The invention relates to a display device for displaying a current hitch angle of a vehicle/trailer combination, which is constituted by a motor vehicle and a trailer. The current hitch angle, which is formed between a longitudinal axis of the motor vehicle and a longitudinal axis of the trailer, is displayable on a hitch angle display of the display device by means of a symbol moving depending on the current hitch angle on the hitch angle display.

Systems are already known from the prior art, by means of which a collision of a motor vehicle with objects can be prevented. For example, US 7,109,854 B2 discloses a system, in which an environment of the motor vehicle is captured by means of a detector device. An evaluation device calculates the object-free space, in which the motor vehicle can be maneuvered. By means of a further detector device, motor vehicle components and for example also a trailer and the dynamic parameters of the current driving situation, such as for example speed or steering angle, can in particular be captured. Depending on this information and depending on the captured object-free movement space, a prediction can then be made if a possible critical situation, in particular a collision, between the motor vehicle and a vehicle/trailer combination, respectively, which is constituted by a motor vehicle and a trailer, and an object can arise.

Furthermore, US 2014/0324295 A1 discloses a hitch angle observation display. A captured scene of the hitch between the motor vehicle and an attached vehicle is displayed. An overlay is laid onto the captured image by means of a control device, wherein the hitch angle can be displayed with a maximum hitch angle in the overlay.

It is the object of the present invention to provide a display device as well as a method, by means of which a hitch angle can be more intuitively displayed.

This object is solved by a display device as well as by a method according to the independent claims. An aspect of the invention relates to a display device for displaying a current hitch angle of a vehicle/trailer combination, which is constituted by a motor vehicle and a trailer. The current hitch angle, which is formed between a longitudinal axis of the motor vehicle and a longitudinal axis of the trailer, is displayable on a hitch angle display of the display device by means of a symbol moving depending on the current hitch angle on the hitch angle display.

The hitch angle display is formed as a circular ring sector display and the current hitch angle is displayable on the circular ring sector display by means of the symbol.

In other words, the moving symbol can move radially along the circular ring sector display and thereby display the current hitch angle. Thereby, the current hitch angle can be displayed in intuitively improved manner for a viewer of the display device. In particular, it is thereby allowed that a display can be provided for the user or for the viewer, on which the viewer can see, how the current hitch angle behaves in particular with respect to a maximum hitch angle and how far the current hitch angle is still away from the maximum hitch angle, respectively. Thereby, it is allowed that a critical situation of the vehicle/trailer combination can be prevented in particular in steering operations.

According to an advantageous form of configuration, a first maximum hitch angle of the vehicle/trailer combination and a second maximum hitch angle of the vehicle/trailer combination can be displayable by means of the circular ring sector display, wherein the first maximum hitch angle is displayable independently of the second maximum hitch angle, wherein the first maximum hitch angle is determinable depending on a first decision criterion and the second maximum hitch angle is determinable depending on a second decision criterion. In particular, it is thereby allowed that the first maximum hitch angle can be different from the second maximum hitch angle. It is also possible that both maximum hitch angles are identically formed. In particular, the first decision criterion and/or the second decision criterion can be determined by an evaluation device of the display device. For example, the first and/or the second decision criterion can be dependent on a loading, a loading state, a loading weight, a loading area of the trailer. It is also possible that the first and/or the second decision criterion are for example dependent on a street alignment, on which the vehicle/trailer combination is located, and dependent on a tunnel width, on which the vehicle/trailer combination is located, respectively. It is also possible that for example information of a navigation system about a future route can be taken into account. In particular, it is then possible that for example swerving of the trailer to the left viewed in principal direction of travel of the vehicle/trailer combination can turn out greater than for example to the right. Thus, the two maximum hitch angles are determinable independently of each other. Thereby, the first maximum hitch angle and independently thereof the second maximum hitch angle can in particular be displayed reliably and individually to the current situation. Thereby, improved operation of the vehicle/trailer combination in the road traffic is allowed.

