System comprising a motor-driven trailer and a tow bar

Abstract

A system comprising a motor-driven trailer and a tow bar for connecting the trailer to a vehicle, in particular to a bicycle, wherein the tow bar comprises a vehicle-side end for connecting to the vehicle and a trailer-side end for connecting to a trailer connector of the trailer, wherein the tow bar is connected to the trailer such that the tow bar is pivotable relative to the trailer along a pivot path between a lowered position and a raised position, wherein the system comprises at least one first sensor element for detecting the position of the tow bar along the pivot path and a control unit in communication with the at least one first sensor element, wherein the control unit is adapted to put the system in an operating mode in which a motor of the trailer supports a movement of the trailer and in a parking mode in which a brake of the trailer is used to stop a movement of the trailer depending on the position of the tow bar along the pivot path, wherein the system is put in the parking mode when the tow bar is in the raised position and in the operating mode when the tow bar is in the lowered position.

Description

Technical Field

[0001] The present invention relates to a system comprising a motor-driven trailer and a tow bar for attaching the trailer to a vehicle, particularly a bicycle. Background Technology

[0002] Motor-driven trailers are self-propelled by a motor, typically powered by a battery. Such motor-driven trailers can be designed to automatically follow vehicles connected to them via a tow bar, specifically, they can accelerate when the towing vehicle accelerates, or they can apply the brakes when the towing vehicle applies the brakes. In this way, by accelerating or decelerating the trailer, the distance between the motor-driven trailer and the vehicle can be measured and maintained within a specified range. Such tow bars and trailers are known from, for example, EP 3416860B1 and GB 2560883A.

[0003] When a motor-driven trailer is not attached to a vehicle, it may be advantageous to allow the trailer to move. The trailer can be pushed or towed, for example, by a person holding a tow bar. Typically, when using a motor-driven trailer in trolley mode, the trailer can follow the person in the same manner as previously explained by maintaining a constant distance between the trailer and the person.

[0004] It is important not to rely on the use of a trailer, but to safely prevent the trailer from moving accidentally, especially when the trailer is parked. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a system comprising a motor-driven trailer and a tow bar that is particularly safe to use.

[0006] This invention achieves this objective through its subject matter. Advantageous embodiments are disclosed in the specification and accompanying drawings.

[0007] In the system of the present invention comprising a motor-driven trailer and a tow bar (the tow bar being used to connect the trailer to a vehicle, particularly a bicycle), the tow bar includes a vehicle-side end for connection to the vehicle and a trailer-side end for connection to a trailer connector of the trailer, wherein the tow bar is connected to the trailer such that the tow bar is pivotable relative to the trailer along a pivot path between a lowered position and a raised position, wherein the system includes at least one first sensor element for detecting the position of the tow bar along the pivot path, and a control unit in communication with the at least one first sensor element, wherein the control unit is adapted to place the system in an operating mode and a parking mode according to the position of the tow bar along the pivot path, wherein in the operating mode the trailer's motor supports the movement of the trailer, and in the parking mode the trailer's brake is used to stop the movement of the trailer, wherein the system is placed in the parking mode when the tow bar is in the raised position; and in the operating mode when the tow bar is in the lowered position.

[0008] In the system of the present invention, the tow bar is pivotable relative to the trailer. The tow bar can pivot upward from a lowered position to a raised position, or downward from a raised position to a lowered position. The lowered position can be, for example, a substantially horizontal orientation of the tow bar, and the raised position can be, for example, a substantially vertical arrangement of the tow bar. The lowered and / or raised positions can be defined by a specific angular position of the tow bar relative to the trailer, but can also be understood as a range of angles relative to the trailer. For example, an angular range of ±10° to 20° around the horizontal direction of the tow bar can be understood as a lowered position. The tow bar not being in the raised position can be considered as the tow bar being in the lowered position, and therefore the system is in operating mode.

