Driver assistance system and method for coupling a trailer to a towing vehicle

Abstract

To provide a driver support system for helping a driver estimate a three-dimensional position of a draw bar eye about a towing vehicle while a rear side approaches a trailer.SOLUTION: A static guidepost is displayed in a video image, and a coupling mouth 31 arranged on a towing vehicle can be brought into contact with a draw bar eye 40 held on the trailer by a draw bar 41 along the static guidepost. Then, the present invention is based on a purpose of providing a driver support system for helping a driver estimate a three-dimensional position of the draw bar eye 40 about the towing vehicle while a rear side approaches the trailer. The purpose is achieved by arranging a video camera 10 separately from a coupling 30 in a vertical direction and forming a static guidepost formed by two beam corridors gathered at a rear side of the towing vehicle and arranged at both sides of a vehicle longitudinal direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a driver assistance system for coupling a trailer to a towing vehicle, according to the features of the preamble of claim 1. Furthermore, the present invention can also be realized in a corresponding method. [Background technology]

[0002] When coupled, the towing vehicle and trailer form an articulated truck and trailer assembly. To couple the trailer, the towing vehicle with the coupling moves backward toward the static trailer until the drawbar eye formed on the trailer's drawbar is correctly inserted into the coupling mouth of the coupling and locked therein by the coupling bolt or locking bracket. However, since the towing vehicle used for this purpose has a coupling retraction far inward toward the rear axle of the towing vehicle, evaluating the spatially relative positions of the coupling and drawbar eye in the trailer assembly with the truck and center axle trailer is particularly difficult.

[0003] Prior art has already made efforts to simplify the coupling process of towing vehicles and trailers with driver assistance systems for the driver. DE 10 2014 012 330 A1 describes a system having a video camera that records the coupling and rear environment with a drawbar eye in video images. A guide is displayed on a screen positioned in the driver's field of view as bearing assistance, which includes horizontal height guides and vertical guides. A disadvantage of this known driver assistance system is that the driver, with a target cross formed from the height guide lines and guides, has only a two-dimensional representation available for the approach of the towing vehicle without spatial depth estimation.

[0004] EP 1 377 062 B1 discloses a rear-view camera mounted on a passenger car, which records an image displayed on a screen. The screen is visible from the driver's seat, and the image includes auxiliary line images, which indicate the direction of reversing directly based on the position of the trailer coupling. The relative position of the trailer coupling and the corresponding part of the trailer-side coupling in the vehicle's longitudinal axis can be recorded by additional horizontal lines oriented laterally to the vehicle's longitudinal axis. Since passenger cars typically do not have height-controllable air suspension, an estimate of the height between the trailer coupling and the corresponding part is not provided and is not relevant. [Overview of the Initiative]

[0005] Therefore, the present invention is based on the objective of providing a driver assistance system that helps the driver estimate the three-dimensional position of the drawbar eye with respect to the towing vehicle while the rear is approaching the trailer.

[0006] The fundamental object of the present invention is solved by the features of the independent claims. The coupling is typically a jaw coupling or hook coupling to a track.

[0007] According to claim 1, the video camera is positioned perpendicularly away from the coupling, which results in spatial depth in the video image. The perpendicular distance to the coupling can, in principle, be achieved above or below the coupling by a video camera mounted above the coupling, taking into account the preferred mounting conditions on the towing vehicle. A video camera mounted below the coupling is often in an exposed position and is therefore exposed to an increased risk of damage. The video camera is positioned on the coupling along the longitudinal axis of the vehicle in such a way that the coupling is positioned outside the video image of the video camera. Typically, the camera is positioned facing the trailer behind the coupling. Therefore, the components of the coupling are not visible in the video image.

[0008] The beam corridor is statically positioned as an overlay on the video image of a video camera. For this purpose, the beam corridor can be fixedly positioned on the lens of the video camera. Alternatively, the beam corridor is generated in the video image by the video camera's image processing software or applied as an overlay on the video camera's image sensor. In a further embodiment, the beam corridor can be placed across the video image of a display device.

