Device and method for monitoring a vehicle-trailer system

Abstract

A device (200) for monitoring a vehicle-trailer system (100) consisting of a vehicle (102) and a trailer (104) comprises a determination unit (202). The determination unit (202) is designed to determine a weight of the trailer (104) and an angle enclosed by a longitudinal axis (108) of the vehicle (102) and a longitudinal axis (112) of the trailer (104). The proposed device (200) further comprises an output unit (204) designed to output information to a driver of the vehicle (102), and a control unit (206).The control unit (206) is designed to determine a position of the center of gravity (116) of the trailer (104) based on a time series of the angle and to perform a simulation of the vehicle-trailer system (100) based at least on the weight of the trailer (104) and the position of the center of gravity (116) of the trailer (104) in order to determine an individual speed limit for the vehicle-trailer system (100). The control unit (206) is further designed to generate an output to a driver of the vehicle (102) based on the individual speed limit for the vehicle-trailer system (100) and to control the output unit (204) to output the output to the driver.

Description

[0001] The invention relates to a device for monitoring a vehicle-trailer system. The invention further relates to a method for monitoring a vehicle-trailer system.

[0002] The center of gravity of a trailer should be as far forward as possible to ensure safe driving. If too much cargo is placed at the rear of the trailer, it becomes dangerous to drive at high speeds, making the towing vehicle and trailer highly unstable and causing a driver to easily lose control of the vehicle and trailer.

[0003] DE 10 2022 211 436 A1 discloses a method for creating a vehicle model for a motor vehicle. In this method, a reversing tractor-trailer combination is modeled as an unstable inverse double pendulum.

[0004] US 11 315 258 B1 discloses an optical system for tracking the course and position of a trailer relative to a tractor. The system uses reference points attached to the trailer.

[0005] Further technological background is revealed in DE 10 2022 117 856 A1 and DE 10 2019 109 604 A1.

[0006] The object of the invention is to provide a device and a method for monitoring a vehicle-trailer system that enables safe driving.

[0007] This object is achieved by a device having the features of claim 1 and by a method having the features of the independent method claim. Advantageous further developments are specified in the dependent claims.

[0008] The proposed device for monitoring a vehicle-trailer system consisting of a vehicle and a trailer comprises a determination unit. The determination unit is designed to determine a weight of the trailer and an angle enclosed by a longitudinal axis of the vehicle and a longitudinal axis of the trailer. The proposed device further comprises an output unit designed to output information to a driver of the vehicle, and a control unit. The control unit is designed to determine a position of the center of gravity of the trailer based on a time series of the angle and to perform a simulation of the vehicle-trailer system based at least on the weight of the trailer and the position of the center of gravity of the trailer in order to determine an individual speed limit for the vehicle-trailer system.The control unit is further configured to generate an output to a driver of the vehicle based on the speed limit individual for the vehicle-trailer system and to control the output unit to output the output to the driver.

[0009] The vehicle-trailer system is a combination comprising the vehicle and the trailer. The vehicle is, for example, a motor vehicle, in particular a passenger car. The vehicle and the trailer are connected via a connecting element, for example, a trailer coupling of the vehicle.

[0010] The device is designed to determine a speed at which the vehicle-trailer combination can be driven safely. To do this, the determination unit first determines the angle enclosed by a longitudinal axis of the vehicle and a longitudinal axis of the trailer. This angle indicates how the vehicle and trailer are aligned relative to one another and is re-determined, for example, at regular intervals to generate the time series of the angle. The time series indicates how the trailer moves relative to the vehicle. Based on this relative movement, the control unit then determines the weight of the trailer and the position of the trailer's center of gravity. The control unit then simulates the vehicle-trailer system based at least on these variables. The control unit can also receive further variables for this purpose, for example from the vehicle.In one embodiment, the control unit is configured to receive at least one of the following variables and to take it into account when performing the simulation of the vehicle-trailer system: the weight of the vehicle, a position of the vehicle's center of gravity, a current speed of the vehicle, a longitudinal acceleration of the vehicle, and a lateral acceleration of the vehicle. The simulation is used to determine how the vehicle-trailer combination behaves at different vehicle speeds. In particular, the simulation is used to determine the speed above which safe driving is no longer possible because the vehicle-trailer system becomes too unstable. For example, this speed can be used as the speed limit.To enable even safer driving, a lower speed can also be used, for example, a speed 5 km / h below the speed at which the vehicle-trailer system becomes too unstable. Furthermore, the speed limit determined by the control unit can be set so that it does not exceed a legally prescribed speed limit for a vehicle-trailer combination. The speed limit determined by the control unit is then used as the basis for generating and delivering an output to the driver. For example, the speed limit can be displayed to the driver.If the determined speed limit is below a predetermined threshold, for example, 50 km / h or 30 km / h, a warning can be generated and issued indicating that the vehicle-trailer combination cannot be driven safely and that the trailer may need to be reloaded. The device determines a speed limit specific to the vehicle-trailer system and communicates it to the driver. This enables the vehicle-trailer combination to be driven safely.

