Coupling a trailer to a tractor

Abstract

The invention relates to a method (400) for assisting a process of coupling a tractor (105) to a trailer (110), comprising steps of measuring (410) a relative roll angle (210) between the tractor (105) and the trailer (110); and providing (420) a warning signal (308) if a value of the measured relative roll angle (210) exceeds a predetermined threshold (240).

Description

[0001] Coupling a semi-trailer to a tractor

[0002] The present invention relates to a commercial vehicle comprising a tractor with a semi-trailer. In particular, the present invention relates to the coupling of the semi-trailer to the tractor.

[0003] A commercial trailer for road transport has one or more axles with road wheels at its rear end and is designed at its front end to rest on and be pulled by a tractor unit. Such a trailer is also known as a semi-trailer, semi-trailer, or semi-trailer. The tractor unit can also be called a tractor unit. During coupling, the trailer initially rests on support legs at the front. The tractor unit reverses under the trailer and raises it, thus relieving the load on the support legs. The tractor unit can be coupled to the trailer, and the support legs can be retracted.

[0004] To increase the utilization of the tractor unit, it is desirable to automate the coupling process between the tractor unit and the trailer. This can involve force-locking the two vehicles together. Furthermore, an electrical connection, a communication connection, or a compressed air connection can be established between the tractor unit and the trailer.

[0005] If the ground is uneven, the tractor and / or the trailer may be tilted at different angles during the coupling process, which may disrupt the establishment of one of the connections between the tractor and the trailer.

[0006] WO 2022 / 077063 A1 relates to a technique for loading or unloading a vehicle trailer with loading ramps attached to the rear of the vehicle. In order to enable another vehicle to safely drive over the loading ramps even on sloping ground, it is proposed to make the lengths of the loading ramps as well as the pitch and roll angles of the vehicle trailer controllable. One object of the present invention is to provide an improved technique for carrying out a coupling process between a semi-trailer and a tractor. The invention solves this problem by means of the subject matter of the independent claims. Subclaims specify preferred embodiments.

[0007] According to a first aspect of the present invention, a method for assisting a coupling operation of a tractor to a trailer comprises steps of detecting a relative roll angle between the tractor and the trailer; and providing a warning signal if an amount of the detected relative roll angle exceeds a predetermined threshold.

[0008] The absolute roll angle of a vehicle is typically defined as the orientation of the vehicle around its longitudinal axis. A vertical line, whose direction corresponds to that of gravity, is used as a reference. When the vehicle is upright, the absolute roll angle is 0°.

[0009] A relative roll angle between the tractor and the trailer refers to a deviation in the alignment of the two vehicles about their roll axes. In other words, the relative roll angle can indicate how much one of the vehicles is twisted relative to the other about its longitudinal axis. The relative roll angle can also be determined if the longitudinal axes of the vehicles do not intersect at a single point or are offset from each other. The relative roll angle can be measured directly between the vehicles. Alternatively, the absolute roll angles of both vehicles can be determined and subtracted from each other. For example, if the tractor is tilted by +5° and the trailer by -5° from the vertical, the relative roll angle can be 10°.

[0010] The coupling process here is defined as moving the tractor unit towards the semi-trailer, preferably including coupling, i.e. the frictional connection of the two vehicles to one another. A fifth wheel coupling can be attached to the tractor unit and a king pin to the semi-trailer, and coupling can involve closing the fifth wheel coupling with the king pin inserted. It has been recognized that the relative roll angle between the vehicles is less important for a safe coupling process than the absolute roll angle of one of the vehicles relative to the ground. In practice, for example, it can happen that the semi-trailer is not in a vertical position for a coupling process, for example because the ground has given way unevenly after it was parked due to rain or snow.Likewise, the tractor may be oriented differently than vertically during the coupling process, for example, due to an uneven surface or a structural feature of the ground. In such cases, monitoring the relative roll angle can help ensure a safe coupling process.

[0011] The warning can be directed to an automatic control system for the coupling process or to a person controlling the coupling process. During an automatic coupling process, the warning signal can prevent the vehicles from approaching further or from coupling up. Likewise, the lifting of the trailer's support legs can be prevented. The warning can prevent damage to one of the vehicles during the coupling process. In particular, it can prevent damage to an element of an automatic electrical or pneumatic coupling between the vehicles due to a lack of alignment between the tractor and the trailer. The relative roll angle can be monitored selectively, periodically, or continuously during a coupling process.

