Vision system for a vehicle and method for switching between image areas displayed by the vision system

Abstract

Method for switching between a first and second image area (7, 8) on a display device in a vehicle with a towing vehicle (5) and a trailer (6) pivotably mounted on the towing vehicle (5), comprising: Acquisition of initial image data by a first image acquisition device (2a, 2b) of a first recording area; Acquisition of second image data by a second image acquisition device (3a, 3b) of a second recording area overlapping the first recording area, wherein the first and second image acquisition devices (2a, 2b, 3a, 3b) have different optical properties; Processing the first and second image data to extract the first image area (7) from the first image data and to extract the second image area (8) from the second image data; Display of the first image area (7) and / or the second image area (8) which corresponds as closely as possible to the first image area (7) in the same display field of the display device (1a, 1b); Continuous determination of an articulation angle between the towing vehicle (5) and the trailer (6) by means of an articulation angle determination device; Switching or blending the display of the first image area (7) and the display of the second image area (8) based on a switching condition defined by a kink K D is determined, wherein at the switching time the first image data of the first image area (7) correspond to the image data of the second image area (8) such that the images perceptible to a user on the display device (1a, 1b) on the basis of the first and second image data are almost identical.

Description

[0001] The invention relates to a vision system for a vehicle and a method for switching between or fading image areas displayed by the vision system, as well as to a vehicle having a mirror replacement system which is the vision system according to the present disclosure.

[0002] Common vision systems that utilize a main camera and, for example, a wide-angle camera are used, for example, as mirror replacement systems in vehicles. The main camera represents a main field of view, and the wide-angle camera a wide-angle field of view. According to UN / ECE-R46, for example, the main field of view represents a Group II field of view, and the wide-angle field of view represents a Group IV field of view, in order to display vehicle-side fields of view and / or fields of view to the driver.

[0003] DE 10 2010 032 411 A1 relates to a system for monitoring the surroundings of a vehicle by means of at least one image capture unit which can record a detection area which is larger than an environmental area to be monitored, wherein a section selection means is provided for automatically selecting at least one section of the image capture unit recording which shows the environmental area to be monitored, based on at least one parameter which is related to the relative position of the towing vehicle and the trailer.

[0004] DE 10 2015 218 033 A1 relates to a method for improving rear visibility in a motor vehicle.

[0005] For certain driving situations, it is necessary to change the main camera's displayed field of view in order to view other areas around the vehicle. An example of such a driving situation is cornering, where a trailer of the vehicle moves further into the main field of view, causing the main field of view to display less or no relevant surrounding information.

[0006] One problem in particular is that the aperture angle of the main camera is severely restricted in order to achieve the highest possible resolution, e.g. to meet the requirements of the above-mentioned Group II field of view or to achieve the sharpest and highest possible resolution image.

[0007] In special driving situations, such as the curves mentioned above, it is possible, especially with a vision system that uses a main camera and a wide-angle camera installed on a vehicle with a swiveling trailer, that the limit of the main camera's recording range is quickly reached and it is necessary to switch to the wide-angle camera's field of view in order to display relevant information.

[0008] The object of the invention is to provide a vision system, especially an indirect vision system, which enables a driver of a vehicle with a towing vehicle and a trailer pivotably attached to the towing vehicle to perceive the vehicle surroundings, in particular the rear trailer area, at any time by appropriately switching between cameras with different optical properties.

[0009] A further object of the invention is to provide a method for switching between image areas on a display device of the vision system such that the driver of the vehicle is essentially unaware of a change between the recording areas of different optical cameras. A further object of the present invention is to provide a vehicle with a mirror replacement system that is the vision system according to the invention. Description of the invention

[0010] The above objects are achieved by a method having the features of claim 1, a vision system having the features of claim 4, and a vehicle having the features of claim 16. Preferred embodiments are specified in the dependent claims.

[0011] A method according to an embodiment of the present invention switches between a first and a second image area on a display device in a vehicle having a towing vehicle and a trailer pivotally mounted on the towing vehicle. The first image area, which is displayed to a driver on a display device, for example a monitor mounted on the towing vehicle, is obtained, for example, by first image data being captured and processed by a first image recording device of a first recording area. The second image area, which can be displayed on the display device, is extracted from second image data captured by a second image recording device of a second recording area. The second recording area that can be captured by the second image recording device overlaps with the first recording area that can be captured by the first image recording device.The first image recording device and the second image recording device preferably have different optical properties, such as different aperture angles, directory curves and / or angular resolutions. The optical properties of the first and second image recording devices, which are preferably attached to a towing vehicle of the vehicle, are preferably such that legal regulations are met, particularly in Europe, for example, as specified by Regulation No. 46 of the United Nations Economic Commission for Europe (UN / ECE (Addendum 45, Revision 6). This regulation provides, for example, for a main mirror (large) (according to ECE-R46 "Main Mirror (Large) Group II") and a wide-angle mirror (according to ECE-R46 "Wide-angle Mirror Group IV") in addition to other mirrors.The first image capture device according to the present invention is, for example, a main camera capable of capturing the Group II field of view defined in the above rule, and the second image capture device according to the present invention is, for example, a wide-angle camera capable of capturing a wide-angle field of view according to the Group IV field of view according to UN / ECE-R46. Additionally or alternatively, other fields of view (not required by law or regulation) around the vehicle can be captured and displayed.

