METHOD FOR DRIVE CONTROL OF A MOTOR VEHICLE WITH SINGLE-WHEEL DRIVE, DRIVE CONTROL DEVICE, DRIVETRAIN AND MOTOR VEHICLE

Description

[0001] The invention relates to two methods for controlling the drive of a motor vehicle with independent wheel drive at two wheels, a first sensor, and a second sensor by means of a control unit, wherein the control unit comprises an evaluation unit and a control unit. The invention further relates to a drive control device for controlling the drive of a motor vehicle with independent wheel drive at two wheels, in particular according to one of the aforementioned methods. The invention further relates to a drive train for a motor vehicle with such a drive control device and to a motor vehicle with such a drive train.

[0002] The motor vehicle in question can be of any type and design. In particular, it refers to a car weighing less than 3.5 tons, for example, a sports car, a coupé, a station wagon, or a sport utility vehicle (SUV).

[0003] In motor vehicles, methods are already known from the prior art that aim to control the rotational speeds and torques applied to individual vehicle wheels in order to ensure good traction for each wheel. For example, methods are known that monitor and ensure such traction during acceleration, braking, cornering, or on challenging surfaces such as ice, sand, or gravel.

[0004] Traction at a vehicle wheel depends primarily on the wheel's slippage relative to the road surface. Slippage occurs during driving, especially when accelerating or braking, but should be kept below certain limits to achieve good traction and maintain the wheel's ability to transfer power to the road surface and its lateral stability. These abilities decrease when the limits are exceeded and slippage increases, and are completely or almost completely lost when the traction limit is exceeded, resulting in wheel spin or locking.

[0005] All modern vehicles are equipped with an anti-lock braking system (ABS), which briefly releases the brakes during braking if a wheel is at risk of locking up. This allows the vehicle to remain steerable during hard braking thanks to the maintained lateral grip of the wheels, and to come to a stop more quickly than if the wheels were locked. In addition to ABS, other methods exist for distributing brake pressure between the vehicle's wheels.

[0006] Furthermore, vehicles in which a drive mechanism acts on a pair of wheels, or, in the case of all-wheel drive, on all wheels, are typically equipped with differentials. These differentials allow for different rotational speeds of two wheels within a pair, for example, to compensate for the different radii along which the wheels roll when cornering. Without a differential, and thus without the necessarily identical rotational speed of a pair of wheels, at least one of the wheels would slip during such a cornering maneuver.

[0007] Furthermore, WO 2017 / 044741 A1 and US 2009112436 A1 disclose vehicles in which wheels are driven, but at least the features of the characterizing part of claims 1 and 2 are not provided.

[0008] In the aforementioned motor vehicles, the powertrain design is complex and requires significant investment. In particular, such a powertrain necessitates a large number of components and assemblies, which also leads to an increased susceptibility to failure.

[0009] It is also known from the prior art to provide drive devices for individual wheel drive on at least two vehicle wheels, which are provided directly or indirectly via a transmission for driving the respective vehicle wheel.

[0010] The present invention aims to provide an improvement or an alternative to the prior art. This objective is achieved by a method according to a first aspect of the invention as defined in claim 1, by a second aspect of the invention as defined in claim 2, by a drive control device according to a third aspect of the invention as defined in claim 13, by a drive train according to a fourth aspect of the invention as defined in claim 14, and by a motor vehicle according to a fifth aspect of the invention. Advantageous embodiments are specified in the dependent claims.

[0011] It should be expressly noted that, within the scope of the present patent application, indefinite articles and indefinite numerical indications such as "one...", "two..." etc. are generally to be understood as minimum indications, i.e., as "at least one...", "at least two..." etc., unless it is clear from the context or the specific text of a particular passage that only "exactly one...", "exactly two..." etc. is meant there.

[0012] Furthermore, all numerical data as well as information on process parameters and / or device parameters are to be understood in a technical sense, i.e., as being subject to the usual tolerances. Even the explicit indication of the limitation "at least" or "minimum" or similar should not be interpreted as meaning that "exactly one" is meant when "one" is used without the indication of "at least" or similar.

[0013] Where elements are designated by means of a numbering system, for example "first component," "second component," and "third component," this numbering is solely for differentiation purposes and does not imply any dependency between the elements or a mandatory sequence. This means, for example, that a device does not need to have a "first component" to be able to have a "second component." Similarly, the device can include a "first component" and a "third component" without necessarily having a "second component."

[0014] The first aspect of the invention relates to a method for controlling the drive of a motor vehicle with individual wheel drive on two vehicle wheels and a first sensor by means of a control unit, wherein the control unit comprises an evaluation unit and a control unit, and wherein the method comprises the steps: a. Acquisition of actual vehicle data using the first sensor, in particular at the vehicle wheels, b. Receiving and evaluating the actual vehicle data using the evaluation unit, wherein a maximum vehicle value, in particular maximum slip, is stored on the evaluation unit, c. Determining an actual vehicle value, in particular an actual slip, from the actual vehicle data using the evaluation unit, d. Comparing the determined actual vehicle value with the maximum vehicle value, in particular the maximum slip, using the evaluation unit, e. Transmitting an instruction for an action from the evaluation unit to the control unit when the actual vehicle value exceeds the maximum vehicle value, f. Execution of the action by the control unit. The following terms should be explained in this context:

