Motor vehicle with an optical arrangement for detecting interior objects in the invisible spectral range

Abstract

Motor vehicle (1), comprising: - a vehicle interior (2) with a cockpit area (4) which is at least partially bounded by a windshield (5) and an instrument panel (6) arranged below it, and an interior mirror (7) arranged in front of or above an upper section (5a) of the windshield (5) as well as - an optical arrangement (9) designed for indirect cockpit area detection from above, comprising the following: - a reflective section (10) of the windshield (5) which is designed on the inside of the vehicle to reflect detection light (11) in a predetermined invisible spectral range, in particular infrared light, and - an upper detection device (12) arranged in the interior of the vehicle (2) on the interior mirror (7) or in its vicinity, facing the reflective section (10) of the windshield (5), which is arranged and designed to detect the detection light (11) that is reflected vertically or at least obliquely upwards by objects located in the cockpit area (4) in the direction of the reflective section (10) of the windshield (5) and from there to the upper detection device (12).

Description

Technical field

[0001] The invention relates to a motor vehicle with an optical arrangement for detecting interior objects in the invisible electromagnetic spectral range, in particular in the infrared range. Technical background

[0002] To ensure the correct and reliable functioning of the many auxiliary and control systems on board a modern motor vehicle, which are crucial for its operation or occupant safety, continuous monitoring of the vehicle interior is common practice. At least part of this monitoring is typically based on optical detection. To enable sufficient optical detection, the interior is illuminated with light in the appropriate wavelength range. To avoid disturbing the occupants with visible light, this illumination is predominantly in the invisible light spectrum (most often using infrared light). For these reasons, a motor vehicle typically incorporates several systems capable of processing light in the invisible spectrum.

[0003] Optical detection has so far almost exclusively taken place via a direct optical path, where the detection device (e.g., a camera) has a direct line of sight to the object to be detected. Beyond this, only in specific cases where the position or condition of the driver's eyes needs to be precisely monitored while driving is it known to detect the driver's face frontally via a light path similar to that used in head-up displays. This path is reflected off the windshield and leads to an infrared camera located in the vehicle's instrument panel.

[0004] For example, US Patent 5,734,357 A discloses a display device for projecting a virtual image containing vehicle-related information into the driver's field of vision while driving, also known as a head-up display (HUD). The optical unit of the HUD, as described in US Patent 5,734,357 A, which is mounted in the vehicle's instrument panel, includes, in addition to components for generating the display image, an adjustable mirror for adapting the HUD's optical path to the driver's current eye position, and an infrared camera for photographing the driver's face. The infrared light reflected from the driver's face travels backward to the infrared camera via the HUD's optical path; that is, it is also reflected off a combiner lens of the HUD, which is part of the windshield. The driver's eye position is determined from the photographed image, and the mirror is adjusted accordingly.

[0005] Furthermore, US 2002 / 0116106 A1 discloses a motor vehicle with a monitoring arrangement comprising one or more active pixel cameras for image capture inside or outside the vehicle and for using this information to control other vehicle systems, such as the airbag, air conditioning, or driver fatigue detection. In particular, several infrared transmitters and receivers are arranged at various positions within the vehicle, typically positioned for optimal resolution with a direct line of sight to the objects being monitored in the passenger compartment. Specifically, a transmitter and receiver pair is also described that is located in the instrument panel opposite the windshield, so that the infrared light emitted towards or reflected by the driver's face is reflected onto the windshield in a manner similar to a head-up display.A suitable coating may be provided for the windshield to ensure the required reflectivity in the infrared range used.

[0006] Furthermore, a system for monitoring the alertness of a motor vehicle driver is known from US 2015 / 0124068 A1. The system comprises an infrared flash for emitting infrared light towards the driver, an infrared camera mounted in the instrument panel area for capturing an image illuminated by the flash, and a reflective infrared film embedded in the windshield of the motor vehicle. In particular, by reflecting the infrared light reflected from the driver's face off the windshield on its way to the infrared camera, shadows cast by the steering wheel are avoided. A similar arrangement for the purpose of driver monitoring is also known from US 2006 / 0098166 A1.

