A method for controlling the distance between a trailer and a connecting rod.

Abstract

The present invention relates to a trailer having at least one driven wheel, comprising: an energy source designed to supply energy to a wheel drive system; a braking system for decelerating at least one wheel; a connecting rod designed to be connected to a towing system and movably mounted on the trailer; a displacement sensor designed to measure the relative position of the connecting rod with respect to the trailer; a speed measuring device designed to determine the travel speed based on measured speeds of the trailer and / or the connecting rod; and an electronic control unit, wherein the control unit is designed to shift the relative position of the neutral point with respect to the trailer from a zero point according to the determined travel speed, calculate a control deviation using the distance between the neutral point and the measured position of the connecting rod, and activate the wheel drive system and / or braking system using the control deviation.

Description

[Technical Field]

[0001] The present invention relates to a trailer provided with a wheel drive device and a method for controlling such a trailer. [Background Art]

[0002] Conventional driven trailers use force measurement sensors, specifically strain gauges, to measure the force generated between the trailer and the towing vehicle for controlling the driving of the trailer. These force measurement sensors are known to be susceptible to external influences, especially environmental influences such as temperature and humidity variations. Furthermore, the connection between a trailer and a towing vehicle according to the prior art is always rigid, and thus is susceptible to the influence of axial forces as well as lateral forces between the trailer and the towing vehicle. In particular, in a system comprising a trailer and a towing vehicle, strong vibrations and even resonance vibrations may occur. This causes the force measurement sensor to generate a large amount of measurement data, resulting in a high evaluation processing load on the control unit. It is also difficult to distinguish measurement data essential for controlling the trailer from background noise caused by vibration and other disturbance variables. This not only impairs ride comfort but also increases energy consumption.

[0003] A motor-driven trailer for bicycles is known from US Patent Application Publication No. 2012 / 0037435A1. The trailer described therein is connected to a bicycle via a drawbar, 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 compressive force if the trailer is faster than the bicycle, and measures a tensile force if the trailer lags behind the bicycle. The motor accelerates the trailer in accordance with the force measured by the force measurement sensor.

[0004] U.S. Patent No. 8,365,849B2 describes a system for towing a trailer. The trailer comprises an electric motor, a brake, a tow bar, and a force measuring sensor located on the tow bar. The trailer is accelerated via the motor or braked via the brake in response to a mechanical force measured in the force sensor.

[0005] German Patent Application Publication No. 102010051838A1 describes a bicycle trailer. The trailer is equipped with electromechanisms that can function as brakes and motors so that the trailer does not have a significant reactive effect on the bicycle when the bicycle is pushed or braked. Various sensors are described to achieve this. For example, pedal pressure sensors, braking force sensors provided on the brake levers, and force measuring sensors provided at the connection between the bicycle and the trailer are proposed. Signals from these sensors are transmitted to an electronic logic circuit, which then acts on the electromechanisms and / or brakes. The force measuring sensor can be used to determine whether the bicycle is applying tensile or compressive force to the trailer. Depending on the measured signal, the motor or brakes are activated to readjust the relative position of the trailer to the bicycle. As an alternative to force measurement, a preload measuring system is proposed. In the preload measuring system, a pressure sensor records the pressure change in a cylinder, or a position sensor measures the position of a spring-loaded support disc. While this type of preload measurement system reduces the coupling stiffness between the trailer and the bicycle, interference, specifically pulsating feedback effects, still remain.

[0006] German Patent Application Publication No. 102006009862A1 describes a bicycle push trailer for driving and braking a bicycle. In this bicycle push trailer, a battery is mounted on the trailer frame as inertial mass, so that the battery swings forward during braking and backward during acceleration. The battery is connected in an articulated manner to a current position transmitter and a Bowden cable via a control lever. During the braking process, an electric motor is regenerated via the current position transmitter, while a mechanical brake is actuated via the Bowden cable.

[0007] U.S. Patent Application Publication 2013 / 0311058A1 discloses a method for controlling a trailer driven by an electric motor.