[0012] In one embodiment, a force-locking coupling of the tractor unit to the trailer is only enabled if the magnitude of the detected relative roll angle is below the predetermined threshold. In particular, a lock between the tractor unit and the trailer can be held in the open position. This prevents tractive forces from being transferred between the vehicles, which are twisted too far relative to each other about their longitudinal axes and therefore potentially unstable. If coupling is enabled, the force-locking connection of the tractor unit to the trailer can be controlled manually or automatically. The relative roll angle can also be reduced automatically. This can occur in all cases or only when the magnitude of the roll angle exceeds its assigned threshold. Preferably, the relative roll angle is continuously measured during a coupling process.This allows for the fact that the tractor unit may change its absolute roll angle when approaching the trailer, for example when driving over a threshold or through a depression.

[0013] It is preferred that reducing the relative roll angle comprises unilaterally raising and / or lowering one of the vehicles on a left or right side. This allows the affected vehicle to be rotated about its longitudinal axis, such that its absolute roll angle is changed. In particular, the absolute roll angle of one of the vehicles can be brought closer to the roll angle of the other vehicle in order to reduce the relative roll angle. It is also possible to rotate both vehicles in opposite directions about their respective longitudinal axes. For this purpose, for example, the tractor unit can be raised on its left side and the trailer on its right side. Preferably, not only the relative roll angle is minimized, but the amounts of both absolute roll angles are minimized. This allows the two vehicles to be better aligned both with respect to one another and with the vertical.

[0014] In one embodiment, a left and a right support leg are attached to the trailer, which can be retracted or extended independently of each other. Reducing the relative roll angle involves retracting or extending one of the support legs.

[0015] In one embodiment, to control the roll angle of the semi-trailer, only one of its support legs can be extended or retracted while the other remains stationary. In another embodiment, the support legs can also be extended or retracted in opposite directions simultaneously. In both embodiments, the semi-trailer can be uprighted or its absolute roll angle can be adjusted to an absolute roll angle of the tractor. Reducing the amount of the relative roll angle can also involve tilting a coupling device of the tractor about the longitudinal axis of the tractor. A fifth wheel plate can be attached to the tractor, on which the front end of the semi-trailer rests when coupled. A coupling for connecting the tractor to the semi-trailer in a tractive force-locking manner can be arranged on the fifth wheel plate, so that it can be referred to as a fifth wheel coupling plate.The coupling device can be controlled, for example, pneumatically or hydraulically in its orientation around the longitudinal axis of the tractor. The roll angle of the tractor can be relative to the fifth wheel plate, and the relative roll angle can indicate a difference between the roll angle of the fifth wheel plate and the roll angle of the semi-trailer.

[0016] A discrepancy between the pitch angles of the semi-trailer and the tractor unit is usually compensated for by a joint in the fifth wheel coupling. This allows for compensation for deviations that occur during travel, for example when driving through a dip. However, height differences caused by a discrepancy in the pitch angle or that generally exist when coupling the fifth wheel coupling plate to the semi-trailer are problematic. This can lead to an air gap between the coupling device of the tractor unit and the trailer, thus causing the coupling process to fail or even causing damage to the coupling device. For this purpose, a relative height between the tractor unit and the semi-trailer can optionally be determined. A warning signal can be issued if the determined relative height lies outside a predetermined range.Due to the warning signal, an automatic docking procedure may be interrupted or aborted as described herein with respect to an excessive roll angle.

[0017] The detected relative height can further preferably be automatically controlled within the predetermined range. A vehicle can be raised or lowered only at the rear, only at the front, or both at the front and rear. Preferably, at least one of the vehicles is raised or lowered at an end facing the other vehicle. Advantageously, the same actuators that can also be used to minimize the relative roll angle can be used to compensate for the relative height. Coupling the tractor unit with the trailer can only be enabled once the relative height has also fallen below a predetermined value.

