fillers are electrically insulating and have high thermal conductivity. The resistance of the fillers ranges between 10 11 Ωx m and 10 20 Ωx m (ohm-meter), while the thermal conductivity ranges between 14 Watt / mK and 400 Watt / mK (watt / (meter·kelvin)).

[0026] Of course, other suitable electrically insulating fillers can also be considered.

[0027] According to an embodiment of the housing structure according to the present invention, the heating device integrated in the frame region surrounding the radiation window has a strip conductor assembly preferably fully integrated in the material of the frame region, and the strip conductor assembly is configured such that when a voltage / current is applied to the strip conductor assembly, at least the frame region of the housing structure is at least locally heated due to the power loss associated with the (ohmic) resistance of the strip conductor assembly.

[0028] In a particularly easy-to-implement but still effective manner, the strip conductor assembly can be formed by means of a printing process, especially in the case of using a conductive ink. It is also proposed that the strip conductor assembly has at least one strip conductor formed by means of a printing process, especially a silver paste printing process. [[ID=A]]

[0029] However, alternatively, it can also be envisaged that the heating device integrated in the frame region surrounding the radiation window is formed by a conductive filler at least partially embedded in the material of the frame region, especially a plastic material. Copper particles, aluminum particles, iron particles, silver particles and / or graphite particles are provided as suitable fillers. As an addition or alternative, fillers made of carbon black and / or CNT (carbon nanotube) can also be used.

[0030] The advantage of this solution of configuring the heating device in the frame region surrounding the radiation window is that the entire housing structure can be manufactured by means of an injection molding process.

[0031] In particular, the conductive filler is at least partially embedded in the material of the frame region of the housing structure, especially a plastic material, such that when a voltage / current is applied to the region in which the conductive filler is embedded, at least the frame region of the housing structure is at least locally heated due to the power loss associated with the resistance of this region.

[0032] It is particularly preferably proposed that fillers that increase the thermal conductivity of the material / plastic material are embedded in the material of the frame region, especially a plastic material, at least in one region of the frame region of the housing structure.

[0033] Equally preferably, these fillers are fillers made of boron nitride (especially hexagonal boron nitride), fillers made of magnesium oxide, fillers made of aluminum oxide, fillers made of aluminum nitride, fillers made of aluminum silicate and / or fillers made of zinc sulfite, where, however, other fillers can also be envisaged in principle.

[0034] In this regard, it is preferably proposed that the region of the frame region of the housing structure in which fillers that increase the thermal conductivity of the material are embedded is in thermally conductive connection with the radiation window of the housing structure.

[0035] For example, it is conceivable and preferred that a region of the frame region of the housing structure, in which a filler for increasing the thermal conductivity of the material is embedded in the material of the frame region, is integrally formed with the radiation window.

[0036] A significant advantage of these implementation variants is that the thermal energy released by the heating device can reach the radiation window particularly well in a heat-conducting manner.

[0037] On the other hand, by using such a filler that increases the thermal conductivity of the material of the frame region of the housing structure, passive cooling of the radiation window can be achieved in summer, for example, because the thermal energy is transferred (removed) from the radiation window to the frame region of the housing structure, which results in cooling of the radar device at least partially or locally accommodated by the housing structure.

[0038] Preferably, the frame region of the housing structure, in particular the region of the frame region of the housing structure in which the heating device is integrated, is completely coated with a plastic material, in particular by means of an injection molding process, in order to achieve encapsulation of the heating device, which provides particularly efficient protection against weather influences.

[0039] An embodiment of the housing structure according to the invention provides that the housing structure is implemented as a multi-layered and in particular three-layered body, in particular manufactured by means of a plastic injection molding process, wherein the multi-layered body has an outer layer made of at least substantially radar-transparent plastic material, in which a filler for increasing the thermal conductivity of the plastic material is at least locally embedded.

[0040] In addition to the outer layer, an intermediate layer is also used, which is also made of plastic material, wherein a heating device is at least locally formed in the intermediate layer.

[0041] Finally, an inner layer made of plastic material is optionally provided, which covers the intermediate layer, in particular the heating device, thereby achieving encapsulation of the heating device.