[0008] European Patent Application Publication No. 3416860A1 relates to a method for controlling a driven trailer and a motor-driven trailer. The method includes, in particular, the step of defining a neutral position at a distance between the trailer and the towing vehicle. The deviation of the distance between the trailer and the towing vehicle from the neutral position is measured and output as a distance value. If the distance between the trailer and the towing vehicle decreases by at least one first distance value relative to the neutral position, the trailer is electrically braked. If the distance between the trailer and the towing vehicle decreases by at least one second distance value relative to the neutral position (the second distance value being greater than the first distance value), the trailer is mechanically braked independently of the electric brake. If the distance between the trailer and the towing vehicle increases by a third distance value relative to the neutral position, the trailer is accelerated by an electric motor. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] U.S. Patent Application Publication No. 2012 / 0037435A1 [Patent Document 2] U.S. Patent No. 8,365,849B2 [Patent Document 3] German Patent Application Publication No. 102010051838A1 [Patent Document 4] German Patent Application Publication No. 102006009862A1 [Patent Document 5] U.S. Patent Application Publication No. 2013 / 0311058A1 [Patent Document 6] European Patent Application Publication No. 3416860A1 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] Based on this, the objective of the present invention is to enable the driven trailer to be controlled with the utmost precision. [Means for solving the problem]

[0011] This objective is achieved by the trailer described in claim 1 and the method for controlling the distance described in claim 10. Advantageous embodiments are described in the dependent claims and specification.

[0012] A trailer according to the present invention, having at least one driven wheel, ● An energy source designed to supply energy to a wheel drive system, ● A braking device for slowing down at least one wheel, ●A connecting rod designed to connect to a towing device and movably mounted on the trailer, ● A displacement sensor designed to measure the relative position of the connecting rod to the trailer, ● A speed measuring device designed to determine the travel speed based on measured speeds of the trailer and / or connecting rod, ● Electronic control device and Equipped with, ●The control device is ○According to the determined travel speed, the relative position of the neutral point to the trailer is shifted from the zero point. The control deviation is calculated using the position of the neutral point and the measured position and distance between the connecting rods. It is characterized by being designed to operate the wheel drive system and / or braking system using control deviation.

[0013] A trailer has one or more wheels. Therefore, it can stand upright on its own, or only in combination with a towing vehicle, or can be held upright by a driver. At least one of the wheels is driven by a drive unit. The drive unit is preferably an electric motor. The electric motor can be designed as a wheel hub motor or mounted on the trailer and can drive a driven wheel via a drive shaft. Furthermore, the trailer has an energy source to supply energy to the drive unit. In the case of an electric motor, the energy source may be a battery. Fuel cells or solar power can also be used. If an internal combustion engine is used, a fuel tank with a corresponding fuel supply device is used. In addition to the drive unit, the trailer also has a brake unit that acts on at least one wheel to slow down the wheel and, consequently, the trailer. The drive unit and brake unit can be designed to act independently on various wheels if the trailer has multiple wheels. The brake unit may have a mechanical brake, such as a disc brake or block brake, by braking at least one wheel or an axle fixed to the wheel. Furthermore, the braking system may include a device designed to activate the drive system and produce a braking effect. In the case of an electric motor, this may be the regenerative motion of the electric motor, which produces electric braking. In the case of an internal combustion engine, by stopping the fuel supply and not outputting driving force, the internal friction of the internal combustion engine is used as an engine brake, resulting in braking.

[0014] The trailer is equipped with a connecting bar designed to be connected to a towing device. The towing bar is used to connect to the towing vehicle, and the towing bar is attached to the vehicle by the towing device. The towing vehicle may, specifically, be a bicycle. The trailer may be towed by a person or an animal by the towing device.

[0015] The connecting rod is fixed to the trailer by a bearing, such that the connecting rod can move relatively to the trailer body. Appropriate bearings such as linear guides or ball bearings can be used for installation. Different degrees of freedom can be provided to the connecting rod according to the characteristics of the bearing. The bearing absorbs force only in directions in which it does not provide degrees of freedom to the connecting rod.

[0016] The trailer has a displacement sensor. The displacement sensor is designed to measure the relative position of the connecting rod with respect to the trailer. For this purpose, the displacement sensor determines a point fixedly connected to the connecting rod in a coordinate system fixed relative to the displacement sensor. The orientation of the coordinate system of the displacement sensor is fixed relative to the bearing to which the connecting rod is attached. For example, if the mounting portion is rotatable about the vertical axis of the trailer, the relative position of the connecting rod with respect to the trailer is defined as the relative position of the connecting rod with respect to the portion of the trailer rotatable together with the mounting portion. Therefore, due to the corresponding rotation of the bearing, the measured position of the connecting rod does not change relatively to the corresponding portion of the trailer. When the connecting rod is rigidly coupled to a towing vehicle or a towing device, the position of the towing vehicle or towing device relative to the trailer is calculated by adding corresponding distance vectors.

