Driver Assistance System

Abstract

The disclosure relates to a driver assistance system for a motor vehicle, such as a truck. The driver assistance system includes an environment camera with an image sensor and an optical system. The driver assistance system also includes an imaging unit and a display element in the interior of the motor vehicle. The environment camera, the imaging unit, and the display element form a digital exterior mirror, where the digital exterior mirror is arranged such that at least two visual field regions, namely a first visual field region and a second visual field region, are mapped with different magnifications.

Claims

1. A driver assistance system for a motor vehicle, the driver assistance system comprising: an environment camera including an image sensor and an optical system; an imaging unit; a display element in an interior of the motor vehicle; wherein the environment camera, the imaging unit, and the display element form a digital exterior mirror, the digital exterior mirror arranged such that at least two visual field regions, a first visual field region and a second visual field region, are mapped with different magnifications.

2. The driver assistance system of claim 1, wherein the digital exterior mirror is arranged such that the at least the two visual field regions are mapped with different angular resolutions.

3. The driver assistance system of claim 1, wherein the environment camera detects electromagnetic radiation in a wavelength range between approximately 300 nm and approximately 2000 nm.

4. The driver assistance system of claim 1, wherein the environment camera comprises a wavelength band-pass filter with a passband of approximately 400 nm to approximately 750 nm.

5. The driver assistance system of claim 1, wherein the optical system implements the different magnifications.

6. The driver assistance system of claim 1, wherein: the optical system includes a rotation-symmetric design; and the optical system and the image sensor are aligned with one another such that an optical axis of the optical system passes near to an area centroid of a measurement surface of the image sensor.

7. The driver assistance system of claim 1, wherein the optical system has a non-rotation-symmetric design.

8. The driver assistance system of claim 1, wherein: the image sensor comprises a sensor surface; the optical system is configured such that the first visual field region is mapped similarly to a wide-angle lens on a first region of the sensor surface of the image sensor; and the second visual field region of the digital exterior mirror is mapped similarly to a telephoto lens on a second region of the sensor surface.

9. The driver assistance system of claim 1, wherein the first visual field region covers an angle of greater than 50° and the second visual field region covers an angle of less than 30°.

10. The driver assistance system of claim 1, wherein each magnification used corresponds to an integer.

11. The driver assistance system of claim 10, wherein each magnification used corresponds to an even number, multiple of the basic scale.

12. The driver assistance system of claim 1, wherein the imaging unit is arranged such that image data of the environment camera are rescaled and undergo rectification, before being reproduced by the display element.

Description

DESCRIPTION OF DRAWINGS

[0022] FIG. 1 is a block diagram of a truck with a driver assistance system, including an environment camera with an optical system and an image sensor.

[0023] FIG. 2 a top view of the truck with an indication of two field view regions of the environment camera.

[0024] FIG. 3 a top view of an example of the environment camera for implementing different angular resolutions for the two visual field regions with an imaging concept for one of the two visual field regions.

[0025] FIG. 4 the top view of the example of the environment camera for implementing different angular resolutions for the two visual field regions with an imaging concept for the other of the two visual field regions.

[0026] FIG. 5 the top view of another example of the environment camera for implementing different angular resolutions for the two visual field regions with an imaging concept for one of the two visual field regions.

[0027] FIG. 6 the top view of the alternative configuration of the environment camera for implementing different angular resolutions for the two visual field regions with an imaging concept for the other of the two visual field regions.

[0028] Corresponding parts are provided with the same reference numerals in all figures.

DETAILED DESCRIPTION

[0029] A driver assistance system 2 described by way of example in the following and sketched in FIG. 1. The driver assistance system 2 may be installed in a truck 4 and serves to support a vehicle driver or operator when driving the truck 4. The driver assistance system 2 includes an environment camera 6 having an image sensor 8 and an optical system 10. The driver assistance system 2 also includes an imaging unit 12, an image evaluation unit 14, and a display element in the form of an LCD screen 16. With the help of these modules an electronic or digital exterior mirror is implemented, to replace the conventional exterior mirror or side mirror.

