WO2025153417A1

WO2025153417A1 - Trailer, tractor-trailer-combination and method for operating a tractor-trailer-combination

Info

Publication number: WO2025153417A1
Application number: PCT/EP2025/050622
Authority: WO
Inventors: Rahul BALASUBRAMANIAN
Original assignee: ZF CV Systems Global GmbH
Current assignee: ZF CV Systems Global GmbH
Priority date: 2024-01-18
Filing date: 2025-01-13
Publication date: 2025-07-24
Anticipated expiration: 2026-07-18

Abstract

The invention relates to a trailer (12) for a tractor-trailer-combination (10), the trailer (10) comprising a first axle (16), an electric machine (18) coupled to the first axle (16), a battery (20) connected to the electric machine (18), a thermal conditioning unit (22) for thermally conditioning (81 ) the battery (20) and a control unit (24) configured to control the electric machine (18) and the thermal conditioning unit (22). The control unit (24) comprises a conditioning mode (56), wherein the control unit (24) is configured in the conditioning mode (56) to control the electric machine (18) to convert (80) a given motion (26) of the first axle (16) to an electric power (28) and to control the thermal conditioning unit (22) to thermally condition (81) the battery (20) using the electric power (28) converted (80) from the given motion (26).

Description

Trailer, tractor-trailer-combination and method for operating a tractor-trailer-combination

The invention relates to a trailer for a tractor-trailer-combination, to a tractor-trailer- combination and to a method for operating a tractor-trailer-combination.

In modern day electric vehicles, temperature conditioning of the battery is a crucial process due to the limited band of efficient operation of a battery system and deterioration of the lifespan of the battery when operated in extreme thermal conditions.

Thermal conditioning of the battery before operating the vehicle is a solution widely used in electric vehicles. Typically, a thermal conditioning unit warms up or cools down the battery to an efficient temperature zone before the vehicle is driven to ensure that the battery operates in its safe temperature band right from the beginning. This feature improves the lifetime of the battery.

Conditioning is typically done by connecting the vehicle to the power grid. The vehicle consumes power from the grid and uses the power to only run the thermal conditioning unit of the vehicle. Typically, the system does not charge the batteries in the meantime. Once the battery is brought to the required temperature zone, the charging operation of the battery starts or the operator of the vehicle starts driving the vehicle.

A problem with this solution is that this cannot be achieved when the vehicle has no access to a power grid, as may be the case in the countryside, for example.

If conditioning is not possible due to a lack of access to a power grid, the operator typically uses the vehicle at the non-efficient or life-affecting temperature zone, anyway. This can result in a deterioration of the lifespan of the battery.

Electrified trailers are slowly gaining attention and popularity in the market. These trailers are typically towed by electric, hybrid or conventional (i.e. internal combustion i powered) tractors. An electrified trailer comprises its own electric motor and battery. The battery should preferably be thermally conditioned before use to improve its lifespan.

Electrified trailers have several advantages. They may serve as an electric driving unit that can be combined with a conventional tractor, thus effectively rendering the resulting tractor-trailer-combination a hybrid vehicle with the corresponding advantages, such as recuperation of kinetic energy. If, for example, the tractor is a purely electrically driven tractor, the electrified trailer may effectively serve as a range extender, since the resulting tractor-trailer-combination comprises the battery capacity of both the tractor battery and the trailer battery.

Typically, the battery of the electrified trailer is charged at a stationary charging port of the power grid, for example in a yard, in a resting area for trucks and drivers or at a gas station. If the tractor-trailer-combination comprising the electrified trailer is started from a charging port, the battery can easily be conditioned beforehand as needed. If, however, the tractor-trailer-combination is started from a place without such a charging port, conditioning of the battery before the start is not possible.

Even if a charging port is available, it is also inconvenient for the driver to always spend sufficient time at the charging port. Furthermore, a dedicated parking place for a tractor-trailer-combination, such as in resting areas, may comprise only one charging port. If the tractor also comprises a battery, which needs to be conditioned, this may increase the inconvenience and the driver may have to wait even longer and switch the connection to the charging port between the tractor battery and the trailer battery.

It is an object of the invention to improve convenience in operating a tractor-trailer- combination having an electrified trailer.

This object is achieved by a trailer in accordance with claim 1 .

The trailer comprises a first axle, an electric machine coupled to the first axle, a battery connected to the electric machine, a thermal conditioning unit for thermally conditioning the battery, and a control unit configured to control the electric machine and the thermal conditioning unit. The control unit may also be configured to control other components of the trailer.

