A drive unit for a trailer, vehicle combination comprising a drive unit and a trailer and a control system for controlling propulsion and steering of a drive unit

Abstract

The invention relates to a drive unit (1) for a trailer, a vehicle combination (8) comprising a drive unit (1) and a trailer (9) and a control system (10) for controlling propulsion and steering of said drive unit (1).

Description

[0001] A DRIVE UNIT FOR A TRAILER, VEHICLE COMBINATION COMPRISING A DRIVE UNIT AND A TRAILER AND A CONTROL SYSTEM FOR CONTROLLING PROPULSION AND STEERING OF A DRIVE UNIT

[0002] TECHNICAL FIELD

[0003] The invention relates to a drive unit for a trailer, a vehicle combination comprising a drive unit and a trailer and a control system for controlling propulsion and steering of said drive unit.

[0004] BACKGROUND ART

[0005] Automation is in general related to highly repetitive operations with a need for high capacity. When it comes to transportation of goods there are standardizations of specific units that create productivity gains in the transportation over different categories, for example air, sea, rail and on-road. One of the most common types is the 20 foot and 40-foot container.

[0006] Even though automation is on the rise, the design of the tractor, truck or other types of prime movers have not changed much. Much of the repetitive operations are performed within an enclosed space such as a port, warehouse or construction site. In these enclosed spaces, having a vehicle that is easy to turn while transporting the containers is beneficial.

[0007] There is thus room for improvement in this field.

[0008] SUMMARY

[0009] An object of the present disclosure is to provide a drive unit for a trailer, a vehicle combination comprising a drive unit and a trailer and a control system for controlling propulsion and steering of said drive unit that seeks to mitigate, alleviate, or eliminate one or more of the aboveidentified deficiencies in the art and disadvantages singly or in any combination.

[0010] This object is obtained by a drive unit for a trailer, wherein the drive unit, in a first aspect, comprises:

[0011] - a frame comprising at least one pair of wheels arranged on either transverse side of the frame,

[0012] - a power source arranged on the frame arranged to provide power to the drive unit,

[0013] - an electronic control unit arranged to control propulsion and steering of the drive unit,

[0014] - at least one steering actuator comprising a drive unit end connected to a steering arrangement on the frame and a trailer end arranged to be disconnectedly attached to a trailer, - at least one steering actuator comprising a steering end arranged to be connected to a rotatable steering arrangement that is rotatably movable relative the drive unit and is attached to a trailer, and a motor end arranged to be disconnectedly attached to the drive unit,

[0015] - wherein providing the steering actuator with a retract or extend command from the electronic control unit, turns the drive unit by the steering actuator pushing on the frame of the drive unit rotatable steering arrangement such that the drive unit rotates relative the rotatable steering arrangement. A drive unit according to the invention allows for significant productivity gains for road transportation and the focus has been to take an outside-in approach based on the basics for high capacity, repetitive transports, which is two 20-foot container or one 40-foot container. The drive unit has a low profile and is very space efficient, leading to that the drive unit can operate within small spaces. Furthermore, by having an actuator pushing and pulling on the frame to steer, steering is made simple and cost-effective.

[0016] The electronic control unit may be arranged to receive control commands to be executed by the electronic control unit of the drive unit by remote control, by a teleoperator or by an autonomous drive system.

[0017] The steering end may be rotatably movable around a vertical axle relative the drive unit. The vertical axle may extend vertically (e.g. using ground or vehicle platform / undercarriage main surface as a reference).

[0018] In this way, the electronic control unit is adaptable towards several different ways of communication to receive commands.

[0019] The steering actuator may be an electro-mechanical actuator or a hydraulic actuator. These types of actuators have been shown to be most efficient with regards to power to weight ratio and ease of use. Other types of actuators are of course also possible.

[0020] The power source may be a fuel cell, battery or a combustion engine. The drive unit may be powered by any suitable power source that can provide electric power and power to drive the wheels of the drive unit.

