Trailer and method for adjusting distance between trailer and connecting rod

Abstract

The trailer is provided with at least one driven wheel. Comprising an energy source configured to supply energy to a wheel drive, a brake means for decelerating the at least one wheel, a connecting rod configured to be connected to a traction means and movably supported on a trailer, a displacement sensor configured to measure a position of the connecting rod relative to the trailer, a speed measuring device configured to determine a travel speed on the basis of a measurement of a speed of the trailer and / or the connecting rod, and an electronic regulator, the regulator being configured to move a position of a neutral point relative to the trailer starting from a zero point depending on the determined travel speed, an adjustment deviation is calculated using the distance between the position of the neutral point and the measured position of the connecting rod, and a wheel drive and / or a brake device is actuated using the adjustment deviation.

Description

TECHNICAL FIELD

[0001] The present application relates to a trailer with wheel drives and to a method for maneuvering such a trailer. BACKGROUND

[0002] Driven trailers according to the prior art use force measuring sensors, in particular strain gauges, for the purpose of maneuvering the trailer drives, which measure forces occurring between the trailer and the towing vehicle. It is known that these force measuring sensors are susceptible to external influences, in particular to environmental influences, such as temperature fluctuations and humidity fluctuations. Furthermore, according to the prior art, the connection between the trailer and the towing vehicle is always rigid and thus susceptible to axial and lateral forces between the trailer and the towing vehicle. In particular, strong vibrations can occur in the trailer-towing vehicle system up to resonant oscillations. This results in the force measuring sensors generating a plurality of measurement data, which in turn leads to a high evaluation effort for the control unit. It is also difficult to distinguish the measurement data important for the control of the trailer from ground noise generated by vibrations and other disturbing variables. This in particular affects the driving comfort and increases the energy consumption.

[0003] A motor-driven trailer for a bicycle is known from US 2012 / 0037435 Al. The trailer described there is connected to the bicycle by means of a drawbar, wherein the drawbar has a force gauge and the trailer has a motor. Depending on the speed difference between the bicycle and the trailer, the force gauge measures a compression force when the trailer is faster than the bicycle or a traction force when the trailer lags behind the bicycle. The motor accelerates the trailer depending on the force measured by the force measuring sensor.

[0004] US 8,365,849 B2 describes a system for towing a trailer. The trailer comprises an electric motor, a brake, a drawbar and a force measuring sensor arranged on the drawbar. Depending on the mechanical force measured on the force gauge, the trailer is accelerated by the motor or braked by the brake.

[0005] DE 10 2010 051 838 Al describes a trailer for a bicycle, wherein the trailer comprises an electric motor which can be used not only as a brake but also as a motor in order to prevent the trailer from exerting a significant counteraction on the bicycle when the bicycle is pushed and braked. In order to achieve this, different sensors are described. A pedal pressure sensor, a brake force sensor arranged in the brake lever and a force measuring sensor arranged in the connection between the bicycle and the trailer are thus proposed. The signals of these sensors are transmitted to an electronic logic circuit which in turn actuates the electric motor and / or the brake. By means of the force measuring sensor it is possible to ascertain whether the bicycle is exerting a traction force or pressure on the trailer, wherein the motor or the brake is actuated in dependence on the measured signal in order to make the trailer follow the bicycle. As an alternative to force measurement, a pre-tension measuring system is proposed, wherein either a pressure sensor senses a pressure change in a cylinder or a position sensor measures the position of a disc which is supported by means of a spring. This pre-tension measuring system, although having a less rigid coupling between the trailer and the bicycle, also still retains an interfering, in particular pulsating, feedback effect.

[0006] DE 10 2006 009 862 Al describes a bicycle trailer for driving and braking a bicycle, wherein a battery as an inertial mass is supported in the frame of the trailer so that it oscillates forwards in braking movements and backwards in acceleration movements. The battery is connected via a control lever to a position actual value sensor and to a Bowden cable. During braking, the electric motor is operated regeneratively by means of the position actual value sensor, while at the same time the mechanical brake is activated by means of the Bowden cable.

[0007] US 2013 / 031 1058 Al discloses a method for actuating a trailer driven with an electric motor.

[0008] EP 3 416 860 Al relates to a method for actuating a driven trailer and to a motor-driven trailer. The method has, inter alia, a step in which a distance between the trailer and the towing vehicle is defined as a neutral position. A deviation of the distance between the trailer and the towing vehicle from the neutral position is measured and output as a distance value. When the distance between the trailer and the towing vehicle decreases relative to the neutral position by at least a first distance value, the trailer is electrically actuated to brake. When the distance between the trailer and the towing vehicle decreases relative to the neutral position by at least a second distance value, wherein the second distance value is greater than the first distance value, the trailer is mechanically actuated to brake independently of the electrically actuated brake. When the distance between the trailer and the towing vehicle increases relative to the neutral position by a third distance value, the trailer is accelerated by means of the electric motor. SUMMARY

[0009] Starting from this, the task of the present application is to achieve a sensitive adjustment of the driven trailer as far as possible.