[0018] In a further preferred embodiment, the adjustment of the relative roll angle and the adjustment of the relative height can also be performed simultaneously. For example, if the trailer is to be rotated counterclockwise along its longitudinal axis, the right support leg can be extended and / or the left one retracted. If the trailer is to be raised at the front, both support legs can be extended. Both maneuvers can be combined by extending the right support leg and leaving the left one either stationary or also extended.

[0019] The relative height is preferably related to the coupling device and refers to the mutual height deviation of the vehicles. The relative height can be zero if the upper edge of the coupling device is exactly level with the lower edge of the semi-trailer. The range can extend upwards and / or downwards from this height.

[0020] A coupling operation can be carried out safely if the upper edge of the coupling device is a predetermined amount lower than the lower edge of the semi-trailer, allowing the tractor to drive underneath the semi-trailer. However, a coupling operation can also be carried out if the upper edge of the coupling device is a few millimeters higher than the lower edge of the semi-trailer before the tractor approaches the semi-trailer, allowing the semi-trailer to be slightly lifted by reversing. In both cases, however, a predetermined distance from the relative height of zero must not be exceeded.

[0021] The invention can be implemented by means of a control system. According to a further aspect of the present invention, a control system for supporting a coupling process between a semitrailer and a tractor comprises a sensing device for determining a relative roll angle between the tractor and the semitrailer; and a control device for providing a warning signal if the magnitude of the relative roll angle exceeds a predetermined threshold. The control device can be configured to carry out a method described herein in whole or in part. For this purpose, the processing device can be implemented electronically and comprise a programmable microcomputer or microcontroller, and the method can be in the form of a computer program product with program code means. The computer program product can also be stored on a computer-readable data carrier.Features or advantages of the method can be transferred to the device or vice versa.

[0022] In one embodiment, the control system comprises an actuator for controlling a roll angle of the tractor and / or the trailer. An actuator for controlling a height of the tractor and / or the trailer may also be provided. The actuators may also be integrated with one another.

[0023] According to yet another aspect of the present invention, a vehicle comprises a control system described herein. The vehicle may, in particular, comprise a tractor and / or a trailer.

[0024] Yet another aspect of the present invention relates to a vehicle system comprising a tractor and a semi-trailer. The vehicle system, which may also be referred to as a semi-trailer, comprises a control system as described herein. The control system may be configured to support an automatic coupling process of the semi-trailer to the tractor. Components comprised by the control system may be provided alternatively on the tractor and / or on the semi-trailer.

[0025] The invention will now be described in more detail with reference to the accompanying figures, in which:

[0026] Figure 1 shows a vehicle system with a tractor and a semi-trailer;

[0027] Figure 2 shows an exemplary relative position of a tractor unit in relation to a semi-trailer;

[0028] Figure 3 a control system; and

[0029] Figure 4 shows a flow diagram of a first method.

[0030] Figure 1 shows a vehicle system 100 comprising a tractor unit 105 and a trailer 110. The tractor unit 105 can be separated from the trailer 110, for example, to be connected to another trailer 110. A vertical dashed line indicates the point at which the vehicles 105, 110 can be separated from each other. Connecting the vehicles 105, 110 is referred to as coupling, and separating them is referred to as uncoupling.

[0031] During coupling, the vehicles 105, 110 are positioned on a surface 115 that is ideally flat and horizontal, but in practice is occasionally inclined, uneven, or capable of varying loads. A technique described herein relates to a coupling process between the vehicles 105, 110, even under such difficult conditions. The tractor 105 is brought closer to the trailer 110 until the vehicles 105, 110 can be coupled together.

[0032] Figure 2 shows an exemplary relative position of a tractor 105 relative to a trailer 110. The view shown corresponds to a longitudinal section through the vehicle system 100 of Figure 1 along a plane containing the dashed line. The vehicles 105, 110 are each symbolized here as squares. Each square is bisected both longitudinally and transversely by a dashed line, with a longitudinal axis 202 of the associated vehicle 105, 110 running through an intersection point of the dashed lines.