The control unit comprises a conditioning mode. The control unit may also comprise other modes. When the control unit is in the conditioning mode, the control unit is configured to control the electric machine to convert a given motion of the first axle to an electric power and to control the thermal conditioning unit to thermally condition the battery using the electric power converted from the given motion.

In the conditioning mode, the electric machine of the trailer is effectively operated as a generator, generating electric power from the given motion. This electric power can advantageously be used to power the thermal conditioning unit and to power the thermal conditioning of the battery.

The term “a given motion” refers to a motion which the trailer performs and which is typically powered by external forces, i.e. not by the trailer or its electric machine itself. The given motion can, in particular, be powered by a tractor, which can be connected to the trailer in a tractor-trailer-combination. Thus, the trailer can effectively be configured to use power generated by the tractor or - in simplified terms - to “steal” power from the tractor.

Thereby it becomes possible for the driver to start a trip with a tractor-trailer- combination without having ensured and finished a thermal conditioning of the battery of the trailer. Instead, the conditioning can be performed after the start of the trip, preferably right after the start of the trip.

Thus, the convenience for the driver is improved without deteriorating the battery of the trailer. Also, since the driver does not have to wait at a stationary charging port for the thermal conditioning to finish, the overall waiting time is reduced and the economic efficiency for the fleet owner is improved.

An electric machine can generally be used as a motor to propel the trailer. The same electric machine can also be operated as a generator and charge the battery when the wheels are rotated by external forces - e.g. during braking or coasting. In electrified trailers, in addition the electric machine can be operated as a generator whenever required during a trip, since the trailer is also propelled by a tractor. The power generated by the electric machine can be used to operate the thermal conditioning unit of the trailer. The electric machine operating as a generator may in particular controlled in such a way that only a small amount of power is generated, which is sufficient to run the thermal conditioning unit and condition the battery. Once the battery conditioning is complete, the battery can be used for normal operation, particularly to provide power for driving the vehicle. The electric machine may in particular be controlled by using an algorithm which considers ambient and battery temperature, conditioning time, vehicle speed, vehicle dynamic conditions etc.

The control unit of the trailer may in particular be configured to control the thermal conditioning unit on the basis of one or more parameters, such as ambient temperature, battery temperature, vehicle speed, vehicle dynamic conditions or the like. The trailer and/or the tractor may generally comprise one or more sensors for measuring one or more parameters of or around the vehicle, such as ambient temperature, battery temperature, vehicle speed, vehicle dynamic conditions or the like.

According to an embodiment, the thermal conditioning unit comprises a heating unit and/or a cooling unit for the battery, wherein conditioning the battery comprises heating or cooling the battery. Thus, depending on the expected environmental conditions, the battery may be heated or cooled as necessary.

According to an embodiment, the control unit is configured to assume the conditioning mode upon startup of the trailer. This advantageously ensures that the battery of the trailer is immediately conditioned as needed and that the electric machine and the battery of the trailer can be used as early as possible for driving the trailer and, thus, the tractor-trailer-combination.

In general, the control unit may comprise an operating mode, which is different from the conditioning mode. The operating mode may be a mode, in which the electric machine and the battery of the trailer are employed to drive the trailer. According to an embodiment, the control unit comprises an operating mode, wherein the trailer comprises a sensor for detecting a parameter of the battery, wherein the control unit is configured to switch from the conditioning mode to the operating mode, when the parameter meets a control condition. The control condition may comprise that the parameter is above or below a predetermined threshold value. The control condition may comprise that the parameter is within a predetermined interval. The automatic switching from the conditioning mode to the operating mode based on the parameter and the control condition further improves convenience for the driver, since switching does not need to be performed manually. Also, this can ensure that switching is performed at essentially optimal conditions, so that the protection of the battery against early deterioration is further improved.

According to an embodiment, the sensor is a temperature sensor, wherein the parameter is a temperature. This embodiment can provide for highly precise information regarding the condition of the battery of the trailer and can, thus, further improve the process of conditioning the battery. This further improves the life span of the battery.

According to an embodiment, the control unit is configured to switch from the conditioning mode to the operating mode, when a predetermined time has lapsed with respect to a predetermined event. This embodiment is very simple to implement but nevertheless provides for a beneficial process of conditioning the battery. The predetermined event may be, for example, a startup of the trailer, a startup of a tractor connected to the trailer, or a beginning of a trip with a trailer.