[0010] This task is solved by a trailer according to claim 1 and a method for adjusting a distance according to claim 10. Advantageous embodiments are the subject of the dependent claims and the description.

[0011] The trailer with at least one driven wheel according to the application comprises

[0012] - an energy source, which is configured to supply energy to the wheel drive,

[0013] - a braking device for decelerating the at least one wheel,

[0014] - a connecting rod, which is configured to be connected to the traction device and to be movably supported on the trailer,

[0015] - a displacement sensor, which is configured to measure the position of the connecting rod relative to the trailer,

[0016] - a speed measuring device, which is configured to determine a travel speed on the basis of a measurement of the speed of the trailer and / or of the connecting rod, and

[0017] - an electronic controller,

[0018] and characterized in that

[0019] - the controller is configured to

[0020] - move the position of the neutral point relative to the trailer from a zero point in dependence on the determined travel speed,

[0021] - calculate an adjustment deviation using the distance between the position of the neutral point and the measured position of the connecting rod, and

[0022] - actuate the wheel drive and / or the braking device using the adjustment deviation.

[0023] The trailer has one or more wheels. That is to say, the trailer can stand upright by itself, or only in combination with a towing vehicle, or be held upright by an operator. At least one of the wheels is driven by a drive. The drive is preferably an electric motor. The electric motor can either be embodied as a hub motor, or be mounted on the trailer and drive the driven wheel via a drive shaft. Furthermore, the trailer has an energy source, by means of which the drive is supplied with energy. This can be a battery in the case of an electric motor. However, a fuel cell or a photovoltaic cell can also be used. When an internal combustion engine is used, a corresponding fuel tank with a fuel supply is used. In addition to the drive, the trailer also has brake means which act on at least one wheel in order to decelerate the wheel and thus the trailer. As long as the trailer has a plurality of wheels, the drive and the brake means can be configured such that they can act on different wheels separately from one another. Here, the brake means can have a mechanical brake, for example a disc brake or a shoe brake, by means of which at least one wheel or a shaft fastened on the wheel is braked. However, the brake means can also comprise means which are configured to operate the drive such that the drive produces a braking action. This can be a generator-like operation of the electric motor in the case of an electric motor, which leads to an electric brake. This can be an interruption of the fuel supply in the case of an internal combustion engine, so that the internal combustion engine does not output drive power in order to use the internal friction of the internal combustion engine as a motor brake which leads to braking.

[0024] The trailer has a connecting rod which is configured to be connected to towing means. In order to be connected to a towing vehicle, a towbar is used, which is attached to the vehicle by means of the towing means. The towing vehicle can in particular be a bicycle. The trailer can also be towed by a person or an animal using the towing means.

[0025] The connecting rod is fastened to the trailer using a bearing, so that the connecting rod can move relative to the rest of the trailer. In order to bear, suitable bearings such as linear guides or ball bearings can be used for this purpose. Depending on the embodiment of the bearing, different numbers of degrees of freedom can be provided for the connecting rod. The bearing only receives forces in directions in which the bearing does not have a degree of freedom for the connecting rod.

[0026] The trailer has a displacement sensor. The displacement sensor is configured to measure the position of the connecting rod relative to the trailer. To this end, the displacement sensor determines a point fixedly connected with the connecting rod in a coordinate system fixed with the displacement sensor. The coordinate system of the displacement sensor is fixed relative to the orientation of the support for the connecting rod. For example if the support is rotatably supported about a vertical axis of the trailer, the position of the connecting rod relative to the trailer is defined as the position of the connecting rod relative to the part of the trailer that can be rotated with the support. The measured position of the connecting rod relative to the corresponding part of the trailer thus remains constant when the support is correspondingly rotated. As long as the connecting rod is fixedly connected with the towing vehicle or the towing means, the position of the towing vehicle or the towing means relative to the trailer can be calculated by adding a corresponding distance vector.

[0027] The trailer has a speed measuring means. The speed measuring means is configured to determine the travel speed. To this end, the speed measuring means uses a measurement of the speed of the trailer and / or the connecting rod relative to a world coordinate system. The measurement of the speed of the trailer and / or the connecting rod is thus absolute or relative to a fixed world and not relative to a movable coordinate system, for example the above-mentioned coordinate system of the displacement sensor. According to embodiments, the speed measuring means can be configured to perform these measurements.