[0009] Based on the specific sizes of the coupling mouth and drawbar eye, as well as the angles resulting from a specific installation position and camera tilt, the size of the drawbar eye in the video image increases as the towing vehicle approaches the trailer, according to the orientation and size of the beam corridor. The beam corridor is, in particular, aligned symmetrically with the longitudinal axis of the vehicle. The drawbar eye can have standardized and / or invariant characteristics as a reference element, which is located within or held within the beam corridor as the towing vehicle approaches the trailer. The reference element is preferably the outer diameter of the drawbar eye.

[0010] Due to the spatial orientation of the beam corridor, the position of the trailer's drawbar eye can be estimated both in terms of its lateral position relative to the beam corridor and its height. If the video camera is positioned vertically above the coupling, the following applies: the lower the drawbar eye or its reference element, the greater the distance from the video camera, and the smaller it appears relative to the beam corridor. The higher the drawbar eye or its reference element, the shorter the distance to the video camera, and the larger it appears relative to the beam corridor. Due to the tapered alignment of the beam corridor, the drawbar eye or its reference element moves along the longitudinal axis relative to the beam corridor as the towing vehicle approaches, and the driver can also estimate the distance along the vehicle's longitudinal axis.

[0011] In addition to the spatial estimation of the position of the drawbar eye or its reference element, the vertical offset position of the video camera relative to the coupling also provides a safety advantage, as it eliminates the need to reach the coupling mouth for maintenance or cleaning of the video camera. Jaw couplings, in particular, always carry the risk of the spring-loaded bolt loosening from its open position and snapping forward towards the closed position, which can result in serious hand injuries, for example. The structural distance between the video camera and the coupling means that there is no lubricant or wear on the coupling mouth or coupling bolt that could reach the video camera and cause it to fall into it, thus reducing contamination in any way.

[0012] In a particular preferred embodiment, each beam corridor has an inner boundary and an outer boundary, and for correct coupling, the reference element of the drawbar eye is positioned in the video image between the inner and outer boundary of both beam corridors when the coupling mouth and the drawbar eye are approaching. Thanks to the beam corridors, the relative position of the drawbar eye can be estimated in both the lateral and longitudinal axes of the vehicle. The inner and outer boundary lines define the width of the related beam corridor, from which the height information of the coupling relative to the drawbar eye can be derived particularly well.

[0013] If the drawbar eye, for example, its outer diameter, protrudes laterally beyond the inner and outer boundaries of both beam corridors, the coupling fixed and mounted with respect to the video camera is in too low a position. The static and always the same size beam corridor of the video camera is relatively too close to the drawbar eye and protrudes relatively large beyond the inner and outer boundaries in the video image.

[0014] On the other hand, if, for example, its outer diameter aligns within the inner boundary lines of both beam corridors, the coupling fixed and mounted with respect to the video camera is in a position that is too high. The static and always equally large beam corridors of the video camera leave too much space vertically away from the drawbar eye, which is relatively small in the video image and does not protrude beyond the inner boundary line.

[0015] This has the advantage that the outer diameter of the drawbar eye is clearly visible, especially in video images, even under diffuse lighting conditions. While it is also possible to use the inner diameter of the drawbar eye as a reference element for the trailer, the visible end of the inner diameter of the drawbar eye is difficult to see. Furthermore, lubricant deposits also mislead the estimation of the inner diameter's position relative to the beam corridor in video images. In principle, it is also possible to determine a reference element positioned statically from the drawbar and scale the beam corridor to it. If this reference element, positioned away from the drawbar, is provided with an offset, correct placement of the drawbar eye into the coupling is also possible as long as the reference element is held between the inner and outer boundaries of both beam corridors.

[0016] The distance between the inner and outer boundaries of the beam corridor may depend particularly on the tolerance of the coupling mouse and / or drawbar eye. The coupling tolerance indicates the deviation of the coupling to the drawbar eye, under which correct coupling is still possible. The larger the margin of tolerance for the coupling mouse, the greater the distance between the inner and outer boundaries of the beam corridor can be.

[0017] The distance between the inner and outer boundary lines preferably decreases as the distance along the vehicle's longitudinal axis increases, i.e., each beam corridor tapers in the vehicle's longitudinal axis as the distance increases.