The control unit may, for example, comprise a drive mode as part of the operating mode. When in the drive mode, the control unit may be configured to control the electric machine to convert an electric power supplied by the battery to drive the trailer. Thus, in the drive mode the electric machine may be operated as a motor to drive the trailer and, thus, the tractor-trailer-combination. The separate drive mode improves control of the components.

The control unit may, for example, comprise a recuperation mode as part of the operating mode. In the recuperation mode, the control unit may be configured to control the electric machine to convert a given motion of the first axle to an electric power and to control the electric machine and the battery to charge the battery using the electric power converted from the given motion. Thus, in the recuperation mode the electric machine may be used as a generator. In contrast to the conditioning mode, however, the electric power generated by the electric machine operating as a generator is used to charge the battery in the recuperation mode. In the conditioning mode, the electric power generated by the electric machine is used to power the thermal conditioning unit and to thermally condition the battery. It is also advantageous to not charge the battery before it is conditioned as needed. This is because charging may also unnecessarily deteriorate the battery, when the battery is not in its optimal condition or condition range.

The trailer may, for example, be a semi-trailer or a full trailer. The trailer may, in general, comprise at least one axle but may also comprise two or more axles.

The object is also achieved by a tractor-trailer-combination comprising a tractor and a trailer, wherein the trailer is configured in accordance with a trailer as described above.

According to an embodiment, the tractor comprises an internal combustion drive system. This means that the tractor comprises an internal combustion engine and no electric drive system. In this scenario, the trailer having the electric machine and the tractor having an internal combustion drive system together form a tractor-trailer- combination that has both an internal combustion drive system and an electric machine. This tractor-trailer-combination effectively comprises a hybrid drive system. An advantage, thus, is that the electrified trailer can add a recuperation function to the tractor-trailer-combination, which the tractor having the internal combustion drive system does not have on its own.

The tractor may alternatively comprise a hybrid drive system. A hybrid drive system comprises both an internal combustion engine and an electric machine and battery. An advantage in this example is that the additional battery of the trailer provides for a higher range of electrically driving the tractor-trailer-combination and for a reduction of fuel consumed by the internal combustion engine. As a further alternative, the tractor may comprise an electric drive system. Such a tractor comprises an electric machine and a battery to drive the tractor but does not comprise an internal combustion engine to drive the tractor. An advantage in this example is that the battery of the trailer effectively extends the capacity or range of the battery of the tractor and the tractor-trailer-combination as a whole. In this example, the proposed trailer also improves the convenience for the driver. Even though the battery of the tractor may need to be conditioned with the power from a power grid and at a charging port, the fact that the battery of the trailer does not also need to be conditioned at this charging port reduces the waiting time at the charging port, at least and especially if there is only one charging port available.

The trailer and/or the tractor may comprise a signaling unit and may be configured to communicate a status information to an operator, e.g. a driver, of the tractor-trailer- combination. The signaling unit may be an acoustic signaling unit, a visual signaling unit, such as a display, or it may be a wireless communication module configured to transmit the status information to a mobile device carried by the operator. It is also possible to provide multiple and/or different signaling units. The status information may comprise an information on whether or not the control unit is in the conditioning mode. The status information may comprise an information on a parameter, in particular a temperature, of the battery. Communicating the status information to the operator can improve the life span of the battery, since the operator is then able to adapt his or her behavior of operating a tractor-trailer-combination in a manner that is beneficial to the life span of the battery.

In general, the trailer and/or the tractor may or may not comprise a charging unit for their respective battery. A thermal conditioning unit may be provided none the less.

Generally, an electric machine can be controlled using torque requests. A relation between torque and power generated can be defined by and based on the requirements of the thermal conditioning unit.

The object is also achieved by a method as defined in the corresponding independent claim for operating a tractor-trailer-combination comprising a tractor and a trailer. The trailer may in particular be configured as a trailer as described above. The tractor-trailer-combination may in particular be configured as a tractor-trailer- combination as described above.

The trailer comprises a first axle, an electric machine coupled to the first axle, a battery for the electric machine and a thermal conditioning unit for thermally conditioning the battery.

The method comprises the steps of converting a given motion at the first axle to an electric power by the electric machine and thermally conditioning the battery using the electric power converted from the given motion. These steps are typically performed at the same time. Thus, advantageously, the electric power converted by the electric machine is used directly for thermally conditioning the battery and is not stored in an intermediate energy storage, such as an additional battery.