[0007] Due to the current interior architecture of a motor vehicle, it is not always possible to achieve direct optical detection, i.e., with a detection device positioned directly opposite the object. Some areas of the vehicle interior, such as the area in front of and above the instrument panel relevant for a gesture camera, can be permanently or temporarily obscured by other objects during driving, for example, by steering wheel movements. An obstacle in the path between the detection device and the target object causes a shadow, which can affect the system's function in an uncontrolled manner. While this problem can be addressed, for example, by using multiple detection devices mounted at various locations within the vehicle, as described in US 2002 / 0116106 A1, this is not always feasible due to reasons of cost-effectiveness, limited installation space, ergonomics, and / or aesthetics.

[0008] It is therefore an object of the present invention to provide a motor vehicle with an optical arrangement for detecting interior objects in the invisible electromagnetic spectrum, in particular in the infrared range, which enables an improvement with regard to the visibility of objects for a detection device and / or its space-saving or discreet placement in the motor vehicle. Disclosure of the invention

[0009] This problem is solved by a motor vehicle according to claim 1 and by a motor vehicle according to claim 6. Further embodiments are specified in the dependent claims.

[0010] According to a first embodiment, a motor vehicle is provided, comprising: - a vehicle interior with a cockpit area located at the front in the direction of travel, occupied and used by a driver during operation, which is at least partially bounded by a windshield and an instrument panel located below it, and an interior mirror arranged in a manner known per se in front of or above an upper section of the windshield, which is designed for the driver to observe the area behind the motor vehicle; and - an optical arrangement designed for indirect cockpit area detection from above, comprising the following: - a reflective section of the windshield, which is designed on the inside of the vehicle to reflect detection light in a predetermined invisible spectral range, in particular infrared light, and - A first / upper detection device located in the vehicle interior, on or near the rearview mirror and facing the reflective section of the windshield, designed and configured to detect the light reflected vertically or at least obliquely upwards by objects in the cockpit area towards the reflective section of the windshield and from there to the upper detection device. The upper detection device can, for example, be a suitable camera.

[0011] Here, terms such as "above", "below", "upwards", "front" and the like are to be understood in a conventional motor vehicle coordinate system, with a horizontal X-axis in the longitudinal direction of the vehicle, corresponding to the direction of travel, a horizontal Y-axis perpendicular to this in the transverse direction of the vehicle, and a vertical Z-axis perpendicular to this, pointing upwards from a vehicle floor to a vehicle roof (cf. Fig. 1 and Fig. 2).

[0012] One aspect of the invention is to raise the reflectance in the invisible spectral range of the upper detection device in the aforementioned reflective section of the windshield to an optically usable level by suitable measures known to those skilled in the art, and to use this surface as a mirror for an indirect optical path, i.e., an upward path via reflection from the windshield, between a predetermined target area at the bottom of the cockpit and the detection device located further up in the area of ​​the rearview mirror. This path is not previously present in the vehicle. (Further details of the relative arrangement of the reflective section of the windshield and a surface of the upper detection device designed for light incidence can, for example, be chosen in a specific application depending on the vehicle geometry and the desired target area of ​​the vehicle interior to be detected.)Some possible examples are given below.

[0013] The "reflective section" mentioned herein can be implemented as a partial section of the windshield, for example, by applying a special reflective layer (e.g., film, etc., see below) to the windshield specifically for this purpose. However, this is not mandatory; the "reflective section" can alternatively extend over the entire windshield surface and may already be intended for other purposes within the vehicle. For instance, for sunlight protection, many modern vehicles have their windshields coated with an infrared filter, such as a coating. Such an existing filter can also be used for the described function of the invention—optionally with suitable optimization of the vehicle's interior reflectivity.

[0014] With such an optical arrangement, the cockpit area can be captured from above and / or obliquely from the front, i.e., from the direction of the reflective section of the windshield, a direction that would not be accessible via direct optical detection. Furthermore, this effectively avoids the shadows cast by other objects in the cockpit, as mentioned earlier.

[0015] Furthermore, the area around the rearview mirror often allows for a particularly space-saving and discreet placement of a detection device. The upper detection device can be mounted in or on the back of the rearview mirror facing the reflective surface of the windshield, and / or in a position obscured from the view from the passenger compartment by the rearview mirror or its mounting bracket. Unlike in the instrument panel, there may be sufficient free space available in this location within the vehicle for the upper detection device.