It has further proven advantageous if the display device comprises an evaluation device, by means of which the first maximum hitch angle and/or the second maximum hitch angle are determinable depending on a parameter characterizing the current vehicle/trailer combination and/or on a further parameter characterizing the current environment of the vehicle/trailer combination as the first or the second decision criterion. The maximum hitch angle is in particular that angle, at which the motor vehicle and the trailer just do not yet contact each other. The parameter characterizing the current vehicle/trailer combination can for example be a speed of the vehicle/trailer combination and a loading state and a type of trailer of the vehicle/trailer combination, respectively. The further parameter characterizing a current environment of the vehicle/trailer combination can for example be a quality of the road and a curve radius, respectively, or a tunnel width. Furthermore, a road width can for example also be regarded as a further parameter characterizing the current environment of the vehicle/trailer combination. In particular, a plurality of the parameters characterizing the current vehicle/trailer combination and/or of the further parameter characterizing the current environment of the vehicle/trailer combination can then be incorporated in the first and/or the second decision criterion, and therefore the first and/or the second decision criterion can be evaluated depending on the two

characterizing parameters. In particular, they are variable parameters such that the first maximum hitch angle and the second maximum hitch angle are not fixedly, but variably formed. In other words, the maximum hitch angles are determined depending on situation.

It is also advantageous if the circular ring sector display is divided into at least three, in particular five, circular ring sector sections, wherein an approach of the current hitch angle to a first maximum hitch angle of the vehicle/trailer combination and/or to a second maximum hitch angle of the vehicle/trailer combination is displayable by means of the circular ring sector sections. For example, a central circular ring sector section of the three circular ring sector sections can then display a safe hitch angle. In other words, a hitch angle, which is located in this circular ring sector section, cannot result in the trailer and the motor vehicle contacting each other. In contrast, it can be displayed in the outer circular ring sector sections that an approach of the current hitch angle to this maximum hitch angle, at which the motor vehicle and the trailer would contact each other, is given. Thereby, an intuitive display can be provided, by means of which for example a driver of the vehicle/trailer combination gets intuitively displayed the current hitch angle in relation to the maximum hitch angles.

In a further advantageous form of configuration, the at least three circular ring sector sections, in particular the five circular ring sector sections, are displayable distinguishable in terms of color. Thereby, it is allowed that the circular ring sector sections can be perceived by a driver of the motor vehicle in improved manner and he can in particular even more intuitively perceive the approach of the current hitch angle to the maximum hitch angles.

It is also advantageous if a first one of the circular ring sector sections is displayable in green, at least a second one of the circular ring sector sections is displayable in yellow and at least a third one of the circular ring sector sections is displayable in red. By the first circular ring sector section, which is formed green, it is in particular displayed that the current hitch angle is still acceptably far away from the maximum hitch angle. In the second circular ring sector section, which is in particular formed yellow, it can in particular be that the current hitch angle has already approached to the maximum circular ring sector, but a critical situation cannot yet occur. In particular in the third circular ring sector section, which is in particular displayed in red, there can then be the possibility that the vehicle/trailer combination contacts the motor vehicle and thus the current hitch angle has approached to a maximum hitch angle. In particular in the configuration with five circular ring sector sections, it can occur that the central first circular ring sector section is formed green, the second circular ring sector sections following the green circular ring sector section in both directions are formed yellow and two red circular ring sector sections are formed following the two yellow circular ring sector sections.

According to a further advantageous form of configuration, the moving symbol can be displayable as a triangle. In particular, the current hitch angle is displayable by the triangle, which is in particular formed extensively in color. In particular, the triangle is extensively black and displays the angle in particular by an apex of the triangle on the corresponding circular ring sector display. In particular, the apex of the triangle is overlapping with the angle of the longitudinal axis of the trailer. Thereby, the current hitch angle can be very intuitively perceived by a driver of the vehicle/trailer combination.

It is also advantageous if the moving symbol is displayable movable in an interior of the circular ring sector display only within a radially inner boundary of the circular ring sector display and a radially outer boundary of the circular ring sector display. Thereby, a space saving circular ring sector display can be formed since the moving symbol only moves within the already displayed circular ring sector display.

It has further proven advantageous if a further display is formed at least between a radially inner boundary of the circular ring sector display and a central point of the circular ring sector display, on which a further symbol is displayable. Thereby, it is allowed that further information for example relating to the vehicle/trailer combination can be displayed on the further display. Thus, a display device can be provided, by means of which additional information can be displayed besides the current hitch angle.