[0018] The video camera is conveniently positioned along the longitudinal axis of the vehicle. This results in the advantage that the video camera is optimally aligned with the coupling direction, the static beam corridor is positioned symmetrically with the coupling, and there is no need for lateral correction when displaying the video image.

[0019] It is also beneficial when the coupling has a cone-shaped extended wall section and the video camera is positioned above the cone-shaped extended wall section. The extended wall section surrounds an axially open entrance opening to accommodate the drawbar eye, and as the towing vehicle approaches, the extended wall section is used to allow the coupling to shift towards the drawbar eye within a certain limit by catching the drawbar eye, and the drawbar eye enters its end position through the extended wall section. The coupling terminates in its rear position due to the extended wall section. The video camera positioned above the extended wall section is consequently never covered by the coupling portion, but always provides a clear view in the direction of the trailer and the drawbar eye.

[0020] The coupling is advantageously equipped with a coupling connection flange and a coupling bolt mounted perpendicularly within the coupling mouth for mounting on the towing vehicle, and the video camera is positioned in the longitudinal axis of the vehicle on the side of the coupling bolt facing away from the connection flange. In this mounting position, the camera is also positioned between the coupling bolt and the free side of the coupling mouth, and the coupling bolt, also provided in the longitudinal axis of the vehicle, is not in the video camera's field of view.

[0021] The coupling may have, for example, a collision protection plate positioned above the coupling mouse, and the video camera may be fixed behind the collision protection plate. The collision protection plate primarily protects the coupling components mounted above the coupling mouse, particularly the locking mechanism, from damage caused by a misaligned drawbar eye. If the video camera is positioned behind the collision protection plate, the camera is also protected from mechanical damage between the couplings.

[0022] The collision protection plate is preferably designed with an opening, and the video camera is arranged in alignment with the opening. As a result, on the one hand, the camera has a clear view to the rear in the direction of the trailer, and on the other hand, it has the advantage of being protected by the collision protection plate. The opening should be of the required size, and the video camera should be spaced from the opening up to a certain limit, such that the outer diameter of the drawbar eye only extends partially into the opening and contact with the video camera is impossible.

[0023] According to a further particular embodiment, the driver assistance system can influence the engine control and / or transmission control and / or brake control and / or the height control of the air suspension, either automatically or when the driver releases it.

[0024] According to this embodiment, the driver assistance system is an autonomous assistance system that approaches and couples to the trailer without the driver having to do anything.

[0025] According to the inventive method for coupling a trailer to a towing vehicle, the guiding marks are visualized by two beam corridors arranged symmetrically with respect to the longitudinal axis of the vehicles converging towards each other behind the towing vehicle.

[0026] In a particularly advantageous process step, each beam corridor has an inner boundary line and an outer boundary line, and it can be provided that when the reference element of the drawbar eye is arranged in the video image between the inner and outer boundary lines of both beam corridors while the coupling mouth and the drawbar eye are approaching, a correct coupling appears.

[0027] Advantageously, the drawbar eye projecting above both outer boundary lines in the video image preferably visualizes lifting the towing vehicle by its air suspension.

[0028] On the other hand, the drawbar eyes positioned within the two inner boundary lines in the video image can preferably be used to visualize the towing vehicle being lowered by its air suspension. [Brief explanation of the drawing]

[0029] For a better understanding, the present invention will be described in more detail below with reference to seven drawings. [Figure 1] Figure 1 is a side view of a jaw coupling with a video camera positioned correctly in front of the drawbar eye immediately before coupling. [Figure 2] Figure 2 is a video image showing the beam corridor and drawbar eye corresponding to the situation in Figure 1. [Figure 3] Figure 3 is a side view of a jaw coupling with a video camera positioned too low in front of the drawbar eye, immediately before the coupling. [Figure 4] Figure 4 is a video image showing the beam corridor and drawbar eye corresponding to the situation in Figure 3. [Figure 5] Figure 5 is a side view of a jaw coupling with a video camera positioned too high in front of the drawbar eye, immediately before the coupling. [Figure 6] Figure 6 is a video image showing the beam corridor and drawbar eye corresponding to the situation in Figure 5. [Figure 7] Figure 7 is a front view of a jaw coupling with a collision protection plate and a video camera. [Modes for carrying out the invention]

[0030] Figure 1 is a side view of the jaw coupling 30 and the video camera 10 attached thereto. The video camera 10 and the display device 11 shown in Figure 2 are part of a driver assistance system. The display device 11 is located in the driver's cab (not shown) of the towing vehicle, and therefore within the driver's field of view.