[0012] With the method of the present invention, the above-mentioned first image area and / or the second image area are displayed in a same display field of a display device. The display device, which is, for example, an LED display, is preferably designed such that a plurality of image data, for example acquired by different image recording devices, can be displayed in the same display field. According to the method of the present invention, either the first image area or the second image area is displayed on the display field. According to the method of the present invention, the image areas are preferably adjusted and / or blended in such a way that the user hardly notices this switching between the first and second image areas.Because the image properties (and the properties of the image recording devices) are very similar or identical in the area between the image area recorded by the first camera and the area recorded by the second camera, the driver only notices the switching or cross-fading upon close inspection when switching between the first and second images in this area. In this context, the terms switching or cross-fading encompass both an "abrupt" switching between the first and second image areas, in which, even with precise temporal resolution, either only the first image area or only the second image area is displayed, and a "smooth" switching between the first and second image areas, in which, with precise temporal resolution, the first image area is gradually faded out and overlaid by the second image area.

[0013] According to the method of the present invention, a knuckle angle between the towing vehicle and the trailer is further continuously determined by a knuckle angle determination device. The knuckle angle determination device is, for example, a processor that acquires rotational speed information from wheels or axles of the towing vehicle and the trailer in order to calculate a knuckle angle therefrom. Determining a knuckle angle between a towing vehicle and a trailer is generally known and can also be determined using other techniques, such as detecting the rear edge of the trailer, e.g., by image recognition from a captured image. Other knuckle angle determination methods are possible, using, for example, existing sensors (ABS).

[0014] According to the method of the present invention, switching occurs between the display of the first image area and the display of the second image area based on a switching condition. According to one exemplary embodiment, this switching condition is, for example, a defined articulation angle between the towing vehicle and the trailer. Switching according to the present invention occurs such that, at the switching time, the first image data of the first image area correspond to the second image data of the second image area such that the images perceivable by a user on the display device based on the first and second image data are virtually identical.In other words, the first and second image areas extracted from the first and second image data are displayed to the driver of the vehicle in such a way that the smallest possible image difference results, in particular with regard to the optical properties of the image, so that an image displayed to the driver before switching is almost identical to the image displayed after switching.

[0015] According to a further development of the method according to the invention, switching occurs between the display of the first image area and the display of the second image area when the currently determined articulation angle is above or below a defined articulation angle. Preferably, the defined articulation angle lies within a articulation angle range with a lower articulation angle limit and an upper articulation angle limit, whereby a tolerance range can be defined to prevent constant switching between the two image areas in the event of small changes in the current articulation angle around the defined articulation angle. Such rapid back-and-forth switching between the display of the first image area and the display of the second image area would be perceived by the driver as "flickering" on the display device.

[0016] To prevent the aforementioned "flickering," the first image recording device is preferably activated to display the first image area when the articulation angle reaches the lower limit of the articulation angle range. If the first image recording device is already active, i.e., the first image area is displayed, it remains active. However, if the second image recording unit is active, i.e., the second image area is displayed, switching to the first image recording device occurs. Subsequently, switching from the first image recording device to the second image recording device occurs when the current articulation angle reaches the defined articulation angle.

[0017] When the current articulation angle reaches the upper limit of the articulation angle, the second image capture device is activated. If the second image capture device is already active, it remains active. If, however, the first image capture device is active, the system switches to the second image capture device. Subsequently, the system switches from the second image capture device to the first image capture device when the current articulation angle reaches the defined articulation angle. An active image capture device means that images captured by it are displayed.

[0018] If the current bending angle reaches the defined bending angle without having previously reached the lower or upper limit of the bending angle since the last switching operation, no switching takes place, which prevents rapid switching back and forth between the display of the first image area and the display of the second image area if the current bending angle changes only slightly around the defined bending angle.

[0019] According to a default setting, the first image area is displayed until the current articulation angle reaches either the defined articulation angle or the upper articulation angle limit. When the vehicle is parked, the current system state is saved, i.e., for example, information about the current articulation angle, currently displayed image areas or image information, currently activated display, etc. If the vehicle is started after parking the vehicle, in which the current articulation angle reaches the defined articulation angle or the upper articulation angle limit, then, according to the invention, the second image area is displayed, for example, if it was saved before parking.