[0015] A control system is understood as a multi-step process in which an actual value is compared with a target value, and an action, in particular a control action, is executed depending on the difference and / or the ratio of the two values. The difference and / or the ratio can also determine the intensity of the action. A control system is executed, in particular, as a rapid sequence of loops, in which steps of the process, in particular all steps of the process, are carried out in each loop. However, not all steps of a control process are necessarily carried out in every loop, but can, for example, be carried out once or only after a certain number of iterations. A change in the action can occur in each loop, especially if carrying out the action in the previous loop would lead to a change in the difference or the ratio.This has led to changes in the relationship between the actual and target values. A change could be, for example, a change in the intensity of the action or its cancellation. Multiple actions can also be performed simultaneously.

[0016] Single-wheel drive is understood to be a drive that only acts on a single vehicle wheel and does not mechanically have a driving effect on other vehicle wheels or is not directly influenced by the driving state of other vehicle wheels.

[0017] The motor vehicle preferably has two pairs of wheels, the respective wheels of which are arranged on the same axis of rotation, in particular on the same wheel axle or wheel shaft, and are each arranged on opposite outer sides of the motor vehicle. Preferably, the motor vehicle has a pair of front wheels and a pair of rear wheels.

[0018] A control unit is understood to be a device by means of which a control procedure can be carried out and which is particularly suitable for receiving, processing, and transmitting signals, especially digital signals. A control unit is, for example, designed as a microcontroller and / or integrated circuit.

[0019] An evaluation unit is understood to be a device that enables the evaluation of signals, particularly by comparing the signals with each other or by performing calculations using these signals. An evaluation unit is typically suitable for receiving, processing, and transmitting signals, especially digital signals, and is designed, for example, as a microcontroller and / or integrated circuit.

[0020] A control unit is understood to be a device by means of which control can be performed, i.e., by means of which a technical system can be influenced. A control unit is typically suitable for receiving, processing, and sending signals, especially digital signals, and is designed, for example, as a microcontroller and / or integrated circuit. The control preferably acts on at least one drive device, a brake, and / or a transmission.

[0021] The evaluation unit and the control unit can be combined into a single circuit, so that the control unit is implemented as a single circuit that performs the functions of both the evaluation and control units. Therefore, the fact that the control unit comprises both an evaluation unit and a control unit means that the control unit possesses the functionalities of both. Alternatively, the evaluation unit and the control unit can also consist of separate components.

[0022] Actual vehicle data, as defined in the present invention, provides information about physical quantities measurable on the motor vehicle, such as rotational speeds, velocities, forces, torques, pressures, distances, accelerations, or decelerations. Actual vehicle data can also provide information about the difference and / or ratio of two such physical quantities. Actual vehicle data can be measured directly or indirectly using sensors and is typically acquired in each loop of a control procedure. A suitable sensor could be, for example, a speed, velocity, force, torque, pressure, displacement, or acceleration sensor.

[0023] In the following, "exceeding" means exceeding the maximum vehicle value due to the actual vehicle value, and "falling short" means falling below the maximum vehicle value due to the actual vehicle value, unless otherwise stated.

[0024] An actual vehicle value is a value that can be determined from the actual vehicle data. It is either a quantity directly represented in the actual vehicle data or a derived quantity resulting from data processing. A derived quantity is, in particular, a difference, such as a differential speed, or a ratio. A vehicle value is typically determined in each loop of a control procedure, but alternatively, it can be determined after a specific number of iterations.

[0025] The maximum vehicle value is understood as a limit value that serves as a reference point when compared to the actual vehicle value. Within a control procedure, a different conclusion and, if applicable, a different action are derived from falling below the maximum value than from exceeding it. If the actual vehicle value equals the maximum vehicle value, this can be classified as either falling below or exceeding it, with the maximum value being chosen accordingly.

[0026] An action is understood as an influencing of a technical system, which can be designed in any way. In particular, an action is a change in a setting, especially a torque, of a drive device, especially on a single-wheel drive.

[0027] The execution of the action by the control unit is understood to mean that the control unit influences the technical systems of the motor vehicle in accordance with the instruction, for example assigning an increased or decreased torque to a drive device and, in particular, transmitting corresponding signals to this drive device.

[0028] By means of the method according to the first aspect of the invention, the individual wheel drives can be used together in an advantageous way to drive the motor vehicle, so that the motor vehicle can be operated effectively and safely.

[0029] The second aspect of the invention relates to a method for controlling the drive of a motor vehicle with individual wheel drive on two vehicle wheels, a first sensor and a second sensor by means of a control unit, wherein the control unit has an evaluation unit and a control unit, and wherein the method comprises the steps: a. Acquisition of actual vehicle data using the first sensor, in particular at the vehicle wheels, b. Acquisition of a driving request using the second sensor, c. Receiving and evaluating the actual vehicle data and the driving request using the evaluation unit, wherein a maximum vehicle value, in particular maximum slip, is stored on the evaluation unit, d. Determining a physical actual vehicle value, in particular an actual slip, using the evaluation unit, e. Comparing the determined actual vehicle value with the maximum vehicle value, in particular the maximum slip, using the evaluation unit, f. Transmitting an instruction for an action from the evaluation unit to the control unit when the actual vehicle value exceeds or is about to exceed the maximum vehicle value due to the driving request, g. Execution of the action by the control unit.