[0031] The jaw coupling 30 includes a coupling mouth 31 that opens to the rear and a connecting flange 33 for fixed mounting of the jaw coupling 30 on the towing vehicle, particularly on the vehicle frame 38 of the towing vehicle. The coupling mouth 31 is formed by an extended wall section 32, which completely encloses the inlet opening 37 in the circumferential direction and is open on one side in the axial direction. The video camera 10 is mounted above the coupling mouth 31 in the longitudinal axis Z of the vehicle (see Figure 2).

[0032] In the example shown in Figure 1, the drawbar eye 40, mounted on the end of the drawbar 41, is oriented correctly directly in front of the inlet opening 38. With the help of the drawbar 41 and the drawbar eye 40, the trailer (not shown) is releasably mounted to the towing vehicle. As the towing vehicle moves rearward in direction R, the drawbar eye 40 enters the jaw coupling 30 through the inlet opening 37 and, after approaching its end position, is held there swivelably within the jaw coupling 30 by the coupling bolt 34.

[0033] Before the trailer is coupled, the coupling bolt 34 is in the open position, which can be achieved by using the operating lever 39. When the jaw coupling 30 contacts the drawbar eye 40, the spring-loaded coupling bolt 34 snaps into its closed position, and the inner diameter Φ of the drawbar eye 40 I It penetrates completely. In its closed position, the coupling bolt 34 travels vertically through the coupling mouth 31 of the jaw coupling 30, which is clearly shown in detail in Figure 7 and is supported on the opposite side of the coupling mouth 31.

[0034] The extended wall section 32 of the coupling mouth 31 facilitates the pickup of the jaw coupling 30 that is not properly aligned with the drawbar eye 40, and thus expands the allowable space of the coupling mouth 31. The allowable space defines an area within which, when a towing vehicle is moving in reverse in direction R, the drawbar eye 40, which is aligned perpendicularly or laterally offset to the jaw coupling 30, slides into the inlet opening 37 by contacting the extended wall section 32.

[0035] The scenario illustrated in Figure 1 is presented to the driver on the display device 11 in a video image 20 transmitted by a video camera 10 according to Figure 2. In the video image 20, the rear area behind the towing vehicle to be coupled and the trailer's drawbar eye 40 are shown. The jaw coupling 30 is not shown in the video image 20 because it is located outside the area captured by the video camera 10.

[0036] For estimating the relative position of the drawbar eye 40 to the towing vehicle, a guide 21 is shown in the display device 11 in the form of two beam corridors 22 that taper towards the rear. The two beam corridors 22 are aligned symmetrically with respect to the vehicle's longitudinal axis Z, and in each case, one of the beam corridors 22 is positioned on one side of the vehicle's longitudinal axis. Each beam corridor 22 has an inner boundary line 23 facing the other beam corridor 22 and an outer boundary line 24 facing away from the other beam corridor 22. The inner boundary line 23 leaves space from the outer boundary line 24 at a distance perpendicular to it. The distance is the distance D from the video camera 10 along the vehicle's longitudinal axis Z. Z When it increases, it decreases.

[0037] This is the inner diameter Φ I As it is more clearly visible in the video image 20, the alignment of the beam corridor 22 and distance a as a reference element of the trailer is its outer diameter Φ AIn the present case, it corresponds to a known, normal standard-sized drawbar eye 40. However, in principle, the inner diameter Φ I or another reference element arranged in a static manner on the trailer can also be used, and if necessary, an offset to the position of the drawbar eye 40 can be applied.