According to a further advantageous form of configuration, the further symbol can be a picture of the motor vehicle with a picture of the attached trailer, wherein the further display is formed such that a picture of the hitch angle between a longitudinal axis of the picture of the motor vehicle and a longitudinal axis of the picture of the trailer is displayable depending on the current hitch angle. Thereby, a still more intuitive display of the current hitch angle is allowed for the viewer since a picture of the motor vehicle with a picture of the trailer is displayed besides the moving symbol within the circular ring sector display. In particular, the picture of the trailer is then moved with respect to the picture of the motor vehicle on the display depending on the current hitch angle such that the driver of the motor vehicle can more intuitively perceive the current hitch angle in relation to the motor vehicle.

It has further proven advantageous if a still further symbol is displayable on the further symbol by the further display, which is in particular a warning symbol. For example, the warning symbol can be formed as a triangle with an exclamation mark. It is also possible that the still further symbol differs from the further symbol in color. For example, the still further symbol can be formed red. In particular, if the current hitch angle should for example approach to one of the two maximum hitch angles, thus, a warning symbol can be generated as the still further symbol and more intuitively warn the driver of the vehicle/trailer combination of reaching the maximum hitch angle such that a critical situation between the motor vehicle and the trailer can in particular be prevented. It is also possible that exceeding a maximum weight of the vehicle/trailer combination for example for a bridge can for example be displayed by the warning symbol and thus it can be displayed to the driver that the weight is exceeded. Thereby, critical situations of the vehicle/trailer combination in the road traffic can be prevented in improved manner. It is also advantageous if the still further symbol is displayable by the further display depending on a parameter characterizing the environment of the vehicle/trailer combination and/or a parameter characterizing the vehicle/trailer combination. In particular, the warning symbol can for example be displayed if the vehicle/trailer combination should exceed a prescribed speed. It is also possible that the still further symbol can be displayed if for example the vehicle/trailer combination enters a tunnel as the environment, but a height of the vehicle/trailer combination exceeds a tunnel height. Thus, it can be intuitively displayed if the vehicle/trailer combination can get into a critical situation both characterizing to the vehicle/trailer combination and characterizing to the environment of the vehicle/trailer combination.

A further aspect of the invention relates to a method for displaying a current hitch angle of a vehicle/trailer combination on a display device, which is constituted by a motor vehicle and a trailer. The current hitch angle, which is formed between a longitudinal axis of the motor vehicle and a longitudinal axis of the trailer, is displayed by means of a symbol moving depending on the current hitch angle on the display device. The current hitch angle is displayed as a symbol on a circular ring sector display of the display device.

According to an advantageous form of configuration, a further parameter characterizing the environment of the vehicle/trailer combination can be determined by means of a capturing device of the motor vehicle and/or a parameter characterizing the vehicle/trailer combination can be determined by means of a capturing device of the motor vehicle, wherein a first maximum hitch angle and/or a second maximum hitch angle are determined depending on the parameter characterizing the vehicle/trailer combination and/or depending on the further parameter characterizing the environment of the vehicle/trailer combination and/or a still further symbol is displayed depending on the parameter characterizing the vehicle/trailer combination and/or on the further parameter characterizing the environment of the vehicle/trailer combination. The capturing device can for example be a camera of the motor vehicle or for example a navigation system of the motor vehicle. It is also possible that the two capturing devices, which capture the further parameter characterizing the environment of the vehicle/trailer combination and the parameter characterizing the vehicle/trailer combination, are the same capturing devices.

A still further aspect of the invention relates to a computer program product with program code means, which are stored in a computer-readable medium to perform the method according to any one of the previously mentioned aspects when the computer program product is run on a processor of an electronic control unit. A still further aspect of the invention relates to a display device for displaying a current hitch angle of a vehicle/trailer combination, which is constituted by a motor vehicle and a trailer. The current hitch angle, which is formed between a longitudinal axis of the motor vehicle and a longitudinal axis of the trailer, is displayable on a hitch angle display of the display device by means of a symbol moving depending on the current hitch angle on the hitch angle display. A first maximum hitch angle of the vehicle/trailer combination and a second maximum hitch angle of the vehicle/trailer combination are displayable by means of the hitch angle display, wherein the first maximum hitch angle is displayable independently of the second maximum hitch angle, wherein the first maximum hitch angle is determinable depending on a first decision criterion and the second maximum hitch angle is determinable depending on a second decision criterion.