The method may comprise beginning a trip with the tractor-trailer-combination.

Over a first time duration after beginning the trip, the method comprises the steps of driving the tractor-trailer-combination by a drive system of the tractor, converting a given motion at the first axle to an electric power by the electric machine and thermally conditioning the battery using the electric power converted from the given motion. The first time duration may correspond to the conditioning mode as mentioned above.

Over a second time duration after the first time duration the method comprises the step of driving the tractor-trailer-combination by both the electric machine of the trailer and the drive system of the tractor. The second time duration may correspond to the drive mode as mentioned above.

In an example, a trailer as described above may be towed by a conventional tractor, i.e. , a tractor having an internal combustion drive system. The operator does not need to wait for a charging slot when battery conditioning for the trailer is required. The operator may be provided with an option to drive the tractor-trailer-combination for a predetermined amount of time, for 5 minutes, for example. This can be done even when no charging slot is available. The conventional tractor can be operated basically independently from the outside temperature. Due to the motion of the tractor, the wheels of the trailer also rotate and drive the electric machine. The electric machine in turn is operated as a generator and the power generated is used to operate the thermal conditioning unit and not to charge the battery. During this time, it is preferred to perform no operation of the trailer other than thermal conditioning. The thermal conditioning unit brings the battery into an operating temperature condition. After this, the battery of the trailer is ready to provide all necessary operations like traction support or powering constant loads. This prevents the trailer battery from operating in extreme temperature conditions and at the same time the process of conditioning the battery by plugging the electric trailer to a power grid is skipped. The operator is able to drive off and utilize the functions of the trailer’s electric drive system after a short delay.

In another example, a trailer as described above is towed by an electric tractor, i,e. a tractor that comprises an electric drive system. The operator does not need to wait for a charging slot when battery conditioning is required. The operator may be provided with an option to drive the tractor-trailer-combination for a predetermined amount of time, for 5 minutes, for example. If the operator is willing to operate the electric tractor outside the operating temperature of its battery, the tractor can be driven. Due to the motion of the tractor, the wheels of the trailer also rotate and drive the electric machine of the trailer. If the operator is not willing to operate the electric truck outside the operating temperature of its battery and a charging slot is available, then the tractor alone can be connected to the grid and pre-conditioned before driving the tractor-trailer-combination. Additional time at the charging station required to condition the battery of the electric trailer can be avoided if there are no other ports available. The electric machine in turn is operated as a generator and the power generated is used to operate the thermal conditioning unit and not to charge the battery. During this time, is it preferable to perform no operation of the trailer other than thermal conditioning. The thermal conditioning unit brings the battery into an operating temperature condition. After this, the battery of the trailer is ready to provide all necessary operations like traction support or powering constant loads. Thus, the dependency on the charging port for battery pre-conditioning of the tractor- trailer-combination can effectively be reduced. Less time must be spent at a charging station for pre-conditioning a battery under extreme climate conditions. An electric trailer without a provision to charge from external grid power can also benefit from the proposed methods and devices. The lifetime of the trailer battery can be increased. Replacement procedures can be reduced, while customers might hesitate to replace a trailer battery as frequently as a tractor battery. The increased lifetime reduces total cost of ownership. The overall efficiency of battery performance can be increased.

The described aspects, i.e. trailer, tractor-trailer-combination and method, may further be improved by features or embodiments of the other aspects, equivalently if applicable.

The invention will hereinafter be described with the help of schematic drawings showing examples.

Fig. 1 shows a tractor-trailer-combination.

Fig. 2 shows a control unit.

Fig. 3 shows a method for operating a tractor-trailer-combination.

Fig. 4 shows a method for operating a tractor-trailer-combination.

Fig. 6 shows a tractor-trailer-combination at a charging station.

Fig. 7 shows a tractor-trailer-combination at a charging station.

Fig. 8 shows a tractor-trailer-combination at a charging station.

Fig. 9 shows a tractor-trailer-combination at a charging station. Fig. 10 shows a tractor-trailer-combination at a charging station.

Fig. 1 shows tractor-trailer-combination 10 comprising a trailer 12 and a tractor 14. The trailer 12 comprises a first axle 16, an electric machine 18 coupled to the first axle 16, and a battery 20 connected to the electric machine 18.

