Method and device for coupling an electric machine

Abstract

The invention relates to a device for coupling a second electric machine to a wheel of a vehicle by means of a decoupling unit while the vehicle has been driven by a first electric machine. The device is configured to determine that the second electric machine is to be coupled to a wheel of the vehicle. The device is configured to cause, in response to the determination, at least one scenario measure by means of which a user of the vehicle can perceive the coupling of the second electric machine.

Description

Technical Field

[0001] The invention relates to a method and a corresponding device for coupling an electric machine to an axle of a motor vehicle. Background Art

[0002] An electrically driven motor vehicle may include one or more electric machines which are fixedly connected to axles of the vehicle, for example the front axle or the rear axle, in order to drive the axles and thus the vehicle.

[0003] In all-wheel drive vehicles, the two axles of the vehicle are usually driven by a dedicated motor group. A decoupling unit can be provided between at least one axle and the respective motor group to selectively decouple the motor group from the axle, for example when all-wheel operation is not required and / or desired for driving the vehicle.

[0004] The decoupling unit may have a dead time in order to couple the electric machine group to the axle and subsequently generate a drive torque at the axle. This dead time and the resulting (possibly smooth) increase in the additional drive torque or torque may be perceived by the vehicle user as unpleasant and / or slow or not sporty enough. Summary of the invention

[0005] The present invention relates to the technical object of increasing the comfort and / or sportiness of the vehicle in an efficient manner when coupling an electric machine of the vehicle.

[0006] This task is solved by each independent claim. Advantageous embodiments are further described in the dependent claims. It should be noted that the additional features of the claims dependent on the independent claims can constitute an independent invention independent of the combination of all features of the independent claims without the features of the independent claims or in combination with only some of the features of the independent claims, which can be the technical solution of the independent claims, divisional applications or subsequent applications. The same applies to the technical teachings described in the specification, which can form inventions independent of the features of the independent claims.

[0007] According to one aspect, a device is provided for coupling a second electric machine to a wheel of a (motor) vehicle by means of a decoupling unit, in particular by means of a clutch, for example by means of a dog clutch. The vehicle can already be driven by a first electric machine. The first electric machine can be designed to drive a first axle of the vehicle and the second electric machine can be designed to drive a second axle of the vehicle, on which the at least one wheel to be driven of the vehicle is arranged. The first axle can be the front axle of the vehicle and the second axle can be the rear axle of the vehicle. Alternatively, the first axle can be the rear axle and the second axle can be the front axle.

[0008] The decoupling unit can be designed to decouple the second electric machine from the wheels (to be driven), in particular from the second axle, in the open state. Furthermore, the decoupling unit can be designed to couple the second electric machine to the wheels, in particular from the second axle, in the closed state, so that (when a torque is generated by the second electric machine) the wheels and / or the second axle are driven by the second electric machine.

[0009] The vehicle can thus have a (purely) electric all-wheel drive, in which the second electric machine can be decoupled from the second axle of the vehicle (via a decoupling unit) if necessary (in order to achieve the most efficient possible operation of the vehicle). On the other hand, the second electric machine can be coupled again to the second axle (for example in order to provide an increased drive torque for the vehicle).

[0010] The device is provided for determining that the second electric machine is to be coupled to the wheels of the vehicle. For example, it can be detected that an additional drive torque is required to drive the vehicle (in addition to the drive torque caused by the first electric machine), which can be provided by the second electric machine (after coupling).

[0011] The vehicle may include dedicated control elements, in particular shift paddles (on the steering wheel) and / or a kick-down pedal and / or an operating button or key (which enables a user of the vehicle, in particular the driver, to explicitly request the coupling of the second motor). The device may be configured to detect the operation of the control element. Based on the detected operation, it is then determined that the second motor should be coupled to the wheels of the vehicle. Subsequently, the coupling of the second motor (via the (closed) decoupling unit) to the vehicle wheels can also be achieved. By providing a dedicated control element for requesting the coupling of the second motor, the coupling of the second motor can be achieved particularly conveniently.

[0012] In particular, by providing a dedicated control and / or operating element, it is possible to switch the coupling unit into the closed state (in order to couple the second electric machine to the wheels, in particular to the second axle) before the vehicle user requests additional power via the vehicle accelerator pedal (for example, to start an overtaking process). A torque and / or power increase can then be brought about (via the second electric machine) without delay (in response to the actuation of the accelerator pedal).