[0033] It can be seen that the squares representing the vehicles 105, 110 are each rotated by an absolute roll angle 205 relative to a vertical. As a result, the vehicles 105, 110 are rotated relative to each other by a relative roll angle 210. The absolute roll angles 205 are opposite to each other, whereby the relative roll angle 210 can be determined as the difference between the absolute roll angles 205. If the relative rotation is strong enough so that an amount of the relative roll angle 210 exceeds a predetermined threshold value, large forces can occur when coupling the tractor 105 to the trailer 110, which can endanger the stability of the vehicles 105, 110.

[0034] Also shown in Figure 2 is a relative height 215 between the tractor unit 105 and the trailer 110. The relative height 215 is represented here as the vertical distance between the longitudinal axes 202 of the vehicles 105 and 110. In order to drive the tractor unit 105 to the trailer 110, it can be ensured that the relative height 215 lies within a predetermined range, in which a relative height 215 is usually zero. The view is taken in the direction of travel of the vehicles 105, 110, so that a left side 203 is on the left and a right side 204 is on the right.

[0035] It should be noted that in practice, the longitudinal axes 202 of the vehicles 105, 110 are rarely exactly aligned with each other, but rather enclose an angle with each other or are horizontally offset by a certain amount. The determination of the relative roll angle 210 or the relative height 215 in the area of ​​a coupling device between the tractor 105 and the trailer 110 can nevertheless be carried out in a manner described herein. Minor disturbances or inconsistencies in the determination of the relative roll angle or the relative height can be neglected.

[0036] Regarding values ​​and their comparison, a representation is shown in the right-hand section of Figure 2. A value 225 is determined on a predetermined scale 220. A value 225 that lies above the line designated zero is positive; a value 225 below it is negative. The absolute value 230 of a positive value 225 corresponds to the unchanged value 225; that of a negative value 225 corresponds to its value 225 multiplied by (-1).

[0037] A value 225 can be compared to a range 235. It can be determined whether the value 225 lies within or outside the range 235. Boundaries of the range 235 can be included in the range 235 or excluded from it. A value 225 can also be compared to a threshold 240. It can be determined whether the value 225 lies below, at, or above the threshold 240. Figure 3 shows an exemplary control system 300 for supporting an automatic coupling process of a tractor 105 to a trailer 110. The illustrated control system 300 is, by way of example, largely symmetrically constructed, in that some components are provided on both the tractor 105 and the trailer 110. However, it may also be sufficient to provide such a component only on one side, i.e., only on the tractor 105 or only on the trailer 110.It should also be noted that some components of the tractor 105 and the trailer 110 that perform the same function with respect to the technology proposed herein may be implemented differently, as will be described in more detail below.

[0038] In the illustrated embodiment, the control system 300 on the tractor 105 side comprises a control device 305, a first sensor 310, a second sensor 315, and a first actuator 320 and a second actuator 325. In some embodiments, only one sensor 310, 315 or only one actuator 320, 325 is provided. Further preferably, an interface 330 is provided for communication with a component on the trailer 110 side. The interface 330 can be implemented wired or wirelessly.

[0039] The control device 305 can comprise a conventional control unit with a processing device. Optionally, the control device 305 is configured to perform tasks other than those described herein. It is also preferred that the control device 305 be connected to another component on board the tractor 105, in particular to allow interaction with the other component or a person. Further preferably, the control device 305 is configured to output a warning signal 308. In one embodiment, the warning signal 308 can be output to a control unit or control system via an interface. In another embodiment, the warning signal 308 can be output to a person in the area of ​​the vehicle system 100, in particular to a driver of the tractor 105.

[0040] The first sensor 310 is preferably fixedly attached to the tractor 105 and configured to scan the trailer 110. Scanning is more preferably performed contactlessly, for example, using an ultrasonic sensor, a radar sensor, or a LiDAR sensor. Optionally, a signal generator, a marker, or a reflective element is attached to the trailer 110 to facilitate scanning by the first sensor 310. A marker can be made of a retroreflective material, for example. The first sensor 310 can determine a relative orientation of the trailer 110 with respect to the tractor 105. The first sensor 310 is preferably provided in the region of a coupling device between the tractor 105 and the trailer 110.

