Camera arrangement for a vehicle, and method for operating a camera arrangement

Abstract

The invention relates to a camera arrangement (1) for a vehicle, comprising: an interior camera (11) which is directed into a vehicle interior of the vehicle; an exterior camera (12) which is arranged on an inner side of a vehicle window (2) of the vehicle and is configured to detect a detection region lying outside the vehicle through a through-region (21) of the vehicle window; and a heat transfer element (13) for transferring waste heat produced during operation of the interior camera (11) to the through-region (21) of the vehicle window (2).

Description

[0001] Camera arrangement for a vehicle and method for operating a camera arrangement

[0002] The present invention relates to a camera arrangement for a vehicle and a method for operating such a camera arrangement. In particular, the invention relates to a camera arrangement comprising an interior camera directed into the interior of a vehicle for detecting one or more vehicle occupants and an exterior camera arranged on the inside of a vehicle window for detecting the vehicle's surroundings within the context of an automated driving function.

[0003] Various driver assistance systems are known from the current state of the art, which can increase safety and / or comfort for a driver or vehicle occupants by providing automated driving functions. For example, driver assistance systems can take over certain driving tasks or even control the vehicle autonomously within the framework of partially automated driving, highly automated driving, or fully automated driving.

[0004] Examples of driver assistance systems that automatically intervene in vehicle control include longitudinal guidance systems, lateral guidance systems, and systems with coupled longitudinal and lateral guidance. Some common longitudinal guidance systems are automatic speed limiting, automatic cruise control (for example, Dynamic Cruise Control - DCC in BMW Group vehicles), or adaptive cruise control (Adaptive Cruise Control or Active Cruise Control - ACC). Examples of systems that also intervene in lateral guidance include lane keeping assistants or steering and lane guidance assistants. Lateral guidance systems, longitudinal guidance systems, or coupled longitudinal and lateral guidance systems can, for example, implement a so-called hands-off or feet-off functionality, which relieves the driver of certain steering or other control functions.Take over pedal operation tasks.

[0005] Typically, such driver assistance systems utilize environmental sensors to detect the vehicle's surroundings. These sensors may include an external camera, particularly one facing forward. Such an external camera, sometimes also called a driving camera, is often mounted on the inside of the windshield and configured to capture the area in front of the vehicle through a clear section of the windshield. This clear section refers to an area of ​​the windshield within the external camera's field of view, allowing the camera to detect the surroundings through this optically transparent portion of the windshield.

[0006] For certain automated driving functions to be available, it is crucial that the exterior camera has a clear view. To ensure a consistently clear view for the exterior camera through the window's clear opening, an electric window heater is often provided. This heater warms the clear opening, preventing condensation, such as moisture, ice, or snow. For example, the window heater can consist of one or more heating wires extending through the clear opening in the window.

[0007] A disadvantage of such an electric windshield heater is that it requires dedicated electrical energy from the vehicle's electrical system.

[0008] In addition to one or more external cameras of the type described above, modern motor vehicles often include one or more interior cameras installed inside the vehicle. These can be used to monitor the driver's condition, for example, their attention or fatigue, and potentially other occupant-related information that may be relevant, for example, for the operation of an automated driving function.

[0009] Conventional interior cameras typically generate a significant amount of heat in a small installation space and therefore require cooling. This cooling is usually achieved using the airflow from the vehicle's climate control system. To ensure optimal coverage of relevant areas of the vehicle interior, interior cameras are generally mounted near the rearview mirror and overhead consoles. This places them in close proximity to the area of ​​the windshield that needs to be kept clear of fog and ice for the exterior camera. The close proximity of the interior camera, which needs cooling, and the area of ​​the windshield that needs heating results in low energy efficiency for the overall system.

[0010] It is an object of the present invention to provide a camera arrangement and a method for operating a camera arrangement which at least partially overcome the disadvantages described in the prior art.

[0011] This task is solved by the subject matter of the independent claims. Advantageous further developments are specified in the dependent claims.

[0012] A first aspect of the invention relates to a camera arrangement for a vehicle. The camera arrangement comprises an interior camera directed into the interior of the vehicle and an exterior camera which is arranged on the inside of a vehicle window and configured to capture a detection area located outside the vehicle through a passage area of ​​the vehicle window.

[0013] The interior camera can be arranged and configured in a manner known per se, particularly for recording one or more vehicle occupants. For example, the interior camera can be specifically directed at the face of the vehicle's driver and provide relevant information for attention monitoring or similar purposes.

[0014] For example, the interior camera can be located in or on an interior rearview mirror of the vehicle.

[0015] The external camera can be, in particular, a forward-facing camera that provides information about a section of the vehicle's surroundings in front of it to a driver assistance system. For example, this information can be used to operate a lateral and / or longitudinal automated driving function, such as adaptive cruise control, lane keeping assist, steering and lane guidance assist, or a highway pilot.