[0042] The above-mentioned layers of the housing structure body are preferably formed in a three-dimensional manner.

[0043] Here, in principle, it is conceivable that the plastic material of the outer layer is the same as or at least substantially the same as the plastic material of the intermediate layer and / or the inner layer.

[0044] In order to supply electrical energy to the preferably completely encapsulated heating device, the housing structure preferably has electrical connection terminals guided through the inner layer.

[0045] The invention also relates to a component for temperature control of a radar sensor in a vehicle, which is in particular used for defrosting and / or de-icing the radar sensor as required and for cooling as required.

[0046] The component has at least one radar sensor and a housing associated with the at least one radar sensor, and the at least one radar sensor is at least partially or locally received in the housing.

[0047] In this regard, it is particularly proposed that the housing associated with the at least one radar sensor is at least partially or locally formed by the housing structure of the type according to the present invention.

[0048] In this regard, it is recommended that at least one radar sensor of the component is preferably received in the housing in a fully encapsulated manner.

[0049] Finally, the present invention relates to a radar device for a vehicle, wherein the radar device has at least one antenna element and the housing structure of the type according to the present invention. Here, the radiation window of the housing structure is designed such that electromagnetic waves emitted and / or received by the at least one radar device pass through the radiation window, and the at least one antenna element is arranged adjacent to the radiation window.

[0050] The present invention will be described in more detail with reference to the accompanying drawings and by means of embodiments.

[0051] In the drawings:

[0052] Figure 1 An exemplary embodiment of the housing structure according to the present invention is schematically shown in a top view of the radiation window;

[0053] Figure 2 Schematically shown along Figure 1 the section line A-A in

[0054] Figure 3 Schematically shown according to Figure 1 a decomposition view of the individual components of an exemplary embodiment of the housing structure according to the present invention.

[0055] The exemplary embodiment of the housing structure 1 according to the present invention shown in the drawings is a housing structure 1 for a vehicle radar device (not shown in the drawings).

[0056] The housing structure 1 is on the one hand used to protect the radar device, in particular at least one antenna element of the radar device, from the intrusion of dust and water.

[0057] On the other hand, the housing structure 1 provides active temperature control and passive temperature control for the radar device or the radar sensor received in the housing structure 1.

[0058] The active temperature control is carried out by the heating device 4 integrated in the housing structure 1, and the passive cooling of the radar sensor received in the housing structure 1 is achieved based on the optimized thermal conductivity of the housing structure 1.

[0059] The housing structure 1 has a radiation window 2 that is at least partially or locally formed of a plastic material, wherein the material permittivity and dielectric constant of the plastic material of the radiation window 2 are respectively within the typical ranges for radar applications. Thus, the material of the radiation window 2 is invisible to the electromagnetic waves of the radar device.

[0060] As can especially be seen from Figure 2 the cross-sectional view, the housing structure 1 has a frame region 3 that surrounds the radiation window 2, and a heating device 4 is integrated in this frame region.

[0061] It is especially proposed here that fillers are embedded in the plastic material of the radiation window 2, and these fillers increase the thermal conductivity of the plastic material of the radiation window 2.

[0062] These fillers that increase the thermal conductivity of the plastic material are preferably boron nitride.

[0063] Although not shown in the drawings, it is conceivable that the heating device 4 integrated in the frame region 3 that surrounds the radiation window 2 of the housing structure 1 has a strip conductor assembly that is preferably fully integrated in the material of the frame region 3, and this strip conductor assembly is configured such that when a voltage and / or a current is applied to the strip conductor assembly, at least the frame region 3 of the housing structure 1 is at least locally heated, specifically due to the power loss associated with the ohmic resistance of the strip conductor assembly.

[0064] In this regard, it is especially conceivable that the strip conductor assembly has corresponding strip conductors formed by a printing process, especially a silver paste printing process.

[0065] Alternatively, the heating device 4 integrated in the frame region 3 that surrounds the radiation window 2 can also be formed by conductive fillers that are at least partially embedded in the material of the frame region 3 of the housing structure 1, especially a plastic material.