[0030] In some implementations, the environment camera 6, or at least the optical system 10 of the environment camera 6, is positioned approximately in the region in which the conventional side mirror is normally arranged, and the optical system 10 of the environment camera 6 is aligned in the direction of the rear of the truck 4, so that with the help of the digital exterior mirror, as indicated in FIG. 2, a rear and side region of the environment of the truck 4 is detected by the environment camera 6 and reproduced on the LCD screen 16, arranged in the passenger compartment or driver's cab of the truck 4.

[0031] In some examples, the LCD screen 16 has an upper region and a lower region. A first visual field region 18 is reproduced during operation in the lower region having a greater surface area than the upper region. A second visual field region 20 is shown in the upper region with a smaller surface area than the lower region. As such, the LCD screen 16 essentially reproduces precisely what the driver would observe by a conventional exterior mirror, which is typically made from two individual mirrors, with similarly different surface areas, or mirror surfaces.

[0032] The image data for the two regions of the LCD screen 16 are generated with the help of just one image sensor 8 and an optical system 10, where the image sensor 8 is substantially constructed with identical pixels, which particularly have a uniform sensor surface.

[0033] The image sensor 8 is, however, at least virtually, divided into two regions, such that the image data generated by the pixels of the first area P18 are reproduced in the lower region of the LCD screen 16 and the image data generated by the second area P20 are displayed in the upper region of the LCD screen 16. For the two regions P18, P20 different magnifications, more precisely different angular resolutions, are implemented.

[0034] Therefore, the optical system 10 is designed so that the first visual field region 18 is mapped as if by a wide-angle lens on the first region of the sensor surface and the second visual field region 20 is mapped as if by a telephoto lens on the second region of the sensor surface.

[0035] Here, the second visual field region 20 extends over an angle of 25° starting from the side 22 of the truck 4, so that in this way the following traffic is particular is detected. The first visual field region 18 immediately follows the second visual field region 20 and extends over an angle of 60°, so that a total angle of 85° is detected.

[0036] As already mentioned above, for each of the two visual field regions 18, 20 a separate angular resolution is used. In some examples, the angular resolution in the second visual field region 20 corresponds to three times the angular resolution in the first visual field region 18. Since a single optical system 10 is used for the environment camera 6 and the design of the optical system 10 is subject to certain technical limits, there is no uniform value for the angular resolution for the two visual field regions 18, 20 across the respective overall visual field region 18, 20. Instead the optical system 10 has a gradually changing angular resolution in the transition area, thus in the region of the transition between the two field view regions 18, 20.

[0037] Resulting warping and distortion are eliminated during data processing in the imaging unit 12. Therefore, rectification is performed, during which the course of the angular resolution is modified by electronic post-processing of the image data, so that in the displayed images each visual field region 18, 20 over the entire respective visual field region 18, 20 has a uniform angular resolution and accordingly there is an abrupt transition between the two field view regions 18, 20. Therefore, the angle-dependent angular resolution in the second visual field region 20 is scaled up to the border with the first visual field region 18 and in the first visual field region scaled down to the border with the second visual field region 20, where for this purpose known image data rescaling algorithms are used.

[0038] The implementation of the different angular resolutions for the two visual field regions 18, 20 takes place in FIG. 3 and FIG. 4 with the help of a rotation-symmetric optical system 10, represented in the figures by a single lens. The optical axis 24 of the rotation-symmetrical optical system 10 is, more or less, arranged offset to the image sensor 8, so that the optical axis 24 does not run through the area centroid or midpoint of the measurement surface or sensor surface of the image sensor 8, but near and offset to this at the area centroid. Moreover, the optical system 10 is over-dimensioned compared to the image sensor 8, so that despite the offset arrangement the optical system 10 fully covers the image sensor. Such a configuration allows the spherical apparition known from spherical lenses to be specifically used to implement the different angular resolution.

[0039] Alternatively, in some examples, a non-rotation-symmetric optical system 10 is used, which is positioned in most cases in front of the sensor surface of the image sensor 8, as shown in FIG. 5 and FIG. 6. In this case, the optical system 10 has a more complex geometry, attributable to basic prismatic forms.

[0040] The disclosure is not restricted to the examples described above. On the contrary, other variants of the disclosure can be inferred from it by a person skilled in the art, without deviating from the subject matter of the disclosure. Particularly, all individual features described in connection with the exemplary embodiment can also be combined in other ways, without deviating from the subject matter of the disclosure.