[0038] In each beam corridor 22, the outer diameter Φ between the inner boundary line 23 and the outer boundary line 24 A so that a section of the reference element, for example, the outer diameter Φ of the drawbar eye 40 A As long as it covers both beam corridors 22, the beam corridor 22 visualizes the correct alignment of the drawbar eye 40 of the joker coupling 30 to the driver during the reverse R. During the reverse R, the driver operates the towing vehicle in such a way that a section of the outer diameter Φ A is held between the inner boundary line 23 and the outer boundary line 24 in both beam corridors 22. As the towing vehicle approaches a static trailer on the longitudinal axis Z of the vehicle, the image of the drawbar eye 40, and thus its outer diameter Φ A in the video image 20 increases in the same way as the size of the beam corridor 22. When the drawbar eye 40 exits the lower edge of the video image 20, the driver can estimate that contact will occur immediately between the coupling nose 31 and the drawbar eye 40.

[0039] Figures 3 to 6 illustrate a situation where the towing vehicle is at the center of the longitudinal axis Z of the vehicle in front of the drawbar eye 40, but the air suspension height adjustment is set incorrectly. As the towing vehicle approaches, the drawbar eye 40 moves over or passes under the coupling nose 31, thus causing serious damage to the towing vehicle.

[0040] In the side view, Figure 3 shows a vertical position of the joker coupling 30 that is too low. For the correct storage of the drawbar eye 40 into the coupling nose 31, the towing vehicle has to be lifted by the air suspension.

[0041] The drawbar eye 40 is positioned relatively close to the video camera 10, and the drawbar eye 40 appears larger in the video image 20 according to Figure 4 than the static, always equal-sized beam corridor 22. Outer diameter Φ A It protrudes beyond both the inner boundary line 23 and the outer boundary line 24 of both beam corridors 22. In order to continue coupling, a larger vertical distance is established between the towing vehicle and the video camera, and the outer diameter Φ of the drawbar eye 40 is shown in the video image 20. A It must be lifted by its air suspension until it moves between the inner boundary line 23 and the outer boundary line 24 of both beam corridors 22.

[0042] In the side view, Figure 5 shows the vertical position of the jaw coupling 30, which is too high. For the drawbar eye 40 to properly enter the coupling mouth 31, the towing vehicle must be lowered by the air suspension.

[0043] The drawbar eye 40 is positioned relatively far from the video camera 10, and in the video image 20 of Figure 6, the drawbar eye 40 appears smaller than the static, always equal-sized beam corridor 22. Outer diameter Φ A It is positioned between the beam corridors 22 and extends just to the extent of the inner boundary line 23. In order to continue coupling, the towing vehicle establishes a smaller vertical distance between the video camera and the drawbar eye, and the outer diameter Φ in the video image 20 A It must be lowered by its air suspension until it moves between the inner boundary line 23 and the outer boundary line 24 of both beam corridors 22.

[0044] Figure 7 shows a front view of the jaw coupling 30. The collision protection plate 35 is mounted vertically above the coupling mouth 31. If the jaw coupling 30 is set too low, the collision protection plate 35 covers a portion of the locking mechanism, particularly the operating lever 39 on the vehicle longitudinal axis Z from the rear, to avoid damage caused by the drawbar eye 40 during coupling of the trailer.

[0045] In the longitudinal axis Z of the vehicle, the collision protection plate 35 protrudes rearward beyond the extended wall section 32, and the video camera 10 is positioned essentially above the free end of the extended wall section 32.

[0046] Along the longitudinal axis Z of the vehicle, an opening 36 is formed in the collision protection plate 35, and the video camera 10 is aligned behind it. The opening 36 is of the size required for this method, and even if the drawbar eye 40 strikes the collision protection plate 35 with a large force, the known outer diameter Φ of the drawbar eye 40 is not affected. A However, the video camera 10 is positioned at a distance from the opening 36 so that it cannot come into contact with the opening 36 and penetrate deeply enough to cause damage. [Explanation of symbols]