[0030] In addition to the above explanations regarding the terminology of the first aspect of the invention, which also applies to the second aspect, the following clarification is provided: For the purposes of the present invention, a driving request is a control command for changing the vehicle's state, for example, changing the driving speed. A driving request is entered manually by an operator, for example, by pressing a pedal or by changing a set speed on a cruise control device. Alternatively and / or additionally, a driving request is entered by a vehicle control system, such as an adaptive cruise control device, a distance control system, a parking assistant, an emergency braking assistant, and / or a lane keeping assistant.

[0031] An impending exceedance is understood to occur when, based on a forecast, it is foreseeable or appears that a driving request will lead to a change in the actual vehicle value, resulting in an exceedance. Such a forecast is obtained, for example, from extrapolation or a simulation calculation, which the evaluation unit generates based on actual vehicle data and / or external data such as weather conditions, road surface, road profile, and / or speed limits. In one embodiment, such a forecast is calculated and updated continuously, i.e., repeatedly at short intervals.

[0032] By means of the method according to the second aspect of the invention, the individual wheel drives can be advantageously used together to drive the motor vehicle, so that the motor vehicle can be operated effectively and safely. Furthermore, the method according to the second aspect of the invention allows dangerous or uncomfortable driving situations to be avoided in advance.

[0033] The driving situation is understood to be the sum of all circumstances that influence the motor vehicle, such as the road surface, the road layout, a speed limit, the vehicle speed, acceleration or deceleration, or the condition of the vehicle wheels.

[0034] Particularly preferred in the methods according to the first or second aspect of the invention are the actual vehicle data recorded, from which the actual slip at at least one vehicle wheel can be determined, such as the rotational speed of the vehicle wheel and the relative speed of the vehicle to the ground. The evaluation unit then determines the actual slip of the vehicle wheel from the actual vehicle data and compares it with a maximum slip value. Advantageously, the slip can be used as a control variable to infer the traction and lateral grip of the wheels, thus ensuring safe and stable driving behavior.

[0035] It is particularly advantageous to determine the actual slip for all vehicle wheels driven by individual wheel drive. This allows detection when the slip changes only on individual wheels due to an asymmetrical demand or load, for example, during cornering. With this method, a differential function between these wheels is then created.

[0036] In one embodiment of the second aspect of the invention, the evaluation unit transmits an instruction to the control unit to initiate an action if the actual vehicle value threatens to exceed the maximum vehicle value due to an impending change in the vehicle's driving situation. For example, an action is then executed when entering a curve and an exceedance is imminent, even without a driving request. In this way, dangerous or uncomfortable driving situations can be better avoided proactively.

[0037] In a preferred embodiment of a method according to the first or second aspect of the invention, the method is repeated, particularly several times per second, and executed again without any action being performed when the actual vehicle value falls sufficiently below the maximum vehicle value. This repetition, especially in rapid succession, enables continuous monitoring that also captures very rapid changes in vehicle states. For the purposes of the first aspect of the invention, "sufficiently below" means any deviation below the maximum value; for the purposes of the second aspect of the invention, it means a deviation below the maximum value at which, with regard to a driving requirement and / or an impending change in the driving situation of the vehicle, no deviation above the maximum value is to be expected.

[0038] In the method according to the first or second aspect of the invention, the actual vehicle value, in particular the actual slip, is determined for each driven vehicle wheel and compared with a maximum vehicle value, in particular maximum slip, assigned to that vehicle wheel using the evaluation unit. In this way, the traction and lateral control capability of the driven vehicle wheels can be ensured, and safe and stable driving behavior of the vehicle can be achieved. The actual vehicle value is determined for all vehicle wheels driven by means of individual wheel drive and compared with a respective maximum vehicle value.

[0039] In a preferred embodiment of the method according to the first or second aspect of the invention, after an action has been performed for a defined period of time, if the maximum vehicle value continues to be exceeded or is still at risk of being exceeded, the evaluation unit transmits an instruction for a further action to the control unit, and the control unit executes the further action. This further action may be the same action with a greater or lesser intensity, or it may be a different action, in particular one that represents a greater intervention in the vehicle's driving behavior. In this way, the method is designed such that the intervention occurs in stages and, in particular, becomes increasingly intensive with each stage. The aim is thus to achieve the least possible intervention at each stage, while simultaneously counteracting an exceedance safely and effectively.

[0040] In the method according to the first or second aspect of the invention, an action is a change in the torque applied to a vehicle wheel, particularly to a vehicle wheel where the actual torque value exceeds or is at risk of exceeding the maximum vehicle value. A change can, for example, be an increase or a reduction in the torque. A change in torque selected according to the driving situation can relieve the load on the vehicle wheel, thus compensating for or preventing an exceedance. The torque can also be changed at a different vehicle wheel than the one where an exceedance exists or is at risk, in order to compensate for or prevent the exceedance.For example, when driving around a curve, an inside wheel and an outside wheel influence each other, and an oversteer can be compensated for by an action on the affected wheel or an opposing action on the opposite wheel.