A still further aspect of the invention relates to a motor vehicle with a display device. The motor vehicle is in particular formed as a passenger car.

Advantageous forms of configuration of the display device are to be regarded as advantageous forms of configuration of the method, of the computer program product and of the motor vehicle, respectively. Thereto, the display device as well as the motor vehicle comprises concrete features, which allow a method or an advantageous form of configuration thereof.

Further features of the invention are apparent from the claims, the figures and the descrip tion of figures. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of figures and/or shown in the figures alone are usable not only in the respectively specified combination, but also in other combinations or alone without departing from the scope of the invention. Thus, implementations are also to be considered as encompassed and dis closed by the invention, which are not explicitly shown in the figures and explained, but arise from and can be generated by separated feature combinations from the explained implementations. Implementations and feature combinations are also to be considered as disclosed, which thus do not have all of the features of an originally formulated independ ent claim. Moreover, implementations and feature combinations are to be considered as disclosed, in particular by the implementations set out above, which extend beyond or de viate from the feature combinations set out in the relations of the claims. In the following, the invention is explained in more detail based on preferred embodiments as well as with reference to the attached drawings.

There show:

Fig. 1 a schematic top view to a vehicle/trailer combination with an embodiment of a display device;

Fig. 2 a schematic view of an embodiment of a display device; and

Fig. 3 a further schematic view of an embodiment of the display device.

In the figures, identical or functionally identical elements are provided with the same reference characters.

Fig. 1 shows a motor vehicle 1 with an attached trailer 2, which in the coupled state form a vehicle/trailer combination 3, schematically in a plan view. The motor vehicle 1 is designed in particular as a passenger car. The motor vehicle 1 is used as a tractor unit of the vehicle/trailer combination 3, and it is also possible for the motor vehicle 1 to be designed as a truck or a camper, for example.

The motor vehicle 1 has a longitudinal axis L1 . The trailer 2 is coupled to vehicle 1 via a trailer hitch 4. The motor vehicle 1 also has a capturing device 5, by means of which a shape of an area 6 of motor vehicle 1 facing the trailer 2 is detected. The capturing device 5 can also be used to detect a form of an area 7 of the trailer 2 facing to the motor vehicle 1. It is possible that with capturing device 5 both areas 6 and areas 7, can be detected. It is also possible, for example, that at least one additional detection device can be provided on the motor vehicle 1 and/or the trailer 2, which can cover the areas 6, 7. The capturing device 5 can be designed in particular as a camera and, for example, capture the corresponding areas 6, 7 by means of an image processing program. It is also possible that capturing device 5 can be designed as a lidar sensor or radar sensor or ultrasonic sensor and can detect the areas 6, 7 accordingly. An arbitrary combination of the different sensor types is also possible in order to measure the ranges 6, 7. It is also possible that capturing device 5 or the other capturing device is arranged on trailer 2. The capturing dievice 5 can be used to determine a first characteristic location 8 in area 6 of the motor vehicle 1 , where the motor vehicle 1 would contact the trailer 2 in the critical situation. Furthermore, a second characteristic location 9 in area 7 can be detected by means of the capturing device 5, at which the motor vehicle 1 would be touched in the critical situation of the trailer 2. Furthermore, it may be provided that a third characteristic location 10 in area 6 of the motor vehicle 1 may be determined by means of the capturing device 5, which in a further critical situation would contact the motor vehicle 1 with the trailer 2. It is also possible that the capturing device 5 can be used to detect a fourth characteristic location 1 1 , which is within the area 7 of the trailer 2, and which would be in contact in the critical situation of the trailer 2 and the motor vehicle 1. In particular, the critical situation can be a so-called jack knife effect (jack-knife) in which a critical situation could occur on both sides, seen from the longitudinal axis L1. This can lead to a critical situation on both sides. With the jack knife effect, the vehicle/trailer combination 3 buckles. In other words, the trailer 2 moves relative to the motor vehicle 1 so that the motor vehicle 1 and the trailer 2 can touch each other. In particular, it is presumed that the third characteristic location 10 and the fourth characteristic location 1 1 are formed on a second side, wherein the second side is facing to a first side, and the first side and the second side being separated from each other by the longitudinal axis L1 . The third characteristic location 10 and the fourth characteristic location 1 1 are formed on a second side.