[0047] 10 video cameras 11 Display Devices 20 video images 21 Guidepost 22 Beam Corridor 23. Inner boundary of the beam corridor 24. Outer boundary of the beam corridor 30 Coupling / Jaw Coupling 31 Coupling mice 32 Extension wall section 33 Connecting flange 34 Coupling bolts 35 Collision protection plate 36. Opening protection plate 37 Entrance opening 38. Vehicle Frame Towing Vehicle 39. Operating lever 40 Drawbar Eye 41 Drawbars a Inner / outer border distance D Z Distance along the longitudinal axis of the vehicle R: Towing vehicle in reverse Z is the longitudinal axis of the vehicle. Φ A Outer diameter of the drawbar eye Φ I Inner diameter of the drawbar eye The invention described in the original claims of this application is listed below. [1] A driver assistance system for coupling a trailer to a towing vehicle, A video camera (10) attached to the aforementioned towing vehicle, The driver comprises an associated display device (11) in the field of view, In the video image (20), a static guide (21) is displayed, and along it, a coupling mouth (31) positioned on the towing vehicle can make contact with a drawbar eye (40) held on the trailer by a drawbar (41). A driver assistance system characterized in that the video camera (10) is positioned at a vertical distance from the coupling (30), and the static guide is formed by two beam corridors (22) positioned on both sides of the vehicle's longitudinal axis (Z) that converge toward each other at the rear of the towing vehicle. [2] The driver assistance system according to [1], wherein each of the beam corridors (22) has an inner boundary line (23) and an outer boundary line (24), and for correct coupling, the reference element of the drawbar eye (44) is positioned in the video image (20) between the inner boundary line (23) and the outer boundary line (24) of both beam corridors (22) while the coupling mouse (31) and the drawbar eye (40) are approaching. [3] The driver assistance system according to [2], characterized in that the reference element is the outer diameter (ΦA) of the drawbar eye (40). [4] The driver assistance system according to [2] or [3], characterized in that the distance (a) between the inner boundary line (23) and the outer boundary line (24) of each beam corridor (22) depends on the tolerance of the coupling mouse (31) and / or the drawbar eye (44). [5] The driver assistance system according to [4], characterized in that the distance (a) is smaller than the increasing distance (DZ). [6] The driver assistance system according to any one of [1] to [5], characterized in that the video camera (10) is located in the longitudinal axis (Z) of the vehicle. [7] The driver assistance system according to any one of [1] to [6], characterized in that the coupling mouse (31) has a cone-shaped expanded wall section (32), and the video camera (10) is positioned above the cone-shaped expanded wall section (32). [8] The coupling (30) comprises a coupling connection flange (33) for mounting on the towing vehicle and a coupling bolt (34) vertically mounted in the coupling mouth (31), The driver assistance system according to any one of [1] to [7], characterized in that the video camera (10) is positioned in the vehicle longitudinal axis (Z) on the side of the coupling bolt (34) facing away from the connecting flange (33). [9] The driver assistance system according to any one of [1] to [8], characterized in that the coupling (30) has a collision protection plate (35) positioned above the coupling mouse (31), and the video camera (10) is positioned behind the collision protection plate (35).

[10] The driver assistance system according to [9], characterized in that the collision protection plate (35) is formed together with an opening (36), and the video camera (10) is positioned in alignment with the opening (36).

[11] The driver assistance system according to any one of [1] to

[10] , characterized in that the driver assistance system affects engine control and / or transmission control and / or brake control and / or air suspension height control automatically or when the driver takes their hands off the wheel.

[12] A method for coupling a trailer to a towing vehicle using a video camera (10) mounted on the towing vehicle and an associated display device (11) positioned in the driver's field of view, The static guidepost (21) becomes visible in the video image of the display device (11), and the coupling mouth (31) of the coupling (30) positioned along it on the towing vehicle contacts the drawbar eye (40) which is held on the trailer by the drawbar (41). The method is characterized in that the guidepost (21) is visualized by two beam corridors (22) arranged symmetrically with respect to the longitudinal axis (Z) of the vehicle, which converge toward each other at the rear of the towing vehicle.

[13] The method according to

[12] , wherein each of the beam corridors (22) has an inner boundary line (23) and an outer boundary line (24), and correct coupling appears when the reference element of the drawbar eye (40) is positioned in the video image (20) between the inner boundary line (23) and the outer boundary line (24) of both beam corridors (22) while the coupling mouse (31) and the drawbar eye (40) are approaching each other.

[14] The method according to

[13] , characterized in that a drawbar eye (40) projected above both outer boundary lines (24) in the video image (20) visualizes the lifting of the towing vehicle by its air suspension.