[0013] The device may also be designed to execute at least one scenario-based measure in response to the determination, by which the coupling of the second electric machine is made perceptible to a user of the vehicle, in particular a driver.

[0014] For example, it can be determined at the recognition time that the second electric machine should be coupled to the wheels of the vehicle (in particular to the second axle). Furthermore, at the subsequent coupling time, the device can couple the second electric machine to the wheels of the vehicle (in particular to the second axle) via the decoupling unit. This can be achieved by closing the decoupling unit.

[0015] The device can be configured to prepare scenario-based measures between the recognition time and the coupling time in such a way that at the coupling time a user of the vehicle can perceive the coupling of the second electric machine, in particular through additional vehicle acceleration and / or (additional and / or changed) noises and / or (additional and / or changed) graphical displays.

[0016] The actual coupling of the second electric machine to the wheels of the vehicle, in particular to the second axle, can for example cause basic acceleration and / or basic jerk (ruck) and / or basic noise and / or basic display. These can be designed so that they are respectively perceived by the user as relatively weak and / or disturbing and / or not perceived at all. The at least one scenario-based measure is intended (at the moment of coupling) to

[0017] - Causes scenario-based accelerations that exceed the baseline acceleration (e.g. 10% or more); and / or

[0018] - Causes situational jerks that exceed baseline jerks (e.g. 10% or more); and / or

[0019] - induces scene-based noise that exceeds the base noise (e.g. 10% or more);

[0020] - Provoking a situational display that differs from the basic display (for example by (additional and / or changed) animation and / or coloring and / or graphic elements of the display).

[0021] In this case, the situational acceleration and / or the situational jerk and / or the situational noise and / or the situational display can be so strong that they can be perceived by the user as a driving experience.

[0022] The coupling of the second electric machine can thus be contextualized in a clear and additionally perceptible manner in order, for example, to increase the comfort of the vehicle in an effective manner.

[0023] The device can be configured to reduce the torque caused by the first electric machine before the coupling moment within the scope of the scenario-based measures, in particular to reduce it by a torque reserve. For example, the first electric machine can provide a target torque at the recognition moment. The device can reduce the torque caused by the first electric machine (until the coupling moment) to a reduced torque in order to generate a torque reserve. The reduced torque can be, for example, 5% or more lower than the target torque.

[0024] The device can also be configured to increase the torque caused by the first electric machine again at the coupling time of the second electric machine, in particular to increase the torque reserve. Thus, a perceptible (as a driving experience) scenario of the coupling of the second electric machine can be achieved in a particularly effective manner.

[0025] The device can be provided to reduce the torque caused by the first electric machine, in particular smoothly (and therefore imperceptibly to the user), from the moment of recognition until the moment of coupling. Furthermore, the device can be provided to suddenly increase the torque caused by the first electric machine at the moment of coupling, in particular to increase it by a torque reserve. The coupling can thus be contextualized in a particularly comfortable manner.

[0026] Alternatively or additionally, the device can be configured to increase the speed of the second electric machine to an overspeed before the coupling time within the scope of the scenario-based measures, which is greater than the target speed of the second electric machine for coupling. The target speed can depend on the current speed of the vehicle wheels.

[0027] The device can be configured to determine the current rotational speed of the wheel (at the time of identification). Based on this, a target rotational speed of the second electric machine for coupling can be determined, for example, so that the target rotational speed corresponds to the current rotational speed of the wheel (taking into account the transmission ratio between the shaft of the second electric machine and the axle of the wheel).

[0028] The second motor can be adjusted to an extra high speed (between the recognition time and the coupling time), which is higher than the target speed by, for example, 5% or more. In particular, the speed of the second motor can be increased to the extra high speed from the recognition time until the coupling time.

[0029] Furthermore, the second electric machine can be coupled to the wheels of the vehicle via the decoupling unit at the coupling time. Due to the very high rotation speed of the second electric machine and due to the inertia of the shaft of the second electric machine, effects that can be perceived by the user are generated, in particular in terms of additional acceleration of the vehicle and / or noises emitted by means of one or more loudspeakers and / or graphical displays by means of one or more screens of the vehicle displaying operating options. Thus, the coupling of the second electric machine can be contextualized in a particularly comfortable and / or sporty manner.