[0066] These conductive fillers are, for example, copper particles, aluminum particles, iron particles, or graphite particles, and / or particles made of carbon black and / or CNT (carbon nanotubes).

[0067] In this design, the conductive fillers should be at least partially embedded in the material of the frame region 3 of the housing structure 1, especially a plastic material, so that when a voltage and / or a current is applied to the region in which the conductive fillers are embedded, at least the frame region 3 of the housing structure 1 is at least locally heated due to the power loss associated with the resistance of this region.

[0068] Likewise, in an exemplary embodiment of the housing structure 1 according to the present invention shown in the drawings, it is also proposed that fillers for increasing the thermal conductivity of the material are embedded in the material of the frame region 3, in particular in a plastic material, at least in a region of the frame region 3 of the housing structure 1.

[0069] It is hereby proposed that a region of the frame region 3 of the housing structure 1 in which fillers for increasing the thermal conductivity of the material are embedded in the material of the frame region 3 is in thermally conductive connection with the radiation window 2 of the housing structure 1.

[0070] An exemplary embodiment of the housing structure 1 according to the present invention is preferably formed entirely of a plastic material as part of an injection molding process.

[0071] Reference Figure 3 to the drawings shows that an exemplary embodiment of the housing structure 1 according to the present invention has an outer layer 5 that is three-dimensional and made of at least substantially radar-transparent plastic material, in which fillers for increasing the thermal conductivity are at least partially embedded.

[0072] The housing structure 1 also has an intermediate layer 6 made of a plastic material, in particular a three-dimensional layer, in which a heating device 4 is at least partially formed.

[0073] The housing structure 1 also includes an inner layer 7 made of a plastic material, in particular a three-dimensional inner layer 7 made of a plastic material, which covers the intermediate layer 6, in particular the heating device 4.

[0074] From Figure 3 the exploded view in it can also be seen that the housing structure 1 has electrical connection terminals 8 that are guided through the inner layer 7 and are used to supply electrical energy to the heating device 4 integrated in the intermediate layer 6 as needed.

[0075] The present invention is not limited to the exemplary embodiments shown in the drawings, but rather results from an overview of all the features disclosed herein.

[0076] List of reference numerals

[0077] 1 Housing structure

[0078] 2 Radiation window

[0079] 3 Frame region

[0080] 4 Heating device

[0081] 5 Outer layer

[0082] 6 Intermediate layer

[0083] 7 Inner layer

[0084] 8 Electrical connection terminal

Claims

1. A housing structure (1) for a vehicle radar device, wherein, The housing structure (1) includes a radiation window (2) formed at least partially or locally of a plastic material, wherein the material permittivity and dielectric constant of the plastic material of the radiation window (2) are selected such that electromagnetic waves emitted and / or received by the radar device can preferably pass through the radiation window (2) with at least near-zero attenuation, especially with an attenuation of at most 6 dB during a single pass, and wherein the housing structure (1) includes a frame region (3) surrounding the radiation window (2), in which a heating device (4) is integrated, and wherein a filler for increasing the thermal conductivity of the plastic material of the radiation window (2) is embedded in the plastic material of the radiation window (2).

2. The housing structure (1) according to claim 1, Among them, The dielectric constant of the filler embedded in the plastic material of the radiation window (2) is selected such that the filler is at least substantially transparent to the electromagnetic waves emitted and / or received by the radar device.

3. The housing structure (1) according to claim 1 or 2, Among them, The filler embedded in the plastic material of the radiation window (2) includes boron nitride, especially hexagonal boron nitride, magnesium oxide, aluminum oxide, aluminum nitride, aluminosilicate, and / or zinc sulfite.

4. The housing structure (1) according to any one of claims 1 to 3, Among them, The heating device (4) integrated in the frame region (3) surrounding the radiation window (2) includes a strip conductor assembly preferably fully integrated in the material of the frame region (3), the strip conductor assembly being configured such that when a voltage is applied and / or current is supplied, the strip conductor assembly at least locally heats the frame region (3) of the housing structure (1) due to power losses associated with the ohmic resistance of the strip conductor assembly.