[0011] In one embodiment, the control unit is designed to determine the individual speed limit for the vehicle-trailer system, additionally taking into account at least one curve radius. The vehicle-trailer system becomes unstable, for example, when the lateral acceleration of the vehicle exceeds a limit value dependent on the weight of the trailer and the position of the trailer's center of gravity. If the lateral acceleration becomes too great, the vehicle-trailer system begins to roll. From the curve radius, a vehicle speed corresponding to this maximum lateral acceleration can be determined and used as the basis for determining the speed limit. In this embodiment, the control unit can, for example, determine a speed for a plurality of curve radii that corresponds to the greatest still safe lateral acceleration.The lowest of the speeds determined in this way can then be used to determine the speed limit.

[0012] In a further embodiment, the determination unit comprises a navigation module that is designed to provide navigation data. The control unit can be designed to determine, on the basis of the navigation data, at least one future route section that will be driven by the vehicle in the future, and to determine the individual speed limit for the vehicle-trailer system, additionally taking into account the at least one future route section. In this embodiment, the speed limit is determined, for example, taking into account a future route of the vehicle or part of the vehicle's route. If the future route section contains many tight bends, the vehicle-trailer combination cannot travel as fast as on a substantially straight section of road without the vehicle-trailer system becoming unstable.Accordingly, the speed limit can be determined more reliably by additionally taking the future route section into account. For example, the control unit can use the navigation data to determine the smallest curve radius on the vehicle's future route section and take this into account when determining the individual speed limit for the vehicle-trailer system.

[0013] In a further embodiment, the determination unit is configured to determine at least two future route sections based on the navigation data. The control unit can further be configured to determine an individual speed limit for each of the future route sections, taking the at least two future route sections into account. In this embodiment, the speed limit is determined section by section. For example, the speed limit for each curve on a route is determined based on the curve radius of the respective curve. The speed limit is thus dynamically adjusted depending on the route.In particular, the maximum speed can also be increased on essentially straight sections of road, which leads to greater acceptance of the speed limit by the driver.

[0014] In a further embodiment, the control unit is designed to numerically determine a derivative of the angle based on the time series of the angle and to determine the individual speed limit for the vehicle-trailer system, additionally taking into account the derivative of the angle. For example, the derivative of the angle can be determined as dθdt=wi−wi−1ti−ti−1 where w i the angle at time t i and i is an index of the time series. Using a Fourier transform F, the numerically determined derivative of the angle can be smoothed. F(θ˙)[β]=βF(θ)[β].

[0015] To determine the derivative of the angle, the time series can be Fourier transformed, multiplied by the frequency, and then back-transformed. Any noise in the time series corresponds to a constant term in the Fourier-transformed time series and can be subtracted before the back-transformation.

