Method for transporting a second vehicle by means of a first vehicle

Abstract

The invention relates to a method for transporting a second vehicle (20) by means of a first vehicle (10) which has a first control unit (22). The two vehicles (10, 20) are coupled together by at least one connection (26) and form a combination (21). At least the second vehicle (20) comprises an electric drive (30) or an E-axle module (56) and a second control unit (28). According to the method, a) the selection of a recuperation strategy (74) for recovering electric energy in the second vehicle (20) is carried out such that electric loads integrated into the low-voltage onboard electrical system (40) of the second vehicle are supplied, and a battery (42) is not discharged or is charged; b) the first vehicle (10) is supported in acceleration or deceleration phases by correspondingly actuating the electric drive (30) or the E-axle module (56) of the second vehicle (20); and c) the deceleration according to step b) is maximized by the second vehicle (20) while taking into consideration the limits of the drive stability of the combination (21) formed by the first vehicle (10) and the second vehicle (20).

Description

[0001] Method for transporting a second vehicle by means of a first vehicle

[0002] Technical area

[0003] The invention relates to a method for transporting a second vehicle by means of a first vehicle with a first control unit, wherein the vehicles are coupled to one another by at least one connection and form a vehicle combination, and at least the second vehicle comprises an electric drive or an electric axle module and a second control unit. Furthermore, the invention relates to the use of the method for transporting a second vehicle by means of a first vehicle.

[0004] State of the art

[0005] DE 101 57 976 A1 relates to a control system for a combination vehicle having a tractor and a trailer. The control system comprises a computer, a memory accessible by the computer, sensors operatively connected to the computer, output signals from the computer, and at least two brake control units for wheels of the trailer. The brake control units are connected to the computer, and the computer receives input signals from the sensors of the combination vehicle and calculates braking movements to control the movement of the combination vehicle.

[0006] EP 2 039 577 B2 discloses a combination of a towing device, an electric vehicle, and a towing vehicle for towing the electric vehicle. The electric vehicle comprises a high-voltage line for supplying power from a storage device via an inverter to a drive motor, a storage device control unit for controlling the storage device, a vehicle control unit for controlling the drive motor and the high-voltage line, a low-voltage line for supplying voltage to the inverter, the storage device control unit, and the vehicle control unit, and a communication network for transmitting signals between the vehicle control unit, the inverter, and the storage device control unit.The towing device includes a connection tool mounted between the electric vehicle and the towing vehicle and transmitting a towing force of the towing vehicle to the electric vehicle, and a communication cable detachably connected to a connection port connected to the communication network and arranged in the towing vehicle.

[0007] The drive motor prioritization control unit connects to the vehicle control unit. The towing device also has a power supply cable that is detachably connected to a power supply connector connected to the low-voltage line and connects a current / voltage source located in the towing vehicle to the low-voltage line.

[0008] One application particularly common in the USA for transporting or towing vehicles is pulling a vehicle along, for example behind a mobile home. The towed vehicle is towed for long periods of time and over long distances. This does not involve towing a vehicle that has been involved in an accident or has been damaged, or a vehicle that needs to be removed from a no-parking zone, but rather the targeted transport of an intact vehicle. The towed vehicle is either parked with its drive axle on a dolly (“Dolly Tow”) or rolls with all four wheels directly on the road. For this to happen, vehicles with an internal combustion engine must be put into neutral, thus decoupling the engine and drive axle. In addition, the braking system of the towed vehicle is connected mechanically, pneumatically, or electrically to the towing vehicle so that the latter can brake mechanically.Finally, a 12-volt electrical system, i.e. a low-voltage network of the towed vehicle, is connected in some variants to the towing vehicle so that it does not discharge during longer journeys.

[0009] Today's electric vehicles generally lack a shiftable transmission or a detachable clutch on their main drive axle, and the permanent magnet electric motors typically installed make it difficult to tow long distances. Without active control, the electric motor would continuously generate current or voltage, which would lead to electrical or thermal damage to the entire electric drive after a short period of driving.