[0020] The above-described inventive method for switching between image areas can be used, for example, in a vision system according to an embodiment of the present invention.

[0021] The vision system according to the exemplary embodiment of the present invention is used for a vehicle having a towing vehicle and a trailer pivotally mounted on the towing vehicle. According to the exemplary embodiment, the vision system preferably has at least one first image recording device for acquiring first image data of a first recording area and at least one second image recording device for acquiring second image data of a second recording area overlapping the first recording area, wherein the first and second image recording devices have different optical properties. As mentioned above, the first image recording device is, for example, a main camera and the second image recording device is a wide-angle camera. The main camera can, for example, have a smaller aperture angle and a higher resolution than the second image recording device.The optical properties include, for example, angular resolution, aperture angle and / or distortion.

[0022] The first and second image pickup devices have, for example, an optical image sensor and corresponding optical systems such as lenses.

[0023] Where reference is made in this description to fields of vision or viewing areas, this means corresponding viewing areas as defined in the applicable national regulations, for example for Europe in the above-mentioned ECR-R46, preferably those which are prescribed for display in these legal regulations (fields of vision).

[0024] The vision system according to the exemplary embodiment of the present invention further comprises a device for processing the first and second image data to extract a first image region from the first image data and a second image region from the second image data. The first and second image regions are such that they provide a nearly congruent image.

[0025] The vision system according to the exemplary embodiment of the present invention further comprises a display device for displaying the first image area and the second image area, respectively, in a single display field. By displaying the first image area and the second image area in the same display field, the surroundings of the vehicle can be displayed to the driver in such a way that, depending on certain driving situations, either the image from the first image recording device (main camera with high resolution) or the image from the second image recording device (wide-angle camera with lower resolution) is displayed.

[0026] The vision system according to the exemplary embodiment further comprises a bend angle determination device for continuously determining the bend angle between the towing vehicle and the trailer. The bend angle determination device can, for example, actively determine the bend angle between the towing vehicle and the trailer independently or receive a signal containing information about the bend angle from an external device.

[0027] The vision system according to the preferred embodiment further comprises a display switching device for switching between the display of the first image area and the display of the second image area based on a switching condition. The switching condition is, for example, a defined bending angle that is determined or received by the bending angle determination device. The switching takes place according to the method described above, i.e., preferably such that, at the switching time, the first image data of the first image area correspond to the image data of the second image area such that the images perceivable by a user on the display device based on the first and second image data are almost congruent. This ensures that the user hardly notices the switching between the image areas.This is achieved in particular by the fact that corresponding image data in the first and second image areas each differ by preferably a maximum of 30 pixels on the display device, which, for a display device with a pixel center-to-center pitch of, for example, 0.18525 mm, corresponds to a pitch of 5.5575 mm. Depending on the display device and / or the distance to a viewer of the display device, the above-mentioned maximum number of pixels can vary.

[0028] In the vision system according to the present embodiment, for example, the distance between the first and second image pickup devices is preferably in a range of 10 mm to 500 mm, i.e., the image pickup devices are preferably arranged on the vehicle at a maximum distance of this distance from one another. It should be noted that the closer the two image pickup devices are to each other, the easier it is to display images that are as congruent as possible to the user at the time of switching between the first and second image areas.

[0029] As mentioned above, the first recording area of ​​the first image recording device and the second recording area of ​​the second image recording device overlap, making it possible to display image areas on the display device that have essentially the same image content but were recorded with different optical characteristics. According to the preferred embodiment, the first and second image recording devices have, for example, different aperture angles, wherein the optical axes in the first and second image recording devices are aligned with each other at an orientation angle of preferably 0° to 60° depending on their aperture angles. This makes it possible to capture a correspondingly large area next to the vehicle by using the first and second image recording devices.

[0030] According to the vision system of the preferred embodiment, it is possible to suitably determine the orientation angle of the first or second image recording device, for example, by a developer of the vision system, by displaying a reference point on the display device, wherein this reference point corresponds to the same pixel coordinates / image data in the first and second image areas. The image recording devices are preferably fixedly aligned with one another on the vehicle, or alternatively, in the case of movable cameras, can also be mechanically adjusted by the vehicle user. This allows, for example, the user of the vision system to select any point, such as the rear area of ​​the trailer, as the reference point, so that at the time of switching at this reference point, the image data of the first and second image areas match as closely as possible.

[0031] As an alternative to the user-defined setting of the reference point mentioned above, it is possible that the reference point is predefined or can be adjusted depending on the trailer height and / or trailer length or other vehicle geometries.