[0017] The trailer has a speed measuring device. The speed measuring device is designed to determine the travel speed. For this purpose, the speed measuring device uses measurements of the relative speed of the trailer and / or the connecting rod with respect to the world coordinate system. Therefore, the measurement of the speed of the trailer and / or the connecting rod is an absolute speed, that is, a speed relative to the stationary world, not a speed relative to a moving coordinate system, for example, the coordinate system of the aforementioned displacement sensor. According to one embodiment, the speed measuring device may be designed to perform these measurements.

[0018] The trailer has an electronic control unit designed to operate the drive and brake systems. Accordingly, the drive and / or brake systems vary the output driving force and / or braking force to accelerate or decelerate the trailer. The operation of the control unit can be defined by control specifications. Control specifications may be, for example, electronic circuits integrated into the control unit or computer programs stored in the control unit. The control unit may be a microcontroller. The control unit takes control deviation into consideration as an input signal. The control specifications may have components that calculate control signals proportional to the control deviation, proportional to the change in the control deviation, and proportional to the integral of the control deviation, respectively. By configuring the control specifications in a manner suited to the characteristics of the trailer, as well as the drive and brake systems, the drive and brake systems can be operated in an optimal manner. Ideally, this can achieve one or more control targets. It is preferable that the control deviation be as constant and low as possible. Furthermore, it is preferable that the control deviation be corrected promptly after it occurs. The challenge associated with this is that disturbance variables can affect the system. This includes, in particular, changes in the speed of the towing vehicle or towing device. Other environmental conditions, such as surface irregularities or wind speed fluctuations, also contribute to the disturbance variables. As soon as these types of disturbance variables affect the control deviation, the control system attempts to quickly minimize the deviation by correspondingly activating the wheel drive and braking systems. Collision between the connecting rod and other components of the trailer must be avoided at all costs.

[0019] The control device calculates a control deviation by calculating a difference between a neutral point and a position of the connecting rod. Like the position of the connecting rod, the neutral point is defined relative to the trailer, specifically within the coordinate system of the displacement sensor. If no control deviation exists, the trailer is neither accelerated nor decelerated. The computing device determines the neutral point using the travel speed. The relationship between the neutral point and these measurement variables can be stored in the control device, for example, in the form of a stored computer program, an algorithm, or a lookup table. The control device is designed such that the neutral point is defined relative to the trailer, that is, within the coordinate system of the displacement sensor, in accordance with the travel speed. For this purpose, the control device shifts the neutral point relative to a stationary zero point with respect to the trailer, that is, the coordinate system of the displacement sensor.

[0020] Shifting the neutral point in accordance with the measured speed has the advantage that sensitive control which is not influenced by the trailer on the driver or the towing vehicle can be achieved in a simple manner.

[0021] According to the above, the actuation of the wheel drive device and the braking device that accelerate or decelerate the trailer depends on the control device and the control deviation. It is generally advantageous if the control device does not output an actuation signal that causes strong acceleration or deceleration in response to a very small control deviation. Optimal control is not possible due to measurement uncertainty and inaccuracies of mechanical or electrical means. Therefore, the control device is usually designed such that a sufficiently large control deviation is required to trigger an actuation signal that causes appropriately strong acceleration or deceleration. Accordingly, the control strategy does not need to react excessively sensitively to control deviations. The disadvantage of such a control strategy is that, in order to generate a sufficiently large control deviation, a large distance between the connecting rod and the trailer is required even during normal operation. If unforeseen additional disturbance variables occur, further changes arise between the connecting rod and the trailer. This change can be large enough to cause a collision between the connecting rod and other components of the trailer.

[0022] One solution to this problem is to increase the degrees of freedom of movement of the connecting rod between each end stop. However, the installation space required for this is inconvenient from a trailer design perspective. This invention solves this dilemma. According to this invention, the control device is designed to change the neutral point used to calculate the control deviation according to the travel speed. Depending on the characteristics of the control device, the neutral point thus changed can be moved closer to the trailer's center of gravity at high speeds, or it can be moved further away from the trailer. By changing the neutral point in this way, the degrees of freedom of movement available to the connecting rod can be virtually extended. This allows for larger control deviations that enable finer control without the risk of the connecting rod colliding with the trailer body. This eliminates the need to provide more installation space.

[0023] According to one embodiment of the present invention, the trailer is characterized in that the displacement sensor is designed as an inductive displacement sensor, a capacitive displacement sensor, or a resistive displacement sensor.

[0024] The above sensor typically consists of a fixed part and a movable part. A change in the relative position between the parts causes a change in the electromagnetic properties of the fixed part, which is measured and output as a distance measurement signal by calculation using a proportionality constant or a corresponding function. Preferably, the sensor target is fixed to a connecting rod, and the signal receiver is fixed to the trailer. This signal receiver measures the change in distance between the signal receiver and the sensor target by the change in inductance.