[0041] The second sensor 315 may comprise an acceleration sensor, an inertial platform, or a similar sensor configured to determine an absolute roll angle of the tractor 105 with respect to the Earth's gravitational field. Optionally, the second sensor 315 may be sensitive about multiple axes and thus also determine a pitch angle or a yaw angle of the tractor 105.

[0042] The first actuator 320 is configured to control the height of a rear end of the tractor 105. Preferably, two first actuators 320 are provided, which can be operated independently of one another to raise or lower the rear end of the tractor 105 on the left and right, independently of the other side. Purely by way of example, the first actuator 320 is depicted as an air bellows of a pneumatic vehicle. Other implementations are also possible.

[0043] The second actuator 325 is configured to influence the height and / or roll angle of a coupling element for the semitrailer 110 on the tractor 105. The coupling element comprises, for example, a fifth wheel plate 335, which is preferably designed as a fifth wheel coupling plate. The second actuator 325 comprises, for example, two pneumatic or hydraulic actuators, one of which is provided on the left side 203 and one on the right side 204 of the tractor 105. Other embodiments are also possible here.

[0044] In the embodiment shown, the semitrailer 110 is provided with a control device 305, a first sensor 310, a second sensor 315, and a first actuator 320, corresponding to the tractor unit 105. The functions of these components are described with reference to the components on the tractor unit 105 and can be applied accordingly on the semitrailer 110. Two support legs 340 can be provided on the semitrailer 110, one of which is mounted at the front left in the direction of travel and the other at the front right in the direction of travel. The support legs 340 are designed to support a load in a front region of the semitrailer 110 relative to the ground 115 when the front of the semitrailer 110 is not resting on the fifth wheel plate 335 of the tractor unit 105. A support leg 340 can be retracted or extended, for example, pneumatically, hydraulically, or by electric motor.It is particularly preferred that the left support leg 340 and the right support leg 340 can each be retracted and extended independently of one another. Even more preferably, an associated load sensor 345 is provided on each of the support legs 340, which is configured to determine a load of the trailer 110 acting on the support leg 340.

[0045] Figure 4 shows a flowchart of a method 400 for supporting a coupling process between a tractor unit 105 and a trailer 110. In a step 405, a request for automatic coupling can be determined. At this point in time, the tractor unit 105 and the trailer 110 are not connected to each other and are within a shunting distance, which can be, for example, a few decimetres to a few metres. In another embodiment, a manually controlled coupling process can be initiated in this step.

[0046] In a step 410, a relative roll angle 210 and / or a relative height 215 between the tractor 105 and the trailer 110 can be determined. In a step 415, it can be determined whether the relative height 215 is within an adjustment range that can be overcome by actuators 320, 325, 340.

[0047] If the relative height 215 exceeds the setting range, a warning can be provided in a step 420. The warning can be provided to a person performing the coupling process or to a controlling system. Conditions for an automatic coupling process can then be improved, for example, by filling or supporting the ground 115. As part of an automatic coupling process, actuations of actuators 320, 325, 340 can be stopped in step 420. The method 400 can end unsuccessfully in a step 425, in which the tractor 105 and the trailer 110 are free and not coupled to one another.

[0048] If it is determined in step 415 that the relative altitude is within the adjustment range, a step 430 may determine whether the determined relative roll angle 210 is less than a predetermined tolerance. If this is not the case, a step 435 may determine whether a control system 300 is available for the relative roll angle 210. If no control system 300 is available, the method 400 may end via step 420 in step 425.

[0049] Otherwise, in a step 440, it can be determined whether the relative roll angle 210 is less than a predetermined adjustment range of the control system 300. Again, the method 400 via step 420 can terminate unsuccessfully in step 425 if the relative roll angle 210 exceeds the predetermined adjustment range. Otherwise, in a step 445, the relative roll angle 210 can be adjusted by actuating at least one of the actuators 320, 325, 340 such that the relative roll angle 210 is reduced.

[0050] In step 450, it can be determined whether the relative height deviation 215 lies outside a predetermined range. In this case, the relative height deviation 215 can be minimized. This step can also be started directly from step 430 if it was determined there that the relative roll angle is smaller than the predetermined tolerance. In step 450, at least one of the actuators 320, 325, 340 can be controlled such that the height deviation is controlled within the predetermined range or approximated to a predetermined value 225 within the range.