[0032] According to the vision system of the present embodiment, the reference point lies specifically on a plane perpendicular to the roadway, passing through a point in the region of the rear edge of the trailer with the defined articulation angle and through the first and second image recording devices. This allows, for example, the user of the vision system to shift the reference point to this plane as desired and to define a suitable reference point at which the displayed image data are virtually identical at the time of switching. For example, in order to be able to observe the rear edge of the trailer, the reference point is preferably spaced from the first or second image recording device and is defined in the region of the rear edge of the trailer at the defined articulation angle.

[0033] In order to be able to display as wide an area as possible next to and behind the vehicle or the trailer, the optical properties of the first and second image recording devices are preferably different with regard to angular resolution, aperture angle and / or distortion.

[0034] According to the invention, the second image recording device is, for example, not as high-resolution as the first image recording device, or has the same resolution, so that overall a cost-effective system can be created.

[0035] In the vision system according to the preferred embodiment, the defined bend angle, which defines the switching condition, is defined within a bend angle range with a lower bend angle limit and an upper bend angle limit. As described above with reference to the method according to the invention, this prevents rapid switching between the display of the first image area and the display of the second image area, which would be perceived as annoying by the user if the current bend angle changes only slightly around the defined bend angle.

[0036] According to the vision system of the present embodiment, it is further possible for the defined articulation angle to change within the articulation angle range depending on the driving situation. In this way, it is possible to determine the optimal articulation angle at which switching between the image areas should occur in response to different driving situations.

[0037] According to the invention, a vehicle is further provided with a mirror replacement system, i.e. a camera / monitor system, which is the vision system described above. Short description of the characters

[0038] The invention is described below purely by way of example with reference to the accompanying figures, in which like reference numerals designate like or similar components. They show: Fig. 1 is a schematic representation of a vision system according to an embodiment of the present invention; Fig. 2 a plan view of a vehicle carrying the Fig. 1 shown vision system is used; Fig. 3 a side view of the Fig. 2 vehicle shown; Fig. 4 a plan view of the vehicle showing the vision system according to Fig. 1, according to a first driving condition; Fig. 5 a schematic representation of the display of recording areas and image areas in the Fig. 4 shown first driving condition; Fig. 6 a plan view of the vehicle using the vision system according to Fig. 1, according to a second driving condition; Fig. 7 a schematic representation of the display of recording areas and image areas in the Fig. 6 shown second driving state, at the time of switching; Fig. 8 a plan view of the vehicle using the vision system according to Fig. 1, according to a third driving condition; Fig. 9 a schematic representation of the display of recording areas and image areas in the Fig. 8 shown third driving state, after a switching time; Fig. 10 is a diagram illustrating display switching according to a preferred embodiment of the invention; Fig. 11 a plan view of a vehicle using the vision system according to Fig. 1, to clarify the Fig. 10 shown switching procedure; Fig. 12 another illustration of the display of recording areas and image areas, similar to Fig. 7 at the time of switching; Fig. 13 an exemplary illustration to illustrate the imaging of the first and second image areas with different directory curves; and Fig. 14 a simplified schematic representation of the method according to an embodiment of the invention. Description of preferred embodiments

[0039] Fig. 1 shows a vision system according to an embodiment of the invention with display devices 1a, 1b, image recording devices 2a, 2b, 3a, 3b and processing devices 4a, 4b.

[0040] The image recording devices 2a, 3a are preferably arranged on one side of a vehicle and connected to the display device 1a via the processing device 4a. The image recording devices 2b, 3b are arranged on the opposite side of the vehicle, as in Fig. 2, and is connected to the display device 1b via the processing device 4b. According to the preferred embodiment, the processing device 4a, 4b comprises a bend angle determination device (not shown in detail), an image data processing device, and a display switching device.

[0041] For the sake of simplicity, only the display device 1a, the image recording devices 2a, 3a, and the processing device 4a are described below. However, the explanations apply analogously to the display device 1b, the image recording devices 2b, 3b, and the processing device 4b on the opposite side of the vehicle.

[0042] As in Fig. As shown in Figure 1, according to the embodiment, two image pickup devices 2a, 3a are provided on one side of the vehicle. Any number of additional image pickup devices can be used. According to the embodiment, the image pickup devices 2a, 3a are preferably spatially spaced from each other in a range between 10 mm and 500 mm. The image pickup device 2a is, for example, a wide-angle camera with low resolution, and the image pickup device 3a is, for example, a main camera with high resolution. According to the embodiment, the two image pickup devices have different optical properties.

[0043] The processing device 4a, which has the above-mentioned display switching device (not shown), is designed to switch between an image captured by the image capture device 2a and an image captured by the image capture device 3a, each of which is displayed on the display device 1a. In the preferred embodiment, the display device 1a has a single display panel for displaying either the image captured by the image capture device 2a or the image captured by the image capture device 3a. The display device 1a can also have multiple display panels on which identical or different images captured by the image capture devices 2a, 2b can be displayed. The display device 1a serves, for example, as a mirror replacement system for a vehicle.