[0030] The device can be configured to drive the centrifugal force unit (e.g., flywheel) in particular by the second motor before the coupling moment within the scope of the scenario-based measures. In addition, the second motor and the driven centrifugal force unit can be coupled to the wheels of the vehicle via the decoupling unit at the coupling moment, so that the driven centrifugal force unit generates a user-perceivable effect, in particular, an additional vehicle acceleration and / or a noise emitted by one or more loudspeakers and / or a graphic display by one or more screens displaying an operating scheme of the vehicle. Thus, the coupling can be scenario-based in a particularly comfortable and / or sporty manner.

[0031] It should be noted that one or more of the scenario-based measures described in this document may be used in a corresponding manner to generate an additional (perceptible) vehicle deceleration (eg when coupling a second electric machine in order to recover electrical energy from the vehicle's kinetic energy).

[0032] The device can be configured in particular to determine that the second electric machine should be coupled to the wheels of the vehicle for recuperation. The speed of the second electric machine is then adjusted to a reduced speed that is less than a target speed of the second electric machine before the coupling time within the scope of the scenario-based measures.

[0033] The device can also be configured to couple the second electric machine to the wheels of the vehicle via the decoupling unit at the coupling time, so that due to the reduced rotational speed of the second electric machine and due to the inertia of the shaft of the second electric machine, a user-perceptible effect is generated, in particular in terms of additional vehicle deceleration and / or noise generated by means of one or more loudspeakers and / or by means of a graphic display of one or more screens displaying an operating concept of the vehicle. The coupling can thus be contextualized in a particularly comfortable and / or sporty manner.

[0034] The device may be configured to determine the driving speed and / or acceleration of the vehicle (e.g., the driving speed and / or acceleration at the time of identification). The one or more scenario-based measures may then be initiated as a function of the driving speed and / or acceleration of the vehicle. In particular, the extent and / or intensity of the one or more scenario-based measures may be adjusted as a function of the driving speed and / or acceleration, such as the level of the torque reserve of the first motor initiated within the scope of the scenario-based measures and / or the level of the ultra-high speed of the second motor initiated within the scope of the scenario-based measures.

[0035] Here, the device may be configured to cause the one or more scenario-based measures when the driving speed is less than a speed threshold and / or when the acceleration is less than an acceleration threshold. Alternatively or additionally, the device may be configured to not cause and / or prohibit the one or more scenario-based measures when the driving speed is greater than a speed threshold and / or when the acceleration is greater than an acceleration threshold. Alternatively or additionally, the extent of the one or more measures, in particular the level of the torque reserve and / or the level of the ultra-high speed, is reduced with increasing driving speed and / or with increasing acceleration, and / or is increased with decreasing driving speed and / or with decreasing acceleration.

[0036] Therefore, the coupling of the second electric machine can be scenario-based according to the current driving speed and / or the current acceleration of the vehicle, so that, for example, the comfort and / or driving experience of the vehicle can be further improved.

[0037] Alternatively or additionally, the one or more scenario-based measures may be triggered based on one or more environmental conditions of the vehicle environment. An exemplary environmental condition is the friction coefficient of the lane on which the vehicle is traveling. Alternatively or additionally, the one or more scenario-based measures may be triggered or not triggered based on data from a vehicle navigation system, for example, based on the type of road on which the vehicle is traveling (e.g., highway, local highway, city street, recreational street, etc.). Thus, for example, the comfort and / or driving experience of the vehicle may be further improved.

[0038] According to a further aspect, a (road) motor vehicle, in particular a car or a truck or a bus or a motorcycle, is described, which comprises a device as described herein.

[0039] According to another aspect, a method is provided for coupling a second electric machine to at least one wheel of a (motor) vehicle by means of a decoupling unit (for example by means of a clutch) while the vehicle is already driven by a first electric machine. The method comprises determining that the second electric machine is to be coupled to a wheel of the vehicle. The method further comprises initiating at least one contextualization measure in response to the determination, by means of which the coupling of the second electric machine is made perceptible to a user of the vehicle.

[0040] According to another aspect, a software (SW) program is described. The SW program can be configured to run on a processor (eg, on a control unit of a vehicle) and thereby perform the method described herein.

[0041] According to another aspect, a storage medium is described. The storage medium may include a SW program which is arranged to be run on a processor and thereby to perform the method described herein.

[0042] It should be noted that the methods, devices and systems described herein can be used not only individually, but also in combination with other methods, devices and systems described herein. In addition, each aspect of the methods, devices and systems described herein can be combined with each other in a variety of ways. In particular, the features of the claims can be combined with each other in a variety of ways. In addition, the features listed in brackets should be understood as optional features. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention is described in detail below with the help of embodiments.