[0016] In a further embodiment, the control unit is configured to model the vehicle-trailer system as a double pendulum. The simulation includes at least one numerical solution of the vehicle-trailer system modeled as a double pendulum. For example, equations of motion for the vehicle-trailer system can be formulated and solved numerically using the Lagrange formalism. The equations of motion can be derived from the Lagrange function L = K - V of the double pendulum. Here, K is the kinetic energy and V is the potential energy. The equations of motion can then be solved numerically as part of the simulation. For the simple case where the potential energy V = 0 and the center of gravity of the vehicle is in the center of the vehicle, the equations of motion for the double pendulum are as follows: M2L2((d2θ2dt2)sin(θ1−θ2)+(d2θ2dt2)cos(θ1−θ2))+(M1+M2)L1(d2θ1dt2)=0 L1((d2θ1dt2)cos(θ1−θ2)−(d2θ2dt2)sin(θ1−θ2))+L2(d2θ2dt2)=0

[0017] Where L1 is the distance of the vehicle's center of gravity from a rotational axis around which the vehicle and trailer can rotate freely. L2 is the distance of the trailer's center of gravity from the rotational axis. M1 is the weight of the vehicle. M2 is the weight of the trailer. θ1 is the angle formed by the vehicle's longitudinal axis and the vehicle's direction of travel. θ2 is the angle formed by the vehicle's longitudinal axis and the trailer's longitudinal axis.

[0018] To increase the accuracy of the simulation, further properties of the vehicle-trailer system can be modeled. For example, friction can be modeled as conservative forces if the first angle θ1 and the second angle θ2 are small, even though friction is generally not a conservative force. This can be done, for example, in the form of a potential term V in the Lagrange equations. Friction is modeled, for example, as a conservative force in the direction of the road or the direction of travel of the vehicle. Furthermore, a force exerted by the vehicle on the vehicle-trailer system during a steering maneuver can be modeled. For this purpose, the terms of the kinetic energy K can be adjusted before the equations of motion are determined. For example, the vehicle exerts a force Φ(t) on an axis of rotation defined by the front wheels of the vehicle.A coordinate transformation of the Lagrange equations can be performed to reshape the coordinates to follow the force Φ(t). This results in new terms in the kinetic energy K, since the entire vehicle-trailer system now rotates according to Φ(t).

[0019] In a further embodiment, the control unit is configured to determine a ratio of the product M2L2 of the weight of the trailer and the distance of the trailer's center of gravity from the front of the trailer to the weight of the vehicle M1. The control unit can further be configured to generate a warning to the driver if the ratio exceeds a predetermined value. The control unit can further be configured to control the output unit to output the warning. The larger the product M2L2 is compared to the weight of the vehicle M1, the larger the ratio and the more unstable the vehicle-trailer system is. If the product M2L2 is large, for example, the trailer is overloaded or the load is located too far back in the trailer. In this embodiment, the driver is additionally warned of these dangerous situations, enabling even safer driving.The predetermined value can be determined, for example, from a simulation of the vehicle-trailer system.

[0020] In a further embodiment, the control unit is designed to determine the individual speed limit for the vehicle-trailer system by determining the vehicle speeds at which the vehicle-trailer system behaves chaotically. In general, a system behaves chaotically when small changes in the initial conditions lead to completely different results. In order to determine the vehicle speeds at which the vehicle-trailer system behaves chaotically, the equations of motion of the vehicle-trailer system can be examined during the simulation using known methods from perturbation theory. It is also possible to numerically determine one or more Lyapunov exponents based on the equations of motion in order to determine the vehicle speeds at which the vehicle-trailer system behaves chaotically.

[0021] In a further embodiment, the determination unit comprises an angle measuring module that is arranged on the connecting element that connects the vehicle and the trailer, and is designed to measure the angle enclosed by the longitudinal axis of the vehicle and the longitudinal axis of the trailer. The angle measuring module detects a rotational movement about a rotational axis perpendicular to the longitudinal axes of the vehicle and the trailer. The angle measuring module can in particular comprise one or more sensors, for example mechanical sensors or Hall sensors, to detect the rotational movement. Furthermore, the angle measuring module can comprise one or more encoders to be able to quantify the rotational movement.The direct measurement of the angle enclosed by the longitudinal axis of the vehicle and the longitudinal axis of the trailer is particularly reliable and can be carried out with high accuracy, so that the time series of the angle enclosed by the longitudinal axis of the vehicle and the longitudinal axis of the trailer can be determined particularly reliably.