[0010] Description of the invention

[0011] According to the invention, a method for transporting a second vehicle by means of a first vehicle with a first control unit is proposed, wherein the vehicles are coupled to one another by at least one connection and form a combination and at least the second vehicle comprises an electric drive or an e-axle module and a second control unit, and wherein the following method steps are carried out: a) selection of a recuperation strategy for recovering electrical energy in the second vehicle such that electrical consumers are supplied in its low-voltage on-board network and a battery is not discharged or charged;b) supporting the first vehicle in acceleration or deceleration phases by appropriately controlling the electric drive or the e-axle module of the second vehicle and c) maximising a deceleration according to method step b) by the second vehicle, taking into account the limits of the driving stability of the vehicle combination formed by the first vehicle and the second vehicle.;

[0012] The method proposed by the invention enables the transport of an electric vehicle over long distances in towing mode on four rolling wheels, without the need for a separate transport base and without the risk of damage to the electric vehicle for the reasons outlined above. Furthermore, it ensures that a discharge of, for example, a 12-volt battery in the low-voltage circuit is avoided, all functions are permanently maintained, and no additional power supply from the towing vehicle, i.e., the first vehicle, is required.

[0013] In a further embodiment of the method proposed according to the invention, according to method step a), the battery charge level and consumption in the low-voltage vehicle electrical system are recorded continuously or at specific times, and an inverter of the electric drive is controlled accordingly. This allows the recuperation power of the electric drive to be adapted to the consumption occurring in the low-voltage vehicle electrical system or to the charge level of the battery present in the low-voltage system.

[0014] In an advantageous embodiment of the method proposed according to the invention, according to method step a), when the battery is discharged, an increase in the power of a DC / DC converter arranged between a high-voltage electrical system and the low-voltage electrical system of the second vehicle is requested, which is obtained from the rolling movement of the second vehicle according to the recuperation strategy.

[0015] In the method proposed according to the invention, the first and the second vehicle are connected to one another via a wireless communication connection between the first control unit and the second control unit.

[0016] This means that data and information are exchanged between the two vehicles forming the vehicle combination while driving.

[0017] In an advantageous development of the method proposed according to the invention, in the case where both vehicles are equipped with an electric axle module and traction batteries, the recuperation strategy for recovering electrical energy and feeding it into the traction batteries is decided based on the elevation profile of a route. The method proposed according to the invention enables the selection of a recuperation strategy based on the desired state of charge of the respective traction batteries at the destination of the route.

[0018] According to the method proposed by the invention, the traction batteries recuperate in equal proportions according to a first recuperation strategy (A) and have first and second increased states of charge at the destination.

[0019] Alternatively, in the method proposed according to the invention, according to a second recuperation strategy (B), it can be achieved that only the first vehicle recuperates electrical energy and its traction battery assumes a charge state “almost fully charged” upon reaching the destination.

[0020] Finally, in the method proposed according to the invention, it is possible, according to a third recuperation strategy (C) to be applied, for only the second vehicle to recuperate electrical energy and for its traction battery to assume a charge state of “almost fully charged”.

[0021] In the method proposed according to the invention, the limits of the driving stability of the vehicle combination are taken into account according to method step c) on the basis of one or more of the following criteria:

[0022] Crosswind acting on the team,

[0023] gradient of the route,

[0024] friction coefficient of the road surface,

[0025] Steering movement of the first vehicle,

[0026] Lateral inclination of the vehicles,

[0027] Relative movement of the two vehicles to each other,

[0028] Detection of vibrations / rocking.

[0029] In an advantageous embodiment of the method proposed by the invention, if the first vehicle is powered by an internal combustion engine, electrical energy is recuperated via the second vehicle, which alone decelerates the vehicle-trailer combination. Thus, the method proposed by the invention can also be used to decelerate a conventional vehicle using an electrically powered vehicle integrated into a vehicle-trailer combination.

[0030] In an advantageous development of the method proposed according to the invention, the first vehicle and the second vehicle or their control units are coupled to one another via a wireless communication connection, via which information regarding the time and intensity of recuperation is transmitted to the second vehicle.

[0031] In the method proposed by the invention, a controlled emergency braking of the second vehicle can advantageously be initiated if the connection between the first and second vehicles is interrupted. If the second vehicle is equipped with at least one driver assistance system, it can be controlled and guided to the side of the road to avoid endangering other road users. This represents a further safety improvement achievable with the method proposed by the invention.

[0032] In the method proposed according to the invention, the traction battery of the second vehicle can be charged with adjustable power, wherein the recuperation power can be adjusted depending on a length of the planned route, its gradient and a maximum permissible load for the first vehicle.

[0033] Finally, the invention relates to the use of the method for transporting a second vehicle by means of a first vehicle, wherein at least one of the vehicles comprises a traction battery and an electric drive or an e-axle module.