[0044] Figure 1 illustrates exemplary components of a vehicle;

[0045] Figure 2a shows an exemplary time profile of the motor speed within the scope of a coupling process;

[0046] Figure 2b shows an exemplary time profile of a rotational torque and / or a drive torque caused by an already coupled electric machine within the context of a coupling process of a further electric machine;

[0047] Figure 3 A flow chart shows an exemplary method for coupling an electric machine to an axle of a vehicle. DETAILED DESCRIPTION

[0048] As mentioned at the beginning, this article is about how to improve the user's comfort when coupling with an electric machine. In this context, Figure 1 An exemplary vehicle 100 is shown, which includes a first electric machine 101 which is designed to drive a first axle 111 (eg, a rear axle) of the vehicle 100. The first electric machine 101 may optionally be fixedly coupled to the first axle.

[0049] The vehicle 100 further includes a second electric machine 102 which is configured to drive a second axle 112 (eg, a front axle) of the vehicle 100. A decoupling unit 103 (eg, a dog clutch) may be provided between the second electric machine 102 and the second axle 112 and is configured to selectively couple or decouple the second electric machine 102 to the second axle 112.

[0050] The vehicle 100 may also include one or more control elements 104, which enable a user of the vehicle 100, in particular a driver, to control the driving of the vehicle 100. Exemplary control elements 104 are an accelerator pedal (eg a kick-down pedal) and / or paddle shifters.

[0051] Figure 1The vehicle 100 shown in FIG. 1 is therefore an all-wheel drive vehicle 100 in which all wheels of the vehicle 100 can be driven by one or more electric machines 101, 102, respectively, indirectly via axles 111, 112. In certain driving situations, it may be advantageous, especially in terms of energy consumption, to decouple the second electric machine 102 from the second axle 112. This is the case in particular when the first electric machine 101 can provide a sufficiently large torque to drive the vehicle 100, for example when driving at a constant speed on a highway.

[0052] The (control) device 110 of the vehicle 100 may recognize and / or determine that the second electric machine 102 is to be coupled to the second axle 112, for example in order to provide an additional drive torque. The second electric machine 102 may then be activated and the rotational speed of the second electric machine 102 adapted to the current driving speed of the vehicle 100 and / or the current rotational speed of the second axle 112. Furthermore, the second electric machine 102 may also be coupled to the second axle 112 via the decoupling unit 103, in particular by closing the decoupling unit.

[0053] The coupling process brought about by the decoupling unit 103 may have a certain dead time. This may result in the torque brought about by the second electric machine 102 being transmitted to the second axle 112 with a time delay and / or with a certain starting gradient (i.e. smoothly). This may be uncomfortable for the user of the vehicle 100, in particular the driver. In addition, such a smooth coupling of the second electric machine 102 requires the use of a relatively complex clutch in the decoupling unit 103, which is associated with additional costs and / or installation space and / or weight.

[0054] A method is described herein, by which an active scenario of the coupling process is caused, which scenario can be perceived by a user of the vehicle 100, in particular the driver. In the scope of scenario, one or more scenario measures can be caused, which at least partially lead to an increase in additional torque and / or drive torque (associated with the coupling process) that can be perceived by the driver. Therefore, the comfort of the user can be improved. In addition, it is possible to use a relatively low-cost clutch, in particular a dog clutch, in the decoupling unit 103.

[0055] The (control) device 110 can recognize, for example, based on an actuation of a control element 104 of the vehicle 100 that the second electric machine 102 is to be coupled to the second axle 112. The control element 104 can be, for example, a shift paddle and / or a kick-down pedal. Thus, a control element 104 can be provided that enables a user of the vehicle 100 to explicitly initiate the coupling of the second electric machine 102.

[0056] like Figure 2a and 2bAs shown, for example, it can be recognized at recognition time 201 that the second motor 102 should be coupled to the second axle 112. In response to this, the second motor 102 can be activated and accelerated (see Figure 2a ). For example, a target speed 211 can be determined for the second electric machine 102, which depends on the driving speed of the vehicle 100 and / or the speed of the second axle 112. The target speed 211 can correspond, for example, to the speed of the second axle 112 (depending on the transmission ratio of the optional transmission of the decoupling unit 103).