[0021] When the power source is a battery, the drive unit may comprise a DC / DC-converter. In order to be able to provide the correct voltage level to the different components of the drive unit, one or more DC / DC-converters may be installed on the drive unit. An example may be a DC / DC- converter from 400V (standard voltage for current vehicle batteries) to 80V / 86V (common voltage for electro-mechanical actuators).

[0022] The drive unit may comprise at least two pairs of wheels arranged on the frame. In this way, greater loads can be driven by the drive unit.

[0023] The forward-most pair of wheels may be steerable. In this way, the steering of the drive unit can be made easier and be made more precise.

[0024] The drive unit further may comprise a compressor arranged in the frame for changing a pressure of an air suspension of one pair of wheels. In this way, the total friction between the wheels and the ground can be reduced to simplify turning the drive unit.

[0025] The electronic control unit of the drive unit is software defined / driven Accordingly, the electronic control unit may be software-implemented having control circuitry, a memory unit, input / output interfaces and any other module / interface as appreciated by a skilled person in the art. As long as the software is running, the drive unit is operational. Should any software failure or communication failure of the electronic control unit be identified, the drive unit will stop operating as a safety measure and come to a safe stop. In other words, the electronic control unit may rely on the software to remain operational, having a software-controlled failsafe system / feature / module / unit. Further, by having the electronic control unit be software defined adds to the flexibility of the drive unit as additional features can be added by upgrading the software of the electronic control unit or adding new software.

[0026] This object is further obtained by a vehicle combination comprising a drive unit according to the above description, wherein the drive unit connected to a trailer by that the rotatable steering arrangement is rotatably attached to the drive unit.

[0027] An advantage with this is that the drive unit and trailer make up a unit that can transport standard 20-foot and 40-foot ISO containers as well as other types of cargo transportable by trailer. The vehicle combination is for instance suitable for use in ports, between larger warehouses and similar.

[0028] The at least one steering actuator may be arranged in a forward direction and connected to a forward connection point of the trailer. The at least one steering actuator may alternatively be arranged in a rearward direction and connected to a rearward connection point of the trailer. This makes the drive unit flexible in its attachment to a trailer and the way the drive unit is attached can be chosen depending on the type of trailer and cargo to be transported on the trailer.

[0029] The trailer may comprise a battery pack for driving one or more axles of the trailer. In addition to the power source of the drive unit, the trailer may itself have a power source connected to one or more motors for driving one or more of its axles. Other power sources such as fuel cells are also possible.

[0030] An auxiliary trailer can be connectable to the trailer of the vehicle combination. In this way, the drive unit may drive two trailers with the same or different cargo loaded onto them. The trailers may have the same or different lengths and use connection systems between them known in the art.

[0031] This object is further obtained by a control system for controlling propulsion and steering of a drive unit according to the above description. The control system is arranged to be implemented in an electronic control unit connected to at least one steering controller, wherein the at least one steering controller is arranged to provide control output signal to a steering actuator, wherein the electronic control unit is arranged to receive control input signals from a control input source.

[0032] The control input source may be selectable in the electronic control unit and may be one of:

[0033] - Radio remote control,

[0034] - Teleoperator,

[0035] - Autonomous drive system.

[0036] This allows for flexibility of use of a drive unit containing such a control system.

[0037] There is also provided another aspect of the drive unit. In order to avoid undue repetition, the advantages and benefits of corresponding features of the first aspect will not be repeated for the second aspect. As appreciated, the corresponding features of the second aspect may comprise common advantages and benefits as the features of the first aspect.

[0038] The second aspect discloses a drive unit that comprises:

[0039] - a frame comprising at least one pair of wheels arranged on either transverse side of the frame,

[0040] - a power source arranged on the frame arranged to provide power to the drive unit, - an electronic control unit arranged to control propulsion and steering of the drive unit,

[0041] - at least one steering actuator comprising a drive unit end connected to a steering arrangement on the frame and a trailer end arranged to be disconnectedly attached to a trailer,

[0042] - wherein providing the steering actuator with a retract or extend command from the electronic control unit turns the drive unit by the steering actuator pushing on the frame.