[0044] As in Fig. 2, the vehicle comprises, for example, a towing vehicle 5 and a trailer 6 pivotably attached thereto.

[0045] The Fig. The image recording device 2a shown in Fig. 1 with a first viewing angle α1 serves to capture first image data of a first recording area, wherein in Fig. 2 the projection α1* of the viewing angle can be seen, which extends horizontally, ie approximately parallel to a flat road surface. The image recording device 3a with a second viewing angle γ1 serves to capture second image data of a second recording area overlapping the first recording area, wherein in Fig. 2 the projection γ1* of the viewing angle is shown, wherein the first and second image pickup devices 2a, 3a, as mentioned above, have different optical properties.

[0046] Especially, as in Fig. For example, as shown in Figure 2, the aperture angle of image pickup device 2a is larger than the aperture angle of image pickup device 3a. Consequently, the second recording area is larger than the first recording area. According to the present embodiment, image pickup device 3a is a high-resolution camera, and image pickup device 2a is a low-resolution wide-angle camera. Fig. 2 represents first and second recording areas in a horizontal plane.

[0047] Fig. 3 shows that in Fig. 2 shown vehicle from the side with corresponding vertical projections γ2*, α2* the angle of view of the image recording devices 2a, 3a is approximately perpendicular to a flat road surface. In Fig. 3 only the image recording device 2a can be seen.

[0048] As mentioned above, the image pickup device 3a covers a field of view corresponding to a "large primary mirror (Group II)" according to ECE-R46, and the image pickup device 2a covers a field of view corresponding to a wide-angle mirror (according to ECE-R46 "wide-angle mirror Group IV"). Other suitable defined fields of view can be covered by the image pickup devices 2a, 3a in accordance with national regulations.

[0049] As in the Fig. 2 and Fig. 3, the image recording devices 2a, 3a are arranged such that the respective recording areas in the horizontal plane and the recording areas in the vertical plane overlap.

[0050] The Fig. The processing device 4a shown in Figure 1 comprises the display switching device (not shown) which, when a suitable switching condition is present, switches between an image area located in the first recording area and a corresponding image area located in the second recording area and displays it on the display device 1a. The switching condition is, for example, a bending angle defined between the towing vehicle 5 and the trailer 6, as described later.

[0051] Fig. 4 shows a plan view of the Fig. 2 and Fig. 3 shows the vehicle with the towing vehicle 5 and the trailer 6 in a first driving state. The first driving state is specifically such that the articulation angle between the towing vehicle 5 and the trailer 6 is 0°.

[0052] In the first driving state, the driver of the vehicle is shown a first image area 7 on the display device 3a, as shown in Fig. 5. The first image area 7 is extracted from the image data of the first recording area such that, according to the exemplary embodiment, the rear area of ​​the trailer 6 is displayed. Fig. Figure 5 shows, in dashed lines on the left side, the first recording area that can be covered by the image recording device 3a. According to the present embodiment, in the Fig. 4 shown driving situation, the first image area 7 (bordered area on the left side in Fig. 5) shown to the driver of the vehicle on the display device 1a, as shown in Fig. 5 on the right side. The image displayed in this way (right side in Fig. 5) preferably has high resolution.

[0053] Fig. Figure 5 further shows, in the center, a second recording area that can be captured by the second image recording device 2a. As schematically illustrated in the figure, the second recording area has a wider angle than the first recording area, as indicated by the reference points K, P, B, and T.

[0054] Referring to Fig. 6 shows a second driving situation in which a bending angle K is formed between the towing vehicle 5 and the trailer 6. According to the present embodiment, the bending angle K is continuously determined by the above-mentioned bending angle determination device contained in the processing device 4a, 4b.

[0055] As can be seen by comparing the Fig. 5 and Fig. As can be seen in Figure 7, the first image area 7 moves with the trailer end as the articulation angle K increases (trailer tracking) and reaches Fig. 7, left side, the outer area of ​​the image data of the recording area of ​​the first image recording device 3a, more precisely the outer area of ​​the sensor, and at the same time the trailer 6 reaches a defined bending angle K described in more detail later D . At the Fig. 6 shown driving situation can also, as in Fig. 7 (center), a second image area 8 is shown, which is extracted from the image data captured by the wide-angle image recording device 2a. The area shown on the left side in Fig. The first image area 7 shown in Figure 7 corresponds to the second image area 8, as shown in Fig. 7 middle. The first image area 7, as shown in Fig. 7 on the left side, corresponds to a section of the first recording area, and the second image area 8, as shown in Fig. 7, shown in the center, corresponds to a section of the second recording area, whereby the image data of the first image area 7 and the image data of the second image area 8 correspond in that they appear to a viewer as identical images when displayed on the display device. The first and second image areas 7, 8 are thus almost identical, but have different resolutions.