[0057] As a scenario-based measure, the second electric machine 102 can be accelerated to an ultra-high speed 212 that is higher than the target speed 211 before the coupling time 202 for coupling with the second axle 112. Figure 2a 2 is shown as a time profile 215 of the rotational speed 210 illustrated in , which shows the rotational speed 210 of the second electrical machine 102 as a function of the time 200 .

[0058] The second electric machine 102 therefore has an excessively high rotational speed 212 at the coupling time 202, which is higher than the target speed 211 by an offset value 213 (e.g. 5% or more or 10% or more). Thus, when the second electric machine 102 is coupled, an additional acceleration of the vehicle 100 is caused, which is perceived by the user of the vehicle 100 as a driving experience when the second electric machine 102 is switched on.

[0059] Alternatively or additionally, as a scenario-based measure, the torque caused by the first electric machine 101 on the first axle 111 may also be reduced before the second electric machine 102 is coupled, such as Figure 2b As shown in the example. The first motor 101 causes a target torque 221, for example, before the coupling process (for example, at the identification time 201). In response to the identification of the second motor 102 to be coupled, from the identification time 201, the torque 220 caused by the first motor 101 can be reduced to a reduced torque 222 (the reduced torque is lower than the target torque 221 (for example, 5% or more or 10% or more)).

[0060] An additional torque reserve 223 can be generated by reducing the torque 220 caused by the first electric machine 101. At the coupling time 202, the torque 220 caused by the first electric machine 101 can be increased again to the target torque 221, so that the additional torque reserve 223 (as a driving experience) can be felt by the user of the vehicle 100. This is exemplified by Figure 2b A time profile 225 of the torque 220 in FIG.

[0061] Therefore, one or more scenario-based measures can be initiated within the scope of coupling the second motor 102 in order to improve the comfort of the vehicle 100 user. In this case, the one or more scenario-based measures can be initiated according to the respective current driving speed of the vehicle 100 (at the recognition time 201). In this case, the extent of the one or more scenario-based measures can be reduced as the driving speed increases. If necessary, the one or more scenario-based measures can be initiated only when the driving speed of the vehicle 100 is less than a speed threshold. On the other hand, if necessary, a smooth coupling of the second motor 102 can be initiated if the driving speed of the vehicle 100 is greater than a second speed threshold.

[0062] As mentioned at the beginning, the electric vehicle 100 usually has no clutch between the one or more motors 101, 102 and one or more wheels of the vehicle 100, but is directly coupled. In an all-wheel drive vehicle 100, one or more motors 101, 102 can be installed for each axle 111, 112 and directly coupled to the corresponding driven axles 111, 112. This direct coupling allows the electric drive to perform very dynamically in terms of torque increase according to the driver's expectations (e.g. pedal requirements). Usually, one driven axle 111 in the vehicle 100 is sufficient to make the vehicle 100 travel at a fixed speed (at a constant driving speed), so the other axle 112 can be deactivated or even decoupled due to efficiency advantages. This coupling and decoupling can be performed in the background as imperceptibly as possible to the user and / or smoothly in terms of torque increase or reduction.

[0063] Coupling or decoupling electric machine 102 via decoupling unit 103 usually results in a dead time during the torque increase. As a result, the torque increase is delayed and / or smoothed under dynamic accelerator pedal requests compared to systems without decoupling unit 103 or with decoupling unit 103 permanently closed.

[0064] In this context, it is proposed that (at least at a driving speed below a speed threshold and / or depending on the driving speed and / or depending on one or more external boundary conditions) the dead time of the decoupling unit 103 is not masked by a delayed and / or smoothed torque increase, but that the decoupling unit 103 is intentionally switched on (i.e. closed) in a situational manner by a specific torque increase. The switching on can thus be used as a means of arousing the user's emotions.

[0065] For this purpose, as a measure, coupling and / or direct shifting can be initiated by user interaction at control element 104 (eg shift paddles and / or a kick-down pedal). The user can thus operate control element 104 to initiate coupling of second electric machine 102 .

[0066] Another exemplary scenario-setting measure is to overspeed the uncoupled (second) motor 102 before coupling in order to use the moment of inertia as additional punch potential. During coupling, this punch potential can generate additional acceleration peaks and / or additional acoustic overshoots, which can be used for scenario-setting.