[0022] In a further embodiment, the determination unit comprises an image capture module that is arranged and configured to capture an image of the trailer and generate image data corresponding to the image. The determination unit can comprise an image processing module that is configured to process the image data and, based on the image data, to determine the angle enclosed by the longitudinal axis of the vehicle and the longitudinal axis of the trailer. The image capture module comprises, in particular, a rear-facing camera of the vehicle that captures light in the optical spectrum and / or in the infrared spectrum. The capture of light in the infrared spectrum has the additional advantage that the image capture module can capture the image of the trailer even in poor lighting conditions, for example at night.The image acquisition module can also comprise a time-of-flight camera, a radar system, or a lidar system to generate a three-dimensional image of the trailer, particularly in the form of a point cloud. In particular, the image acquisition module is configured to capture an image sequence comprising consecutive images of the trailer. In such an embodiment, the image data corresponds to the image sequence. From the image data, the image processing module can reliably determine a position of the trailer relative to the vehicle using known image processing methods. This position can, for example, be compared with a neutral position of the trailer, in which the longitudinal axes of the vehicle and the trailer are parallel, in order to determine the angle subtended by the longitudinal axis of the vehicle and the longitudinal axis of the trailer.From image data corresponding to chronologically successive images of the trailer, the time series of the angle enclosed by the longitudinal axis of the vehicle and the longitudinal axis of the trailer can thus be easily determined.

[0023] In a further embodiment, the determination unit comprises a force sensor configured to determine a force exerted by the trailer on the vehicle. The determination unit can be configured to determine the weight of the trailer based on the force exerted by the trailer on the vehicle. For example, the weight can be determined from the maximum force exerted by the trailer on the vehicle when the vehicle starts moving. In this embodiment, the weight of the trailer is determined automatically using the force sensor. This allows the weight determined using the control unit to be checked for plausibility reliably and without manual intervention.

[0024] In a further embodiment, the determination unit comprises a user input module configured to receive the weight of the trailer as a user input. The user input module may, for example, comprise a rotary dial with a push-button function, a touch input field, an interior camera, or a microphone. The user input may, in particular, be in text form, spoken form, a gesture, and / or an interaction with a user interface. In this embodiment, the weight of the trailer is entered, for example, by the vehicle driver. This allows the weight determined using the control unit to be checked for plausibility.

[0025] The invention further relates to a method for monitoring a vehicle-trailer system comprising a vehicle and a trailer. The method comprises at least the following steps: a) An angle enclosed by a longitudinal axis of the vehicle and a longitudinal axis of the trailer is determined. b) A weight of the trailer and a position of the center of gravity of the trailer are determined on the basis of a time series of the angle. c) A simulation of the vehicle-trailer system is carried out at least on the basis of the weight of the trailer and the position of the center of gravity of the trailer in order to determine a speed limit individual for the vehicle-trailer system. d) An output is generated to a driver of the vehicle based on the speed limit individual for the vehicle-trailer system. e) The output is given to the driver.

[0026] The method has the same advantages as the claimed device. In particular, the method can be further developed with the features described in this document in connection with the device. Furthermore, the device described in this document can be further developed with the features described in this document in connection with the method.

[0027] Embodiments of the invention are explained in more detail below with reference to the figures, in which: Fig. 1 shows a schematic representation of a vehicle-trailer system; Fig. 2 shows a schematic representation of a device for monitoring the vehicle-trailer system according to an embodiment; and Fig. 3 is a flowchart of a method for monitoring the vehicle-trailer system according to one embodiment.

[0028] Fig. 1 shows a schematic representation of a vehicle-trailer system 100. The vehicle-trailer system 100 is a combination of a vehicle 102 and a trailer 104, which are connected via a connecting element 214 (cf. Fig. 2) are connected.