In the depicted example, the trailer 12 comprises three axles. The term “first” is only used for ease of reference. While in the example, the first axle 16 is also a first axle with respect to a driving direction 21 of the tractor-trailer-combination 10, this is not mandatory. Instead, the first axle 16 with the electric machine 18 can be a second, third, or other axle with respect to the driving direction. Also, more than one axle with an electric machine may be provided. Generally, the tractor may have two or more than two axles and the trailer may have any number of axles.

The trailer 12 comprises a thermal conditioning unit 22, which may also be referred to as a thermal management system, for thermally conditioning the battery 20. The trailer 12 further comprises a control unit 24 configured to control the electric machine 18 and the thermal conditioning unit 22.

The control unit 24 may comprise several modes of operation and comprises a conditioning mode. The control unit 24 is configured in the conditioning mode to control the electric machine 18 to convert a given motion 26 of the first axle 16 to an electric power 28. The control unit 24 is also configured in the conditioning mode to control the thermal conditioning unit 22 to thermally condition the battery 20 using the electric power 28 converted from the given motion 26. The control unit 24 of the trailer 12 is configured to assume the conditioning mode upon startup of a trailer 12.

The thermal conditioning unit 22 of the trailer 12 comprises a heating unit 30 and/or a cooling unit 32 for the battery 20. Conditioning the battery 20 comprises heating or cooling the battery 20, by the heating unit 30 or the cooling unit 32, respectively.

The control unit 24 of the trailer 12 comprises an operating mode and a sensor 34, in particular a temperature sensor 36, for detecting a parameter 38, in particular a temperature 40, of the battery 120. The control unit 24 is configured to switch from the conditioning mode to the operating mode, when the parameter 38 meets a control condition. The control condition may be “if the parameter 38 is higher than a predetermined threshold value”, for example.

The tractor 14 comprises a drive system 41 , for example an internal combustion drive system 42, a hybrid drive system 44 or an electric drive system 46.

The tractor 14 comprises a signaling unit 48 and is configured to communicate a status information 50 to an operator 52 of the tractor-trailer-combination 10. The status information 50 comprises at least one of an information 54.1 on whether or not the control unit 24 is in the conditioning mode and an information 54.2 on the parameter 38, in particular the temperature 40, of the battery 20.

Fig. 2 shows the control unit 24 of the trailer 12 of Fig. 1 in more detail. The control unit 24 comprises a conditioning mode 56 and an operating mode 58.

The control unit 24 is configured in the conditioning mode 56 to control the electric machine 18 to convert a given motion 26 of a first axle 16 to an electric power 28. The control unit 24 is also configured in the conditioning mode 56 to control the thermal conditioning unit 22 to thermally condition the battery 20 using the electric power 28 converted from the given motion 26.

The control unit 24 comprises a drive mode 60 as part of the operating mode 58. In the drive mode 60, the control unit 24 is configured to control the electric machine 18 to convert an electric power 28 supplied by the battery 20 to drive the trailer 12.

In Fig. 2, the control unit 24 further comprises a recuperation mode 62 as part of the operating mode 58. In the recuperation mode 62, the control unit 24 is configured to control the electric machine 18 to convert a given motion 28 of the first axle 16 of the trailer 12 to an electric power 28. In the recuperation mode 62, the control unit 24 is further configured to control the electric machine 18 and the battery 20 to charge the battery 20 using the electric power 28 converted from the given motion 26. Fig. 3 shows a method 64 for operating a trailer or a tractor-trailer-combination comprising a trailer, for example as depicted in Fig. 1 . A control unit of the trailer comprises a conditioning mode 64 and an operating mode 58. The control unit is configured to assume the conditioning mode 64 upon a startup 66 of the trailer. The trailer further comprises a sensor 34, in particular a temperature sensor 36, for detecting a parameter 38, in particular a temperature 40, of a battery of the trailer. The control unit is configured to switch from the conditioning mode 64 to the operating mode 60 when the parameter 38 meets a control condition 68.

Fig. 4 shows a method 69 for operating a trailer or a tractor-trailer-combination comprising a trailer, for example as depicted in Fig. 1 . A control unit of the trailer is configured to switch from a conditioning mode 64 to an operating mode 60 when a predetermined time 70 has lapsed with respect to a predetermined event 72.

Fig. 5 shows a method 73 for operating a tractor-trailer-combination, for example tractor-trailer-combination 10 of Fig. 1 , comprising a tractor and a trailer. The trailer comprises a first axle, an electric machine coupled to the first axle, a battery for the electric machine, and a thermal conditioning unit for thermally conditioning the battery.