[0056] Fig. 7 specifically shows a switching point in time at which the display switches from the first image area 7 to the second image area 8. In Fig. 7 On the right side, the stylized image contents of image areas 7 and 8 are shown simultaneously in the line style of their original image areas (left side and in the middle of the figure) for illustrative purposes.

[0057] Fig. 7 further shows on the left side a point 9 which indicates any reference point on the trailer 6. Fig. 7 shows in the middle a point 10 which indicates the same reference point on the trailer 6.

[0058] As shown on the right side in Fig. As can be seen in Figure 7, these two reference points 9, 10 are essentially at the same positions at the switching or crossfading time. The offset of the two points 9, 10 depends essentially on the distance and alignment angle of the image pickup devices from each other, as well as on the optical properties of the image pickup devices, such as distortion, aperture angle, and angular resolution.

[0059] Fig. Figure 6 further shows a reference point P, which according to the embodiment lies on a plane E passing through a point in a region of the rear edge of the trailer 6 and through the first image recording device 3a. This reference point P is also shown in Fig. 7 on the left side and in the center and contained in the respective image areas 7, 8. The respective orientation angles of the first and second image recording devices 2a, 3a are determined by the reference point P displayed on the display device, which corresponds to the same pixel coordinates in the first and second image areas 7, 8.

[0060] As in Fig. As shown on the right side of Figure 7, at the time of switching from the display of the first image area 7 to the display of the second image area 8, the images perceived by the user are almost identical. Specifically, corresponding image data in the first and second image areas 7, 8 differ by, for example, a maximum of 30 pixels on the display in order to provide such an impression or perception for the user. Fig. For example, on the right side of Figure 7, the above-mentioned reference points 9 and 10 are spaced apart by a certain number of pixels. At the reference point P, the corresponding pixels of the first and second image areas are almost congruent, with the distance between corresponding pixels of the first and second image areas increasing with increasing distance from the reference point P.

[0061] Fig. 8 shows a third driving situation, where compared to Fig. 6 the articulation angle between the towing vehicle 5 and the trailer 6 has increased further. As in Fig. 9, in this driving situation the second image area 8 of the wide-angle image recording device 2a, to which in Fig. 7 has been switched, as shown in Fig. 9 left side, the first image recording device 3a can no longer capture the rear edge of the trailer 6 because the rear edge of the trailer 6 is outside the first recording area.

[0062] Fig. 9 thus shows, on the right side, the user of the vision system a display of the second image area 8 of the wide-angle image recording device 2a, switched from the display of the first image area 7 of the image recording device 3a with high resolution, as in the Fig. 5 and Fig. 7. The switching time is determined depending on a switching condition, which according to the preferred embodiment is defined by the bending angle.

[0063] With reference to the Fig. 10 and Fig. 11 describes a method in which the switching condition depends on the articulation angle between the towing vehicle and the trailer.

[0064] According to the embodiment, the switching condition depends specifically on a defined bending angle K D which is in a given bending angle range K B with a lower bending angle limit K U and an upper bending angle limit K O lies, as in the Fig. 10 and Fig. 11 shown.

[0065] In Fig. 10, the solid line indicates the activation of the first image pickup device, the dotted line indicates the activation of the second image pickup device, the black dot indicates switching between both image pickup devices, and the circle indicates maintaining the current activation state of an image pickup device.

[0066] As in Fig. 10 when the instantaneous articulation angle between the towing vehicle 5 and the trailer 6 exceeds the lower articulation angle limit K Ureached, the first image recording device 2a is activated and the first image area 7 is displayed on the display device, as shown in Fig. 5. If, as in Fig. 10, the instantaneous bending angle is the defined bending angle K D then reached for the first time, the second image recording device is switched over and the second image area 8 is displayed on the display device, as shown in Fig. 9. This switching time is shown in Fig. 7 illustrates, as described above.

[0067] If the current bending angle exceeds the upper bending angle limit K O achieved, as in Fig. 10, and then again the defined bending angle K D , the system switches back to the first image capture device.

[0068] As in Fig. 10, switching between the first and second image recording device only takes place when the defined bending angle KD is reached and the lower or upper bending angle limit has previously been reached at least once. This prevents rapid successive switching between the first image recording device and the second image recording device.

[0069] In Fig. 10, the switching between the activation of the image recording devices is summarized by the following rules: Rule Ia: “If the bending angle exceeds the lower bending angle limit K U reached, the first image recording device is activated (if it is already active, it remains active; if the second image recording device is active, it switches to the first image recording device)"; Rule Ib: “Subsequent switching from the first image acquisition unit to the second image acquisition unit when the defined bending angle K D is achieved”; Rule IIa: “If the articulation angle exceeds the upper articulation angle limit K O reached, the second image recording device is activated (if the second image recording device is already active, it remains active; if the first image recording device is active, the system switches to the second image recording device)"; Rule IIb: “Subsequent switching from the second image recording device to the first image recording device when the defined bending angle K D is achieved”; and Rule III: “If the bending angle exceeds the defined bending angle K D reached without first reaching the lower bending angle limit K U or the upper bending angle limit K O reached, no switching occurs”.