[0041] In a single-wheel drive system, the torque is changed by influencing a component associated with that wheel, such as a drive unit or a transmission. In a drive system that acts on multiple vehicle wheels, a change in torque at a single wheel is achieved, for example, by influencing a drive unit, a transmission, or a differential.

[0042] In a preferred embodiment of this system, the torque at one vehicle wheel is reduced while the torque at another is simultaneously increased. This relieves the load on a wheel that is experiencing or at risk of oversteering, for example, during cornering, as the load on opposing wheels is balanced during cornering. Such a method can also result in particularly good handling, for example, when driving on very uneven surfaces.

[0043] In a preferred embodiment of a method according to the first or second aspect of the invention, an action is a braking intervention at a vehicle wheel, in particular at a vehicle wheel where the actual vehicle value exceeds or is at risk of exceeding the maximum vehicle value. Depending on the driving situation, such a braking intervention can lead to a reduction in load on the vehicle wheel, thus compensating for or preventing an exceedance. A braking intervention is also possible at a vehicle wheel corresponding to the one where an exceedance has occurred or is at risk, just as a change in torque is possible. Furthermore, a braking intervention can also be accompanied by a change in torque at the same or a different vehicle wheel.

[0044] Braking intervention is achieved, for example, by activating a brake located on a vehicle wheel, on an individual wheel drive or in a drive train, or by an electric machine on an individual wheel drive or in a drive train using recuperation.

[0045] In a preferred embodiment of a method according to the first or second aspect of the invention, a. in a first step a change of torque is carried out on a vehicle wheel and b. in a second step a braking intervention on a vehicle wheel is only carried out as an action if, after the first step, in particular after a first defined period of time over which the first step was carried out, the actual vehicle value continues to exceed the maximum vehicle value or an exceedance continues to be imminent.

[0046] The first and second steps are to be understood as steps in the process flow that are performed in each loop or after a specific number of repetitions of the aforementioned steps. First, the first step is inserted into the process and, under the aforementioned condition, is replaced or supplemented by the second step. In the first step, the intensity of the change is increased, particularly over the initial time period, i.e., the torque is increased or decreased. The process is therefore executed multiple times, and the first step is performed in each iteration. Only if there is no change in the exceedance or the imminent exceedance is the second step additionally or supplementarily executed.

[0047] This method prioritizes torque modification over braking. The primary goal is to counteract exceeding or impending exceedance of the limit, ideally by changing the rotational speed, before any braking intervention is even considered. Depending on the vehicle design and driving situation, torque modification can be less noticeable and / or more energy-efficient than braking.

[0048] In a preferred embodiment of a method according to the first or second aspect of the invention, one action is the activation of a drive device. In this way, the total available drive power is increased and, depending on the arrangement of the drive devices in operation, can be distributed between the vehicle wheels for stable and safe driving behavior of the motor vehicle.

[0049] The engaged drive device particularly preferentially powers a vehicle wheel that was not driven before the drive device was engaged. In this way, for example, another vehicle wheel or pair of wheels can transfer a drive load to the road surface, so that the total drive load required in a driving situation is distributed across more vehicle wheels. The vehicle wheels that were driven before the action are thus relieved of the load, resulting in more stable and safer vehicle handling.

[0050] The preference is still given a. before engaging the drive device, the actual vehicle value is determined at the previously driven vehicle wheels, and b. after engaging the drive device, the actual vehicle value is determined at the vehicle wheels driven before engaging the drive device, as well as at the vehicle wheels driven by the engaged drive device.

[0051] The method according to the first or second aspect of the invention is thus also applied to the vehicle wheels that are only then driven after the drive device has been switched on, in order to achieve safe and stable driving behavior with these as well.

[0052] Preferably, the engaged drive device acts on a wheel shaft and drives one or, in particular, both front wheels of the vehicle. Specifically, the drive device acts via a differential on two wheel shafts, each assigned to one of the front wheels of the vehicle, which are preferably arranged coaxially. In one embodiment of such a design, the individual wheel drives act on two rear wheels of the vehicle, and by engaging the drive device on the wheel shaft, an all-wheel drive is created, enabling particularly stable and safe handling even on very challenging surfaces. Furthermore, the engaged drive device on the wheel shaft is preferably an electric motor.

[0053] In the aforementioned embodiment, it is preferred a. in a first step, a change in torque and / or a braking intervention is carried out on a vehicle wheel, and b. in a second step, the activation of the drive device is only carried out as an action if, after the first step, in particular after a second defined period of time over which the first step was carried out, the actual vehicle value continues to exceed the maximum vehicle value or an exceedance is still imminent.

[0054] The first and second steps are to be understood as steps in the process flow that are performed in each loop or after a specific number of repetitions of the aforementioned steps. First, the first step is inserted into the process and, under the aforementioned condition, is replaced or supplemented by the second step. In the first step, the intensity of the change and / or the braking intervention is increased, particularly over the second time period; that is, the torque is continuously increased or decreased, and / or the braking intervention is continuously intensified. The process is thus executed multiple times, and the first step is performed in each iteration. Only if there is no change in the exceedance or the imminent exceedance is the second step additionally or supplementarily executed.In a further embodiment, within the first step, the change in torque and the braking intervention can be preferred over each other in any order. In particular, in the first step, the change in torque as described above can be preferred over the braking intervention.