[0034] Advantages of the invention

[0035] The solution proposed according to the invention makes it possible to move an electric vehicle over long distances in tow mode behind a first, towing vehicle with four rolling wheels, i.e. without having to use a trailer or the like. Electrical or thermal overload can be avoided by applying the method proposed according to the invention. A battery arranged in the low-voltage circuit of the second vehicle, in this case the electric vehicle, does not discharge but is fed in an appropriately adjustable manner through recuperative operation of the electric drive unit, so that all functions are permanently maintained and no additional energy supply from the towing vehicle, i.e. the first vehicle, is required.

[0036] Furthermore, the method proposed by the invention ensures that no additional load is placed on the first, i.e., the towing vehicle, resulting in lower fuel consumption and less wear on its brakes. Furthermore, such a combination can be significantly improved in drivability, since the additional weight of the towed vehicle is either not noticeable or only slightly noticeable.

[0037] By using the method proposed according to the invention, freely controllable braking of the second vehicle can be achieved in the event of an unintentional uncoupling. Furthermore, the method proposed according to the invention offers the possibility, for example, of conditioning the second, i.e., the towed vehicle, so that it is fully loaded at the destination and can, for example, drive directly into an environmental zone that may exist there, i.e., is immediately ready for use.

[0038] Considering criteria for increasing driving stability or avoiding rocking between the towing vehicle and the towed vehicle can lead to a significant improvement in the driving stability of a combination within the framework of dynamic control. Furthermore, its energy efficiency can be increased if the towing vehicle cannot recuperate, for example, if it is a conventional vehicle with an internal combustion engine. In this case, any electrically generated deceleration is carried out in the towed, electrically powered vehicle. Brief description of the drawings

[0039] Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

[0040] They show:

[0041] Figure 1 A combination of a first towing vehicle and a second towed vehicle, which is an electrically powered vehicle, the two vehicles being coupled to each other via a connection,

[0042] Figure 2 shows a combination of two vehicles, which are electric vehicles and are mechanically coupled to each other via the connection,

[0043] Figures 3 and 3.1 show an altitude or route profile and the charge levels of the traction batteries of two vehicles coupled together according to Figure 2, preferably electrically powered vehicles, as determined by selected recuperation strategies, and

[0044] Figure 4 shows a combination of a first vehicle with an internal combustion engine and a second vehicle coupled to it, which is an electric vehicle.

[0045] Embodiments of the invention

[0046] In the following description of the embodiments of the invention, identical or similar elements are designated by the same reference numerals, whereby a repeated description of these elements is omitted in individual cases. The figures only schematically illustrate the subject matter of the invention.

[0047] Figure 1 shows a schematic view of a vehicle combination 21 comprising a first vehicle 10, which is the towing vehicle, and a second vehicle 20, which is the towed vehicle. The two vehicles 10, 20 form said vehicle combination 21 and are coupled to one another, for example, via a connection 26, which can be designed as a mechanical connection. The first vehicle 10 comprises a first control unit 22 (VCU, Vehicle Control Unit). The vehicle combination 21 is moved in a direction of travel 24, which is predetermined by the first vehicle 10. The second vehicle 20, which is coupled to the first vehicle 10 via the connection 26, has a second control unit 28 (VCU, Vehicle Control Unit). The illustration in Figure 1 further shows that the second vehicle 20 has an electric drive 30, which includes an electric machine 32 and an inverter 34.In addition, a high-voltage battery (not shown in detail) is also present in the second vehicle 20. This battery is part of a high-voltage electrical system 36 into which the electric machine 32 and the inverter 34 are integrated. Furthermore, the second vehicle 20 comprises a DC / DC converter 38, which separates said high-voltage electrical system 36 from another, namely a low-voltage electrical system 40, which typically operates at a voltage level of 12 volts. The low-voltage electrical system 40 contains at least one battery 42, which operates at a voltage level of 12 volts, while the high-voltage electrical system 36 of the second vehicle 20 has a voltage of approximately 400 volts. A positive terminal of the battery 42 is designated by reference numeral 44, while the negative terminal is designated by reference numeral 46.

[0048] If the vehicle combination 21 is moved in the direction of travel 24 by the first vehicle 10 as shown in Figure 1, the second vehicle 20 remains with its four wheels on the roadway, so that kinetic energy can be converted into electrical energy via the electric drive 30. This electrical energy, generated through recuperation, can be fed into the battery 42 of the low-voltage electrical system 40 and supply electrical energy to other consumers integrated into the low-voltage electrical system 40. Accordingly, a separate supply of the second vehicle 20 by the first vehicle 10, for example via the connection 26, is not necessary because the second vehicle 20 is essentially self-sufficient in terms of its energy supply.The second control unit 28 of the second vehicle 20 can control the amount of energy to be recuperated such that the demand of the low-voltage electrical system 40 is met and the battery 42 (12 volts) provided therein also reaches a desired charge level, typically being fully charged. For this purpose, the charge level of the battery 42 and the electrical system consumption, i.e., the consumption in the low-voltage electrical system 40, are continuously recorded, and the inverter 34 of the electric drive 30 is controlled accordingly.