The method 73 of Fig. 5 comprises beginning 75 a trip 76 with the tractor-trailer- combination.

Over a first time duration 78 after beginning 75 of the trip 76, the method 73 comprises driving 79 the tractor-trailer-combination by a drive system of the tractor, for example a combustion drive system, a hybrid drive system and an electric drive system, converting 80 a given motion 26 at the first axle to an electric power 28 by an electric machine and thermally conditioning 81 the battery using the electric power 28 converted from the given motion 26. Thermally conditioning 81 the battery comprises heating 82 or cooling 84 the battery.

Over a second time duration 86 after the first time duration 78, the method 73 comprises driving 87 the tractor-trailer-combination by both the electric machine of the trailer and the drive system of the tractor. The electric machine of the trailer is powered by an electric power provided by the battery.

The method 73 of Fig. 5 may also include the method 64 of Fig. 3 and/or the method 69 of Fig. 4.

Fig. 6 shows a tractor-trailer-combination 10 comprising a tractor 14 and a trailer 12. The tractor-trailer-combination 10 of Fig. 6 may be configured like the tractor-trailer- combination 10 of Fig. 1 and reference numerals a provided accordingly.

In Fig. 6, the tractor 14 comprises a hybrid drive system 44 or an electric drive system 46 and in any of the two cases a battery 88. The tractor 14 further comprises a control unit 90, a thermal conditioning unit 92 for the battery 88 of the tractor 14 and an electric machine 94. The electric machine 94 is coupled to an axle 95 of the tractor 14 and can, thus, drive the axle 95 or generate power from a given motion at the axle 95.

The trailer 12 comprises a first axle 16, an electric machine 18, a battery 20, a thermal conditioning unit 22 and a control unit 24.

The tractor-trailer-combination 10 of Fig 6. is positioned at a charging station 96. The charging station 96 comprises a first charging port 98.1 and a second charging port 98.2. A charging port can generally be any kind of stationary power outlet. Typically, a charging port comprises a standardized socket specifically configured for electrically charging vehicles.

In Fig. 6, the control unit 90 of the tractor 14 is connected to the first charging port 98.1 and the control unit 24 of the trailer 12 is connected to the second charging port 98.2. In this scenario, the control unit 90 of the tractor 14 may charge the battery 88 of the tractor 14 and/or before that, meanwhile, or afterwards control the thermal condition unit 92 of the tractor 14 to thermally condition the battery 88 of the tractor 14 using electric power 28 provided by the first charging port 98.1 . The control unit 24 of the trailer 12 may charge the battery 20 of the trailer 12 and/or before that, meanwhile or afterwards control the thermal conditioning unit 22 of the trailer 12 to thermally condition the battery 20 of the trailer 12 using electric power 28 provided by the second charging port 98.2.

In the scenario depicted in Fig. 6, the thermal conditioning unit 22 may fully thermally condition the battery 20 of the trailer 12 as needed before the tractor-trailer- combination 10 starts a trip. However, it may still be advantageous to control the thermal conditioning unit 22 to thermally condition the battery 20 using electric power 28 converted from a given motion 26 of the first axle 16, for example if there is not enough time to fully thermally condition the battery 20 of the trailer 12 at the charging station 96.

Fig. 7 shows the tractor-trailer-combination 10 of Fig. 6 in a different scenario. The tractor-trailer-combination 10 of Fig. 7 is positioned at a charging station 96, which comprises only one available charging port 98.

The control unit 90 of the tractor 14 can, for example, be connected to the first charging port 98 first. The control unit 90 of the tractor 14 may charge the battery 88 of the tractor 14 and/or before that, meanwhile or afterwards control the thermal conditioning unit 92 of the tractor 14 to thermally condition the battery 88 of the tractor 14 using electric power 28 provided by the charging port 98. Afterwards the control unit 24 of the trailer 12 can be connected to the charging port 98. The control unit 24 of the trailer 12 may charge the battery 20 of the trailer 12 and/or before that, meanwhile, or afterwards control the thermal condition unit 22 of the trailer 12 to thermally condition the battery 20 of the trailer 12 using electric power 28 provided by the charging port 98. A drawback is, however, that the total time needed at the charging station 98 is high, basically twice as high as in the scenario of Fig. 6. Also, it means additional effort for the operator 52.