[0025] The above-mentioned sensor is superior in that it is inexpensive, robust, and highly accurate. Furthermore, the sensor is an electronic component and can be connected to the rest of the electronic equipment particularly easily.

[0026] In a further embodiment, an optical sensor or a radar-assisted sensor is used.

[0027] According to one embodiment, the trailer is characterized in that the connecting rod is attached to the trailer such that it is movable along its longitudinal axis toward the side closer to the trailer and also movable toward the side further away from the trailer.

[0028] The mounting portion according to this embodiment provides the connecting rod with only one degree of freedom in its relative motion to the trailer. Therefore, this ensures that the connecting rod can move only along its longitudinal axis toward the side closer to the trailer, and also toward the side further away from the trailer. The side further away from the trailer is closer to the trailer's center of gravity than the side further away from the trailer. The degree of freedom defined by the mounting portion allows the relative position of the connecting rod to the trailer to be expressed as a scalar distance between the connecting rod and a fixed point on the trailer, i.e., a fixed point in the coordinate system of the displacement sensor. Specifically, the mounting portion may be a linear guide.

[0029] The advantage of using a mounting section on a connecting rod that allows only one degree of freedom along its longitudinal axis is that it can improve control. Specifically, because this type of mounting section limits the degree of freedom, it is easier to model the physical process as the distance changes, and the control device can take the physical process into account.

[0030] According to one embodiment, the trailer has a further mounting portion that allows the displacement sensor and the trailer components rigidly connected to the displacement sensor to rotate relative to the trailer body. Specifically, the further mounting portion may be a mounting portion that rotates about a vertical axis. In this case, all relative details relating to the trailer relate to the displacement sensor and the trailer components rigidly connected to its coordinate system.

[0031] According to one embodiment, the trailer is designed such that the calculation specification shifts the neutral point from the zero point located on the longitudinal axis to a side further away from the trailer along the longitudinal axis by a correction distance that is directly proportional to the value obtained by subtracting the zero speed from the determined travel speed.

[0032] According to this embodiment, the control device calculates the position of the neutral point using a linear relationship. According to this relationship, the neutral point is defined by a correction distance and a zero point on the longitudinal axis. The neutral point corresponds to the zero point after the control device virtually shifts the neutral point along the longitudinal axis by the correction distance, i.e., further away from the trailer's center of gravity. The correction distance is calculated using the travel speed. For this purpose, the zero speed is subtracted from the travel speed, and this difference is multiplied by a proportionality constant.

[0033] According to the following relationship, the position of the neutral point p is equal to the zero position p0 and the correction distance Δ. p It is given by the proportionality constant c, the travel speed v, and the zero speed v0.

[0034]

number

[0035] This relationship means that when the travel speed corresponds to zero speed, the neutral point corresponds to zero, and therefore the neutral point does not shift. Only when the travel speed increases beyond zero speed does the neutral point shift relative to the zero point, moving further away from the trailer. At low speeds, conversely, the neutral point shifts relative to the zero point, moving closer to the trailer. Therefore, at high speeds, the neutral point moves towards the towing device, and at low speeds, it moves away from the towing device.

[0036] The advantage of the aforementioned control device design is that it facilitates precise control. At high speeds, even when there is a large distance between the connecting rod and the side closer to the trailer, the calculated control deviation is minimal. Therefore, the connecting rod is positioned relatively far from the side closer to the trailer. During braking by the towing vehicle, the connecting rod can travel a long distance before reaching the end of the attachment point, i.e., before a collision with other components of the trailer occurs. Therefore, a corresponding large control deviation may occur without a collision.

[0037] Therefore, conversely, at low speeds, a small control deviation is calculated when the distance between the trailer and the connecting bar is small. As soon as the towing vehicle or towing device accelerates, at low speeds the acceleration is usually stronger than at high speeds, and a large control deviation can occur before the connecting bar collides.

[0038] By changing the variable speed of the neutral point, a virtual extension of the free space available to the connecting rod is possible without collision. This utilizes the fact that, in order to prevent corresponding collisions, the connecting rod must, first and foremost, maintain sufficient distance from the side closer to the trailer at high speeds, and further away from the trailer at low speeds. Therefore, the virtual extension allows for greater control deviations.