[0028] The trailer has an electronic regulator configured to actuate the drive and brake means. The drive and / or brake means then change the drive and / or brake force output, thereby accelerating or decelerating the trailer. The regulator can determine the actuation by means of a regulating prescription. The regulating prescription can for example be an electronic circuit integrated into the regulator or a computer program stored on the regulator. The regulator can be a microcontroller for this purpose. The regulator considers a regulating deviation as an input signal. The regulating prescription can respectively have a component that calculates the control signal proportionally to the regulating deviation, proportionally to the change in the regulating deviation and proportionally to the integral of the regulating deviation. By the design of the regulating prescription in coordination with the characteristics of the trailer and the drive and brake means, an optimal actuation of the drive and brake means can be carried out. Optimal can here mean that one or different regulating targets are achieved. It is preferred that the regulating deviation is as constant and small as possible. It is furthermore preferred that the regulating deviation is reduced quickly after its occurrence. It is required here that disturbance variables can act on the system. This includes in particular the towing vehicle or the towing means changing its speed. Ground unevenness or other environmental conditions, such as a changing wind speed, also represent disturbance variables. As soon as such a disturbance variable acts on the regulating deviation, the regulator attempts to minimize the regulating deviation quickly by correspondingly actuating the wheel drive and brake means. Collisions of the connecting rod with other components of the trailer must be unconditionally avoided.

[0029] The control unit calculates the control deviation since it calculates the difference between the position of the neutral point and the position of the connecting rod. As with the position of the connecting rod, the neutral point is defined in particular in the coordinate system of the displacement sensor relative to the trailer. If there is no control deviation, the trailer neither accelerates nor decelerates. In order to determine the neutral point, the control unit uses the driving speed. The correlation between the neutral point and these measured variables can be stored on the control unit, for example in the form of a stored computer program or algorithm or a look-up table. Here, the control unit is designed in such a way that the neutral point is determined relative to the trailer, that is to say in the coordinate system of the displacement sensor, as a function of the driving speed. To this end, the control unit moves the neutral point from a zero point which is fixed relative to the trailer or relative to the coordinate system of the displacement sensor.

[0030] When moving the neutral point as a function of the measured speed, it is advantageous that a sensitive control can be implemented in a simple manner in which the operator or the towing vehicle is not affected by the trailer.

[0031] According to the above description, the control of the wheel drives and brake devices which leads to an acceleration or deceleration of the trailer depends on the control unit and the control deviation. It is generally advantageous if the control unit does not already provide a control signal which leads to a strong acceleration or deceleration in a small control deviation. Measurement inaccuracies and inaccuracies of the mechanical or electrical devices lead to the fact that an optimum control is not achieved. The control unit is therefore generally designed in such a way that a sufficiently large control deviation must be present in order to also cause a control signal which leads to a strong acceleration or deceleration accordingly. That is to say, the control strategy should not respond too sensitively to the control deviation. The disadvantage of such a control strategy is that a large distance between the connecting rod and the trailer must be present even during normal operation in order to produce a sufficiently large control deviation. If additional disturbance variables occur unexpectedly, a further movement between the connecting rod and the trailer will occur. This can be so great that a collision of the connecting rod with other components of the trailer occurs.

[0032] The solution to this problem is to increase the movement freedom which the connecting rod has between the respective end stops. The structural space required for this is disadvantageous for the design of the trailer, however. The present invention solves this problem. According to the invention, the control unit is designed to change the neutral point used to calculate the control deviation as a function of the driving speed. In the case of higher speeds, the neutral point changed in this way can be moved closer to the centre of gravity of the trailer or further away from this centre of gravity, depending on the design of the control unit. By means of this change in the neutral point, a virtual extension of the movement freedom available to the connecting rod is achieved. In this way, larger control deviations can be tolerated which enable a sensitive control without the risk of a collision of the connecting rod with the remainder of the trailer. In this way, it is also avoided that more structural space is provided.

[0033] According to an embodiment of the application, the trailer is characterized in that the displacement sensor is configured as an inductive displacement sensor, a capacitive displacement sensor or a resistance- change displacement sensor.

[0034] The sensor generally consists of a fixed component and a movable component. The change in the relative position to one another is responsible for a change in the electromagnetic properties of the fixed component, which is measured and outputted as a distance measurement signal by calculation of a scaling factor or a corresponding function. Preferably, a sensor target is fastened on the connecting rod and a signal receiver is fastened on the trailer, which measures the change in the distance of the sensor target from the signal receiver by means of a change in the inductance.

[0035] The sensors are characterized in that they are suitable, robust and precise. Furthermore, the sensor is an electronic component, which can be connected to the rest of the electronics particularly simply.

[0036] According to a further embodiment, optical sensors or sensors supported by radar are used.