[0055] With this method, a change in torque and / or braking intervention is preferred over engaging the drive device. The aim is therefore to first counteract exceeding or impending exceedance of the limit, ideally by changing the speed and / or applying the brakes, before engaging the drive device. Depending on the vehicle design and driving situation, a change in torque and / or braking intervention can be more energy-efficient than engaging the drive device.

[0056] In a preferred embodiment of a method according to the first or second aspect of the invention, the actual vehicle data includes the rotational speed of a vehicle wheel. "Includes" here means that the actual vehicle data contains information from which this quantity can be derived. For example, the actual slip can be determined using the rotational speed as an actual vehicle value.

[0057] Alternatively, or furthermore, the actual vehicle data preferably includes the rotational speed of a component of a powertrain. From this, for example, the rotational speed of a vehicle wheel belonging to the powertrain can be determined, whereby a simpler sensor can be used or the sensor can be more easily installed than a sensor on the vehicle wheel itself.

[0058] Alternatively, or furthermore, the actual vehicle data preferably includes the vehicle's speed. From the vehicle's speed and the rotational speed of a wheel, the wheel slip can be determined, for example.

[0059] Alternatively, or furthermore, the actual vehicle data preferably includes a yaw rate and / or a roll rate. From these rates, conclusions can be drawn about the driving situation of the vehicle.

[0060] Alternatively, or furthermore, the actual vehicle data preferably includes torque, for example, from a drive unit. With torque data, the necessary intensity of a speed change can be determined, for example, to counteract an exceedance or impending exceedance.

[0061] Alternatively, or furthermore, the actual vehicle data preferably includes acceleration and / or deceleration. From this data, conclusions can be drawn about the driving situation of the vehicle.

[0062] Accordingly, the first sensor is preferably a speed, velocity, force and / or acceleration sensor, with which the aforementioned vehicle data can be determined.

[0063] The driving requirement is in a preferred embodiment of a method according to the second aspect of the invention. a. an acceleration request and / or b. a braking request and / or c. a steering request and / or d. a gear change request and / or e. a request to change a driving mode.

[0064] For the purposes of the invention, a driving mode is understood to be a sum of vehicle settings, in particular settings of the drives installed in the motor vehicle, especially individual wheel drives. A driving mode can be selected and active from a set of driving modes for a short time, while at another time it is not selected. In particular, the method according to the invention can be carried out in different driving modes. Several driving modes, which relate to different areas of the vehicle settings, can also be activated in parallel and independently of one another. In one embodiment, the selection of a driving mode is carried out manually by an operator of the motor vehicle. For example, the operator can be offered several driving modes for free selection. Alternatively or additionally, the selection of the driving mode can also be carried out by a vehicle control system.For example, appropriate sensors detect when a specific driving situation occurs and automatically select the corresponding driving mode. For instance, the vehicle switches to an off-road driving mode when it detects that the road surface changes from asphalt to gravel or similar. The vehicle also switches to an energy-efficient driving mode when it detects that it is in a traffic jam.

[0065] All of the aforementioned types of driving requirements can influence a driving situation and lead to a dangerous driving situation in which safe and stable driving behavior is not ensured.

[0066] An acceleration or braking request results, for example, from a pedal position and / or cruise control and / or an adaptive cruise control system. A steering request can result, for example, from a steering wheel position and / or lane keeping assist and / or a safety device. A gear shift request results, for example, from the operation of a gear selector lever or switch and / or an automatic transmission and / or kickdown.

[0067] In one embodiment of the method according to the second aspect of the invention, an action is a manipulation of the driving request, in particular a. a reduction of an acceleration request and / or b. a change in the angle of a steering request and / or c. a delay or refusal of a gear change request or a request to change a driving mode.

[0068] Such manipulation can prevent an impending speed limit violation, thus avoiding a dangerous driving situation. For example, an acceleration request during a curve, in which one or more vehicle wheels are already operating near their maximum speed, can be reduced to such an extent that an exceedance does not occur. Changing the angle of a steering input can be used in this method, particularly in vehicles where the steering wheel and vehicle wheels are not mechanically coupled, such as in so-called "steer-by-wire" systems.

[0069] In accordance with the above explanations, the second sensor is, for example, an acceleration sensor and / or a rotation angle sensor for a steering component and / or a sensor for detecting a gear change or a change in driving mode, with which the aforementioned driving requirements can be determined in each case.

[0070] In a preferred embodiment of the method according to the first or second aspect of the invention, the intensity of an action is determined by the evaluation unit as a function of a difference and / or a ratio between the actual vehicle value and the maximum vehicle value. In this way, the action can be selected so that it is simultaneously sufficiently intense to counteract the actual vehicle value exceeding or impending exceedance of the maximum vehicle value, while at the same time being as imperceptible as possible to the occupants of the vehicle and, in particular, to an operator.

[0071] In a further preferred embodiment of the method according to the first or second aspect of the invention, an action is executed until an actual vehicle value is determined that is sufficiently below the maximum vehicle value, and the action is then terminated. This ensures that, after the action is terminated, the actual vehicle value does not immediately threaten to exceed the maximum vehicle value again, and the action is simultaneously limited to a minimum duration. It is particularly preferred that the action is terminated when the actual vehicle value remains sufficiently below the maximum vehicle value for a third defined period.