[0039] It is advantageous for control devices to be designed to operate with larger control deviations. The electronic and mechanical components used introduce errors into the control device. For example, position measurement signals may be affected by noise, or the corresponding analog-to-digital converters may introduce time delays. Due to these inaccuracies, in the case of small control deviations, a relatively large proportion of the control deviation may be attributable to the aforementioned inaccuracies. Using such error-prone control deviations to operate drive and brake devices may result in excessively strong or weak acceleration or deceleration. When large control deviations are used, as provided by the present invention, the corresponding inaccuracies become less significant compared to the remaining control deviations. Therefore, they also do not cause distortion of the control signals.

[0040] According to one embodiment, the trailer is designed such that, when the determined speed is less than the starting speed which is lower than the zero speed, the control device calculates a correction distance that is inversely proportional to the value obtained by subtracting the zero speed from the determined travel speed.

[0041] According to this embodiment, there exists a starting speed lower than zero speed. When the travel speed falls below the limit speed, the aforementioned linear mathematical function is no longer used with a proportionality coefficient to calculate the correction distance. Instead, a monotonically decreasing function is used. The corresponding function is configured to always be consistent with the function at high speeds. Therefore, according to this embodiment, at speeds below the starting speed, i.e., at extremely low speeds, a correction distance greater than the correction distance calculated at the starting speed is calculated.

[0042] This causes the neutral point to shift slightly further toward the side further away from the trailer. Therefore, in the absence of a control deviation, a greater distance exists between the neutral point and the side closer to the trailer. Subsequently, shaking or other instability during starting will not directly cause a collision between the connecting rod and other components of the trailer.

[0043] According to one embodiment, the trailer is characterized in that the control device is designed to activate the wheel drive and / or braking system only when the control deviation exceeds the allowable deviation.

[0044] The advantage of tolerance is that small control deviations will not immediately trigger the wheel drive and / or brakes. Small control deviations can occur, particularly due to uneven tensile loads on connecting rods. Uneven tensile loads are typical when the towing vehicle is a bicycle driven by the driver's pedals. Especially at high speeds, strong acceleration or deceleration is required to prevent even small control deviations at any given time. This places a load on the wheel drive and brakes. Therefore, by providing tolerance, the load on the wheel drive and brakes, as well as the entire trailer, is reduced.

[0045] According to one embodiment, the trailer is characterized in that the control device is designed to calculate an allowable deviation that is directly proportional to the determined travel speed.

[0046] At high speeds, it is advantageous to select a larger tolerance for deviation. In particular, at such speeds, the constant operation of the wheel drive and braking systems accelerates the wear of the aforementioned components.

[0047] According to one embodiment, the trailer is characterized by having a mechanical brake actuator that is designed to mechanically activate the braking device when the distance between the trailer and the connecting rod falls below a limit distance.

[0048] According to this embodiment, the trailer has a mechanical brake actuator for the braking system. The mechanical brake actuator functions as redundancy for the electrical operation of the braking system by the control device. The brake actuator is designed to be mechanically activated as soon as the connecting rod approaches the trailer beyond a critical distance. Specifically, this may be a very short distance between a portion of the connecting rod and, for example, an end stop. However, the brake actuator may also be formed by providing another device on the connecting rod, for example, a protruding catch and a corresponding stop on the trailer.

[0049] The advantage of a mechanical brake actuation system is that it provides effective braking even in the event of a power failure or excessive control lag of the trailer. This prevents collisions between the trailer and the towing device, thus preventing corresponding damage. Therefore, a mechanical brake actuation system enhances the safety of the trailer during operation.

[0050] According to one embodiment, the trailer has a mechanical brake actuation device, a) Equipped with a lever designed to reverse via a connecting rod as soon as the distance falls below the limit distance, b) comprising a cable connected to a braking device and a lever, and designed so that tension is applied when the lever is reversed.

[0051] According to this embodiment, the mechanical brake actuation device is designed as a cable. The cable is actuated by a lever that is reversed by a connecting rod when the distance falls below a critical distance. This type of embodiment is particularly reliable because it uses tested components.

[0052] Furthermore, this objective is achieved by the method of claim 10 for controlling the distance between a trailer equipped with at least one wheel, a wheel drive system, and a braking system, and a connecting rod designed to be connected to a towing system and movably mounted on the trailer. The method is, ● A step of measuring the relative position of the connecting rod to the trailer, ● A step of measuring the speed of the trailer and / or the speed of the connecting rod, ● A step of determining the travel speed based on the speed of the trailer and / or the speed of the connecting rod, ● A step of controlling the operation of the wheel drive system and / or braking system using control deviation. Includes, ●The neutral point position is shifted relative to the trailer from the zero point using the travel speed. ●The control deviation is calculated using the distance between the neutral point and the connecting rod.