[0070] The Fig. 11 and Fig. 12 further show a reference point P, which is selected such that it is provided at the rear edge of the trailer 6. The reference point P is, for example, displayed on the display device to the user or driver according to the embodiment. The user or driver can freely select the reference point P and, for example, as shown in Fig. 11 shown at the rear edge of the trailer 6. As shown in Fig. 12, when switching from the first image area to the second image area, as described above, the edge of the trailer 6 in particular is displayed almost identically between the first image area and the second image area, so the user can perceive almost no difference or pixel displacement between the first image area and the second image area at the reference point.

[0071] In this way, the user can select a suitable area that should be displayed as “congruently” as possible at the time of switching.

[0072] Fig. 13 shows an exemplary method for mapping the first image area 7 and the second image area 8 onto one another in such a way that a nearly congruent image (smallest possible image difference) is created.

[0073] As mentioned above, according to the embodiment, the first recording area, as shown in the top left of Fig. 13, captured by the image pickup device with high resolution, whereas the second recording area, as shown in the top right corner of Fig. 13, is captured by a wide-angle image recording device. The respective distances A1 to A4 correspond to the distances of the respective edges of the first image area 7, shown rectangular in the figure, to the optical axis 9 of the image recording device 3a. Accordingly, B1 to B4 mark the top right in Fig. 13 the respective distances of the edges of the rectangularly represented second image area 8 to the optical axis 10 of the second image recording device 2a.

[0074] Since, as described above, according to the preferred embodiment, the two image pickup devices have different optical properties, for example, different distortion curves, as shown in Fig. 13, can be used according to the Fig. 13 directory curves shown as an example, the first image area 7 and the second image area 8 are mapped onto one another in such a way that essentially congruent images can be perceived.

[0075] The Fig. The directory curves of the image recording devices shown in Figure 13 are merely examples. By using suitable directory curves, it is possible, for example, to achieve very high resolution where it is needed or required, i.e., in the most relevant area of ​​the vehicle's surroundings, which lies within the captured sub-area of ​​the vehicle's surroundings.

[0076] Fig. 14 shows, in a highly simplified manner, the method described above according to an embodiment for illustrating the switching between the display of two corresponding image areas as a function of an articulation angle between a towing vehicle and a trailer.

[0077] In step S1, first and second image data are acquired by image recording devices, which have different optical properties, different recording ranges, and cover different fields of view, as described above. In step S2, first and second image regions that correspond to one another with regard to image information are extracted from the acquired image data, as described above. In step S3, the first or second image region is shown on the display; as described above, this takes place either on the same display field or on different, separate display fields. For example, a high-resolution image can be displayed on one display field and a wide-angle image on an adjacent display field. According to the preferred embodiment, the corresponding first and second image regions are displayed or superimposed on the same display field, as described above.In step S4, the bend angle is determined as described above. In step S5, it is determined whether a switching condition based on the bend angle, as described above, is met. If the condition is met, the display switches to the previously undisplayed image area in step S6. If the condition is not met, the display of the previously displayed image area continues in step S7.

[0078] It is explicitly emphasized that all features disclosed in the description and / or the claims are to be considered separate and independent of each other for the purpose of the original disclosure as well as for the purpose of limiting the claimed invention, regardless of the feature combinations in the embodiments and / or the claims. It is explicitly stated that all range specifications or specifications of groups of units disclose every possible intermediate value or subgroup of units for the purpose of the original disclosure as well as for the purpose of limiting the claimed invention, in particular also as a limit of a range specification. List of reference symbols 1a, 1b display device 2a, 2b first image recording device 3a, 3b second image recording device 4a, 4b processing device 5 towing vehicle 6 followers α1* first projection γ1* second projection 7 first image area 8 second image area 9 Reference point 10 Reference point 11 optical axis 12 optical axis E Level P Reference point