[0016] In a specific configuration, the relative arrangement of the windshield's reflective section and a surface of the upper detection device designed for light incidence is such that light reflected from objects located in the cockpit area in front of and / or above the instrument panel can be detected via the optical path described above. This allows for reliable monitoring of the aforementioned area in the cockpit, which is typically used most actively by the driver and / or front passenger.

[0017] For example, in this configuration, the objects located in front of and / or above the instrument panel can be the hands of an occupant, in particular the driver, of the motor vehicle, and the upper detection device can represent a gesture camera, so that the optical arrangement can serve as a user interface for the occupant to input control commands for other vehicle systems.

[0018] In particular, the reflective section of the windshield may have a layer, coating or film that reflects detection light and is applied inside or on the windshield during vehicle manufacturing or subsequently.

[0019] According to a second embodiment, which can be combined with the above first embodiment, a motor vehicle is provided comprising: - a vehicle interior that is at least partially bounded by a windshield, an instrument panel located below it, and at least one side window; as well as - an optical arrangement designed for indirect lateral detection of the vehicle interior, comprising the following: - a reflective section of the (at least one) side window, which is designed on the inside of the vehicle to reflect detection light in a predetermined invisible spectral range, in particular infrared light, and - A second / lateral detection device located inside the vehicle, facing the reflective section of the side window, designed and configured to detect light reflected by objects inside the vehicle towards the reflective section of the side window and from there to the lateral detection device. The lateral detection device can, for example, be a suitable camera.

[0020] In this embodiment, too, one idea of ​​the invention is to raise the reflectance in the invisible spectral range of the side detection device in the aforementioned reflective section of the side window to an optically usable level by suitable measures known to those skilled in the art, and to use this surface as a mirror for an indirect lateral optical path, i.e., via reflection at the side window, which was not previously present in the motor vehicle, between a predetermined target area in the vehicle interior and a lateral detection device arranged at a suitably appropriate position in the motor vehicle (further forward or rearward, and / or further up or down, such as on a headliner or on the side of a vehicle seat).(Further details of the mutual arrangement of the reflective section of the side window and a surface of the side detection device intended for light incidence may, in a specific application, be chosen depending, for example, on the vehicle geometry and the desired target area of ​​the vehicle interior to be detected. Some possible examples are given below.)

[0021] The "reflective section" mentioned herein can be implemented as a partial section of the side window, for example, by applying a special reflective layer (e.g., film, etc., see below) to the window specifically for this purpose. However, this is not mandatory; the "reflective section" can alternatively extend over the entire window surface and may already be intended for other purposes within the vehicle. For instance, for sunlight protection, many modern vehicles have windows coated with an infrared filter, such as a coating. Such an existing filter can also be used for the described function of the invention—optionally with suitable optimization of the vehicle's interior reflectivity.

[0022] With such an optical arrangement, the vehicle interior can be captured from the direction of the reflective section of the side window, a direction that would not be accessible via direct optical detection. This allows, for example, object surfaces facing the side window to be captured with better resolution than with a direct optical path to a detection device located elsewhere in the vehicle. Furthermore, this avoids the shadows cast by other objects in the vehicle that would otherwise cross a direct optical path.

[0023] In a specific embodiment, the side window is part of a front vehicle door on the driver's side, and the side-mounted detection device is installed in one of the aforementioned cockpit areas, in particular in or on a surface of the instrument panel facing the reflective section of the side window, an A-pillar of the vehicle, or a door sill of said vehicle door. In this way, the side areas of the vehicle interior on the driver's side can be captured, such as a driver profile view, which can be used, for example, for more precise authentication. Alternatively or additionally, in this embodiment, the side window and the side-mounted detection device can also be arranged on the opposite side of the vehicle.The side-mounted detection device can be positioned not only further forward in the cockpit area, but alternatively or additionally in a rear or central area of ​​the vehicle along its longitudinal axis, such as on a B- or C-pillar or a rear door sill, as well as alternatively or additionally on a vehicle seat or its headrest. Vehicle seats and their headrests, in particular, can be especially well-suited for discreetly mounting the side-mounted detection device and / or provide a particularly good view of the object to be detected via the indirect optical path described herein.