[0049] The illustration in Figure 2 shows a vehicle combination 21 in which the first vehicle 10, moving in the direction of travel 24, has a first traction battery 50 and an electric axle module 52. The first vehicle 10 is coupled to the second vehicle 20, which is also an electrically powered vehicle, via the aforementioned connection 26. The second vehicle 20 of the vehicle combination 21 includes a second traction battery 54 and an electric axle module 56.

[0050] In the above context, the E-axle module 52, 56 is understood to be a combination of several components, wherein the components are an electric machine 32, an inverter 34 and, if appropriate, a single-stage or multi-stage transmission.

[0051] The combination 21, comprising the first and the second vehicle 10, 20, accordingly each has traction batteries 50, 54, so that both vehicles 10, 20 are able to recuperate considerable power.

[0052] As can be seen from the illustrations in Figures 3 and 3.1, various recuperation strategies 74 can be implemented on the basis of a downhill journey 60. During a longer downhill journey 60, as schematically indicated in Figure 3, which ends at a destination 68, a decision can be made as to which recuperation strategy 74 the recuperation power should be distributed between the two vehicles 10, 20 according to Figure 2 in order to achieve a desired charge state at the end of the journey, i.e., upon reaching the destination 68. Various recuperation strategies 76 (A), 86 (B), and 92 (C) are explained below with reference to Figures 3 and 3.1.

[0053] The starting point, as shown in Figure 3, is a start 66 of the downhill run 60, at which the traction batteries 50, 54 of the first vehicle 10 and the second vehicle 20, respectively, as shown in Figure 2, each have identical charge levels 70, 72. These levels can, for example, be 50% each at the start 66 of the downhill run 60. When a first recuperation strategy 76 (A) is implemented, recuperation takes place in both vehicles 10, 20 in equal parts during the downhill drive 60 until the destination 68 is reached, so that the respective traction batteries 50, 54 of both vehicles 10, 20 are each charged by an identical proportion 78, 80 when the destination 68 of the downhill drive 60 is reached and an increased state of charge 82, 84 is achieved in both traction batteries 50, 54 according to the first recuperation strategy 76.The respective shares 78, 80 obtained by the first recuperation strategy 76 are identical, as can be seen in the comparison in Figure 3.1.

[0054] If, however, a second recuperation strategy 86 (B) is selected during the downhill journey 60, the first vehicle 10 recuperates a higher power, whereas the second vehicle 20 does not recuperate as shown in Figure 2. As a result, the first traction battery 50 of the first vehicle 10 is significantly more charged at the end of the journey, i.e. upon reaching the destination 68, whereas the second traction battery 54 of the second vehicle 20 has an identical charge level compared to the start of the journey or is somewhat more depleted due to the possible self-consumption of the second vehicle 20. The second recuperation strategy 86 (B) is selected, for example, if the second vehicle 20 either has a defect or is not intended to continue driving on its own at the end of the journey anyway, but is heading to a workshop.

[0055] Finally, as shown in Figure 3, a further, third recuperation strategy 92 (C) is also possible, according to which, for example, the second, towed vehicle 20 recuperates during the downhill ride 60, whereas the towing, first vehicle 10 does not recuperate. In this case, at the destination 68 of the downhill ride 60, the first traction battery 50 of the first vehicle 10 is emptier, i.e., has a lower state of charge, compared to that at the start of the downhill ride 60, whereas the second traction battery 54 of the second vehicle 20 has a state of charge 96 of "almost fully charged". Thus, in this case, the second vehicle 20 could be moved on immediately upon reaching the destination 68, for example, enter an environmental zone with the second traction battery 54 almost fully charged and continue to be used there.

[0056] The illustration in Figure 4 shows a vehicle combination 21 in which the first vehicle 10 is powered by an internal combustion engine 102, whereas the second, towed vehicle 20 is an electrically powered vehicle comprising an e-axle module 52 and a traction battery 50. The two vehicles 10, 20 of the vehicle combination 21 shown in Figure 4 are connected to one another via the connection 26. Furthermore, a wireless communication connection 100 between the two vehicles 10, 20 ensures that information or data can be transmitted between the two control units 22, 28 of the two coupled vehicles 10, 20 that form the vehicle combination 21.