[0009] According to the invention, the tow bar includes at least one first sensor element adapted to detect the position of the tow bar relative to the trailer along a pivoting path, particularly the angular position of the tow bar. Data measured by the sensor element is received by a control unit, which places the system in different modes based on the position of the tow bar. The control unit may be part of the trailer and / or the tow bar. Preferably, the control unit is part of a trailer control unit that controls further functions of the trailer, particularly controlling the movement of the trailer based on the distance between the trailer and a vehicle connected to the trailer via the tow bar, or the distance between the trailer and a person holding the tow bar. According to the invention, the control unit can place the system in an operating mode or a parking mode based on the position of the tow bar. In the operating mode, the motor of the motor-driven trailer is activated to support the movement of the trailer in the manner explained above. In particular, the trailer can be moved to keep the distance between the vehicle or person towing or pushing the trailer constant. Thus, if the distance between the vehicle or person and the trailer increases, the motor can accelerate the trailer, and if the distance between the vehicle or person and the trailer decreases, the motor can reverse the movement of the trailer, and / or a brake may be used. In this operating mode, the tow bar is in a lowered position and is attached to the vehicle or held by a person.

[0010] On the other hand, in the raised position, the trailer is placed in a parking mode via a control unit, thereby using the trailer's brakes to prevent further movement. In parking mode, the motor can stop operating, thus no longer supporting any movement of the trailer. Therefore, when the drawbar is in the raised position, the movement of the trailer is safely prevented. When using a motor-driven trailer, the use of brakes and the possible stopping of the motor result in greater safety because unwanted movement is prevented.

[0011] According to one embodiment, the system is also adapted to detect the direction of movement of the tow bar along the pivot path, wherein the control unit is adapted to use the trailer's brakes when the tow bar moves upward toward the raised position. Specifically, the at least one first sensor and / or control unit can be adapted to detect the direction of movement of the tow bar. According to this embodiment, it is necessary to detect not only whether the tow bar is in the lowered or raised position, but also whether the tow bar is moving upward or downward along the pivot path. The trailer's brakes are used not only when the tow bar reaches the raised position, but also when the tow bar moves upward toward the raised position from the lowered position. According to a corresponding embodiment, the control unit is adapted to increase the braking force of the brakes as the tow bar approaches the raised position. Therefore, the closer the tow bar is to the raised position, the higher the braking force may be. This embodiment allows for a rapid response to a tow bar leaving the lowered position in an upward direction and allows for a smooth stop of the trailer. The upward or downward direction of movement of the tow bar can be detected via sensors that provide different outputs for these two directions of movement. In this respect, more sensors can be provided, which will be explained later.

[0012] According to one embodiment, the control unit is also adapted to place the system in an emergency mode, in which the trailer's brakes are applied with full braking force to achieve emergency braking, wherein the system is placed in emergency mode when the tow bar moves downward from the lowered position along the pivot path. According to this embodiment, the control unit is adapted to place the system in another mode: emergency mode. This is not accomplished by moving the tow bar upward from the lowered position, but by moving the tow bar downward from the lowered position. Once the tow bar leaves the lowered position during its downward movement, the trailer's brakes are applied with full force. By applying full braking force, emergency braking is achieved, and the motor-driven trailer stops as quickly as possible. The tow bar moving downward from the lowered position (and thus leaving the operating mode) usually indicates an accident has occurred. For example, a cyclist riding a bicycle connected to the trailer via the tow bar may have been involved in an accident, or the person pulling the tow bar may have released it. In this situation, it is important to stop the trailer to prevent a collision between the trailer and the user. According to a corresponding embodiment, the system is placed in emergency mode when the tow bar moves downward from the lowered position along the pivot path at a speed greater than or equal to a set speed limit. According to this embodiment, emergency braking occurs only when the tow bar moves downward at a minimum speed or higher. A speed limit can be set so that emergency braking is only performed when the tow bar is falling, but not if the tow bar is gently lowered by the user.

[0013] According to one embodiment, the first sensor element includes one or more of the following: a proximity sensor, an angle sensor, an angle encoder, and a switch (particularly a magnetic switch). Typically, the first sensor element may include a first sensor and a mating member, wherein the sensor may be positioned at the tow bar and the mating member at the trailer; or wherein the sensor may be positioned at the trailer and the mating member at the tow bar. The proximity sensor can detect the distance and / or changes in distance between the sensor and the mating member. The angle sensor or angle encoder can provide an angular position as an output. However, the first sensor element may also be represented by a switch that is activated when the tow bar reaches the raised position. The activated switch then triggers the control unit to initiate a parking mode, and thus activates the brakes. According to the invention, the switch not being activated and therefore the tow bar not being in the raised position can be considered as the tow bar being in the lowered position, and therefore the system being in an operating mode.