In particular in the driving operation of the vehicle/trailer combination 3, a hitch angle a between the longitudinal axis L1 and a longitudinal axis L2 from the trailer 2 can form in various driving situations, which in particular are dependent on drive-dynamic parameters of the vehicle/trailer combination 3. It is provided that this hitch angle a is depicted on a display device 12 of the motor vehicle. In particular, it can also be provided that the display device 12 comprises an evaluation device 13.

Further, it can be provided that the motor vehicle 1 comprises a further capturing device 14, by means of which an environment 15 of the vehicle/trailer combination 3 can be captured.

Fig. 2 shows a schematic view of an embodiment of the display device 12. Thereto, the display device 12 comprises a hitch angle display 16, which is formed as a circular ring sector display 17. It is provided that the current hitch angle a is displayed as a moving symbol 18 on the circular ring sector display 17. Presently, the moving symbol 18 is in particular formed as a triangle. In particular, it is provided that the moving symbol 18 only moves within a radially inner boundary 19 of the circular ring sector display 17 and a radially outer boundary 20 of the circular ring sector display 17 in an interior 21 of the circular ring sector display 17.

In particular, it is allowed that a first maximum hitch angle 22 of the vehicle/trailer combination 3 and a second maximum hitch angle 23 of the vehicle/trailer combination 3 are displayable by means of the hitch angle display 16, in particular by means of the circular ring sector display 17. The maximum hitch angles 22, 23 are in particular those points, at which the characteristic locations 8, 10 of the area 6 and the characteristic locations 9, 1 1 of the area 7 would contact each other. In other words, the maximum hitch angles 22, 23 are those locations, at which the motor vehicle 1 and the trailer 2 would contact each other in a critical situation.

In particular, it is provided that the first maximum hitch angle 22 is displayable and determinable independently of the second maximum hitch angle 23. In particular, the first maximum hitch angle 22 is determinable depending on a first decision criterion and the second maximum hitch angle 23 is in particular determinable depending on a second decision criterion. The first and the second decision criterion can be different, but they can be the same decision criterion. For example, the first maximum hitch angle 22 and/or the second maximum hitch angle 23 can be determined by means of the evaluation device 13 depending on a parameter characterizing the current vehicle/trailer combination 3 and/or a further parameter characterizing the current environment 15 of the vehicle/trailer combination 3 as the first or the second decision criterion. For example, the hitch angles 22, 23 can be determined depending on the environment 15 of the vehicle/trailer combination 3. For example, a road width of the environment 15 of the vehicle/trailer combination 3 can have influence on the maximum hitch angles 22, 23. Then, it is for example possible that, if the road should for example have a side strip, the first hitch angle 22 is formed greater than the second hitch angle 23. As the parameter characterizing the current vehicle/trailer combination 3, for example a loading of the trailer 2. For example, if an object as the loading of the trailer 2 should protrude beyond an outline of the trailer 2, thus, the characteristic location 9, 1 1 of the trailer 2 can also change thereby and thereby correspondingly the maximum hitch angle 22, 23. It is also possible that the parameter characterizing the current vehicle/trailer combination 3 is dependent on a type of trailer of the trailer 2. For example, the type of the trailer 2 can differ by the loading characteristics. Different types can for example be a boat trailer, caravan or loading trailer. The enumeration of the different types of the trailer 2 is only exemplary and not to be regarded as conclusive at all. In particular, Fig. 2 shows that the circular ring sector display 17 comprises at least three, presently five, circular ring sector sections 24a, 24b, 24c. Approach of the current hitch angle a to the first maximum hitch angle 22 of the vehicle/trailer combination 3 and/or to the second maximum hitch angle 23 of the vehicle/trailer combination 3 is in particular displayable by the circular ring sector sections 24a, 24b, 24c. In particular, it can be provided that the circular ring sector sections 24a, 24b, 24c are displayable