[0072] In a further preferred embodiment of the method according to the first or second aspect of the invention, the maximum vehicle value, which is in particular the maximum slip, is the same and fixed for each driven vehicle wheel. Such a fixed maximum vehicle value is then stored on the evaluation unit and does not need to be calculated at any time.

[0073] Alternatively, the maximum vehicle value for two driven wheels is different and fixed. This maximum vehicle value is then adapted to the vehicle's design, for example, the distribution of drive power to the drive units, but still does not need to be calculated at any time.

[0074] Alternatively, the maximum vehicle value can depend on an actual vehicle value and / or a driving situation and / or a driving requirement. The maximum vehicle value is then calculated, for example, by the control unit and can be adjusted to actual vehicle values, driving situations, and / or driving requirements. For instance, a higher maximum vehicle value might be acceptable in one driving situation, while in another, only a lower maximum vehicle value is acceptable to prevent a dangerous driving situation. In this way, the highest possible maximum vehicle value can be selected for each driving situation and driving requirement to minimize the number of interventions in the vehicle's behavior.

[0075] In addition to the aforementioned actual vehicle values ​​and driving requirements, the maximum vehicle value may, for example, depend on a driving mode and / or the actual slip of another vehicle wheel.

[0076] Particularly preferred in an embodiment of the method according to the first or second aspect of the invention is that the maximum vehicle value is a maximum slip and lies between a lower limit of 1.6, 1.7, 1.8, or 1.9% and an upper limit of 2.1, 2.2, 2.3, or 2.4%, or between a combination of these limits, which is situationally determined depending on an actual vehicle value and / or a driving situation and / or a driving requirement. Above the aforementioned ranges, the handling of conventional vehicle wheels is expected to deteriorate significantly. For example, above these ranges, the traction and / or the lateral grip of the vehicle wheel decrease. Slip is understood here to mean both a positive and a negative difference between two rotational speeds, i.e., a difference where the first rotational speed is greater than the second, but also a difference where the first rotational speed is less than the second.For clarity, the specified slip values ​​are not distinguished by sign. The values ​​should therefore be understood as absolute values.

[0077] Preferably, the maximum slip, particularly in a normal driving situation, is 2%. A normal driving situation is understood to be a driving situation that occurs daily in the operation of a motor vehicle; for example, in the case of a passenger car, driving on a highway or motorway in dry weather conditions. The definition of a normal driving situation may depend on the vehicle type and its actual use.

[0078] The third aspect of the invention relates to a drive control device for controlling the drive of a motor vehicle with individual wheel drive on two vehicle wheels, in particular according to a aforementioned method, comprising a. a first sensor for capturing actual vehicle data, in particular at vehicle wheels, b. a control unit comprising an evaluation unit and a control unit, i. the evaluation unit for receiving and evaluating the actual vehicle data, for determining a respective physical actual vehicle value from the actual vehicle data, for comparing the respective determined actual vehicle value with a maximum vehicle value and for transmitting an instruction to the control unit, and ii. the control unit for executing an action based on a transmitted instruction from the evaluation unit.

[0079] The terms used here are to be understood in the same way as described with regard to the first aspect of the invention.

[0080] Such a drive control device enables effective and safe operation of a motor vehicle with individual wheel drive. In particular, this drive control device allows for the implementation of a method according to the first aspect of the invention with the aforementioned features and advantages.

[0081] In a preferred embodiment of the drive control device, a second sensor is provided for detecting a driving request, and the evaluation unit is configured to receive and evaluate the driving request. The terms used here are to be understood in the same way as described with regard to the second aspect of the invention. Advantageously, with such an embodiment, a method according to the first and / or second aspect of the invention can be implemented with the aforementioned features and advantages.

[0082] In a preferred embodiment of the drive control device, the control unit controls a drive device, in particular the torque delivered by the drive device. The drive device is, in particular, a drive device of an individual wheel drive. In this way, the torque applied to a vehicle wheel can be influenced and modified as an action within a drive control method.

[0083] In a further preferred embodiment of the drive control device, the control unit controls a brake, in particular a brake of exactly one vehicle wheel. In this way, the braking force applied to a vehicle wheel can be influenced and changed as an action within a drive control method.

[0084] The first sensor is, for example, a speed, velocity, or acceleration sensor, which then records the corresponding values ​​as actual vehicle data. The second sensor is, for example, an acceleration or yaw rate sensor, or a sensor for detecting a gear change and / or a change in driving mode, which then records the corresponding driving requirements.

[0085] The fourth aspect of the invention relates to a drive train for a motor vehicle, comprising a. two drive devices, each driving exactly one vehicle wheel, b. a aforementioned drive control device according to the third aspect of the invention.