[0014] In one embodiment, the first sensor element includes a proximity sensor and a mating member, the proximity sensor detecting the distance between the proximity sensor and the mating member. The proximity sensor may be disposed at the trailer-side end of the tow bar, and the mating member is opposite the proximity sensor at the trailer connector of the trailer; alternatively, the mating member may be disposed at the trailer-side end of the tow bar, and the proximity sensor is opposite the mating member at the trailer connector of the trailer. The proximity sensor detects the distance and / or changes in distance between the proximity sensor and the mating member. Based on the distance or changes in distance, it can be determined whether the tow bar is in a raised or lowered position, thereby allowing the application of an operating mode or a parking mode. Furthermore, the direction of movement of the tow bar can be detected via this sensor element. Additionally, this sensor allows the application of the described emergency mode (i.e., allowing detection of whether the tow bar has moved downwards from the lowered position, and at what speed).

[0015] According to one embodiment, at least two first sensor elements are provided for detecting the position of the tow bar along the pivot path. Both first sensor elements can be designed and adjusted as described above. Providing two first sensor elements results in an even higher level of safety due to redundancy. If one sensor element fails, the other can still function. Furthermore, providing at least two first sensor elements allows for the determination of the tow bar's direction of movement. According to a corresponding embodiment, the at least two first sensor elements provide different sensor outputs as the tow bar moves along the pivot path. In particular, they provide different sensor outputs when the tow bar moves upward or downward along the pivot path.

[0016] According to one embodiment, the trailer further includes at least one second sensor element for detecting whether a connection has been established between the vehicle-side end of the tow bar and the vehicle. Preferably, the at least one second sensor element is arranged at the vehicle-side end of the tow bar. The at least one second sensor element can detect whether the tow bar is connected to the vehicle. For example, the second sensor element can detect whether the tow bar is connected to a trailer hitch or trailer connector of a car or bicycle. Depending on whether such a connection is detected, the control unit places the system in different modes.

[0017] According to one corresponding embodiment, if the at least one second sensor element does not detect a connection to the vehicle, the control unit is adapted to place the system in a trolley mode, wherein in trolley mode, the control unit limits the maximum speed of the trailer to a first speed limit. Therefore, if the trailer is not connected to the vehicle, it can be used as a trolley, which is pulled by a person holding a tow bar. Limiting the maximum speed of the trailer in trolley mode improves safety. Furthermore, according to another corresponding embodiment, if the at least one second sensor element detects a connection to the vehicle, the control unit may be adapted to place the system in a vehicle mode, wherein in vehicle mode, the control unit limits the maximum speed of the trailer to a second speed limit. The second speed limit may be higher than the first speed limit. Therefore, depending on whether a connection to the vehicle is detected, the system can be limited to different speed limits. In particular, the first speed limit, as a lower speed limit, is set to allow the trailer to move relatively slowly. For example, the first speed limit could be walking speed. This increases safety. To comply with the set speed limits, the control unit may limit the support provided by the motor and / or may use brakes. The second speed limit may be the maximum speed of the trailer.

[0018] According to one embodiment, the at least one second sensor element detects whether the safety pin of the vehicle connector is inserted into a corresponding socket on the vehicle side end of the tow bar. The detection of the safety pin by the at least one second sensor can be interpreted as the trailer being connected to the vehicle. Furthermore, if a connection to the vehicle is detected, the control unit can be adapted to control the motor in a manner different from when such a connection is not detected, and thus control the movement of the trailer, particularly by placing the system in vehicle mode. For example, the control algorithm for controlling the movement of the trailer, executed on the control unit, can be changed in vehicle mode to achieve more flexible movement. Automatic activation of vehicle mode also eliminates the need for the user to manually switch the system to vehicle mode (e.g., by pressing a button, which the user may forget to do). Additionally, the second sensor element can detect whether the safety pin is correctly installed (e.g., whether the safety pin is fully inserted into the socket).