[0024] In particular, the reflective section of the side window may have a layer, coating or film that reflects the detection light inside the vehicle, either during vehicle manufacturing or subsequently applied to or on the side window.

[0025] In both embodiments, the motor vehicle may also have a detection light source designed to illuminate objects to be detected by the upper and / or side detection device.

[0026] In both embodiments, the motor vehicle may also have a control unit which is designed for the particularly time-dependent reading and evaluation of detection light signals detected by the upper and / or side detection device and for controlling other devices in the motor vehicle depending thereon. Brief description of the drawings

[0027] The above aspects of the invention and its embodiments and specific configurations are explained in more detail below with reference to the examples shown in the accompanying drawings. The drawings are purely schematic and are not to be read as being to scale. They show: Fig. 1 a schematic side view of a section of a motor vehicle according to the first embodiment of the invention with an upper detection device arranged on the back of an interior mirror; and Fig. 2 a schematic top view of a section of a motor vehicle according to the second embodiment of the invention, in which the side window is part of a front vehicle door on the driver's side and the side detection device is arranged in the instrument panel. Description of embodiments

[0028] All the various embodiments, variants and specific design features of the motor vehicle according to the invention mentioned above in the description and in the following claims can be found in the Fig. 1 and Fig. The two examples shown are implemented. Therefore, they will not all be repeated below. The same applies accordingly to the definitions and effects of individual features already given above, which are included in the Fig. 1 and Fig. 2 are shown.

[0029] Fig. Figure 1 shows a schematic side view of a section of an example of a motor vehicle 1 according to the first embodiment of the invention.

[0030] The motor vehicle 1 comprises a vehicle interior 2 with a [vehicle type] arranged at the front in the direction of travel X shown, which is operated by a driver ( Fig. Figure 1 shows only his hand 3) occupied and used cockpit area 4, which is at least partially bounded by a windshield 5 and an instrument panel 6 arranged below it (in the Z-direction shown). A steering wheel 8 arranged in front of the instrument panel 6 is also schematically indicated. Furthermore, the motor vehicle 1 has an interior mirror 7 arranged in front of an upper section 5a of the windshield 5, which is designed in a manner known per se for the driver to observe the area behind the motor vehicle 1.

[0031] According to the first embodiment of the invention, the motor vehicle 1 of the Fig. 1 an optical arrangement 9 designed for indirect cockpit area detection from above, comprising the following: - a reflective section 10 of the windshield 5, which is located on the inside of the vehicle to reflect detection light 11 (with a propagation direction opposite to that in Fig. 1. (indicated arrow direction, which serves solely for better visibility) is formed in a predetermined invisible spectral range, in this example infrared light, and - An upper detection device 12 arranged in the vehicle interior 2 on the interior mirror 7 and facing the reflective section 10 of the windshield 5. The upper detection device 12 is arranged and designed to detect the detection light 11, which is reflected vertically or at least obliquely upwards (in the depicted standard vehicle coordinate system XZ) by objects located in the cockpit area 4 in the direction of the reflective section 10 of the windshield 5 and from there to the upper detection device 12. The upper detection device 12 is shown, purely by way of example, as a suitable infrared camera.

[0032] With the optical arrangement 9 according to the Fig. 1. The cockpit area 4 can be detected from above and / or obliquely from the front, i.e., from the direction of the reflective section 10 of the windshield 5, a direction that would not be accessible via direct optical detection. In particular, this effectively avoids shadows cast by other objects in the cockpit area 4, such as the steering wheel 8.

[0033] In this example, the upper detection device 12 is mounted on the rear side 7a of the interior mirror 7, facing the reflective section 10 of the windshield 5, in a position concealed by the interior mirror 7 from the passenger compartment of the vehicle 1. Such a discreetly integrated infrared sensor (the upper detection device 12) in the area of ​​the interior mirror 7 detects light invisible to the human eye from the direction of the reflective section 10 of the windshield 5, in which parts of the cockpit area 4 are reflected. These parts may have been previously illuminated, for example, by suitable illumination from a detection light source (not shown), which is usually already provided in the vehicle 1.