[0043] The electronic control unit may be arranged to receive control commands to be executed by the electronic control unit of the drive unit by remote control, by a teleoperator or by an autonomous drive system.

[0044] The steering actuator may be an electro-mechanical actuator or a hydraulic actuator. Other types of actuators are of course also possible.

[0045] The power source may be a fuel cell, battery or a combustion engine. The drive unit may be powered by any suitable power source that can provide electric power and power to drive the wheels of the drive unit.

[0046] When the power source is a battery, the drive unit may comprise a DC / DC-converter. In order to be able to provide the correct voltage level to the different components of the drive unit, one or more DC / DC-converters may be installed on the drive unit. An example may be a DC / DC- converter from 400V (standard voltage for current vehicle batteries) to 80V / 86V (common voltage for electro-mechanical actuators).

[0047] The drive unit may comprise at least two pairs of wheels arranged on the frame.

[0048] The forward-most pair of wheels may be steerable.

[0049] The drive unit further may comprise a compressor arranged in the frame for changing a pressure of an air suspension of one pair of wheels.

[0050] The electronic control unit of the drive unit is software defined. As long as the software is running, the drive unit is operational. Should any software failure or communication failure of the electronic control unit be identified, the drive unit will stop operating as a safety measure and come to a safe stop. There is further provided a vehicle combination comprising a drive unit according to the second aspect, wherein the drive unit connected to a trailer by that a trailer end of the at least one steering actuator is arranged to be disconnectedly attached to the trailer.

[0051] The at least one steering actuator may be arranged in a forward direction and connected to a forward connection point of the trailer. The at least one steering actuator may alternatively be arranged in a rearward direction and connected to a rearward connection point of the trailer.

[0052] The trailer may comprise a battery pack for driving one or more axles of the trailer. In addition to the power source of the drive unit, the trailer may itself have a power source connected to one or more motors for driving one or more of its axles. Other power sources such as fuel cells are also possible.

[0053] An auxiliary trailer can be connectable to the trailer of the vehicle combination.

[0054] There is also provided a control system for controlling propulsion and steering of a drive unit according to the second aspect. The control system is arranged to be implemented in an electronic control unit connected to at least one steering controller, wherein the at least one steering controller is arranged to provide control output signal to a steering actuator, wherein the electronic control unit is arranged to receive control input signals from a control input source.

[0055] The control input source may be selectable in the electronic control unit and may be one of:

[0056] - Radio remote control, - Teleoperator,

[0057] - Autonomous drive system

[0058] In the following, the first aspect may be referred to as a third example embodiment and the second aspect may be referred to as a first or second example embodiment.

[0059] BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 schematically shows a drive unit according to a first example embodiment,

[0061] Figure 2 schematically shows a drive unit according to a second example embodiment,

[0062] Figure 3 schematically shows a vehicle combination comprising a drive unit and a trailer, Figure 4 schematically shows a chart over a control system for controlling propulsion and steering of a drive unit.

[0063] Figure 5 schematically shows a drive unit according to a third example embodiment.

[0064] DETAILED DESCRIPTION

[0065] Figure 1 schematically shows a drive unit 1 according to a first example embodiment. The drive unit 1 comprises a frame 2 or chassis comprising a pair of longitudinal beams 3 extending in a longitudinal or x-direction and a plurality of cross beams 4 extending between the longitudinal beams 3 in a transverse or y-direction. The frame 2 can be made in one piece or by assembly of a number of separate beams. The drive unit 1 comprises at least one pair of wheels arranged on either transverse side of the frame 2 with one wheel 5 arranged on each longitudinal beam 3. In the example of figure 1, the drive unit 1 comprises two pair of wheels 5a, 5b arranged on the frame 2 with two wheels arranged on each longitudinal beam 3, with one wheel in front of the other. Each wheel for each pair of wheels 5a, 5b are arranged on a same longitudinal position on each longitudinal beam 3 as typical for a car or a truck. The wheels can be arranged on the frame 2 either on an axle running in a transverse direction between the longitudinal beams, similar to on a car or on a truck where each pair of wheels are powered jointly, or on individual axles where each wheel is powered separately.