[0019] According to one embodiment, the control unit is also adapted to place the system in an emergency mode, wherein the trailer's brakes are applied with full braking force to achieve emergency braking, wherein the system is placed in emergency mode when the connection between the tow bar and the vehicle is broken. This emergency mode is activated if a connection previously established between the tow bar and the vehicle is broken for some reason. Specifically, a safety pin disengaging from its corresponding socket during trailer operation (detected by the at least one second sensor element) can be considered an undesirable disconnection. This could occur, for example, if the vehicle's driver is involved in an accident (e.g., if a cyclist falls to the ground). Attached Figure Description

[0020] The embodiments of the present invention will now be explained with reference to the accompanying drawings.

[0021] Figure 1 A side view of the system according to the invention, comprising a motor-driven trailer and a tow bar, is shown in both a lowered and raised position.

[0022] Figure 2 This shows the range of motion when the traction bar is in the lowered position. Figure 1 The trailer.

[0023] Figure 3 The connection between the trailer connector of the trailer and the trailer-side end of the tow bar is shown.

[0024] Figure 4 The vehicle-side end of the tow bar is shown, as well as the connection between the vehicle-side end of the tow bar and the vehicle.

[0025] Figure 5 The system is shown operating in trolley mode.

[0026] Figure 6 A system connected to a bicycle is shown operating in vehicle mode.

[0027] Figure 7 The inputs and outputs of the control unit are schematically shown.

[0028] In the following text, unless otherwise stated, the same reference numerals denote the same objects. Detailed Implementation

[0029] Figure 1A motor-driven trailer 10 and a system for connecting the trailer 10 to a vehicle are shown. The trailer 10 includes a motor 12 powered by a battery 14. In this embodiment, the motor 12 is arranged on the front axle driving the front wheels. However, the motor can typically be arranged anywhere on the trailer and can also be adapted to drive the rear wheels. The trailer 10 includes... Figure 1 The trailer control unit (hereinafter referred to as TCU) is not shown. The trailer control unit controls the movement of the trailer 10. The trailer 10 is self-propelled by a motor, allowing the distance between the trailer 10 and the tow bar 20, and thus the distance between the trailer and the vehicle or person towing or pushing the trailer via the tow bar 20, to be detected and kept constant. This allows the trailer 10 to follow a vehicle or person in a seemingly weightless manner. To achieve this, a control box 16 is provided that allows the measurement of the distance, wherein, in particular, the variable distance between the tow bar and the trailer 10 can be measured and kept constant, as explained in detail in EP 3416860B1.

[0030] The tow bar 20 includes a vehicle-side end 20a for attaching to a bicycle as a vehicle, and a trailer-side end 20b for attaching to a trailer 10 via a control box 16. The tow bar 20 is attached to the trailer 10 such that it is pivotable along a pivot path P between a lowered position L and a raised position R. In the lowered position L, the system can be attached to the bicycle or pulled by a person holding the tow bar 20. In the raised position R, the system is not used and is in a parking mode, as will be explained below.

[0031] Lowering position L and raising position R can be understood as angular values ​​along the pivot path. However, they can also be understood as angular ranges along the pivot path P (e.g., ...). Figure 2 As shown in the diagram, the range of movement of the traction rod 20 along the pivot path can be understood as the lowered position of the traction rod 20. In this embodiment, the traction rod 20 is in the lowered position as long as it is within an angular range of approximately 30° about the horizontal direction of the traction rod 20. Specifically, this includes positions P1 and P2. Position P3 shows the traction rod 20 raised above the lowered position in the direction of the raised position.