[0034] In Fig. 1 is the mutual arrangement of the reflection section 10 of the windshield 5 and a surface 12a of the upper detection device 12 intended for the incidence of light such that detection light 11 reflected from objects located in the cockpit area 4 in front of and / or above the instrument panel 6 can be detected via the optical path described above.

[0035] As in Fig. As shown in Figure 1, in this configuration the objects located in front of and / or above the instrument panel 6 can be, in particular, the hands 3 of an occupant, especially the driver, of the motor vehicle 1. The upper detection device 12 can be a gesture camera, so that the optical arrangement 9 can serve, in particular, as a user interface for the input of control commands for other vehicle systems by this occupant. As shown in Fig. 1 By way of example only, the gesture of the driver's hand 3, which can be detected by the optical arrangement 9, can signal, for example, the selection of a virtual menu display 13 floating in the aforementioned area in front of and above the instrument panel 6, wherein the virtual menu display 13 was generated by a display device 14 mounted on the instrument panel 6.

[0036] In Fig. 1 The reflective section 10 of the windshield 5 has a layer, coating or film 15 that reflects the vehicle interior detection light 11 and is applied to the windshield 5 during vehicle manufacture or subsequently.

[0037] Fig. Figure 2 shows a schematic top view of a section of an example of a motor vehicle 1 according to the second embodiment of the invention, which is particularly similar to the first embodiment according to Fig. 1 can be combined.

[0038] Motor vehicle 1 of the Fig. 2 comprises a vehicle interior 2, which is at least partially enclosed by a windshield (not shown), a space below it (with respect to the drawn standard motor vehicle coordinate system XZ, see also Fig. 1) arranged instrument panel 6, and a side window 16. According to the second embodiment of the invention, the motor vehicle 1 has the Fig. 2 an optical arrangement 17 designed for indirect lateral detection of the vehicle interior, comprising the following: - a reflective section 18 of the side window 16, which is located on the inside of the vehicle to reflect detection light 19 (with a propagation direction opposite to that in Fig. 2 indicated arrow direction, which serves solely for better recognizability) is formed in a predetermined invisible spectral range, in particular of infrared light, and - A lateral detection device 20 arranged in the vehicle interior 2 and facing the reflective section 18 of the side window 16. The lateral detection device 20 is arranged and designed to detect detection light 19, which is reflected by objects located in the vehicle interior 2 towards the reflective section 18 of the side window 16 and from there to the lateral detection device 20. The lateral detection device 20 can, for example, be designed as a suitable infrared camera.

[0039] With the optical arrangement 17 of the Fig. 2. The vehicle interior 2 can be detected from the direction of the reflective section 18 of the side window 16, a direction that would not be accessible via direct optical detection. This allows, for example, the precise detection of object surfaces facing the side window 16, such as a left profile view 21a of the driver's head 21 in Fig. 2. With such an indirect optical path via the side window 16, a shadow is effectively avoided which could be caused by other objects in the motor vehicle 1, such as a steering wheel 8 or the driver's hands, in the case of a direct optical path (e.g. to a camera arranged in the instrument panel 6).

[0040] In Fig. 2 The side window 16 is purely exemplary as part of a front vehicle door 22 on the driver's side, and the side detection device 20 is in a position relating to Fig. 1. The cockpit area 4, as described in more detail, is mounted, in this example, on a surface of the instrument panel 6 facing the reflective section 18 of the side window 16. In this way, the side areas of the vehicle interior 2 on the driver's side can be captured, such as the left driver profile view 21a, which can be used, for example, for more precise driver authentication. Alternatively or additionally, in this embodiment, the side window and the side capture device can also be mounted on the other side, i.e., in the Fig. 2. The side detection device can be arranged not only further forward in the cockpit area 4, but alternatively or additionally in a rear area or a central area of ​​the vehicle 1 in its longitudinal direction X, such as on a B- or C-pillar or a door sill of a rear door. Reference symbol list 1 motor vehicle 2 Vehicle interior 3 Hand 4 Cockpit area 5 Windscreen 5a upper section of the windshield 6 Instrument panel 7 Interior mirrors 7a Back of the interior mirror 8 Steering wheel 9 optical arrangement designed for indirect cockpit area detection from above 10 Reflection section of the windshield 11 Detection light 12 upper detection device 12a Surface of the upper detection device intended for light incidence 13 virtual menu display 14 Display unit 15 Detection light reflective layer, coating or film 16 side window 17 optical arrangement designed for indirect lateral detection of vehicle interior 18 Reflection section of the side window 19 Detection light 20 lateral detection device 21 Driver's head 21a left driver profile view 22 front vehicle door on driver's side