[0053] The method is particularly suitable for implementation using the trailer according to the present invention. Furthermore, the above-mentioned advantages of the trailer and its embodiments according to the present invention apply similarly to the method and its embodiments.

[0054] According to one embodiment, the method is ● Move the connecting rod along its longitudinal axis toward the side closer to the trailer, or toward the side further away from the trailer. ●The neutral point is characterized by shifting it from the zero point located on the longitudinal axis, towards the side further away from the trailer along the longitudinal axis, by a correction distance directly proportional to the value obtained by subtracting the zero speed from the travel speed.

[0055] According to one embodiment, the method is characterized in that, when the determined driving speed is less than the starting speed which is lower than zero speed, the correction distance is calculated to be in a negative proportion relationship with the driving speed.

[0056] According to one embodiment, the method is characterized by activating the wheel drive system and / or braking system only when the control deviation exceeds the allowable deviation.

[0057] According to one embodiment, the method is characterized by calculating the allowable deviation in a relationship directly proportional to the driving speed.

[0058] According to one embodiment, the trailer is characterized by mechanically activating a braking device when the distance between the trailer and the connecting rod falls below a limit distance.

[0059] The present invention will be further described below based on exemplary embodiments. In the accompanying drawings, the figures are as follows: [Brief explanation of the drawing]

[0060] [Figure 1] Trailer and bicycle according to the present invention. [Figure 2] A diagram illustrating the functions of a trailer. [Figure 3] Schematic diagram of a distance measuring device. [Figure 4] A schematic diagram of the vibration distance between the trailer and the towing vehicle. [Figure 5] A schematic diagram of the correction distance as a function of the travel speed. [Modes for carrying out the invention]

[0061] Figure 1 shows a trailer 1 and a bicycle 2 according to the present invention. The trailer 1 and the bicycle 2 are connected by a connecting rod 3. The trailer has a wheel drive system, which is not specifically shown in this figure. The wheel drive system drives the trailer 1 so that it follows the bicycle 2 without the cyclist having to use any muscle strength.

[0062] Figure 2 shows a functional diagram of trailer 1. The functional diagram depicts an acceleration and deceleration device 4, which comprises a wheel drive system and a braking system. The energy required for driving is supplied by an energy source 5. In this process, the drive system and braking system are operated by a control device 6. The operation is carried out in such a way that the cyclist or another towing vehicle is as undetectable as possible to the fact that trailer 1 is following behind the bicycle. To ensure reliable and proper control, a distance measuring device 7 measures the distance between bicycle 2 and trailer 1. The distance is transmitted to the control device 6.

[0063] Figure 3 shows a schematic diagram of the distance measuring device 7. The distance measuring device 7 has a housing 8 that is rigidly connected to the body of the trailer 1. A connecting rod 9 protrudes into the housing. The connecting rod 9 is connected to a sliding part 10 that is movably fixed on a linear guide 11. The linear guide 11 defines the degrees of freedom that can be covered by the connecting rod 9 during relative movement to the housing 8. The degrees of freedom of movement of the connecting rod 9 is limited by the right-hand wall of the housing, and as soon as the connecting rod 9 moves to its maximum extent to the right, the connecting rod contacts the wall via a rubber end stopper 12. On the left side, the degrees of freedom of movement is limited by a rubber end stopper 13. The right side is the side further away from the trailer and corresponds to the side closer to the bicycle. Thus, the left side corresponds to the side closer to the trailer. The corresponding stops in the form of rubber end stops 12, 13 define the ends of the path further away from the trailer and the ends of the path closer to the trailer, where the path can be covered by the connecting rod 9.

[0064] The sensor target 14 is fixed on the connecting rod 9. The displacement transducer 15 allows confirmation of the relative position of the sensor target 14 with respect to the displacement transducer 15. The displacement transducer 15 and its coordinate system are rigidly connected to the housing 8, and by extension, to the trailer 1. Therefore, measuring the relative position of the sensor target 14 with respect to the displacement transducer 15 is equivalent to measuring the connecting rod 8 with respect to the trailer 1. The displacement transducer 15 is an inductive displacement transducer. The sensor target 14 and the displacement transducer 15 form a displacement sensor.

[0065] The control device 6 is designed to calculate the control deviation by subtracting the neutral point position from the measured position of the connecting rod. The control device 6 controls the wheel drive and braking systems based on the control deviation to accelerate or brake the trailer 1. The linear guide 11 allows the connecting rod 9 to move only along a predetermined path relative to the housing 8 and trailer 1, i.e., along the longitudinal axis of the connecting rod 9. The neutral point is also located along the longitudinal axis. Therefore, the control deviation can also be expressed as the distance along the longitudinal axis. The control deviation is positive or negative depending on whether the connecting rod approaches the neutral point on the side further away from the trailer or on the side closer to the trailer relative to the neutral point.