[0029] The vehicle 102 and the trailer 104 are connected in such a way that the vehicle 102 and the trailer 104 can rotate relative to each other about a rotation axis 106 that passes perpendicularly through the connecting element 214. A first angle θ1 is enclosed by a longitudinal axis 108 of the vehicle 102 and a direction of travel 110 of the vehicle 102. A second angle θ2 is enclosed by the longitudinal axis 108 of the vehicle 102 and a longitudinal axis 112 of the trailer 104. A position of a center of gravity 114 of the vehicle 102 is indicated by a first cross in Fig. 1. A position of a center of gravity 116 of the trailer 104 is indicated by a second cross in Fig. 1. A distance of the center of gravity 114 of the vehicle 102 from the axis of rotation 106 is shown in Fig. 1 as L1. A distance of the center of gravity 116 of the trailer 104 from the axis of rotation 106 is Fig. 1 as L2. Using the first angle θ1, the second angle θ2, the distance L1, the distance L2, a weight M1 of the vehicle 102, and a weight M2 of the trailer 104, the vehicle-trailer system 100 can be simulated as a double pendulum. Described below is an apparatus 200 and a method that utilize such a simulation to enable safe driving of the vehicle-trailer system 100.

[0030] Fig. Figure 2 shows a schematic representation of the device 200 for monitoring the vehicle-trailer system 100 according to one embodiment. The device 200 includes a detection unit 202, an output unit 204, and a control unit 206.

[0031] The determination unit 202 is designed to determine the second angle θ2 enclosed by the longitudinal axis 108 of the vehicle 102 and the longitudinal axis 112 of the trailer 104. For this purpose, the determination unit 202 may comprise an image acquisition module 208 and an image processing module 210. The image acquisition module 208 is in the Fig. 1, purely by way of example, as a rear-facing camera of the vehicle 102. The image acquisition module 208 is arranged such that the image acquisition module 208 can capture an image of the trailer 104. The image acquisition module 208 is further configured to generate image data corresponding to the image and transmit it to the image processing module 210. The image processing module 210 can, for example with the aid of known image processing methods, determine the position of the trailer 104 relative to the vehicle 102 and determine the second angle θ2 from the relative position. In order to determine the second angle θ2, the determination unit 202 can further comprise an angle measuring module 212, which is configured to measure the second angle θ2. The angle measuring module 212 is arranged, purely by way of example, on the connecting element 214.

[0032] The determination unit 202 may include a force sensor 216, which, in the illustrated embodiment, is arranged between the vehicle 102 and the connecting element 214. The force sensor 216 measures the force exerted by the trailer 104 on the vehicle 102. Using the force sensor 216, the determination unit 202 may, for example, determine the weight M2 of the trailer 104. In the illustrated embodiment, the determination unit 202 also includes a user input module 218 configured to receive a user input. For example, the determination unit 202 may receive the weight M1 of the vehicle 102 or the weight M2 of the trailer 104 as a user input via the user input module 218.

[0033] The determination unit 202 can further comprise a navigation module 220 configured to provide navigation data of the vehicle 102. The navigation module 220 can, for example, be a navigation unit of the vehicle 102. Alternatively, the navigation module 220 can also be configured to receive and forward the navigation data from a mobile terminal, for example, a smartphone or tablet computer. The navigation data include, for example, the position of the vehicle 102 in a world coordinate system, which the navigation module 220 has determined, for example, using a global satellite navigation system. However, the navigation data can also include map data of the surroundings of the vehicle 102 and / or route data of the planned route of the vehicle 102.

[0034] The output unit 204 is configured to output information to a driver of the vehicle 102. The output unit 204 may, for example, comprise a screen, such as a central information display (CID), a graphical instrument cluster, or a head-up display of the vehicle 102. However, the output unit 204 may also comprise a loudspeaker or headphones. A mobile device of the driver may also form the output unit 204.

[0035] The control unit 206 is shown purely by way of example as a processing unit remote from the vehicle 102, which is connected to the other units of the device 200 via a remote data transmission network 222. For example, the control unit 206 is a server remote from the vehicle 102 or implemented in a cloud computing environment. However, the control unit 206 can also be formed entirely or partially by a processing unit of the vehicle 102. The control unit 206 is designed to process the variables determined and the data generated by the determination unit 202 in order to determine an individual speed limit for the vehicle-trailer system 100. The control unit 206 is further designed to generate a corresponding output based on this speed limit and to control the output unit 204 to output this output to the vehicle driver.How the control unit 206 determines the individual speed limit for the vehicle-trailer system 100 is explained below with reference to . Fig. 3 described in more detail.