Claims

[1] Method for switching between a first and a second image area (7, 8) on a display device in a vehicle with a towing vehicle (5) and a trailer (6) pivotably mounted on the towing vehicle (5), comprising: Acquiring first image data by a first image recording device (2a, 2b) of a first recording area; Acquiring second image data by a second image recording device (3a, 3b) of a second recording area overlapping the first recording area, wherein the first and second image recording devices (2a, 2b, 3a, 3b) have different optical properties; Processing the first and second image data to extract the first image area (7) from the first image data and to extract the second image area (8) from the second image data; Displaying the first image area (7) and / or the second image area (8) corresponding as closely as possible to the first image area (7) in a same display field of the display device (1a, 1b); continuously determining a bending angle between the towing vehicle (5) and the trailer (6) by means of a bending angle determining device; Switching or blending the display of the first image area (7) and the display of the second image area (8) based on a switching condition defined by a defined bend wrap K D is determined, wherein at the switching time the first image data of the first image area (7) correspond to the image data of the second image area (8) such that the images perceivable by a user on the display device (1a, 1b) on the basis of the first and second image data are almost identical. [2] Method according to claim 1, wherein the switching is carried out when a currently determined bending angle is above or below the defined bending angle K D is. [3] Method according to claim 1 or 2, wherein the defined bending angle K D within a bending angle range K B with a lower bending angle limit K U and an upper bend angle limit Ko, and the switching or crossfading is carried out when: the display of the first image area (7) is activated, switching to an activation of the display of the second image area (8) when the bending angle exceeds the defined bending angle K D reached and since the last switching the lower bend angle limit K U at least once; and the display of the second image area (8) is activated, switching to an activation of the display of the first image area (7) when the bending angle exceeds the defined bending angle K D reached and since the last switching at least once the upper bend angle limit K O has reached. [4] Method according to one of claims 1 to 3, in which a basic setting is such that the first image area (7) is displayed until the bending angle either reaches the defined bending angle K D or the upper bending angle limit K O reached. [5] Vision system for a vehicle comprising a towing vehicle (5) and a trailer (6) pivotally mounted on the towing vehicle (5), comprising: at least one first image recording device (2a, 2b) for capturing first image data of a first recording area; at least one second image recording device (3a, 3b) for capturing second image data of a second recording area overlapping the first recording area, wherein the first and second image recording devices (2a, 2b, 3a, 3b) have different optical properties; a device (4a, 4b) for processing the first and second image data to extract a first image area (7) from the first image data and to extract a second image area (8) from the second image data; a display device (1a, 1b) for displaying the first image area (7) and / or the second image area (8) corresponding as closely as possible to the first image area (7) in a same display field of the display device (1a, 1b); a bending angle determination device or method for continuously determining a bending angle between the towing vehicle (5) and the trailer (6); and a display switching device for switching or blending the display of the first image area (7) and the display of the second image area (8) based on a switching condition defined by a defined bend wrap K D is determined, wherein at the switching time the first image data of the first image area (7) correspond to the image data of the second image area (8) such that the images perceivable by a user on the display device (1a, 1b) on the basis of the first and second image data are almost congruent. [6] Vision system according to claim 5, wherein corresponding image data in the first and second image areas each differ by a maximum of 30 pixels on the display of the display device (1a, 1b). [7] Vision system according to claim 5 or 6, wherein the distance between the first and second image recording devices (2a, 2b, 3a, 3b) is preferably in a range between 10 mm and 500 mm. [8] Vision system according to one of claims 5 to 7, wherein the optical axes of the first and second image recording devices (2a, 2b, 3a, 3b) are aligned with each other at an alignment angle of 0° to 60° depending on their aperture angles. [9] Vision system according to claim 8, wherein the respective orientation angle of the first and second image recording devices (2a, 2b, 3a, 3b) is determined by a reference point (P) displayed on the display device (1a, 1b) which corresponds to the same pixel coordinates / image data in the first and second image areas (7, 8). [10] Vision system according to claim 9, wherein the reference point (P) is predefined or adjustable depending on trailer height and / or trailer length. [11] Vision system according to claim 10, wherein the reference point (P) lies on a plane (E) perpendicular to the roadway, which plane passes through a point in a region of the rear edge of the trailer (6) at the defined articulation angle K D and passes through the first or second image recording device (2a, 2b, 3a, 3b). [12] Vision system according to claim 11, wherein the reference point (P) is spaced from the first or second image recording device (2a, 2b, 3a, 3b) and at the defined bending angle K D in the area of ​​the rear edge of the trailer (6). [13] Vision system according to one of claims 5 to 12, wherein the optical properties of the first and second image recording devices (2a, 2b, 3a, 3b) have different angular resolutions, aperture angles and / or distortions. [14] Vision system according to one of claims 5 to 13, wherein the defined bending angle K D in a bending angle range KB with a lower bending angle limit K U and an upper bending angle limit K O lies. [15] Vision system according to claim 14, wherein the defined bending angle K D depending on the driving situation of the vehicle within the articulation angle range K B changes. [16] A vision system according to any one of the preceding claims, wherein the display switching device is adapted to control the switching between the first and second image areas (7, 8) according to the method according to any one of claims 1 to 4. [17] A vehicle having a mirror replacement system which is a vision system according to any one of claims 5 to 16.

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