Fig. 8 shows a tractor-trailer-combination 10 of Figs. 6 and 7 in another scenario. The tractor-trailer-combination 10 is positioned at a charging station 96 in Fig. 8. The charging station 96 comprises one available charging port 98.

In Fig. 8, the control unit 90 of the tractor 14 is connected to the charging port 98 of the charging station 96. The control unit 90 of the tractor 14 may charge the battery 88 of the tractor (14) and before that, meanwhile or afterwards control the thermal conditioning unit 92 of the tractor 14 to thermally condition the battery 88 of the tractor 14 using electric power 28 provided by the charging port 98. In the scenario depicted in Fig. 8, the thermal conditioning unit 92 may fully thermally condition the battery 88 of the tractor 14 as needed before the tractor-trailer- combination 10 starts a trip 76.

In Fig. 8, the tractor-trailer-combination 10 may start a trip after thermally conditioning the battery 88 of the tractor 14. After having started a trip, the tractor-trailer- combination 10 is only driven by the tractor 14. Thus a given motion 26 is generated at the first axle 16 of the trailer 12. The given motion 26 is then converted to an electric power 28 by the electric machine 18. The generated electric power 28 powers the thermal conditioning unit 22 of the trailer 12 to condition the battery 20 of the trailer 12.

Fig. 9 shows a tractor-trailer-combination 10 comprising a tractor 14 and a trailer 12. The tractor-trailer-combination 10 of Fig. 9 may be configured like the tractor-trailer- combination 10 of Fig. 1 and reference numerals are provided accordingly.

In Fig. 9, the tractor 14 comprises an internal combustion drive system 42. The trailer 12 comprises a first axle 16, an electric machine 18, a battery 20, a thermal conditioning unit 22 and a control unit 24.

The tractor-trailer-combination 10 of Fig. 9 is positioned at a charging station 96. The charging station 96 comprises one available charging port 98. The control unit 24 of the trailer 12 is connected to the charging port 98 at the charging station 96. The control unit 24 of the trailer 12 may charge the battery 20 of the trailer 12 and/or before that, meanwhile or afterwards control the thermal condition unit 22 of the trailer 12 to thermally condition the battery 20 of the trailer 12 using electric power 28 provided by the charging port 98. However, time at the charging station 96 can be saved by not or not fully conditioning the battery 20 of the trailer 12 but rather conditioning the battery 20 during a trip by generating electric power 28 from a given motion 26 at the first axle 16, while the trailer 12 is pulled by the tractor 14. Fig. 10 shows the tractor-trailer-combination 10 of Fig. 9 in a different scenario. In

Fig. 10, the tractor-trailer-combination 10 is not connected to a charging port 98 of a charging station 98 to illustrate, that thermal conditioning of the battery 20 of the trailer 12 can be done completely without receiving power from the grid. Instead, the battery 20 can be thermally conditioned during the trip with power 28 generated from a given motion 26 induced by the tractor 14 pulling the trailer 12.

List of References (part of the description)

10 tractor-trailer-combination

12 trailer

14 tractor

16 first axle

18 electric machine

20 battery

21 driving direction

22 thermal conditioning unit

24 control unit

26 motion

28 electric power

30 heating unit

32 cooling unit

34 sensor

36 temperature sensor

38 parameter

40 temperature

41 drive system

42 internal combustion drive system

44 hybrid drive system

46 electric drive system

48 signaling unit

50 status information

52 operator

54.1 information

54.2 information

56 conditioning mode

58 operating mode

60 drive mode

60 operating mode

62 recuperation mode

64 method 66 startup

68 control condition

69 method

70 predetermined time

72 predetermined event

73 method

75 beginning

76 trip

78 first time duration

79 driving

80 converting

81 thermally conditioning

82 heating

84 cooling

86 second time duration

87 driving

88 battery

90 control unit

92 thermal conditioning unit

94 electric machine

96 charging station

98 charging port

98.1 charging port

98.2 charging port

Claims

1. Trailer (12) for a tractor-trailer-combination (10), the trailer (12) comprising a first axle (16), an electric machine (18) coupled to the first axle (16), a battery (20) connected to the electric machine (18), a thermal conditioning unit (22) for thermally conditioning (81 ) the battery (20), and a control unit (24) configured to control the electric machine (18) and the thermal conditioning unit (22), characterized in that the control unit (24) comprises a conditioning mode (56), wherein the control unit (24) is configured in the conditioning mode (56) to control the electric machine (18) to convert (80) a given motion (26) of the first axle (16) to an electric power (28) and to control the thermal conditioning unit (22) to thermally condition (81 ) the battery (20) using the electric power (28) converted (80) from the given motion (26).