[0016] For example, the external camera can be mounted above the rearview mirror on the vehicle's windshield. Accordingly, the area of ​​the vehicle's windshield that can be seen through the camera can extend approximately above the rearview mirror, in or on which the internal camera may be positioned.

[0017] The external camera can be attached to the inside of the vehicle window, for example, using a plastic bracket. This bracket can be shaped to also act as a light shield. For instance, the bracket can frame the area of ​​the window through which the camera passes, blocking light entering through this area, particularly light coming from the sides and rear.

[0018] According to the invention, the camera arrangement further includes a heat transfer element which is designed and arranged to transfer waste heat generated during the operation of the interior camera to the passage area of ​​the vehicle window.

[0019] The statement that the heat transfer element is designed and arranged to transfer waste heat to the passage area does not refer only to embodiments in which the heat transfer element extends completely from the interior camera to the passage area. Rather, according to some embodiments, the heat transfer element may also constitute only a partial section of a heat transfer path from the interior camera to the passage area.

[0020] The invention is based on the idea that, considering the disadvantages described above regarding the need for active heating of the area of ​​the vehicle window in front of the exterior camera on the one hand, and active cooling of the interior camera on the other, necessity can be turned into a virtue by directing at least some of the waste heat generated by the interior camera to the area of ​​the window in order to achieve a heating effect and keep the area of ​​the vehicle window (and thus the field of view of the exterior camera) free of ice and condensation. This allows the waste heat already present in the interior camera to be used effectively. The heat transfer element creates a synergy between the interior camera with its waste heat and the exterior camera with the area of ​​the window to be heated, which increases the overall energy efficiency of the camera system.

[0021] For example, the heat transfer element can extend from the housing of the interior camera towards the area where the windshield passes through. If the interior camera is integrated into a rearview mirror, the heat transfer element can, for example, extend from the housing of the rearview mirror towards the area where the windshield passes through.

[0022] The heat transfer element can extend so far that it reaches the passage area, i.e., is in contact with it; however, this is not necessarily the case.

[0023] For example, it is also conceivable to use embodiments in which the heat transfer element extends from a housing of the interior camera or the interior mirror to a diffusion aperture of the exterior camera, with the diffusion aperture enclosing the passage area of ​​the vehicle window.

[0024] In general, embodiments are possible in which the heat transfer element extends from such a scattering light aperture, which surrounds the passage area, in the direction of the interior camera (such as at least to a housing of the interior camera or an interior mirror in which the interior camera is integrated).

[0025] According to one possible embodiment, the heat transfer element is designed to transfer the waste heat to the passage area, at least partially (for example, section by section), by means of an airflow. In other words, the heat transfer element can be configured to facilitate the targeted transfer of waste heat to the passage area by utilizing the physical principle of heat convection. The airflow transporting the waste heat can be a passive airflow. For example, a chimney effect can be utilized. This is particularly feasible due to the upward rise of waste heat when the passage area of ​​the vehicle window is located above the interior camera.

[0026] The heat transfer element can, for example, comprise or consist of at least one pipe element and / or at least one hose element. The pipe and / or hose element can be designed and arranged in such a way that it directs an airflow towards the area through which the vehicle window passes, thereby transferring the waste heat. For example, the heat transfer element can include a rigid plastic tube.

[0027] It is also within the scope of the invention that the heat transfer element can be designed and arranged to accomplish the transfer of waste heat from the indoor camera to the passage area of ​​the outdoor camera, at least partially (for example, section by section), by utilizing the physical principle of heat conduction. For example, the heat transfer element can comprise a metallic thermal conductivity element to enable heat conduction. The thermal conductivity element can, for example, comprise copper or another highly thermally conductive metal.

[0028] As already mentioned, the interior camera can be arranged in or on a rearview mirror of the vehicle (i.e., integrated into the rearview mirror, for example). According to one possible embodiment, the heat transfer element can comprise a section of a (particularly metallic) rearview mirror base and / or a (particularly metallic) rearview mirror mounting plate, wherein the rearview mirror is attached to the vehicle windshield by means of the rearview mirror base and / or the rearview mirror mounting plate. The rearview mirror base and / or the rearview mirror mounting plate can form at least part of a heat conduction path between the interior camera and the area through which the vehicle windshield passes.

[0029] The camera arrangement can further include at least one heating wire located in the passage area of ​​the vehicle window. For example, the heating wire can be electrically heated to keep the passage area free of ice and fog.