[0086] A drivetrain is understood here to comprise several components serving the propulsion of the motor vehicle, in particular a drive device or several drive devices and the associated output-side components by means of which energy is transmitted from the drive device(s) to the vehicle wheels. The drivetrain can comprise all components serving the propulsion of a motor vehicle, regardless of whether all these components interact with one another or whether they are divided into several drive groups. A drivetrain within the meaning of the invention is also defined in such a way that several drive devices that are not directly mechanically connected or operatively connectable to one another can be assigned to the same drivetrain. The drive devices do not necessarily have to be mechanically connected to one another, but can each be mounted independently, for example, on a wheel axle.For example, each rear wheel of a vehicle can have a drive device with or without its own gearbox, which are basically operated and controlled independently of each other and in particular are not mechanically connected or connectable to each other, but are assigned to the same drive train.

[0087] Advantageously, in a drive train according to the fourth aspect of the invention, the individual wheel drives can be controlled by means of the drive control device in such a way that the motor vehicle can be operated efficiently and safely, whereby in particular a method according to the first and / or second aspect of the invention can be used.

[0088] In a preferred embodiment, each drive device is assigned a transmission. The respective transmission allows the drive device to be operated efficiently over a wide speed range of the vehicle.

[0089] Furthermore, it is preferred if each of the two rear wheels of the vehicle is assigned a drive device for individual wheel drive. In particular, the drive devices assigned to the rear wheels of the vehicle are primary drive devices. A primary drive device is understood to be one that is designed and intended for the continuous and, in particular, sole propulsion of the vehicle. Specifically, it is intended that in a normal driving mode only the primary drive devices are active for propelling the vehicle. If the vehicle has further, secondary drive devices, these are engaged situationally, for example, but are then not intended for the continuous propulsion of the vehicle. Accordingly, a rear-wheel drive with the advantages known to those skilled in the art is then present. In particular, this advantageously results in a sporty vehicle.

[0090] Preferably, the drive devices assigned to the vehicle's rear wheels are electric motors and / or internal combustion engines and / or fuel cells. Each type of drive device offers advantages known to those skilled in the art. Particularly preferred are electric motors, which, as individual wheel drives, can be designed to be especially compact and can also be operated without emissions.

[0091] In a preferred embodiment of the drivetrain, a further drive device for driving the two front wheels of the vehicle is assigned to a wheel shaft acting on two front wheels. This is, in particular, a secondary drive device. A secondary drive device is understood to be one that does not contribute to propulsion in the majority of all driving situations, but is fundamentally capable of propulsion and provides support in certain driving situations. Advantageously, in combination with individual wheel drives arranged on the rear wheels of the vehicle, drive devices are arranged on all vehicle wheels, so that the vehicle is capable of all-wheel drive without the need for a drivetrain acting on multiple pairs of wheels, which would typically entail a complex and expensive drivetrain design.

[0092] A particularly preferred additional drive device is an electric machine, especially an asynchronous motor, capable of recuperation. Recuperation refers to the conversion of the vehicle's mechanical energy into another usable form of energy, particularly electrical energy, thereby braking the vehicle. For this purpose, the electric machine is coupled to a vehicle wheel and driven by it as a generator. By assigning the recuperation function to the additional drive device, it can be designed for efficient recuperation without requiring adjustments to the individual wheel drives.

[0093] In an alternative embodiment, each of the two front wheels of the vehicle is assigned an additional drive device for individual wheel drive. These are, in particular, secondary drive devices. Even with drive devices designed as individual wheel drives on the front wheels, the vehicle is advantageously capable of all-wheel drive if the rear wheels have primary individual wheel drives.

[0094] Particularly preferred are additional drive devices that are capable of recuperation. By assigning the recuperation function to the additional drive devices, these can be designed for efficient recuperation without having to design the individual wheel drives accordingly.

[0095] The fifth aspect of the invention relates to a motor vehicle with a first and a second pair of wheels and with the aforementioned drivetrain. The aforementioned advantages of the drivetrain can be achieved with such a motor vehicle.

[0096] Further advantages, special features and advantageous developments of the invention will become apparent from the following description of preferred embodiments with reference to the figures. This will show Fig. 1 a process diagram of a method according to the first aspect of the invention; Fig. 2 a process diagram of a method according to the second aspect of the invention; Fig. 3 a process diagram of a method according to the first and / or second aspect of the invention; Fig. 4 in a bottom view a highly simplified view of a motor vehicle according to the fifth aspect of the invention in a first representation; Fig. 5 in a bottom view a highly simplified view of the motor vehicle according to Fig. 4in a second representation; Fig. 6 in bottom view a highly simplified representation of a motor vehicle according to the fifth aspect of the invention.

[0097] The embodiments shown here are merely examples of the present invention and should therefore not be interpreted as limiting. Alternative embodiments considered by a person skilled in the art are likewise covered by the scope of protection of the present invention.

[0098] Figure 1Figure 1 shows a process diagram of a method according to the first aspect of the invention. In a first step, actual vehicle data is acquired using the first sensor. This data is then received and evaluated by the evaluation unit in a second step. In a third step, the evaluation unit determines an actual vehicle value from the actual vehicle data. This value is then compared with a maximum vehicle value in a fourth step. If the actual vehicle value is found to be less than the maximum vehicle value, the current loop of the method terminates without further steps, and a new loop begins with the first step.If, however, it is determined that the actual vehicle value is greater than the maximum vehicle value, then in a fifth step the evaluation unit transmits an instruction to a control unit, which is executed by the control unit in a sixth step. The process then repeats itself from the first step in a subsequent loop.