[0037] According to an embodiment, the trailer is characterized in that the connecting rod is movably supported on the trailer along a longitudinal axis of the connecting rod in the direction of a side facing the trailer and a side facing away from the trailer.

[0038] The support according to this embodiment ensures only one degree of freedom of the relative movement of the connecting rod with respect to the trailer. This support is therefore responsible for the fact that the connecting rod can only move along its longitudinal axis in the direction of a side facing the trailer and a side facing away from the trailer. The side facing away from the trailer is closer to the center of gravity of the trailer than the side facing the trailer. By the degree of freedom defined by the support, the position of the connecting rod with respect to the trailer can be expressed as a scalar distance of the connecting rod to a fixed point of the trailer or to a fixed point in the coordinate system of the displacement sensor. The support can in particular be a linear guide.

[0039] It is advantageous to use a support which allows only one degree of freedom of the connecting rod along its longitudinal axis, so that an improved adjustment is possible. That is, this support limits the degrees of freedom, so that it is simpler to model the physical processes upon a change in the distance and to take into account said physical processes by the adjuster.

[0040] According to an embodiment, the trailer has a further support which allows a rotation of the displacement sensor and of the component of the trailer fixedly connected thereto with respect to the rest of the trailer. The further support can in particular be a support which allows a rotation about a vertical axis. In this case, all relative data relating to the trailer refer to the component of the trailer fixedly connected to the displacement sensor and to its coordinate system.

[0041] According to one embodiment, the trailer is characterized in that the calculation rule is configured to move the neutral point from a zero point located on the longitudinal axis by a correction distance in the direction of the side of the trailer away from the neutral point, the correction distance being proportional to the determined travel speed minus a zero speed.

[0042] According to this embodiment, the regulator uses a linear relationship to calculate the position of the neutral point. According to this relationship, the neutral point is defined by a correction distance and a zero point located on the longitudinal axis. After the neutral point has been virtually moved by the regulator by the correction distance along the longitudinal axis away from the center of gravity of the trailer, i.e. in the direction of the side of the trailer away from the neutral point, the neutral point corresponds to the zero point. The correction distance is calculated using the travel speed. For this purpose, the travel speed is reduced by the zero speed and the difference is multiplied by a proportionality factor.

[0043] The position of the neutral point p is obtained using the zero point p0, the correction distance Δp, the proportionality constant c, the travel speed v and the zero speed v0 according to the following relationship,

[0044] p = Δp + p0 = c(v-v0) + p0.

[0045] This relationship means that as long as the travel speed corresponds to the zero speed, the neutral point also corresponds to the zero point and no movement of the neutral point occurs. Only in the case of a rising travel speed that exceeds the zero speed is the neutral point moved relative to the zero point in the direction of the side of the trailer away from the neutral point. At low speeds, the neutral point is moved again relative to the zero point in the direction of the side of the trailer. Thus, at higher speeds, the neutral point is shifted towards the traction means and at lower speeds shifted away from the traction means.

[0046] The described configuration of the regulator is advantageous in that a sensitive regulation is made easy. At high speeds, there can be a large distance between the connecting rod and the side of the trailer towards which it is directed, but despite this, only a small regulation deviation is calculated. Thus, the connecting rod is relatively far away from the side of the trailer towards which it is directed. In the case of a braking process by the towing vehicle, the connecting rod can move very far before it reaches the end of the support or collides with other components of the trailer. Thus, a correspondingly large regulation deviation can occur without a collision.

[0047] Correspondingly, the opposite applies at low speeds, i.e. in the case of a small distance between the side of the trailer towards which the connecting rod is directed and the connecting rod, a small regulation deviation is calculated. As soon as the towing vehicle or the traction means accelerates, where the acceleration is generally greater at low speeds than at high speeds, a large regulation deviation can occur before the connecting rod collides.

[0048] The variable speed movement of the neutral point allows a virtual extension of the free space, which can be provided to the connecting rod without collisions. To this end, it is utilized that the connecting rod must have a large clearance to the side facing the trailer at high speeds and a large clearance to the side facing away from the trailer at low speeds, in order to be able to avoid the respective collision. Greater adjustment deviations can thus also be tolerated by the virtual extension.

[0049] It is advantageous if the adjuster is designed in such a way that it works with a large adjustment deviation. Due to the electronic and mechanical components used, the adjuster has inaccuracies, for example the position measurement signal can be loaded with noise, or a respective analog-digital converter is responsible for a delay in time. These inaccuracies result in the fact that, in the case of small adjustment deviations, a relatively large proportion of the adjustment deviation is attributed to the described inaccuracies. The use of this erroneous adjustment deviation for actuating the drive and brake means can lead to an over- or under- acceleration or deceleration. When using a large adjustment deviation as specified by the present application, the respective inaccuracies are less large compared to the remaining adjustment deviation. These inaccuracies therefore also do not lead to a distortion of the control signal.