[0030] According to a further development, the camera arrangement is configured to transfer heat from the indoor camera to the at least one heating wire via a heat transfer element. The statement that the waste heat is transferred to the at least one heating wire via the heat transfer element means that the heat transfer element forms at least a part (for example, a section) of a heat transfer path between the indoor camera and the heating wire. It is therefore possible, but not necessarily intended, for the heat transfer element to be in direct contact with the indoor camera and / or directly with the heating wire.

[0031] By selectively transferring the waste heat from the interior camera to the heating wire in the passageway, the passageway can be heated by the heating wire using the waste heat already present from the interior camera, thus keeping it free of ice and condensation. According to some embodiments, the heating wire can also be electrically heated. However, embodiments are also conceivable in which the window heating in the passageway does not require an additional electrical supply to the heating wires, and the heating is achieved solely or essentially solely by the waste heat from the interior camera supplied via the heat transfer element.

[0032] A second aspect of the invention is a method for operating a camera arrangement of the type described in the preceding paragraph, namely a camera arrangement in which at least one heating wire is provided in the passage area of ​​the vehicle window. According to the method, the at least one heating wire is supplied with electrical power depending on the operating state of the interior camera in order to keep the passage area free of ice and fog. In particular, the supply of electrical power to the heating wire can be dependent on whether the interior camera is switched on and consequently produces waste heat.

[0033] For example, it can be arranged that at least one heating wire is periodically supplied with electrical power for a specific on-time, followed by a specific off-time. By varying the on-time and off-time, the average electrical power used to heat the area of ​​the vehicle window can be set. If the interior camera is active and therefore produces heat, which is transferred via the heat-conducting element towards the area of ​​the window and thus contributes to heating it, the on-time can be shortened and / or the off-time lengthened to save electrical energy. In some cases, it may even be possible to forgo electrical heating altogether when the interior camera is switched on.

[0034] As a result, the camera arrangement according to the invention can be operated in a particularly energy-efficient manner.

[0035] The invention will now be explained in more detail with reference to exemplary embodiments and the accompanying drawings. These show:

[0036] Fig. 1 shows a conventional camera arrangement with an interior camera integrated into an interior mirror and an exterior camera. Figs. 2A-B show schematic representations of exemplary embodiments of a camera arrangement according to the invention with an interior camera, an exterior camera, and a heat-conducting element.

[0037] Figure 1 shows a conventional camera arrangement in a vehicle with an interior camera 11 integrated into an interior rearview mirror 3 for capturing the driver's position, and an exterior camera 12 arranged above the interior rearview mirror 3 on the windshield 2 of the vehicle. The exterior camera 12 is designed to capture the area in front of the vehicle and can, for example, provide environmental information for an automated driving function such as a lane keeping assist, a steering and lane guidance assist, or a relative distance control. The exterior camera 12 is at least partially mounted in a bracket 121 attached to the windshield 2 below the overhead console, which also serves as a light shield. The light shield 121 encloses a passage area of ​​the windshield 2 (concealed by the light shield 121 in Figure 1) through which the exterior camera 12 captures the area in front of the vehicle.

[0038] Figures 2A and 2B each show an embodiment of a camera arrangement 1 according to the invention in a side cross-sectional view. The camera arrangements 1 according to Figures 2A and 2B are fundamentally constructed like the conventional camera arrangement shown in Figure 1; however, they differ from the conventional camera arrangement in that each additionally includes a dedicated heat transfer element 13 for transferring waste heat generated during the operation of the interior camera 11 to the passage area 21 of the windshield 2. In this way, the waste heat generated by the interior camera 11 can be used to heat the passage area 21 of the windshield 2, which is relevant for the view from the outside by the exterior camera 12, and thus keep it free of ice and fogging.

[0039] In the embodiment shown in Fig. 2A, the heat transfer element 13 is designed as a pipe element to guide a warm airflow from the interior camera to the lens hood. For example, the pipe element 13 can be made of hard plastic. In other words, the embodiment shown in Fig. 2A uses a chimney principle to direct the warm exhaust air from the interior camera 11 onto the passage area 21 of the windshield 2, which is relevant for the view of the exterior camera 12. Through its upper opening, the pipe element 13 can feed the warm air generated by the interior camera 11 below directly into the space enclosed by the bracket / lens hood 121, which borders the passage area 21 of the windshield 2, thus heating the passage area 21 of the windshield 2.For example, the bracket 121, which also functions as a stray light shield, can be shaped in such a way that, together with the passage area 21 of the windshield 2, it defines an essentially closed cavity into which the waste heat from the interior camera 11 is introduced by means of the heat transfer element 13.

[0040] In contrast, in the embodiment shown in Fig. 2B, heat transfer occurs not by means of convection, but by means of conduction. The waste heat from the interior camera 11 is first conducted to the windshield 2 via a metallic interior mirror base 31 and a metallic interior mirror mounting plate 32, by means of which the interior mirror 3 is attached to the windshield 2. For example, the interior mirror mounting plate 32 can be bonded to the windshield 2. The interior mirror base 31 and / or the interior mirror mounting plate 32 can, for example, be made entirely or partially of aluminum.