[0032] The system according to the invention includes two first sensor elements 22, 24, which can... Figure 3As seen in the image, sensor elements 22 and 24 are arranged at the connection between the tow bar 20 and the trailer 10. Each of the two first sensor elements 22 and 24 includes proximity sensors 22a and 24a arranged at the trailer-side end 20b of the tow bar 20, and mating parts 22b and 24b arranged at the trailer connector 15 of the trailer 10. The tow bar 20 is pivotable about axis A relative to the trailer connector 15 of the trailer 10. Figure 3 In (a), this connection is shown in a side cross-sectional view so that only the first sensor element 24 is visible. Figure 3 In section b), a top view of the connection is shown so that both first sensor elements 22 and 24 are visible. Proximity sensor 22a detects the distance between proximity sensor 22a and mating member 22b, while proximity sensor 24a detects the distance between proximity sensor 24a and mating member 24b. Figure 3 As shown, the mating elements 22b and 24b have different shapes. Due to the different shapes of the mating elements 22b and 24b, the proximity sensors 22a and 24a measure different distances of the traction rod 20 to its corresponding angular position about axis A along the pivot path P. Therefore, as the traction rod 20 moves along the pivot path, the two first sensor elements 22 and 24 provide different sensor outputs. The mating elements 22b and 24b can be ferromagnetic elements, and the proximity sensors 22a and 24a can measure the magnetism of these ferromagnetic mating elements 22b and 24b. The angular position of the traction rod 20 along the pivot path can be determined via the two first sensor elements 22 and 24.

[0033] According to the invention, the system includes a control unit, which may be part of a TCU, adapted to place the system in different modes based on the position of the tow bar 20 along the pivot path P. Specifically, the control unit is adapted to place the system in an operating mode where the motor 12 of the trailer 10 supports the movement of the trailer 10, and in a parking mode where the trailer's brakes prevent the movement of the trailer 10. When the tow bar 20 is in the lowered position L, the control unit places the system in the operating mode, and when the tow bar 20 is in the raised position R, the control unit places the system in the parking mode. The position of the tow bar 20 is detected by the two first sensor elements 22, 24. Due to different sensor outputs, the sensor elements are also adapted to provide the direction of movement of the tow bar 20 along the pivot path P. Because of this, the control unit can use the trailer's brakes not only when the tow bar 20 reaches the raised position R, but also when the tow bar 20 has already moved upwards. In particular, the braking force of the brakes can increase as the tow bar 20 approaches the raised position R.

[0034] Therefore, the system according to the invention allows for a distinction between an operating mode and a braking mode. In operating mode, the tow bar, and thus the trailer, can be attached to the vehicle or pulled by a person; the trailer's motor is activated to support its movement. However, in parking mode, the trailer is stopped by using the brakes. Furthermore, in parking mode, the trailer's motor can be deactivated, thus no longer supporting its movement. Therefore, in parking mode, the trailer can be safely stopped.

[0035] exist Figure 4 The diagram schematically illustrates the connection between the tow bar 20 and the trailer 10 to the bicycle. Specifically, the vehicle-side end 20a of the tow bar 20 includes a first socket 26 that receives a trailer hitch 34 connected to a bicycle connector 30 on the tow bar 32. A second sensor element 28 is provided at the vehicle-side end 20a of the tow bar 20 to detect whether a connection has been established between the vehicle-side end 20a of the tow bar 20 and the bicycle 32. The second sensor element 28 detects whether a safety pin 36 is inserted into a corresponding second socket 27.

[0036] If the second sensor element 28 detects pin 36 and thus detects a connection to bicycle 32, the control unit places the system in vehicle mode, where the control unit limits the maximum speed of the trailer to a second speed limit. If the second sensor element 28 does not detect pin 36, it is assumed that no secure connection to the bicycle has been established, and the control unit places the system in trolley mode, where the control unit limits the maximum speed of the trailer to a first speed limit. The second speed limit is higher than the first speed limit. Therefore, by using this second sensor element, the system can distinguish between trolley mode and vehicle mode (in trolley mode, a person can pull the trailer by grabbing the tow bar; in vehicle mode, the trailer is pulled by the bicycle). Setting a lower speed limit in trolley mode improves safety. In particular, because if the safety pin is received in the second socket, the trailer can only move at the maximum speed. In this way, the user is indicated whether the safety pin is inserted. Safety pin 36 is secured to the bicycle connector 30 by a strap 38. However, the second sensor element 28 may also, or alternatively, detect whether the trailer hitch 34 is inserted into the first socket 26.