[0050] According to an embodiment, the trailer is characterized in that the adjuster is designed to calculate a correction clearance which is negatively proportional to the determined travel speed minus the zero speed, when the determined speed ratio is smaller than a start speed of the zero speed.

[0051] According to this embodiment, there is a start speed which is smaller than the zero speed. When the travel speed is below a limit speed, the linear mathematical function with the positive proportionality factor described earlier is no longer used for calculating the correction clearance. Instead, a continuously falling function is used. The respective function is designed in such a way that it continuously merges into the function at higher speeds. Thus, according to this embodiment, at speeds below the start speed, i.e. at very low speeds, a larger correction clearance is calculated than at the start speed.

[0052] This results in the fact that the neutral point is moved slightly further in the direction of the side facing away from the trailer. Thus, in the state without adjustment deviation, there is an increased clearance between the neutral point and the side facing the trailer. The swaying at the start or other instabilities then do not directly lead to a collision of the connecting rod with other components of the trailer.

[0053] According to an embodiment, the trailer is characterized in that the adjuster is designed to actuate the wheel drive and / or the brake means only when the value of the adjustment deviation is greater than a tolerance deviation.

[0054] The tolerance deviation is advantageously small so that the small adjustment deviations are not immediately used to actuate the wheel drive and / or brake means. Small adjustment deviations can occur, inter alia, as a result of uneven traction loads on the connecting rod. Uneven traction loads are typically the case when the towing vehicle is a bicycle that is driven by the pedalling of an operator. Intense acceleration or deceleration is required, inter alia, at high speeds in order to avoid small adjustment deviations at any time. This places a load on the wheel drive and brake means. The provision of the tolerance deviation therefore leads to a reduction in the load on the wheel drive and brake means and on the entire trailer.

[0055] According to an embodiment, the trailer is characterized in that the regulator is configured to calculate the tolerance deviation in direct proportion to the determined travel speed.

[0056] The tolerance deviation is advantageously selected to be larger at greater speeds. Continuous actuation of the wheel drive and brake means at such speeds can lead to accelerated wear of these components.

[0057] According to an embodiment, the trailer is characterized in that there is a mechanical brake actuation means which is configured to mechanically actuate the brake means when the connecting rod is below the limit spacing from the trailer.

[0058] According to this embodiment, the trailer has a mechanical brake actuation means for the brake means. This mechanical brake actuation means serves as a redundancy to the electrical actuation of the brake means by means of the regulator. The brake actuation means is configured in such a way that it is mechanically triggered as soon as the connecting rod is below the limit spacing from the trailer. This can be, inter alia, a very small spacing between a part of the connecting rod and an end stop, for example. However, other means of the connecting rod can also be provided on the trailer, such as a protruding carrier and a corresponding stop, to constitute the brake actuation means.

[0059] The advantage of the mechanical brake actuation means is that it effectively brakes even in the event of an electrical current interruption or too slow regulation of the trailer. Collisions of the trailer with the towing means and corresponding damage can thereby be prevented. The mechanical brake actuation means thus increases the safety of the trailer in operation.

[0060] According to an embodiment, the trailer is characterized in that the mechanical brake actuation means

[0061] a) comprises a lever which is configured to be tipped over by the connecting rod as soon as the limit spacing is undershot, and

[0062] b) comprises a rope drive which is connected to the brake means and to the lever and is configured to be tensioned by the tipping over of the lever.

[0063] According to this embodiment, the mechanical brake actuating means are embodied as a rope drive. The rope drive is actuated by means of a lever, which is flipped over by a connecting rod at a distance below the limit distance. This embodiment uses proven components, so that it is particularly reliable.

[0064] The task is also solved by a method for adjusting the distance between a trailer having at least one wheel, a wheel drive and brake means, and a connecting rod, which is configured to be connected to a traction means and is movably supported fastened on the trailer, comprising the steps

[0065] - measuring the position of the connecting rod relative to the trailer,

[0066] - measuring the speed of the trailer and / or the speed of the connecting rod,

[0067] - determining a travel speed by means of the speed of the trailer and / or the speed of the connecting rod,

[0068] - adjusting the actuation of the wheel drive and / or the brake means using an adjustment offset,

[0069] and characterized in that

[0070] - moving the position of the neutral point relative to the trailer from zero as a function of the travel speed,

[0071] - calculating the adjustment offset using the distance between the position of the neutral point and the position of the connecting rod.