[0066] The drive unit 1 further comprises a power source (not shown) arranged on the frame 2 arranged to provide power to the drive unit 1. The power source may be a fuel cell, battery or a combustion engine. Other suitable power sources are also possible. If the power source is a battery, the drive unit 1 comprises one or more DC / DC-converters to convert the battery's voltage to usable voltages for the various components of the drive unit 1.

[0067] The drive unit 1 further comprises an electronic control unit (not shown) arranged to control propulsion and steering of the drive unit 1. Steering of the drive unit 1 is made by retracting or extending at least one steering actuator 6 comprising a drive unit end 6a connected to a steering arrangement 7 on the frame 2 and a trailer end 6b arranged to be disconnectedly attached to a trailer. The steering actuator 6 is provided with a retract or extend command from the electronic control unit which results in that the drive unit 1 is turned by the steering actuator 6 pushing on the frame 2 via the steering arrangement 7. The steering arrangement 7 is in its most basic form an attachment point for the drive unit end 6a of the steering actuator 6 to be fastened to. The steering arrangement 7 can also be a larger mechanical structure intended to distribute the power exerted on the frame 2 by the steering actuator over more than one attachment point. In the example of figure 1, the drive unit 1 comprises two steering actuators 6', 6” attached to attachment points 7', 7” on either transverse side of the frame 2. The exact longitudinal position of the steering arrangement 7 or the position of the attachment points where the resulting power is distributed can be adapted.

[0068] The electronic control unit is arranged to receive control commands to be executed by the electronic control unit of the drive unit 1 by remote control, by a teleoperator or by an autonomous drive system. The electronic control unit thus comprises one or more transceiver devices, arranged to receive control commands in various ways as well as to transmit data related to the operation of the drive unit 1 such as speed, heading, available power etc. Also, data for diagnostic purposes can be transmitted. The transceiver device(s) are capable of transmitting and receiving by means of a cellular network operating with 4G, 5G, 6G etc. Additionally, Wi-Fi can be used within a well-defined area.

[0069] The steering actuator 6 is an electro-mechanical actuator or a hydraulic actuator. In case of a hydraulic actuator, all necessary peripheral equipment is arranged on the frame 2 of the drive unit 1.

[0070] When using two (or more) pair of wheels 5a, 5b on the drive unit 1, the forward-most pair 5a of wheels may be steerable in order to increase the steerability of the drive unit 1. This can be arranged by the common axle being steerable or by being able to rotate the forward-most separately driven wheels around their vertical axes.

[0071] The wheels of the drive unit 1 may be provided with air suspension. In that case, the drive unit 1 further comprises a compressor (not shown) arranged in the frame 2 for changing a pressure of an air suspension of one pair of wheels.

[0072] In the example embodiment of figure 1, the two steering actuators 6', 6” are arranged in a forward-facing direction or facing towards a front of the drive unit 1. In this embodiment, the trailer ends 6b', 6b” of the steering actuators are arranged to be disconnectedly connected to a forward connection point of a trailer. Figure 2 schematically shows a drive unit 1 according to a second example embodiment. The drive unit 1 of figure 2 is the same as in figure 1 with the exception that the two steering actuators 6', 6” are arranged in a rearward-facing direction or facing away from the front of the drive unit 1. In this embodiment, the trailer ends 6b', 6b” of the steering actuators 6', 6” are arranged to be disconnectedly connected to a rearward connection point of a trailer.

[0073] The drive unit 1 may be equipped with a fifth wheel that mechanically connects the trailer to the drive unit 1. A fifth wheel may be used to distribute the load from the trailer on the drive unit 1 and reduces the stress exerted on the actuators 6', 6”.

[0074] As an alternative to the actuators 6', 6”, it is possible to use a gear ring having a diameter approximately the same size as the width of the drive unit 1. A steering gear connected to an electric motor is connected to the gear ring. This can be implemented in situations where the load from the trailer is small.