[0037] Furthermore, the control unit can be adapted to place the system in an emergency mode, in which the trailer's brakes are applied with full braking force to achieve emergency braking. For example, if the tow bar 20 moves downward along the pivot path P from the lowered position L, particularly if this downward movement occurs at a speed higher than or equal to a set speed limit, the control unit can place the system in emergency mode. Thus, an unintentional drop of the tow bar would cause the trailer to stop. Additionally, the emergency mode can be set and emergency braking initiated when the connection between the tow bar 20 and the bicycle is broken (e.g., if the second sensor element 28 no longer detects the safety pin 36).

[0038] exist Figure 5 In the diagram, the system is shown in trolley mode, where it is pulled by a person 40. As described above, the control unit can put the system into trolley mode (e.g., by using a brake, and / or by limiting the support provided by the trailer's motor), thereby limiting the trailer's maximum speed. If the user 40 is incapacitated, or if the trailer is being pulled by a child, the tow bar 20 will respectively drop or be lowered to a lowered position, thereby achieving emergency braking.

[0039] exist Figure 6 The diagram illustrates a system connected to a bicycle 32. Here, the system is in operating mode when the first sensor elements 22 and 24 detect that the tow bar 20 is in the lowered position. The second sensor element 28 detects the connection between the tow bar and the bicycle 32, causing the system to enter a vehicle mode with a higher speed limit. Specifically, in vehicle mode, the maximum speed of the trailer can be set to a speed limit. Furthermore, in vehicle mode, the control unit can adjust the motor control for greater flexibility.

[0040] exist Figure 7 The diagram schematically illustrates what inputs the TCU is receiving. As mentioned above, the control unit according to the invention can be part of the TCU. The TCU 100 receives inputs from two first sensor elements 22, 24 regarding the position of the tow bar. Furthermore, the TCU 100 receives inputs from a second sensor element 28 indicating the tow bar-bicycle connection and inputs from the control box 16 regarding the distance between the vehicle or user and the trailer. The battery 14 serves as the power source for the TCU 100. The TCU controls the motor 12 based on these inputs and also controls the use of the brakes.

[0041] List of reference numerals in the attached diagram: 10 trailers 12 motors 14 batteries 15 Trailer Connector 16 Control Box 20. Towing bar 20a Vehicle side end of the tow bar 20b Trailer-side end of the drawbar 22, 24 First sensor element 22a, 24a proximity sensors 22b, 24b mating parts 26 First Socket 27 Second socket 28 Second sensor element 30 Bicycle connectors 32 bicycles 34 Trailer coupling device 36 Safety pins 38. Leash 40 people / users 100 TCU (Trailer Control Unit) Axis A L lower position P pivot path Positions P1, P2, P3 R Raise position

Claims

1. A system comprising a motor-driven trailer (10) and a tow bar (20), the tow bar being used to connect the trailer (10) to a vehicle (32), characterized in that, The tow bar (20) includes a vehicle-side end (20a) for connection to a vehicle (32) and a trailer-side end (20b) for connection to a trailer connector (15) of a trailer (10), wherein the tow bar (20) is connected to the trailer (10) such that the tow bar (20) is pivotable relative to the trailer (10) along a pivot path (P) between a lowered position (L) and a raised position (R), wherein the system includes at least one first sensor element (22, 24) for detecting the position of the tow bar (20) along the pivot path (P), and a connection to the at least one first sensor element (22, 24). The system is configured to communicate with a control unit (TCU) that is adapted to place the system in an operating mode and a parking mode based on the position of the tow bar (20) along a pivot path (P). In the operating mode, the motor (12) of the trailer (10) supports the movement of the trailer (10). In the parking mode, the brakes of the trailer (10) are used to stop the movement of the trailer (10). The system is placed in the parking mode when the tow bar (20) is in the raised position (R) and in the operating mode when the tow bar (20) is in the lowered position (L). The first sensor element (22, 24) is characterized in that it includes a proximity sensor (22a, 24a) and a mating member (22b, 24b), wherein the proximity sensor (22a, 24a) detects the distance between the proximity sensor (22a, 24a) and the mating member (22b, 24b), wherein the proximity sensor (22a, 24a) is arranged at the trailer-side end (20b) of the tow bar (20), and the mating member (22b, 24b) is arranged opposite to the proximity sensor (22a, 24a) at the trailer connector (15) of the trailer (10), or wherein the mating member (22b, 24b) is arranged at the trailer-side end (20b) of the tow bar (20), and the proximity sensor (22a, 24a) is arranged opposite to the mating member (22b, 24b) at the trailer connector (15) of the trailer (10).