[0072] The method is particularly suitable for carrying out with a trailer according to the application. The aforementioned advantages of the trailer according to the application and its embodiments also apply in a meaningful manner to the method and its embodiments.

[0073] According to an embodiment, the method is characterized in that

[0074] - moving the connecting rod along a longitudinal axis of the connecting rod in the direction of the side of the trailer or the side facing away from the trailer,

[0075] - moving the neutral point from zero, which lies on the longitudinal axis, along the longitudinal axis in the direction of the side facing away from the trailer by a correction distance, which is proportional to the travel speed minus zero speed.

[0076] According to an embodiment, the method is characterized in that, when the determined travel speed is less than a start speed, which is smaller than the zero speed, a correction distance is calculated, which is proportional to the travel speed with a negative sign.

[0077] According to one embodiment, the method is characterized in that the wheel drive and / or the braking device are operated only when the value of the adjustment deviation is greater than the tolerance deviation.

[0078] According to one embodiment, the method is characterized by calculating a tolerance deviation that is proportional to the driving speed.

[0079] According to one embodiment, the trailer is characterized in that the braking device is mechanically operated when the distance between the trailer and the connecting rod is below the limit distance. Attached Figure Description

[0080] The invention is further illustrated below with the aid of embodiments. The accompanying drawings show:

[0081] Figure 1 The trailer and bicycle according to the present invention;

[0082] Figure 2 Functional diagram of a trailer;

[0083] Figure 3 Schematic diagram of the spacing measuring device;

[0084] Figure 4 A schematic diagram of the oscillation distance between the trailer and the tractor.

[0085] Figure 5 : A diagram showing the correction spacing for driving speed. Detailed Implementation

[0086] Figure 1 A trailer 1 and a bicycle 2 according to the invention are shown. The trailer 1 and the bicycle 2 are connected by a coupling rod 3. The trailer has a wheel drive, not shown separately in this view. By means of the wheel drive, the trailer 1 is driven so that it follows the bicycle 2, without the cyclist having to expend muscle strength for this purpose.

[0087] Figure 2 A functional diagram of trailer 1 is shown. Acceleration and deceleration devices 4, including wheel drives and brakes, are depicted in the diagram. The brakes are powered by an energy source 5. The drives and brakes are controlled by an adjuster 6. This control is performed so that the cyclist or other towing vehicle is as unnoticed as possible as trailer 1 travels behind the bicycle. To ensure proper adjustment, a spacing measuring device 7 measures the distance between the bicycle 2 and trailer 1. This distance is transmitted to the adjuster 6.

[0088] Figure 3A schematic view of the distance measuring device 7 is shown. The distance measuring device 7 has a housing 8, which is fixedly connected with the rest of the trailer 1. A connecting rod 9 extends into the housing. The connecting rod 9 is connected with a slide 10, which is movably fastened on a linear guide 11. The linear guide 11 defines the degrees of freedom, which the connecting rod 9 can pass through in the relative movement with respect to the housing 8. The movement freedom space of the connecting rod 9 is limited on the right side by a wall of the housing, which the connecting rod 9 contacts with a rubber end stop 12 as soon as it has moved as far as possible to the right. On the left side, the movement freedom space is defined by a rubber end stop 13. The right side corresponds to the side of the bicycle facing away from the trailer. The left side thus corresponds to the side facing towards the trailer. The respective stops in the form of the rubber end stops 12, 13 define the end of the path facing away from the trailer and the end of the path facing towards the trailer, which the connecting rod 9 can pass through.

[0089] A sensor target 14 is fastened on the connecting rod 9. A displacement sensor 15 can ascertain the position of the sensor target 14 with respect to the displacement sensor. The displacement sensor 15 and thus its coordinate system are fixedly connected here with the housing 8 and thus with the trailer 1. The measurement of the position of the sensor target 14 with respect to the displacement sensor 15 thus corresponds to a measurement of the connecting rod 8 with respect to the trailer 1. The displacement sensor 15 is an inductive displacement sensor. The sensor target 14 and the displacement sensor 15 form a displacement sensor.

[0090] The regulator 6 is configured to subtract the position of the neutral point from the measured position of the connecting rod and thus to calculate a regulation deviation. Depending on the regulation deviation, the regulator 6 actuates the wheel drive and brake device, so that the trailer 1 is accelerated or braked. By means of the linear guide 11, the connecting rod 9 can only move with respect to the housing 8 and the trailer 1 along a defined path, i.e. along the longitudinal axis of the connecting rod 9. The neutral point also lies on the longitudinal axis. The regulation deviation can thus also be represented by the distance along the longitudinal axis. Depending on whether the connecting rod lies closer to the side facing away from the trailer or closer to the side facing towards the trailer, the regulation deviation is positive or negative.