[0075] Alternatively, the drive unit 1 may comprise a turntable plate onto which the actuators can be attached at the transverse edges. In addition, a combination of a turntable plate and a fifth wheel could be used.

[0076] Figure 3 schematically shows a vehicle combination 8 comprising a drive unit 1 and a trailer 9. Figure 3 shows an example of the application of the drive unit 1 to drive a trailer 9 to form a vehicle combination 8. As mentioned above, the drive unit 1 is attached to the trailer 9 by that at least one steering actuator 6 is arranged in a forward direction and connected to a forward connection point of the trailer 9 or by that at least one steering actuator 6 is arranged in a rearward direction and connected to a rearward connection point of the trailer 9. The trailer 9 is in one example a trailer capable of carrying a 40-foot ISO container. Other types of trailers arranged to carry other types of cargo are of course possible.

[0077] In order to provide additional power to move the vehicle combination 8, the trailer 9 may comprise a battery pack for driving one or more axles of the trailer 9. The trailer 9 may be equipped with electric motors arranged to drive one or more wheel pairs on the trailer 9 in order to increase the total power available to the vehicle combination 8. In addition to a trailer being connected to the drive unit 1, an auxiliary trailer may be connected to the trailer itself thereby making it possible to transport two 40-foot containers or a combination of 40-foot containers and / or 20-foot containers or other cargo types.

[0078] In order to increase the power of a vehicle combination 8 comprising a drive unit and two trailers as well as to assist with turning the vehicle combination 8, a further drive unit 1 may be arranged to be connected to the trailer 9 and to the auxiliary trailer. Typically, this drive unit 1 would have one pair of wheels, but having more than one pair of wheels on the further drive unit 1 is of course possible.

[0079] Figure 4 schematically shows a control system 10 for controlling propulsion and steering of a drive unit 1. The control system 10 is arranged to be implemented in an electronic control unit (ECU) 11 for the drive unit 1. The ECU 11 connected to at least one steering controller 12. The at least one steering controller 12 is arranged to provide a control output signal to a motor 13 of a steering actuator 6', 6”. The electronic control unit 11 is arranged to receive control input signals from a control input source 14. The control input source 14 is selectable in the electronic control unit 11 and is one of radio remote control 14a, a teleoperator 14b or an autonomous drive system 14c.

[0080] In figure 4, it can be seen that the ECU 11 comprises a steering mode selector 15 for selecting the control input source 14a, 14b, 14c to be used. In figure 4, the control input sources are schematically shown to be connected to the ECU.

[0081] In the example of figure 4, the drive unit 1 comprises two steering actuators 6', 6” as in figure 1 and 2. The ECU 11 is thus connected to both a first steering controller 12' and a second steering controller 12”. The first steering controller 12' is connected to a first steering actuator motor 13' that controls the retraction or extension of the first steering actuator 6'. Similarly, the second steering controller 12” is connected to a second steering actuator motor 13” that controls the retraction or extension of the second steering actuator 6”.

[0082] The autonomous drive system further comprises one or more sensors associated with autonomous drive such as lidar, radar or camera. These sensors can of course also be used by the other control input sources described above. Figure 5 schematically shows a drive unit according to a third example embodiment. The drive unit 1 of figure 5 is the same as in figures 1 and 2 with the difference that a steering end 6a; 6a', 6a” of the steering actuator 6; 6', 6” is arranged to be connected to a rotatable steering arrangement 17 that is rotatably movable relative the drive unit and is attached to a trailer, and that a motor end 6b; 6b', 6b” is arranged to be disconnectedly attached to the drive unit 1. When providing the steering actuator 6; 6', 6” with a retract or extend command from the electronic control unit 11, the drive unit 1 is turned by the steering actuator 6; 6', 6” pushing on the rotatable steering arrangement 17 such that the drive unit 1 rotates relative the rotatable steering arrangement 17 and thereby rotates relative the trailer to which it is attached.

[0083] The rotatable steering arrangement 17 may be connected to the trailer by means of fasteners such as bolts, corner castings with matching twist locks or couplings from VBG Group Truck Equipment AB.