[0051] In a step 455, it can be determined whether the relative altitude deviation 215 and / or the relative roll angle 210 have satisfactorily approximated the respective specifications. If this is not the case, the method 400 can branch to step 410 and continue from there.

[0052] Otherwise, method 400 may end in a step 460, in which tractor 105 and trailer 110 may be coupled to each other. For this purpose, a coupling device may be released. In one embodiment, coupling device 335 may be automatically closed to connect tractor 105 to trailer 110 in a traction-locking manner.

[0053] The tractor 105 can then be raised so that the trailer's support legs 340 can be relieved and retracted. The vehicle system 100 can then be ready for operation.

[0054] Reference symbols (as part of the description):

[0055] 100 vehicle system

[0056] 105 tractor

[0057] 110 trailers

[0058] 115 Underground

[0059] 202 Longitudinal axis

[0060] 203 left side

[0061] 204 right side

[0062] 205 absolute roll angle

[0063] 210 relative roll angle

[0064] 215 relative height

[0065] 220 scale

[0066] 225 value

[0067] 230 Amount

[0068] 235 area

[0069] 240 threshold

[0070] 300 tax system

[0071] 305 Control device

[0072] 308 warning signal

[0073] 310 first sensor

[0074] 315 second sensor

[0075] 320 first actuator

[0076] 325 second actuator

[0077] 330 interface

[0078] 335 saddle plate

[0079] 340 support leg

[0080] 345 load sensor

[0081] 400 procedures

[0082] 405 Request for automatic coupling determine relative roll angle and relative altitude relative altitude < setting range?

[0083] stop

[0084] Tractor and trailer free relative roll angle < tolerance?

[0085] Is the relative roll angle control system available? Is the relative roll angle < setting range? Set the relative roll angle

[0086] Adjusting the height deviation finished?

[0087] Release or establish clutch

Claims

Patent claims: 1 . Method (400) for assisting a coupling process of a tractor (105) with a semi-trailer (110), the method (400) comprising the following steps: - detecting (410) a relative roll angle (210) between the tractor (105) and the trailer (110); and - Providing (420) a warning signal (308) if an amount (230) of the detected relative roll angle (210) exceeds a predetermined threshold value (240).

2. Method (400) according to claim 1, wherein a force-locking coupling (335) of the tractor (105) with the trailer (110) is only released if the magnitude of the relative roll angle (210) is below the predetermined threshold value (240).

3. The method according to claim 1 or 2, wherein the relative roll angle (210) is automatically reduced (445).

4. The method of claim 3, wherein reducing (445) the relative roll angle (210) comprises unilaterally raising and / or unilaterally lowering one of the vehicles (105, 110) on a left (203) or right side (204).

5. The method (400) of any one of claims 4, wherein the trailer (110) has left and right support legs (340) mounted thereon, which can be retracted or extended independently of one another; wherein reducing (445) the relative roll angle (210) comprises retracting or extending one of the support legs (340).

6. The method (400) according to any one of claims 4 or 5, wherein a coupling device (335) of the tractor (105) is inclined about the longitudinal axis (202) of the tractor (105).

7. Method (400) according to one of the preceding claims, wherein a relative height (215) between the tractor (105) and the trailer (110) is determined (410); wherein a warning signal (308) is provided if the relative altitude (215) is outside a predetermined range (235).

8. The method (400) of claim 7, wherein at least one of the vehicles (105, 110) is raised or lowered at an end facing the other vehicle (105, 110) to control (450) the relative height (215) into the predetermined range (235).

9. The method (400) of claim 8, wherein the relative height (215) is approximated to a predetermined value (225) within the range (235).

10. A control system (300) for supporting a coupling process between a semi-trailer (110) and a tractor (105), the control system (300) comprising: - a sensing device (310) for determining a relative roll angle (210) between the tractor (105) and the trailer (110); and - a control device (305) for providing a warning signal (308) if an amount (230) of the relative roll angle (210) exceeds a predetermined threshold value (240).

11. A vehicle (105, 110) comprising a control system (300) according to claim 10.

12. A vehicle system (105, 110) comprising a tractor (105) and a trailer (110) and a control system (300) according to claim 10.

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