[0057] Naturally, the first vehicle 10 of the vehicle combination 21 according to Figure 4 has no recuperation option because it is powered by the internal combustion engine 102. In this case, recuperation takes place exclusively via the second vehicle 20. The second vehicle 20 not only supports the braking process proportionally, but is in particular solely responsible for decelerating the vehicle combination 21 as shown in Figure 4. This allows greater energy efficiency to be achieved because the towing vehicle, i.e. the first vehicle 10, does not recuperate. The two control units 22, 28, which are coupled to one another via the wireless communication link 100, communicate with one another so that the second vehicle 20 receives the information as to when and to what extent recuperation should begin.

[0058] The deceleration applied by the towed vehicle, i.e. the second vehicle 20, is maximized, taking into account possible limits of the driving stability of the vehicle combination 21. For example, the recuperation which effects the deceleration of the second vehicle 20 depends, for example, on the crosswind acting on the vehicle combination 21, on strong steering movements of the first vehicle 10 or on the condition or the coefficient of friction of the road surface on which the vehicle combination 21 is traveling. Furthermore, the maximum deceleration that can be achieved by the second vehicle 20 is limited by steep uphill or downhill gradients and by the maximum load or tractive force that can be applied by the first vehicle 10 that moves the vehicle combination 21.

[0059] By activating the second vehicle 20, which is usually the electrically powered vehicle within the vehicle combination 21, its electric drive 30 can be controlled so that no electrical or thermal overload occurs during the transport process. Just enough electrical energy is recuperated to continuously supply the 12-volt consumers in the low-voltage electrical system 40 of the second vehicle 20, preventing the battery 42 from discharging or even allowing it to be charged. The control of the electric drive 30 is set such that it assists the first vehicle 10 during acceleration or braking, thus behaving in such a way that no additional loads occur for the first vehicle 10 during deceleration or acceleration.The solution proposed according to the invention also makes it possible to ensure that, in the event of an interruption in the connection 26 between the first vehicle 10 and the second vehicle 20, the electric drive 30 of the second vehicle 20 comes to a standstill. Through appropriate control, the second traction battery 54 of the second vehicle 20 can be fully charged through continuous recuperation. The cooling system is controlled in such a way that any heat losses occurring in the inverter 34 and the electric machine 32 are dissipated to prevent overheating.

[0060] The low-voltage electrical system 40 shown in Figure 1 with the battery 42 (12 volts) is monitored by a battery sensor so that the current flow from or into the battery 42 is known. When the battery 42 is discharged, an increase in the power of the DC / DC converter 38, which is located between the high-voltage electrical system 36 and the low-voltage electrical system 40 of the second vehicle 20, is requested via a communication connection 100, for example via a CAN bus. The power is not drawn from the high-voltage battery, but rather generated directly through appropriate recuperation from the rolling motion of the second vehicle 20.

[0061] With the method proposed according to the invention, the electric drive 30 or the electric axle module 56 of the towed second vehicle 20 can be controlled in such a way that it supports acceleration or braking processes of the first vehicle 10. The second vehicle 20 is connected to the first, towing vehicle 10 via a wireless communication link 100, so that the second vehicle 20 can determine whether the first vehicle 10 is currently accelerating or decelerating. The current operating point of the electric drive 30 can be transmitted via the communication link 100. Alternatively, it is possible to detect a tension or force sensor or a potentiometer on the coupling of the first vehicle 10 via a mechanical transmission on the coupling, similar to an overrun brake, and to convert this into an electrical control signal for the second vehicle 20.During deceleration, the same logic applies in reverse. When the second vehicle 20 hits the coupling, the travel of the moving element or a force is detected and converted into an electrical signal. The second vehicle 20 uses the received signal to assist the first vehicle 10 and also accelerate or decelerate, thus automatically reducing the control signal again.

[0062] Advantageously, the method proposed according to the invention can control the electric drive 30 of the second vehicle 20 such that it intensively recuperates throughout the entire route 64 and thus charges a high-voltage battery accordingly according to an adjustable power consumption. Setting parameters for the consumed electrical power can be the length of the planned route 64, the gradient, i.e., the elevation profile 62, and a maximum load for the first vehicle 10 in order to achieve optimal charging in each case.

[0063] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, numerous modifications are possible within the scope of the claims, which are within the scope of one skilled in the art.