distinguishable in terms of color. For example, a first circular ring sector section 24a can be formed green, a second circular ring sector section 24b can be formed yellow and at least a third circular ring sector section 24c can be formed red. In the present example, the outer circular ring sector sections 24c are for example formed red, the middle circular ring sector sections 24b are formed yellow and the again central circular ring sector section 24a is formed green. Thereby, the current hitch angle a can in particular be intuitively displayable for a driver of the vehicle/trailer combination 3 depending on the maximum hitch angles 22, 23.

Further, it is in particular possible that a further display 26 is formed between the radially inner boundary 19 of the circular ring sector display 17 and a central point 25 of the circular ring sector display 17, on which a further symbol 27 is displayable. The further symbol 27 is in particular presented as a picture 28 of the motor vehicle 1 with a picture 29 of the attached trailer 2. In particular, the further display 26 is formed such that a picture 30 of the hitch angle a between a longitudinal axis L3 of the picture 28 and a longitudinal axis L4 of the picture 29 is displayable depending on the current hitch angle a. In the method for displaying the current hitch angle a of the vehicle/trailer combination 3 on the display device 2, the current hitch angle a is displayed on the display device 12 by means of the symbol 18 moving depending on the current hitch angle a. The current hitch angle a is displayed on the circular ring sector display 17 of the display device 12 as the symbol 18.

In particular, it is provided that the further parameter characterizing the environment 15 of the vehicle/trailer combination 3 is determined by means of a capturing device 14 of the motor vehicle 1 and/or a parameter characterizing the vehicle/trailer combination 3 is determined by means of a capturing device 5 of the motor vehicle 1 , wherein the first maximum hitch angle 22 and/or the second maximum hitch angle 23 are determined depending on the parameter characterizing the vehicle/trailer combination 3 and/or depending on the further parameter characterizing the environment 15 of the

vehicle/trailer combination 3 and/or a still further symbol 27 is displayed depending on the parameter characterizing the vehicle/trailer combination 3 and/or on the further parameter characterizing the environment 15 of the vehicle/trailer combination 3.

Fig. 3 shows a further embodiment of the display device 12. In the following embodiment, it is in particular visible that the first maximum hitch angle 22 and the second maximum hitch angle 23 are identically formed. Furthermore, it is visible that the hitch angle a can also be displayed between the picture 28 and the picture 29.

In the present embodiment, the moving symbol 18 is in particular in the circular ring sector section 24b, which can in particular be formed yellow. The current hitch angle a is in particular exactly displayed by an apex 31 of the symbol 18.

In Fig. 3, it is illustrated that in particular the further display 26 can display a still further symbol 32 on the further symbol 27. The still further symbol 32 is in particular formed as a warning symbol and can for example be a triangle with an exclamation mark, as present.

In particular, the still further symbol 32 can differ from the further symbol 27 in color. For example, it can be displayed by the still further symbol 32 that the weight of the vehicle/trailer combination exceeds a maximally allowable weight of a road, on which the vehicle/trailer combination 3 moves. It is also possible that for example if the vehicle/trailer combination 3 should be formed higher than a tunnel height, into which the vehicle/trailer combination 3 will enter in the future, this can also be displayed as a still further symbol 32. In particular, the driver of the vehicle/trailer combination 3 can thereby be warned of a critical situation in improved manner. It is also possible that it can be displayed by means of the exclamation mark, if the current hitch angle a should approach to one of the maximum hitch angles 22, 23. In other words, the still further symbol 32 is in particular displayable by the further display 26 depending on a parameter characterizing the environment 15 of the vehicle/trailer combination 3 and/or a parameter characterizing the vehicle/trailer combination 3.

Further, Fig. 3 shows a computer program product 33 with program code means, which are stored in a computer-readable medium to perform a method according to the invention when the computer program product 33 is run on a processor of an electronic control unit.