[0036] Fig. 3 shows a flowchart of a method for monitoring the vehicle-trailer system 100 according to one embodiment.

[0037] The method is started in step S300. In step S302, the second angle θ2 is determined. Step S302 is executed continuously to generate a time series of the second angle θ2. For example, the second angle θ2 is determined at regular intervals to generate the time series. Step S302 can be executed by the determination unit 202. In step S304, the weight M2 of the trailer 104 and the position of the center of gravity 116 of the trailer 104 are determined based on the time series of the second angle θ2. This can be done in particular in an iterative process in which a future value of the second angle θ2 is predicted based on the time series and compared with an actually measured value. This process is repeated until the predicted value and the measured value of the second angle θ2 are identical within a predetermined tolerance range.The prediction can be made using equations of motion that describe the vehicle-trailer system 100, whose parameters are adjusted in each step of the iterative process until the predicted value and the measured value of the second angle θ2 are identical within a predetermined tolerance range. Optionally, the weight M2 of the trailer 104 thus determined can be compared with the weight determined using the force sensor 216 and / or the weight entered by the vehicle driver to verify the determination of the control unit 206. Step S304 can be performed by the control unit 206.

[0038] In step S306, a simulation of the vehicle-trailer system 100 is performed based at least on the weight of the trailer 104 and the position of the center of gravity of the trailer 104. The simulation is then used to determine the individual speed limit for the vehicle-trailer system 100. In one embodiment, the vehicle-trailer system 100 is modeled as a double pendulum. For example, the equations of motion of the vehicle-trailer system 100 are determined using the Lagrange formalism and solved numerically using the variables determined in steps S302 and S304. Other variables, such as the distance L1 and the weight M1 of the vehicle 102, which are not determined in steps S302 and S304, can be determined before the method begins.In one embodiment, the distance L1 and the weight M1 of the vehicle 102 are determined at the factory and stored in a non-volatile memory element of the control unit 206. Step S306 is executed, for example, by the control unit 206.

[0039] As part of the simulation, for example using known numerical methods, it is determined at which speeds the vehicle-trailer system 100 behaves chaotically, i.e. at which speeds small variations in the initial conditions lead to very different results. This maximum speed can be used as the basis for the speed limit. In particular, the simulation can be used to investigate how the vehicle-trailer system 100 behaves when cornering with different curve radii. Based on the navigation data, for example, the curve radius of one or more curves that the vehicle-trailer system 100 will next negotiate can be determined. In one embodiment, a separate speed limit can thus be determined for each section of road immediately in front of the vehicle 102.

[0040] In step S308, an output is then generated to the driver of vehicle 102 based on the speed limit unique to vehicle-trailer system 100. The output may, for example, include the speed limit. The output may further include a warning that vehicle-trailer system 100 cannot be safely driven at a speed above the speed limit. Step S308 may be executed by control unit 206. In step S310, the output is output to the driver. For example, control unit 206 controls output unit 204 to output the output. The method then ends in step S312.

[0041] In the Fig. 1 and Fig. 2, at least the determination unit 202, the output unit 204 and the control unit 206 form the device 200. Further in the Fig. 1 and Fig.Elements and features shown in Figure 2 and mentioned in the preceding description may be part of the device 200. Likewise, method steps described with reference to the device 200 may be part of the claimed method. List of reference symbols 100 vehicle trailer system 102 vehicles 104 followers 106 axis of rotation 108 Longitudinal axis 110 direction of travel 112 Longitudinal axis 114, 116 Focus 200 device 202 Investigation Unit 204 Output unit 206 Control unit 208 Image acquisition module 210 Image processing module 212 angle measuring module 214 connecting element 216 force sensor 218 User input module 220 Navigation module 222 Remote data transmission network L1, L2 distance θ1, θ2 angle