Claims

[1] Motor vehicle (1), comprising: - a vehicle interior (2) with a cockpit area (4) which is at least partially bounded by a windshield (5) and an instrument panel (6) arranged below it, and an interior mirror (7) arranged in front of or above an upper section (5a) of the windshield (5) as well as - an optical arrangement (9) designed for indirect cockpit area detection from above, comprising the following: - a reflective section (10) of the windshield (5) which is designed on the inside of the vehicle to reflect detection light (11) in a predetermined invisible spectral range, in particular infrared light, and - an upper detection device (12) arranged in the interior of the vehicle (2) on the interior mirror (7) or in its vicinity, facing the reflective section (10) of the windshield (5), which is arranged and designed to detect the detection light (11) that is reflected vertically or at least obliquely upwards by objects located in the cockpit area (4) in the direction of the reflective section (10) of the windshield (5) and from there to the upper detection device (12). [2] Motor vehicle (1) according to claim 1, wherein the upper detection device (12) is mounted in or on a rear side (7a) of the interior mirror (7) facing the reflective section (10) of the windscreen (5) and / or in a position concealed by the interior mirror (7) or its mounting for viewing directions from an occupant compartment of the motor vehicle (1). [3] Motor vehicle (1) according to claim 1 or 2, wherein the mutual arrangement of the reflective section (10) of the windshield (5) and a surface (12a) of the upper detection device (12) intended for the incidence of light is such that infrared light falls on this surface (12a), which is reflected perpendicularly or at least obliquely upwards to the reflective section (10) of the windshield (5) by objects located in the cockpit area (4) in front of and / or above the instrument panel (6). [4] Motor vehicle (1) according to claim 3, wherein the objects located in front of and / or above the instrument panel (6) are hands (3) of an occupant, in particular the driver, of the motor vehicle (1), and the upper detection device (12) is a gesture camera. [5] Motor vehicle (1) according to one of the preceding claims, wherein the reflective section (10) of the windshield (5) has a layer, coating or film (15) attached in or on the windshield (5) which reflects detection light (11) on the inside of the vehicle. [6] Motor vehicle (1), in particular according to one of the preceding claims, comprising: - a vehicle interior (2) which is at least partially bounded by a windshield (5), an instrument panel (6) arranged below it, and a side window (16); and - an optical arrangement (17) designed for indirect lateral detection of the vehicle interior, comprising the following: - a reflective section (18) of the side window (16) which is designed on the inside of the vehicle to reflect detection light (19) in a predetermined invisible spectral range, in particular infrared light, and - a lateral detection device (20) arranged in the vehicle interior (2) and facing the reflective section (18) of the side window (16), which is arranged and designed to detect detection light (19) that is reflected by objects located in the vehicle interior (2) in the direction of the reflective section (18) of the side window (16) and from there to the lateral detection device (20). [7] Motor vehicle (1) according to claim 6, wherein the side window (16) is part of a front vehicle door (22) on the driver's side and the side detection device (20) is arranged in a cockpit area (4) located at the front of the vehicle interior (2), in particular in or on a surface of the instrument panel (6), an A-pillar of the motor vehicle (1) or a door sill of said vehicle door (22) facing the reflective section (18) of the side window (16). [8] Motor vehicle (1) according to claim 6 or 7, wherein the reflective section (18) of the side window (16) has a layer, coating or film attached in or on the side window (16) which reflects detection light (19) on the inside of the vehicle. [9] Motor vehicle (1) according to one of the preceding claims, which further comprises a detection light source designed to illuminate objects to be detected by the upper and / or lateral detection device (12, 20) with detection light (11, 19). [10] Motor vehicle (1) according to one of the preceding claims, which further comprises a control unit designed for the particularly time-dependent reading and evaluation of detection light signals detected by the upper and / or lateral detection device (12, 20) and for the dependent control of further devices in the motor vehicle (1).

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