[0084] The rotatable steering arrangement 17 may also be a fifth wheel with a lockable king pin that mechanically connects the trailer to the drive unit 1.

[0085] The rotatable steering arrangement 17 has a diameter of approximately the same length as the width of the drive unit 1.

[0086] The steering actuators 6; 6', 6” are arranged to be attached to the rotatable steering arrangement 17 by means of bolts or screws with a dampener in the attachment between the two. In the example of figure 5, the steering actuators 6; 6', 6” are attached at either transverse side of the rotatable steering arrangement 17.

[0087] The invention aims to build an automated vehicle, that is as simple and cost effective as possible, to move a 40-foot container between locations, for instance in a dock, warehouse, construction site or similar. The use of a commodity trailer and the drive unit provides a simple and reliable solution. To steer the unit, that is operated by radio controller, tele-operation, or an autonomous drive system, electro-mechanical (or hydraulic) actuators are used that are controlled by the vehicle control system, to turn the drive unit.

[0088] Example 1: A drive unit (1) for a trailer, wherein the drive unit (1) comprises:

[0089] - a frame (2) comprising at least one pair of wheels (5; 5a, 5b) arranged on either transverse side of the frame (2), - a power source arranged on the frame (2) arranged to provide power to the drive unit (1),

[0090] - an electronic control unit (11) arranged to control propulsion and steering of the drive unit (1),

[0091] - at least one steering actuator (6; 6', 6”) comprising a drive unit end (6a; 6a', 6a”) connected to a steering arrangement (7) on the frame (2) and a trailer end (6b; 6b', 6b”) arranged to be disconnectedly attached to a trailer (9),

[0092] - wherein providing the steering actuator (6; 6', 6”) with a retract or extend command from the electronic control unit (11), turns the drive unit (1) by the steering actuator (6; 6', 6”) pushing on the frame (2) of the drive unit (1).

[0093] Example 2: The drive unit (1) according to example 1, wherein the electronic control unit (11) is arranged to receive control commands to be executed by the electronic control unit (11) of the drive unit (1) by remote control, by a teleoperator or by an autonomous drive system.

[0094] Example 3. The drive unit (1) according to example 1 or 2, wherein the steering actuator (6; 6', 6”) is an electro-mechanical actuator or a hydraulic actuator.

[0095] Example 4: The drive unit (1) according to any one of examples 1-3, wherein the power source is a fuel cell, battery or a combustion engine.

[0096] Example 5: The drive unit (1) according to example 4, wherein when the power source is a battery, the drive unit (1) comprises a DC / DC-converter.

[0097] Example 6: The drive unit (1) according to any one of the preceding examples, wherein the drive unit (1) comprises at least two pairs of wheels (5a, 5b) arranged on the frame (2).

[0098] Example 7: The drive unit (1) according to example 6, wherein the forward-most pair of wheels (5a) are steerable.

[0099] Example 8. The drive unit (1) according to any one of the preceding examples, wherein the drive unit (1) further comprises a compressor arranged in the frame (2) for changing a pressure of an air suspension of one pair of wheels (5; 5a, 5b).

[0100] Example 9: The drive unit (1) according to any one of the preceding examples, wherein a control system (10) implemented in the electronic control unit (11) of the drive unit (1) is software defined. Example 10: A vehicle combination (8) comprising a drive unit (1) according to examples 1 - 9, wherein the drive unit (1) connected to a trailer (9) by that a trailer end of the at least one steering actuator (6; 6', 6”) is arranged to be disconnectedly attached to the trailer.

[0101] Example 11: The vehicle combination (8) according to example 10, wherein the at least one steering actuator (6; 6', 6”) is arranged in a forward direction and connected to a forward connection point of the trailer or wherein the at least one steering actuator (6; 6', 6”) is arranged in a rearward direction and connected to a rearward connection point of the trailer.

[0102] Example 12: The vehicle combination (8) according to example 10 or 11, wherein the trailer (9) comprises a battery pack for driving one or more axles of the trailer.