Claims

[1] Device (200) for monitoring a vehicle-trailer system (100) consisting of a vehicle (102) and a trailer (104), wherein the device (200) comprises an investigation unit (202) designed to determine an angle (θ2) enclosed by a longitudinal axis (108) of the vehicle (102) and a longitudinal axis (112) of the trailer (104); an output unit (204) designed to provide information to the driver of the vehicle (102); and a control unit (206) designed to determine a weight of the trailer (104) and a position of the center of gravity (116) of the trailer (104) on the basis of a time series of the angle (θ2), at least on the basis of the weight of the trailer (104) and the position of the center of gravity (116) of the trailer (104) to carry out a simulation of the vehicle-trailer system (100) in order to determine an individual speed limit for the vehicle-trailer system (100), to generate an output to a driver of the vehicle (102) based on the individual speed limit for the vehicle-trailer system (100) and to control the output unit (204) to issue the output to the driver. [2] Device (200) according to claim 1, wherein the control unit (206) is configured to determine the individual speed limit for the vehicle-trailer system (100) taking into account at least one curve radius. [3] Device (200) according to claim 1 or 2, wherein the detection unit (202) comprises a navigation module (220) configured to provide navigation data; and wherein the control unit (206) is configured to determine, on the basis of the navigation data, at least one future route segment that will be driven by the vehicle (102) in the future, and to determine the individual speed limit for the vehicle-trailer system (100) taking into additional consideration the at least one future route segment. [4] Device (200) according to claim 3, wherein the control unit (206) is configured to determine at least two future route segments on the basis of the navigation data and, taking additional account of the at least two future route segments, to determine an individual speed limit for the vehicle-trailer system (100) and for the respective route segment for each of the future route segments. [5] Device (200) according to one of the preceding claims, wherein the control unit (206) is configured to numerically determine a derivative of the angle (θ2) on the basis of the time series of the angle (θ2) and to determine the individual speed limit for the vehicle-trailer system (100) taking additional account of the derivative of the angle (θ2). [6] Device (200) according to one of the preceding claims, wherein the control unit (206) is configured to model the vehicle-trailer system (100) as a double pendulum and the simulation comprises at least one numerical solution of the vehicle-trailer system (100) modeled as a double pendulum. [7] Device (200) according to one of the preceding claims, wherein the control unit (206) is configured to determine the individual speed limit for the vehicle-trailer system (100) by determining at which speeds of the vehicle (102) the vehicle-trailer system (100) behaves chaotically. [8] Device (200) according to one of the preceding claims, wherein the detection unit (202) comprises an angle measuring module (212) arranged on a connecting element (214) which connects the vehicle (102) and the trailer (104); and wherein the angle measuring module (212) is configured to measure the angle (θ2) enclosed by the longitudinal axis (108) of the vehicle (102) and the longitudinal axis (112) of the trailer (104). [9] Device (200) according to one of the preceding claims, wherein the detection unit (202) comprises an image acquisition module (208) arranged and configured to capture an image of the trailer (104) and to generate image data corresponding to the image; and wherein the detection unit (202) comprises an image processing module (210) configured to process the image data and to determine, on the basis of the image data, the angle (θ2) enclosed by the longitudinal axis (108) of the vehicle (102) and the longitudinal axis (112) of the trailer (104). [10] Device (200) according to one of the preceding claims, wherein the detection unit (202) comprises a force sensor (216) configured to detect a force exerted by the trailer (104) on the vehicle (102); and wherein the detection unit (202) is configured to detect the weight of the trailer (104) based on the force exerted by the trailer (104) on the vehicle (102). [11] Device (200) according to one of the preceding claims, wherein the detection unit (202) comprises a user input module (218) configured to receive the weight of the trailer (104) as a user input. [12] Method for monitoring a vehicle-trailer system (100) consisting of a vehicle (102) and a trailer (104), wherein a) an angle (θ2) enclosed by a longitudinal axis (108) of the vehicle (102) and a longitudinal axis (112) of the trailer (104) is determined; b) on the basis of a time series of the angle (θ2) a weight of the trailer (104) and a position of the center of gravity (116) of the trailer (104) are determined; c) at least on the basis of the weight of the trailer (104) and the position of the center of gravity (116) of the trailer (104) a simulation of the vehicle-trailer system (100) is carried out in order to determine an individual speed limit for the vehicle-trailer system (100); d) based on the speed limit individually set for the vehicle-trailer system (100), an output is generated for a driver of the vehicle (102); and e) the issue is issued to the driver.

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