5. The housing structure (1) according to claim 4, Among them, The strip conductor assembly includes at least one strip conductor formed by a printing process, especially a silver paste printing process.

6. The housing structure (1) according to any one of claims 1 to 3, Among them, The heating device (4) integrated in the frame region (3) surrounding the radiation window (2) is formed by a conductive filler at least locally embedded in the material of the frame region (3), especially a plastic material, the conductive filler being especially copper, aluminum, iron, silver, graphite, carbon black, and / or CNT (carbon nanotube).

7. The housing structure (1) according to claim 6, Among them, The conductive filler is at least locally embedded in the material of the frame region (3), especially a plastic material, such that when a voltage is applied to and / or current is supplied to the region in which the conductive filler is embedded, the frame region (3) of the housing structure (1) is at least locally heated due to power losses associated with the ohmic resistance of the region.

8. The housing structure (1) according to any one of claims 1 to 7, Among them, In at least one region of the frame region (3) of the housing structure (1), a filler that increases the thermal conductivity of the material of the frame region (3), in particular a plastic material, is embedded in the material of the frame region (3), in particular a plastic material; wherein the filler embedded in the material of the frame region (3), in particular a plastic material, preferably comprises boron nitride, in particular hexagonal boron nitride, magnesium oxide, aluminum oxide, aluminum nitride, aluminosilicate and / or zinc sulfite.

9. The housing structure (1) according to claim 8, Among them, The region of the frame region (3) of the housing structure (1) in which a filler for increasing the thermal conductivity of the material is embedded in the material of the frame region (3) is in thermally conductive connection with the radiation window (2).

10. The housing structure (1) according to claim 8 or 9, Among them, The region of the frame region (3) of the housing structure (1) in which a filler for increasing the thermal conductivity of the material is embedded in the material of the frame region (3) is integrally formed with the radiation window (2).

11. The housing structure (1) according to any one of claims 1 to 10, Among them, The frame region (3) of the housing structure (1), in particular the region of the frame region (3) of the housing structure (1) in which the heating device (4) is integrated, is preferably completely coated with a plastic material, in particular as part of an injection molding process.

12. The housing structure (1) according to any one of claims 1 to 11, Among them, The housing structure (1) is configured as a multi-layered and in particular three-layered body, in particular manufactured by means of a plastic injection molding process, wherein the multi-layered body comprises: - an outer layer (5) made of at least substantially radar-transparent plastic material, in which a filler for increasing the thermal conductivity is at least partially embedded; - an intermediate layer (6) made of plastic material, in which the heating device (4) is at least partially arranged; and - an optional inner layer (7) made of plastic material, which covers the intermediate layer (6), in particular covers the heating device (4).

13. The housing structure (1) according to claim 12, Among them, The plastic material of the outer layer (5) is preferably the same as or at least substantially the same as the plastic material of the intermediate layer / or the inner layer (6, 7).

14. The housing structure (1) according to claim 12 or 13, Among them, The housing structure (1) comprises electrical connection terminals (8), which are in particular guided through the inner layer (7) and are used to supply electrical energy to the heating device (4) as required.

15. A component for temperature control of a radar sensor in a vehicle, in particular for defrosting and / or de-icing the radar sensor as required and for cooling as required, wherein, The assembly comprises: - at least one radar sensor; and - a housing associated with the at least one radar sensor, wherein the at least one radar sensor is at least partially or locally accommodated in the housing, wherein the housing associated with the at least one radar sensor is at least partially or locally formed by the housing structure (1) according to any one of claims 1 to 14.

16. The assembly according to claim 15, Among them, The at least one radar sensor is preferably accommodated in the housing in a fully encapsulated manner.

17. A radar device for a vehicle, wherein, The radar device comprises at least one antenna element and a housing structure (1) according to any one of claims 1 to 14, wherein a radiation window (2) of the housing structure (1) is configured to allow electromagnetic waves emitted and / or received by the at least one antenna element to pass through the radiation window (2), and wherein the at least one antenna element is arranged adjacent to the radiation window (2).

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