2. T railer (12) in accordance with claim 1 , wherein the thermal conditioning unit (22) comprises a heating unit (30) and/or a cooling unit (32) for the battery (20) and wherein thermally conditioning (81) the battery comprises heating (82) or cooling (84) the battery (20).

3. Trailer (12) in accordance with one of the preceding claims, wherein the control unit (24) is configured to assume the conditioning mode (56) upon startup (66) of the trailer (12).

4. Trailer (12) in accordance with one of the preceding claims, wherein the control unit (24) comprises an operating mode (60), wherein the trailer (12) comprises a sensor (34) for detecting a parameter (38) of the battery (20), wherein the control unit (24) is configured to switch from the conditioning mode (56) to the operating mode (58) when the parameter (38) meets a control condition (68).

5. Trailer (12) in accordance with claim 4, wherein the sensor (34) is a temperature sensor (36) and wherein the parameter (38) is a temperature (40).

6. Trailer (12) in accordance with one of the preceding claims, wherein the control unit (24) is configured to switch from the conditioning mode (56) to the operating mode (58) when a predetermined time (70) has elapsed with respect to a predetermined event (72).

7. Trailer (12) in accordance with one of the preceding claims, wherein the control unit (24) comprises a drive mode (60) as part of the operating mode (58), wherein in the drive mode (60) the control unit (24) is configured to control the electric machine (18) to convert an electric power (28) supplied by the battery (20) to drive the trailer (12).

8. Trailer (12) in accordance with one of the preceding claims, wherein the control unit (24) comprises a recuperation mode (62) as part of the operating mode (58), wherein in the recuperation mode (58) the control unit (24) is configured to control the electric machine (18) to convert a given motion (26) of the first axle (16) to an electric power (28) and to control the electric machine (18) and the battery (20) to charge the battery (20) using the electric power (28) converted from the given motion (26).

9. Tractor-trailer-combination (10) comprising a tractor (14) and a trailer (12), wherein the trailer (12) is configured in accordance with one of the preceding claims.

10. Tractor-trailer-combination (10) in accordance with claim 9, wherein the tractor (14) comprises an internal combustion drive system (42), a hybrid drive system (44) or an electric drive system (46).

11 . Tractor-trailer-combination (10) in accordance with one of claims 9 to 10, wherein the trailer (12) and/or the tractor (14) comprises a signaling unit (48) and is configured to communicate a status information (50) to an operator (52) of the tractor-trailer-combination (10), wherein the status information (50) comprises at least one of: an information (54.1 ) on whether or not the control unit (24) is in the conditioning mode (56), an information (54.2) on a parameter (38), in particular a temperature (40), of the battery (20).

12. Method (73) for operating a tractor-trailer-combination (10), the tractor-trailer-combination (10) comprising a tractor (14) and a trailer (12), the trailer (12) in particular being configured in accordance with one of claims 1 to 8, the tractor-trailer-combination (10) in particular being configured in accordance with one of claims 9 to 11 , the trailer (12) comprising: a first axle (16), an electric machine (18) coupled to the first axle (16), a battery (20) for the electric machine (18) and a thermal conditioning unit (22) for thermally conditioning (81 ) the battery (20), the method (73) comprising the steps (80, 81 ): converting (80) a given motion (26) at the first axle (16) to an electric power

(28) by the electric machine (18), thermally conditioning (81 ) the battery (20) using the electric power (28) converted (80) from the given motion (26).

13. Method (73) in accordance with claim 12, the method (73) comprising beginning (75) a trip (76) with the tractor-trailer- combination (10), wherein over a first time duration (78) after beginning (75) the trip (76) the method (73) comprises: driving (79) the tractor-trailer-combination (10) by a drive system (41 ) of the tractor (14), converting (80) a given motion (26) at the first axle (16) to an electric power (28) by the electric machine (18) and thermally conditioning (81 ) the battery (20) using the electric power (28) converted (80) from the given motion (26); wherein over a second time duration (86) after the first time duration (78) the method (73) comprises: - driving (87) the tractor-trailer-combination (10) by both the electric machine

(18) of the trailer (12) and the drive system (41 ) of the tractor (14).