[0091] As soon as the connecting rod 9 contacts the rubber end stop 13 facing towards the trailer and in addition moves in the direction of the wall of the housing 8 facing towards the trailer, a lever 16 is flipped over. The lever here rotates about a bearing point 17. By flipping over the lever 16, a rope drive 18 is tensioned. The rope drive 18 is connected with the brake device of the trailer 1. The lever 16 and the rope drive 18 are mechanical brake actuating means, which actuate the brake device as soon as a limit distance between the trailer 1 and the bicycle 2 and the connecting rod 8 connected with the bicycle 2 is undershot.

[0092] Figure 4A schematic diagram shows the oscillating gap 19 between trailer 1 and tractor 2, which is generated by the pedaling of a cyclist. Adjusting this gap 19 by corresponding acceleration and deceleration of trailer 1 results in a large load on the drivetrain.

[0093] Figure 5 A schematic diagram illustrating the correction spacing based on travel speed is shown, wherein the correction spacing on the horizontal axis is illustrated and indicated as "position," and the travel speed on the vertical axis is illustrated and indicated as "speed." In this embodiment, the travel speed corresponds to the trailer speed, but the travel speed may also correspond to the bicycle speed or a calculation of both speeds.

[0094] The correction spacing is used to move the neutral point along the longitudinal axis. Therefore, there is no adjustment deviation at different travel speeds or at different positions of the connecting rod 9 relative to the displacement sensor 15, the housing 8, or the trailer 1.

[0095] This diagram illustrates the positions of connecting rod 9 at four different travel speeds, where there is no adjustment deviation. Position 21 is assigned to zero speed 20. Position 22 is assigned to higher travel speeds. Position 24 is assigned to starting speed 23. Position 25 is assigned to travel speeds below the starting speed.

[0096] As shown in the diagrams for positions 21, 22, and 24, connecting rod 9 must continue to move toward the right side away from the trailer as the travel speed increases, thus eliminating adjustment deviation. This is based on the curve showing the change in the correction pitch, which increases with increasing travel speed and is added to zero to calculate the neutral point. At zero speed 20, there is no correction pitch. Zero corresponds to the neutral point. In the shown state, connecting rod 9 is located midway between the side facing the trailer and the side away from the trailer without adjustment deviation. Above zero speed 20, the correction pitch is positive, causing the neutral point to move toward the side away from the trailer. Below zero speed 20, the neutral point moves toward the side facing the trailer. Therefore, connecting rod 9 must correspondingly move toward or away from the trailer to eliminate adjustment deviation. Below starting speed 23, the correction pitch increases again. Correspondingly, the connecting rod must move slightly further toward the side away from the trailer, thus eliminating adjustment deviation.

[0097] The speed dependency of the correction distance results in the neutral point and thus the connecting rod 9 being closer to the side facing away from the trailer at high speeds. As a result, large adjustment deviations can occur in the braking of the bicycle 2 before the connecting rod 9 comes into contact with the end facing the trailer in the form of the rubber end stop 13. On the other hand, the speed dependency of the correction distance results in the neutral point and thus the connecting rod 9 being closer to the end facing the trailer at low speeds. As a result, large adjustment deviations can occur in the acceleration of the bicycle 2 before the connecting rod 9 reaches the end facing away from the trailer in the form of the rubber end stop 12.

[0098] Large adjustment deviations are less strongly superimposed by noise, which arises as a result of mechanical and electronic inaccuracies of the components used. Large adjustment deviations can thus enable sensitive adjustment. At very low speeds, the correction distance is thus chosen such that the neutral point is slightly further away from the side facing the trailer in order to compensate for jolts or wobbles when starting.

[0099] Furthermore, it is shown in Figure 5 that there is a tolerance deviation 26. The adjustment deviation must be so large that the position of the connecting rod 9 lies outside the respective tolerance deviation in order for the adjuster 6 to actuate the acceleration and deceleration means 4. The tolerance deviation 26 increases as the driving speed increases. This tolerance deviation prevents actuation of the acceleration and deceleration means at a relatively small adjustment deviation. This protects the acceleration and deceleration means and prevents wear.