[15] The method according to

[13] or

[14] , characterized in that a drawbar eye (40) positioned in the video image (20) within the two inner boundary lines (23) visualizes the lowering of the towing vehicle by its air suspension.

Claims

1. A driver assistance system for coupling a trailer to a towing vehicle, A video camera (10) attached to the aforementioned towing vehicle, The system includes an associated display device (11) in the driver's field of view, In the video image (20) transmitted by the video camera (10), a static guidepost (21) is displayed, and along it, a coupling mouth (31) positioned on the towing vehicle can contact a drawbar eye (40) held on the trailer by a drawbar (41). The video camera (10) is positioned at a vertical distance from the coupling (30), and the static guide is formed by two beam corridors (22) positioned on both sides of the longitudinal axis (Z) of the towing vehicle, which converge toward each other at the rear of the towing vehicle. A driver assistance system characterized in that each of the beam corridors (22) has an inner boundary line (23) and an outer boundary line (24), and for correct coupling, the reference element of the drawbar eye (44) is positioned in the video image (20) between the inner boundary line (23) and the outer boundary line (24) of both beam corridors (22) while the coupling mouse (31) and the drawbar eye (40) are approaching.

2. The driver assistance system according to claim 1, characterized in that the reference element is the outer diameter (ΦA) of the drawbar eye (40).

3. The driver assistance system according to claim 1 or 2, characterized in that the distance (a) between the inner boundary line (23) and the outer boundary line (24) of each beam corridor (22) depends on the tolerance range of the coupling mouse (31) and / or the drawbar eye (44).

4. The driver assistance system according to claim 3, characterized in that the distance (a) is smaller than the increasing distance (DZ).

5. The driver assistance system according to any one of claims 1 to 4, characterized in that the video camera (10) is located in the longitudinal axis (Z) of the towing vehicle.

6. The driver assistance system according to any one of claims 1 to 5, characterized in that the coupling mouse (31) has a cone-shaped expanded wall section (32), and the video camera (10) is positioned above the cone-shaped expanded wall section (32).

7. The coupling (30) comprises a coupling connection flange (33) for mounting on the towing vehicle and a coupling bolt (34) vertically mounted in the coupling mouth (31). The driver assistance system according to any one of claims 1 to 6, characterized in that the video camera (10) is positioned in the longitudinal axis (Z) of the towing vehicle on the side of the coupling bolt (34) facing away from the coupling connection flange (33).

8. The driver assistance system according to any one of claims 1 to 7, characterized in that the coupling (30) has a collision protection plate (35) positioned above the coupling mouse (31), and the video camera (10) is positioned behind the collision protection plate (35).

9. The driver assistance system according to claim 8, characterized in that the collision protection plate (35) is formed together with an opening (36), and the video camera (10) is positioned in alignment with the opening (36).

10. A method for coupling a trailer to a towing vehicle using a video camera (10) mounted on the towing vehicle and an associated display device (11) positioned in the driver's field of view, The static guidepost (21) becomes visible in the video image of the display device (11), and the coupling mouth (31) of the coupling (30) positioned along it on the towing vehicle contacts the drawbar eye (40) which is held on the trailer by the drawbar (41). The static guide (21) is visualized by two beam corridors (22) located behind the towing vehicle and arranged symmetrically along the longitudinal axis (Z) of the towing vehicle, converging toward each other. A method characterized in that each of the beam corridors (22) has an inner boundary line (23) and an outer boundary line (24), and correct coupling appears when the reference element of the drawbar eye (40) is positioned in the video image (20) between the inner boundary line (23) and the outer boundary line (24) of both beam corridors (22) while the coupling mouse (31) and the drawbar eye (40) are approaching each other.

11. The method according to claim 10, characterized in that a drawbar eye (40) projected above both outer boundary lines (24) in the video image (20) visualizes the lifting of the towing vehicle by the air suspension.

12. The method according to claim 10 or 11, characterized in that a drawbar eye (40) positioned in the video image (20) within two of the inner boundary lines (23) visualizes the lowering of the towing vehicle by the air suspension.

Images