[0041] Furthermore, a heat transfer element 13 in the form of a metallic heat-conducting element is provided. The heat-conducting element 13 extends from the interior mirror base plate 32 to the passage area 21 of the windshield 2. The heat-conducting element 13 is in contact with one or more heating wires (not shown in Fig. 2B) that extend within the passage area 21 in the windshield 2. The waste heat from the interior camera 11 can thus be fed into the heating wire(s) via the interior mirror base 31, the interior mirror base plate 32, and the metallic heat-conducting element 13, thereby contributing to the heating of the passage area 21 of the windshield 2.

[0042] For example, the heating wire(s) and / or the heat-conducting element 13 may be made of or comprise a particularly conductive metal, such as copper.

[0043] In addition to the waste heat from the interior camera 11 being supplied via the heat-conducting element 13, the heating wire(s) can also be electrically heated. It can be provided that the heating wire(s) are supplied with electrical power depending on the operating state of the interior camera 11. For example, an electrical heating cycle can be adjusted in the switched-on state of the interior camera 11 such that, on average, less electrical power is used to heat the passage area 21 than in the switched-off state of the interior camera 11, since the waste heat from the interior camera 11 is also supplied to the heating wire(s) when the interior camera 11 is switched on. The embodiments according to Figures 2A and 2B can also be combined with each other.This means that several heat transfer elements 13 can be provided, which, for example, are based partly on a chimney effect and partly on heat conduction. For example, in the embodiment according to Fig. 2A, it is conceivable that an additional metallic heat-conducting element extends through the pipe element 13, so that, in addition to heat transfer by means of heat convection, heat can also be conducted directly from the interior camera 11 towards the passage area 21 by means of heat conduction. For example, the heat-conducting element located inside the pipe element 13 can be connected to one or more heating wires extending into the passage area 21, as described above with reference to the embodiment according to Fig. 2B.

[0044] As a result, the described embodiments each represent a particularly energy-efficient camera arrangement 1, in which the waste heat generated anyway by the interior camera 11 is advantageously used to heat the passage area 21 of the windshield 2 in front of the exterior camera 12, which is to be kept free of ice and fog.

Claims

Patent claims 1. Camera arrangement (1) for a vehicle, comprising an interior camera (11) directed into the interior of the vehicle; an exterior camera (12) arranged on the inside of a vehicle window (2) of the vehicle and configured to capture an area outside the vehicle through a passage (21) of the vehicle window (2); and a heat transfer element (13) for transferring waste heat generated during the operation of the interior camera (11) to the passage (21) of the vehicle window (2).

2. Camera arrangement (1) according to claim 1, wherein the heat transfer element (13) extends from a housing (111) of the interior camera (11) or of an interior mirror (3) in which the interior camera (11) is integrated, in the direction of the passage area (21).

3. Camera arrangement (1) according to one of the preceding claims, wherein the heat transfer element (13) extends from a stray light aperture (121) enclosing the passage area (21) in the direction of the interior camera (11).

4. Camera arrangement (1) according to one of the preceding claims, wherein the heat transfer element (13) is arranged to accomplish the transfer of waste heat to the passage area (21) at least partially by means of an airflow.

5. Camera arrangement (1) according to one of the preceding claims, wherein the heat transfer element (13) comprises at least one tube element and / or at least one hose element.

6. Camera arrangement (1) according to one of the preceding claims, wherein the heat transfer element (13) is configured to accomplish the transfer of waste heat to the passage area (21) at least partially by means of heat conduction.

7. Camera arrangement (1) according to one of the preceding claims, wherein the heat transfer element (13) comprises a metallic heat conducting element.

8. Camera arrangement (1) according to one of the preceding claims, wherein the interior camera (11) is arranged in or on an interior mirror (3) of the vehicle.

9. Camera arrangement (1) according to claim 8, wherein the heat transfer element (13) comprises a section of an interior mirror base (31) and / or an interior mirror base plate (32), wherein the interior mirror (3) is attached to the vehicle window (2) by means of the interior mirror base (31) and / or the interior mirror base plate (32).

10. Camera arrangement (1) according to one of the preceding claims, further comprising at least one heating wire arranged in the passage area (21) of the vehicle window (2).

11. Camera arrangement (1) according to claim 10, wherein the camera arrangement (1) is configured to transfer the waste heat to the at least one heating wire by means of the heat transfer element (13).

12. Method for operating a camera arrangement (1) according to claim 10 or 11, wherein the at least one heating wire is supplied with electrical power depending on an operating state of the interior camera (11).

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