[0100] List of reference signs

[0101] 1 trailer

[0102] 2 bicycle

[0103] 3 coupling rod

[0104] 4 acceleration and deceleration means

[0105] 5 energy source

[0106] 6 adjuster

[0107] 7 distance measuring means

[0108] 8 housing

[0109] 9 connecting rod

[0110] 10 slide

[0111] 11 linear guide

[0112] 12 rubber end stop facing away from the trailer

[0113] 13 end stop facing the trailer

[0114] 14 sensor target

[0115] 15 displacement sensor

[0116] 16 lever

[0117] 17 support position

[0118] 18 rope drive

[0119] 19 oscillating spacing

[0120] 20 zero speed

[0121] 21 zero speed position

[0122] 22 higher speed position

[0123] 23 start-up speed

[0124] 24 start-up speed position

[0125] 25 below start-up speed position

[0126] 26 tolerance deviation

Claims

1. Trailer (1) with at least one driven wheel, comprising - an energy source (5) which is configured to supply energy to a wheel drive, - brake means for retarding the at least one wheel, - a connecting rod (9) which is configured to be connected to a traction means and is movably supported on the trailer, - a displacement sensor which is configured to measure the position of the connecting rod (9) relative to the trailer (1), - speed measuring means which are configured to determine a travel speed on the basis of a measurement of the speed of the trailer and / or the connecting rod, and - an electronic regulator (6), characterized in that - the regulator (6) is configured to - move a neutral point relative to the trailer (1) from a zero point in dependence on the determined travel speed, - calculate a regulation deviation using the distance between the position of the neutral point and the measured position of the connecting rod (9), and - actuate the wheel drive and / or the brake means using the regulation deviation. The displacement sensor is configured as an inductive displacement sensor, a capacitive displacement sensor or a resistance change displacement sensor. The connecting rod (9) is movably supported on the trailer (1) along a longitudinal axis of the connecting rod in the direction of a side facing the trailer and a side facing away from the trailer. The regulator (6) is configured to move the neutral point from a zero point located on the longitudinal axis in the direction of the side facing away from the trailer by a correction distance along the longitudinal axis, the correction distance being directly proportional to the determined travel speed minus a zero speed. The regulator (6) is configured to calculate a correction distance which is directly proportional to the determined travel speed minus the zero speed when the determined speed ratio is less than a start speed of the zero speed. The regulator (6) is configured to actuate the wheel drive and / or the brake means only when the value of the regulation deviation is greater than a tolerance deviation. The regulator (6) is configured to calculate a tolerance deviation which is directly proportional to the determined travel speed. There is a mechanical brake actuation means which is configured to mechanically actuate the brake means when a limit distance is undershot between the trailer (1) and the connecting rod (9). The mechanical brake actuation means comprises a lever (16) which is configured to be tipped over by the connecting rod (9) as soon as the limit distance is undershot, and comprises a rope drive (18) which is connected to the brake means and the lever (16) and is configured to be tensioned by the tipping over of the lever (16).

10. Method for regulating the distance between a trailer (1) with at least one wheel, a wheel drive and brake means and a connecting rod (9) which is configured to be connected to a traction means and is movably supported fastened on the trailer (1), the method comprising the steps of - measuring the position of the connecting rod (9) relative to the trailer (1), 2. The trailer (1) according to the preceding claim, characterized in that ​ 3. The trailer (1) according to any one of the preceding claims, characterized in that ​ 4. The trailer (1) according to the preceding claim, characterized in that ​ 5. The trailer (1) according to the preceding claim, characterized in that ​ 6. The trailer (1) according to any one of the preceding claims, characterized in that ​ 7. The trailer (1) according to the preceding claim, characterized in that ​ 8. The trailer (1) according to any one of the preceding claims, characterized in that ​ 9. The trailer (1) according to the preceding claim, characterized in that ​ ​ ​ ​ ​ - measuring a speed of the trailer (1) and / or a speed of the connecting rod (9), - determining a travel speed by means of the speed of the trailer (1) and / or the speed of the connecting rod (9), - adjusting the actuation of the wheel drive and / or the brake means in the event of an adjustment offset, - characterized in that - the position of the neutral point relative to the trailer (1) is moved from zero with the travel speed, - the adjustment offset is calculated using the spacing between the position of the neutral point and the position of the connecting rod.

11. The method as claimed in claim 10, characterized in that - the connecting rod (9) is moved along a longitudinal axis of the connecting rod in the direction of the side facing the trailer or the side facing away from the trailer, - the neutral point is moved from zero, which is located on the longitudinal axis, along the longitudinal axis in the direction of the side facing away from the trailer by a correction spacing, which is directly proportional to the travel speed minus zero speed.

12. The method of claim 11, wherein, When the determined travel speed is less than the zero speed start speed, a correction spacing is calculated which is inversely proportional to the travel speed.

13. The method according to any one of claims 10 to 12, characterized in that, The wheel drive and / or the brake means are actuated only when the value of the adjustment offset is greater than a tolerance offset.

14. The method according to the preceding claim, characterized in that, A tolerance offset is calculated which is directly proportional to the travel speed.

15. The method according to any one of claims 10 to 14, characterized in that, When the spacing between the trailer and the connecting rod is below a limit spacing, the brake means are actuated mechanically.

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