2. The system according to claim 1, characterized in that, The system is also adapted to detect the direction of movement of the tow bar (20) along the pivot path (P), wherein when the tow bar (20) moves upward toward the raised position (R), the control unit (TCU) is adapted to use the brakes of the trailer (10).

3. The system according to claim 2, characterized in that, The control unit (TCU) is adapted to increase the braking force of the brake as the traction rod (20) approaches the raised position (R).

4. The system according to any one of claims 1 to 3, characterized in that, The control unit (TCU) is also adapted to place the system in an emergency mode in which the brakes of the trailer (10) are applied with full braking force to achieve emergency braking, wherein the system is placed in the emergency mode when the tow bar (20) moves downward along the pivot path (P) from the lowered position (L).

5. The system according to claim 4, characterized in that, The system is put into emergency mode when the traction bar (20) moves downward along the pivot path (P) from the lower position (L) at a speed higher than or equal to the set speed limit.

6. The system according to any one of claims 1 to 3, characterized in that, The first sensor element (22, 24) further includes one or more of the following: an angle sensor, an angle encoder, and a switch.

7. The system according to any one of claims 1 to 3, characterized in that, At least two first sensor elements (22, 24) are provided for detecting the position of the traction rod (20) along the pivot path (P).

8. The system according to claim 7, characterized in that, As the traction rod (20) moves along the pivot path (P), the at least two first sensor elements (22, 24) provide different sensor outputs.

9. The system according to any one of claims 1 to 3, characterized in that, The trailer (10) also includes at least one second sensor element (28) for detecting whether the connection between the vehicle side end (20a) of the tow bar (20) and the vehicle (32) has been established.

10. The system according to claim 9, characterized in that, If the at least one second sensor element (28) does not detect a connection with the vehicle (32), the control unit (TCU) is adapted to place the system in a trolley mode, wherein in the trolley mode, the control unit (TCU) limits the maximum speed of the trailer (10) to a first speed limit.

11. The system according to claim 9, characterized in that, If the at least one second sensor element (28) detects a connection with the vehicle (32), the control unit (TCU) is adapted to place the system in vehicle mode, wherein in vehicle mode, the control unit (TCU) limits the maximum speed of the trailer (10) to a second speed limit.

12. The system according to claim 9, characterized in that, If the at least one second sensor element (28) does not detect a connection with the vehicle (32), the control unit (TCU) is adapted to place the system in a trolley mode, wherein in the trolley mode, the control unit (TCU) limits the maximum speed of the trailer (10) to a first speed limit; and if the at least one second sensor element (28) detects a connection with the vehicle (32), the control unit (TCU) is adapted to place the system in a vehicle mode, wherein in the vehicle mode, the control unit (TCU) limits the maximum speed of the trailer (10) to a second speed limit; and wherein the second speed limit is higher than the first speed limit.

13. The system according to claim 9, characterized in that, The at least one second sensor element (28) detects whether the safety pin (36) of the vehicle connector (30) of the vehicle (32) is inserted into the corresponding socket (27) of the vehicle side end (20a) of the tow bar (20).

14. The system according to claim 9, characterized in that, The control unit (TCU) is also adapted to place the system in an emergency mode in which the brakes of the trailer (10) are applied with full braking force to achieve emergency braking, wherein the system is placed in the emergency mode when the connection between the tow bar (20) and the vehicle (32) is disconnected.

15. The system according to any one of claims 1 to 3, characterized in that, The tow bar is used to attach the trailer (10) to the bicycle.

16. The system according to claim 6, characterized in that, The switch is a magnetic switch.

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