[0066] As the connecting rod 9 contacts the rubber end stop 13 closer to the trailer and continues to move toward the wall of the housing 8 closer to the trailer, the lever 16 reverses. At this time, the lever 16 rotates around the bearing point 17. The reversal of the lever 16 puts tension on the cable 18. The cable 18 is connected to the brakes of the trailer 1. The lever 16 and cable 18 form a mechanical brake actuator that activates the brakes as soon as the distance between the trailer 1 and the bicycle 2, and the connecting rod 8 connected to the bicycle 2, falls below the limit distance.

[0067] Figure 4 shows a schematic diagram of the vibration distance 19 between the trailer 1 and the towing vehicle 2 caused by the pedaling of the cyclist. Therefore, if this distance 19 is compensated for by accelerating or decelerating the trailer 1, a significant load will be placed on the drive train.

[0068] Figure 5 shows a schematic diagram of the correction distance as a function of the travel speed. The correction distance is shown on the horizontal axis and labeled "Position," and the travel speed is shown on the vertical axis and labeled "Speed." In this exemplary embodiment, the travel speed corresponds to the trailer speed, but it could also correspond to the bicycle speed or a calculated value of both speeds.

[0069] The correction distance is used for the shift of the neutral point along the longitudinal axis. Therefore, no control deviation exists even when the relative positions of the displacement transducer 15, the housing 8, or the connecting rod 9 with respect to the trailer 1 differ at various travel speeds.

[0070] The figure shows the positions of the connecting rod 9 where there is no control deviation at four different travel speeds. 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.

[0071] Figures for positions 21, 22, and 24 show that as the travel speed increases, the connecting rod 9 needs to move further to the right, further away from the trailer, so that no control deviation exists. This is due to the progression of the correction distance shown, which increases with increasing travel speed and is added to the zero position to calculate the neutral point. At zero speed 20, there is no correction distance. The zero point corresponds to the neutral point. In the illustrated state, the connecting rod 9 is located in the middle between the side closer to the trailer and the side further away from the trailer, and no control deviation occurs. The correction distance becomes positive above zero speed 20, and therefore the neutral point shifts further away from the trailer. Below zero speed 20, the neutral point shifts closer to the trailer. Therefore, to avoid any control deviation, the connecting rod 9 needs to be moved either closer to the trailer or further away from the trailer. Below starting speed 23, the correction distance increases again. Therefore, to avoid any control deviation, the connecting rod needs to move slightly further away from the trailer again.

[0072] The speed dependence of the correction distance means that at high speeds, the neutral point, and consequently the connecting rod 9, moves closer to the side further away from the trailer. As a result, if the bicycle 2 is braked before the connecting rod 9 contacts the end closer to the trailer in the form of the rubber end stopper 13, a large control deviation may occur. Conversely, the speed dependence of the correction distance means that at low speeds, the neutral point, and consequently the connecting rod 9, moves closer to the end closer to the trailer. As a result, if the bicycle 2 is accelerated, a large control deviation may occur before the connecting rod 9 contacts the end further away from the trailer in the form of the rubber end stopper 12.

[0073] Large control deviations are less susceptible to noise caused by mechanical and electronic errors in the components used. Therefore, large control deviations enable more precise control. At very low speeds, the correction distance is selected so that the neutral point is slightly further away from the side closer to the trailer, in order to compensate for sudden movements or vibrations during startup.

[0074] Figure 5 further illustrates the existence of a tolerance 26. The control deviation must be large enough that the position of the connecting rod 9 falls outside the relevant tolerance. This causes the control device 6 to activate the acceleration and deceleration devices 4. The tolerance 26 increases with increasing travel speed. The tolerance prevents the acceleration and deceleration devices from activating with relatively small control deviations. This prevents the acceleration and deceleration devices from being used and thus prevents wear. [Explanation of Symbols]

[0075] 1 trailer 2 Bicycles 3 Connecting rod 4. Acceleration and deceleration devices 5. Energy sources 6. Control device 7. Distance measuring device 8 Housing 9 connecting rod 10 Sliding part 11 Linear Guide 12. Rubber end stoppers further away from the trailer 13. Rubber end stoppers closer to the trailer 14 Sensor Targets 15 Displacement transducer 16 Lever 17 bearing points 18 Cables 19. Vibration distance 20 Zero Speed 21 Position at zero velocity 22 Position at high speed 23 Starting speed 24 Position at starting speed 25 Position at speeds below starting speed 26 Tolerance