[0067] As another exemplary scenario-based measure, a centrifugal force unit (e.g., having a flywheel mass, such as a flywheel) may be driven before the second motor 102 is switched on. The centrifugal force unit may be driven, for example, by the second motor 102. In this case, when the second motor 102 is switched on, the centrifugal force unit may also be coupled to cause additional acceleration, which may be used for scenario-based.

[0068] As a further exemplary scenario measure, the first (e.g. front) motor 102 can provide only a reduced torque 222 before the second (possibly rear) motor 102 is connected via the decoupling unit 103 , thereby increasing the torque potential energy 223 of the entire drive train felt by the user during coupling.

[0069] Figure 3 A flow chart of a (possibly computer-implemented) method 300 for coupling a second electric machine 102 to wheels of a vehicle 100 by means of a decoupling unit 103 while the vehicle 100 is already driven by the first electric machine 101 is shown. The first electric machine 101 may be provided to drive one or more wheels on a first axle 111 of the vehicle 100. When (in particular once) the second electric machine 102 is connected to the second axle 112 and thus to one or more wheels on the second axle 112, the second electric machine 102 may be provided to drive the one or more wheels on the second axle 112 of the vehicle 100.

[0070] Method 300 includes determining 301 that second electric machine 102 is to be coupled to wheels of vehicle 100 (in order to drive the wheels). This may be detected, for example, based on an actuation of control element 104 of vehicle 100. Determination 301 may be performed at detection time 201.

[0071] Furthermore, method 300 includes initiating 302 at least one scenario-based measure in response to determination 301, by which the coupling of second electric machine 102 is made perceptible to a user of vehicle 100. In other words, within the scope of the coupling process, an (additional) scenario-based measure may be initiated, which is perceptible to a user of vehicle 100 (e.g. acoustically and / or as an additional acceleration).

[0072] The coupling of the second motor 102 to the wheels may cause a basic jerk and / or a basic acceleration and / or a basic noise and / or a basic display (for example, due to the closing of the decoupling unit 103). The at least one scenario-based measure may be designed so that a jerk exceeding the basic jerk and / or an acceleration exceeding the basic acceleration and / or a noise exceeding the basic noise and / or a display exceeding the basic display is caused by the measure. Thus, the coupling of the second motor 102 can be perceived by the user as a driving experience (rather than a disturbing effect).

[0073] The measures described here may increase the comfort for a user of vehicle 100 within the context of the coupling of electric machine 102 . Furthermore, a particularly efficient coupling or decoupling of electric machine 102 may be achieved (eg, by using a dog clutch).

[0074] The present invention is not limited to the embodiments shown. In particular, it should be noted that the description and the drawings are intended only to illustrate the principles of the proposed methods, devices and systems by way of example.

Claims

1. A device (110) for coupling a second electric machine (102) to a wheel of a vehicle (100) by means of a decoupling unit (103) while the vehicle (100) is already driven by a first electric machine (101); the device (110) being configured to - determining that the second electric machine (102) should be coupled to a wheel of the vehicle (100); and - in response to the determination, at least one scenario-based measure is initiated, by which the coupling of the second electric machine (102) is made perceptible to a user of the vehicle (100).

2. The device (110) according to claim 1, wherein: The device (110) is configured to: - reducing the torque (220) caused by the first electric machine (101) before the coupling moment (202), in particular reducing it by a torque reserve (223); and - at the coupling time (202) when the second electric machine (102) is coupled, the torque (220) generated by the first electric machine (101) is increased again, in particular by an increased torque reserve (223).

3. The device (110) according to claim 2, wherein: The device (110) is provided for suddenly increasing the torque (220) generated by the first electric machine (101) at the coupling moment (202), in particular increasing it by a torque reserve (223).

4. The device (110) according to any one of claims 2 to 3, wherein: The device (110) is provided for reducing, in particular smoothly, a torque (220) caused by the first electric machine (101) from a recognition time (201) at which it is determined that the second electric machine (102) is to be coupled to a wheel of the vehicle (100) until the coupling time (202).

5. The device (110) according to any one of the preceding claims, wherein The device (110) is configured to: - before the coupling moment (202), increasing the speed (210) of the second electric machine (102) to an ultra-high speed (212), which is greater than a target speed (211) of the second electric machine (102), wherein the target speed (211) depends on the current speed of the wheels of the vehicle (100); - at the coupling time (202), the second motor (102) is coupled to the wheels of the vehicle (100) via the decoupling unit (103), so that due to the very high rotation speed (212) of the second motor (102) and due to the inertia of the shaft of the second motor (102), a user-perceptible effect is generated, in particular in terms of additional vehicle acceleration and / or noise and / or graphic displays.