[0103] Example 13: The vehicle combination (8) according to any one of examples 10-11, wherein an auxiliary trailer is connectable to the trailer (9) of the vehicle combination (8).

[0104] Example 14: Control system (10) for controlling propulsion and steering of a drive unit (1) according to examples 1-9, wherein the control system (10) is implemented in an electronic control unit (11) connected to at least one steering controller (12; 12', 12”), wherein the at least one steering controller (12; 12', 12”) is arranged to provide control output signal to a steering actuator (6; 6', 6”), wherein the electronic control unit (11) is arranged to receive control input signals from a control input source (14).

[0105] Example 15. Control system according to example 14, wherein the control input source (14) is selectable in the electronic control unit (11) and is one of:

[0106] - Radio remote control (14a),

[0107] - Teleoperator (14b),

[0108] - Autonomous drive system (14c).

[0109] The description of the example embodiments provided herein have been presented for purposes of illustration. The description is not intended to be exhaustive or to limit example embodiments to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various alternatives to the provided embodiments. The examples discussed herein were chosen and described in order to explain the principles and the nature of various example embodiments and its practical application to enable one skilled in the art to utilize the example embodiments in various manners and with various modifications as are suited to the particular use contemplated. The features of the embodiments described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products. It should be appreciated that the example embodiments presented herein may be practiced in any combination with each other.

[0110] It should be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed and the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements. It should further be noted that any reference signs do not limit the scope of the claims, that the example embodiments may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware.

[0111] The various example embodiments described herein are described in the general context of method steps or processes, which may be implemented in one aspect by a computer program product, embodied in a computer-readable medium, including computer-executable instructions, such as program code, executed by computers in networked environments. A computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), compact discs (CDs), digital versatile discs (DVD), etc. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

[0112] In the drawings and specification, there have been disclosed exemplary embodiments. However, many variations and modifications can be made to these embodiments. Accordingly, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the embodiments being defined by the following claims. References:

[0113] 1. Drive unit

[0114] 2. Frame

[0115] 3. Longitudinal beams

[0116] 4. Cross beams

[0117] 5. Wheels a. First pair b. Second pair

[0118] 6. Steering actuator a. Drive unit end b. Trailer end

[0119] 7. Steering arrangement

[0120] 8. Vehicle combination

[0121] 9. Trailer

[0122] 10. Control system

[0123] 11. Electronic control unit

[0124] 12. Steering controller

[0125] 13. Motor

[0126] 14. Control input source a. Radio remote control b. Teleoperator c. Autonomous drive

[0127] 15. Steering mode selector

Claims

CLAIMS1. A drive unit (1) for a trailer, wherein the drive unit (1) comprises:- a frame (2) comprising at least one pair of wheels (5; 5a, 5b) arranged on either transverse side of the frame (2),- a power source arranged on the frame (2) arranged to provide power to the drive unit (1),- an electronic control unit (11) arranged to control propulsion and steering of the drive unit (1),- at least one steering actuator (6; 6', 6”) comprising a steering end (6a; 6a', 6a”) arranged to be connected to a rotatable steering arrangement (17) that is rotatably movable relative the drive unit and is attached to a trailer (2), and a motor end (6b; 6b', 6b”) arranged to be disconnectedly attached to the drive unit (1),- wherein providing the steering actuator (6; 6', 6”) with a retract or extend command from the electronic control unit (11), turns the drive unit (1) by the steering actuator (6; 6', 6”) pushing on the rotatable steering arrangement (17) such that the drive unit(I) rotates relative the rotatable steering arrangement (17).

2. The drive unit (1) according to claim 1, wherein the electronic control unit (11) is arranged to receive control commands to be executed by the electronic control unit(II) of the drive unit (1) by remote control, by a teleoperator or by an autonomous drive system.

3. The drive unit (1) according to claim 1 or 2, wherein the steering actuator (6; 6', 6”) is an electro-mechanical actuator or a hydraulic actuator.

4. The drive unit (1) according to any one of claims 1-3, wherein the power source is a fuel cell, battery or a combustion engine.