Claims

Claims 1 . Method for transporting a second vehicle (20) by means of a first vehicle (10) with a first control unit (22), wherein the vehicles (10, 20) are coupled to one another by at least one connection (26) and form a vehicle combination (21), and at least the second vehicle (20) comprises an electric drive (30) or an e-axle module (56) and a second control unit (28), with the following method steps: a) selecting a recuperation strategy (74) for electrical energy in the second vehicle (20) such that electrical consumers integrated in its low-voltage on-board network (40) are supplied and a battery (42) is neither discharged nor charged;b) assisting the first vehicle (10) in acceleration or deceleration phases by appropriately controlling the electric drive (30) or the E-axle module (56) of the second vehicle (20) and c) maximizing a deceleration according to method step b) by the second vehicle (20) taking into account limits of the driving stability of the vehicle combination (21) formed from the first vehicle (10) and the second vehicle (20); 2. Method according to claim 1, characterized in that according to method step a) a charge state of the battery (42) and a consumption in a low-voltage vehicle electrical system (40) are detected and an inverter (34) of the electric drive (30) is controlled accordingly.

3. Method according to claims 1 and 2, characterized in that according to method step a) when the battery (42) is discharged, an increase in the power of a DC / DC converter (38) arranged between a high-voltage electrical system (36) and the low-voltage electrical system (40) of the second vehicle (20) is requested, which increase is determined according to the Recuperation strategy (74) is obtained from the rolling motion of the second vehicle (20). Method according to claims 1 to 3, characterized in that the first vehicle (10) and the second vehicle (20) are connected to one another via a wireless communication link (100) between the first control unit (22) and the second control unit (28) and exchange information. Method according to claims 1 to 4, characterized in that, in the event that both vehicles (10, 20) are equipped with e-axle modules (52, 56) and traction batteries (50, 54), a decision is made according to an elevation profile (62) of a route (64) as to which recuperation strategy (74) is used to recover electrical energy and feed it into the traction batteries (50, 54).Method according to claim 5, characterized in that the recuperation strategy (74) is selected according to a desired state of charge (82, 84; 88, 90; 94, 96) of the traction batteries (50, 54) at the destination (68) of the route (64). Method according to claims 5 and 6, characterized in that, according to a first recuperation strategy (76) (A), the traction batteries (50, 54) recuperate in equal proportions (78, 80) and have first and second increased states of charge (82, 84) at the destination (68). Method according to claims 5 and 6, characterized in that, according to a second recuperation strategy (86) (B), only the first vehicle (10) recuperates electrical energy and its traction battery (50) has a state of charge (88) of "almost fully charged".Method according to claims 5 and 6, characterized in that according to a third recuperation strategy (92) (C) only the second vehicle (20) recuperates electrical energy and its traction battery (54) has a charge state (96) "almost fully charged". Method according to claims 1 to 9, characterized in that, according to method step c), the limits of the driving stability of the vehicle combination (21) are taken into account based on one or more of the following criteria: crosswind acting on the vehicle combination (21), incline or decline of the route (64), coefficient of friction of the road surface, steering movements of the first vehicle (10), lateral inclination of the vehicles (10, 20), relative movement of the two vehicles (10, 20) to one another, detection of vibrations / rocking. Method according to claim 1, characterized in that, if the first vehicle (10) is driven by an internal combustion engine (102), recuperation of electrical energy takes place via the second vehicle (20), and this alone decelerates the vehicle combination (21).Method according to claim 11, characterized in that the first vehicle (10) and the second vehicle (20) or their control units (22, 28) are coupled to one another via a wireless communication link (100), via which information regarding the time and intensity of the recuperation is transmitted to the second vehicle (20). Method according to claims 1 to 11, characterized in that if the connection (26) between the first vehicle (10) and the second vehicle (20) is interrupted, a controlled emergency braking of the second vehicle (20) is initiated or, in the case of a second vehicle (20) equipped with at least one driver assistance system, its controlled navigation to the edge of the roadway is carried out. Method according to claims 1 to 13, characterized in that the traction battery (54) of the second vehicle (20) is charged with an adjustable power, wherein the recuperation power. depending on the length of the planned route (64), its gradient (62) and a maximum permissible load for the first vehicle (10).

15. Use of the method according to one of claims 1 to 14 for Transport of a second vehicle (20) by means of a first vehicle (10), wherein at least one of the vehicles (10, 20) comprises a traction battery (50, 54) and an electric drive (30) or an e-axle module (52, 56).

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