Claims

1. A trailer (1) having at least one driven wheel, 〇 An energy source (5) designed to supply energy to the wheel drive system, A braking device for slowing down at least one wheel, A connecting rod (9) is designed to be connected to a towing device and is movably mounted on the trailer, A displacement sensor designed to measure the relative position of the connecting rod (9) with respect to the trailer (1), A speed measuring device designed to determine the travel speed based on measured speeds of the trailer and / or the connecting rod, 〇Electronic control unit (6) and Equipped with, The control device (6) is ■The design is such that the relative position of the neutral point with respect to the trailer (1) shifts from the zero point according to the determined travel speed. ■The control deviation is designed to be calculated using the distance between the position of the neutral point and the measured position of the connecting rod (9). ■A trailer (1) characterized in that it is designed to operate the wheel drive system and / or braking system using the control deviation.

2. The trailer (1) according to claim 1, characterized in that the displacement sensor is designed as an inductive displacement sensor, a capacitive displacement sensor, or a resistance-type displacement sensor.

3. The trailer (1) according to claim 1 or 2, characterized in that the connecting rod (9) is attached to the trailer (1) such that it is movable along its longitudinal axis toward the side closer to the trailer and also movable toward the side further away from the trailer.

4. The trailer (1) according to claims 1 to 3, characterized in that the control device (6) is designed to shift the neutral point toward a side further away from the trailer along the longitudinal axis from the zero point, located on the longitudinal axis, by a correction distance directly proportional to the value obtained by subtracting the zero speed from the determined travel speed.

5. The trailer (1) according to claims 1 to 4, characterized in that the control device (6) is designed to calculate the correction distance such that, when the determined speed is less than the starting speed which is lower than the zero speed, the correction distance is in a negative proportion relationship with the value obtained by subtracting the zero speed from the determined travel speed.

6. The trailer (1) according to any one of claims 1 to 5, characterized in that the control device (6) is designed to activate the wheel drive device and / or the braking device only when the control deviation exceeds the allowable deviation.

7. The trailer (1) according to claims 1 to 6, characterized in that the control device (6) is designed to calculate the allowable deviation in a relationship directly proportional to the determined travel speed.

8. A trailer (1) according to any one of claims 1 to 7, characterized in that a mechanical brake actuation device is provided, which is designed to mechanically activate the braking device when the distance between the trailer (1) and the connecting rod (9) falls below a limit distance.

9. The aforementioned mechanical brake actuation device is The system includes a lever (16) that is designed to be reversed by the connecting rod (9) as soon as the distance falls below the limit distance, The trailer (1) according to claims 1 to 8, characterized by comprising a cable (18) connected to the braking device and the lever (16), and designed so that tension can be applied when the lever (16) is reversed.

10. A method for controlling the distance between a trailer (1) having at least one wheel, a wheel drive system, and a braking system, and a connecting rod (9) designed to be connected to a towing system and movably mounted on the trailer (1), ○ A step of measuring the relative position of the connecting rod (9) with respect to the trailer (1), ○ A step of measuring the speed of the trailer (1) and / or the speed of the connecting rod (9), ○ A step of determining the travel speed based on the speed of the trailer (1) and / or the speed of the connecting rod (9), The steps include controlling the operation of the wheel drive system and / or braking system using the control deviation, and Includes, The position of the neutral point is shifted relative to the trailer (1) from the zero point using the aforementioned travel speed. A method characterized by calculating the control deviation using the distance between the position of the neutral point and the position of the connecting rod.

11. ○ Move the connecting rod (9) along its longitudinal axis toward the side closer to the trailer, or move it toward the side further away from the trailer. The method according to claim 10, characterized in that the neutral point is shifted along the longitudinal axis from the zero point toward the side further away from the trailer by a correction distance directly proportional to the value obtained by subtracting the zero speed from the travel speed.

12. The method according to claim 11, characterized in that, if the determined driving speed is less than the starting speed which is lower than the zero speed, the correction distance is calculated to be in a negative proportion relationship with respect to the driving speed.

13. The method according to any one of claims 10 to 12, characterized in that the wheel drive device and / or the braking device are activated only when the control deviation exceeds the allowable deviation.

14. The method according to claims 1 to 13, characterized in that the allowable deviation is calculated to be in direct proportion to the driving speed.

15. The method according to any one of claims 10 to 14, characterized in that the braking device is mechanically activated when the distance between the trailer and the connecting rod falls below a limit distance.

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