6. The device (110) according to claim 5, wherein: The device (110) is configured to increase the rotational speed (210) of the second electric machine (102) to the extra-high rotational speed (212) from a detection time (201) at which it is determined that the second electric machine (102) is to be coupled to wheels of the vehicle (100) until the coupling time.

7. The device (110) according to any of the preceding claims, wherein: The device (110) is configured to - determining that the second electric machine (102) should be coupled to the wheels of the vehicle (100) for recovery; - within the scope of the scenario-based measures, before the coupling moment (202), the speed (210) of the second electric machine (102) is adjusted to a reduced speed, which is lower than a target speed (211) of the second electric machine (102), the target speed (211) being dependent on the current speed of the wheels of the vehicle (100); and - at the coupling time (202), the second motor (102) is coupled to the wheels of the vehicle (100) via the decoupling unit (103), so that due to the reduced rotational speed of the second motor (102) and due to the inertia of the shaft of the second motor (102), a user-perceptible effect is generated, in particular in terms of additional vehicle deceleration and / or noise and / or a graphic display.

8. The device (110) according to any one of the preceding claims, wherein The device (110) is configured to - determining at a recognition time (201) that the second electric machine (102) is to be coupled to a wheel of the vehicle (100); - at a subsequent coupling time (202), the second electric machine (102) is coupled to the wheels of the vehicle (100) via the decoupling unit (103), in particular by closing the decoupling unit (103); and - preparing scenario-based measures between the recognition time (201) and the coupling time (202) so that at the coupling time (202) the coupling of the second electric machine (102) is perceptible to a user of the vehicle (100), in particular via additional vehicle acceleration and / or noise and / or a graphic display.

9. The device (110) according to any one of the preceding claims, wherein: - the vehicle (100) comprises a control element (104), in particular a gearshift paddle and / or a kick-down pedal; and The device (110) is configured to detect an actuation of the control element (104); and based on the detected actuation, to determine that the second electric machine (102) is to be coupled to the wheels of the vehicle (100).

10. The device (110) according to any one of the preceding claims, wherein The device (110) is configured to - determining the speed and / or acceleration of the vehicle (100); and - initiating one or more scenario-based measures as a function of the vehicle's (100) driving speed and / or acceleration, in particular adjusting the extent of the one or more scenario-based measures as a function of the driving speed and / or acceleration, such as a level of a torque reserve (223) of the first motor (101) induced within the scope of the scenario-based measures and / or a level of an ultra-high speed (212) of the second motor (102) induced within the scope of the scenario-based measures.

11. The device (110) according to claim 10, wherein: The device (110) is configured to - when the driving speed is less than a speed threshold and / or when the acceleration is less than an acceleration threshold, causing the one or more scenario-based measures; and / or - when the driving speed is greater than the speed threshold and / or when the acceleration is greater than the acceleration threshold, not initiating the one or more scenario-based measures; and / or - reducing the extent of the one or more measures, in particular the level of the torque reserve (223) and / or the level of the overspeed (212), as the driving speed increases and / or as the acceleration increases.

12. The device (110) according to any of the preceding claims, wherein - a first electric machine (101) configured to drive a first axle (111) of the vehicle (100); - the second electric machine (102) is configured to drive a second axle (112) of the vehicle (100); and The first axle (111) is a front axle and the second axle (112) is a rear axle, or the first axle (111) is a rear axle and the second axle (112) is a front axle.

13. The device (110) according to any of the preceding claims, wherein The device (110) is configured to: - before the coupling moment (202), the centrifugal force unit is driven, in particular by the second motor (102); and - at the coupling time (202), the second electric machine (102) and the driven centrifugal force unit are coupled to the wheels of the vehicle (100) via the decoupling unit (103), so that a user-perceptible effect is generated via the driven centrifugal force unit, in particular an additional vehicle acceleration and / or a noise and / or a graphic display.

14. A method (300) for coupling a second electric machine (102) to a wheel of a vehicle (100) by means of a decoupling unit (103) while the vehicle (100) is already driven by a first electric machine (101), the method (300) comprising: - determining (301) that the second electric machine (102) should be coupled to a wheel of the vehicle (100); and In response to the determination (301), at least one scenario-based measure is initiated (302), by which the coupling of the second electric machine (102) is made perceptible to a user of the vehicle (100).

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