5. The drive unit (1) according to claim 4, wherein when the power source is a battery, the drive unit (1) comprises a DC / DC-converter.

6. The drive unit (1) according to any one of the preceding claims, wherein the drive unit(1) comprises at least two pairs of wheels (5a, 5b) arranged on the frame (2).

7. The drive unit (1) according to claim 6, wherein the forward-most pair of wheels (5a) are steerable.

8. The drive unit (1) according to any one of the preceding claims, wherein the drive unit (1) further comprises a compressor arranged in the frame (2) for changing a pressure of an air suspension of one pair of wheels (5; 5a, 5b).

9. The drive unit (1) according to any one of the preceding claims, wherein a control system (10) implemented in the electronic control unit (11) of the drive unit (1) is software defined.

10. A vehicle combination (8) comprising a drive unit (1) according to claims 1-9, wherein the drive unit (1) connected to a trailer (9) by that the rotatable steering arrangement (17) is rotatably attached to the drive unit (1).

11. The vehicle combination (8) according to claim 10, wherein the trailer (9) comprises a battery pack for driving one or more axles of the trailer.

12. The vehicle combination (8) according to any one of claims 10-11, wherein an auxiliary trailer is connectable to the trailer (9) of the vehicle combination (8).

13. Control system (10) for controlling propulsion and steering of a drive unit (1) according to claims 1-9, wherein the control system (10) is implemented in an electronic control unit (11) connected to at least one steering controller (12; 12', 12”), wherein the at least one steering controller (12; 12', 12”) is arranged to provide control output signal to a steering actuator (6; 6', 6”), wherein the electronic control unit (11) is arranged to receive control input signals from a control input source (14).

14. Control system according to claim 13, wherein the control input source (14) is selectable in the electronic control unit (11) and is one of:- Radio remote control (14a),- Teleoperator (14b),- Autonomous drive system (14c).

15. A drive unit (1) for a trailer, wherein the drive unit (1) comprises:- a frame (2) comprising at least one pair of wheels (5; 5a, 5b) arranged on either transverse side of the frame (2),- a power source arranged on the frame (2) arranged to provide power to the drive unit (1),- an electronic control unit (11) arranged to control propulsion and steering of the drive unit (1),- at least one steering actuator (6; 6', 6”) comprising a drive unit end (6a; 6a', 6a”) connected to a steering arrangement (7) on the frame (2) and a trailer end (6b; 6b', 6b”) arranged to be disconnectedly attached to a trailer (9),- wherein providing the steering actuator (6; 6', 6”) with a retract or extend command from the electronic control unit (11), turns the drive unit (1) by the steering actuator (6; 6', 6”) pushing on the frame (2) of the drive unit (1).

16. The drive unit (1) according to claim 15, wherein the drive unit (1) further comprises a compressor arranged in the frame (2) for changing a pressure of an air suspension of one pair of wheels (5; 5a, 5b).

17. The drive unit (1) according to claim 15 or 16, wherein the drive unit end (6a; 6a', 6a”) is a steering end, wherein the steering arrangement is a rotatable steering arrangement (17), wherein the steering end (6a; 6a', 6a”) is arranged to be connected to said rotatable steering arrangement (17) that is rotatably movable relative the drive unit (1) and is attached to a trailer (2), and a motor end (6b, 6b', 6b”) arranged to be disconnectedly attached to the drive unit (1).

18. A vehicle combination (8) comprising a drive unit (1) according to claims 15 to 17, wherein the drive unit (1) connected to a trailer (9) by that a trailer end of the at least one steering actuator (6; 6', 6”) is arranged to be disconnectedly attached to the trailer.

19. The vehicle combination (8) according to claim 16, wherein the at least one steering actuator (6; 6', 6”) is arranged in a forward direction and connected to a forward connection point of the trailer or wherein the at least one steering actuator (6; 6', 6”) is arranged in a rearward direction and connected to a rearward connection point of the trailer.

20. The vehicle combination (8) according to claim 18 or 19, wherein the trailer (9) comprises a battery pack for driving one or more axles of the trailer.

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