[0099] Figure 2Figure 1 shows a process diagram of a method according to the second aspect of the invention. In a first step, actual vehicle data is acquired using the first sensor, and a driving request is acquired using the second sensor. These data are then received and evaluated by the evaluation unit in a second step. In a third step, the evaluation unit determines an actual vehicle value from the actual vehicle data and also predicts an actual vehicle value based on the driving request and the monitoring of a driving situation. Monitoring of the driving situation involves, for example, capturing an upcoming section of road using a camera and detecting an impending curve. In a fourth step, the determined actual vehicle value and / or the predicted actual vehicle value are compared with a maximum vehicle value. The maximum vehicle value is determined first.This can occur in any process loop, depending on the driving situation, or at regular intervals. If the comparison determines that both actual vehicle values ​​are less than the maximum vehicle value, the current loop of the process terminates without further steps, and a new loop begins with the first step. Conversely, if it is determined that one actual vehicle value is greater than the maximum vehicle value, the evaluation unit transmits an instruction to a control unit in a fifth step, which is then executed by the control unit in a sixth step. The process then repeats itself from the first step in the next loop.

[0100] The procedures described above are preferably repeated in rapid succession. If an action based on an instruction from the previous loop is already included in its execution, the instruction can be maintained in the current loop, its intensity can be changed, or it can be replaced by a different action. Figure 3 A corresponding process diagram is shown. It should be explained that in a diamond-shaped element of the diagram, a dashed outgoing line represents the process path followed if the question posed in the diamond-shaped element is answered in the negative. A solid outgoing line represents the process path if the question is answered in the affirmative.

[0101] In Figure 3The first three steps of a procedure are executed first. In the fourth step, the actual vehicle value(s) are compared with the maximum vehicle value(s). If the actual vehicle values ​​are lower than the maximum vehicle values, the system then checks whether an action is already being implemented. If not, the procedure restarts at the first step without issuing any instructions for an action. If, however, an action is in progress, the system checks whether a third time period has elapsed. This third time period begins when the current action first falls below the threshold and is defined to ensure that the current action falls below the threshold before it is canceled. If the third time period expires, the current action is canceled; otherwise, the procedure restarts at the first step with the current action still in progress.At this point, an optional change in the intensity of the action can also be included, in addition to what has been shown.

[0102] If the current vehicle value is greater than the maximum vehicle value, the system checks whether an initial time period has elapsed. This initial time period begins when a torque change is first executed. If the initial time period has not yet elapsed, a torque change is executed for the first time or continues to be executed, and the process is repeated from the first step. Further torque changes can also be performed with an adjusted intensity, in addition to the steps described above.

[0103] Once the first time interval has elapsed, the system checks whether a second time interval has begun. The second time interval starts when a braking intervention is first executed. If the second time interval has not yet elapsed, a braking intervention is performed for the first time or continues, and the process is repeated from the first step. Further braking interventions can also be performed with an adjusted intensity, in addition to the actions described. A braking intervention can be performed either in addition to or instead of a torque change, in which case the torque change is canceled.

[0104] Once the second time period has elapsed, an additional or replacement action is taken by switching on a drive device, or the already switched-on drive device is kept in operation and the procedure is repeated from the first step.

[0105] The three actions are thus arranged sequentially in a cascade. The order within a cascade can vary depending on the design, selected driving mode, and driving situation.

[0106] Figure 4 Figure 1 shows a motor vehicle 1 according to the fifth embodiment, which essentially consists of a body 2 in the floor area of ​​which a wheel axle 3a with a first vehicle wheel 4a and a second vehicle wheel 4b and a wheel shaft 3b with a third vehicle wheel 4c and a fourth vehicle wheel 4d are arranged. The first and second vehicle wheels 4a, 4b are rear vehicle wheels, and the third and fourth vehicle wheels 4c, 4d are front vehicle wheels.

[0107] A first drive device 6a and a second drive device 6b, each a single-wheel drive, are mounted on the wheel axle 3a. A first transmission 7a is associated with the first drive device 6a, through which the first drive device 6a acts on the first vehicle wheel 4a. A second transmission 7b is associated with the second drive device 6b, through which the second drive device 6b acts on the second vehicle wheel 4b. A third drive device 6c engages the wheel shaft 3b via a third transmission 7c. The third drive device 6c is effectively connected to the third transmission 7c, which in turn is effectively connected to the wheel shaft 3b.

[0108] Figure 5 The motor vehicle 1 shows according to Figure 4 with the presentation of further elements, including those already in Figure 4The elements already labelled are not again marked with reference symbols for clarity. The motor vehicle 1 has a control unit 8 which is connected via signal lines 10a, 10b, 10c, 10d, 10e to the first drive device 6a, the second drive device 6b, the third drive device 6c, as well as a first sensor 9a and a second sensor 9b. The first sensor 9a is a speed sensor that detects the rotational speed of the first vehicle wheel 4a. The second sensor 9b is, for example, a rotary angle sensor for detecting the angular position of a steering wheel, so that a steering request can be detected. The control unit 8 can also be connected to other elements of the motor vehicle 1 beyond those shown, such as one of the transmissions 7a, 7b, 7c.

[0109] The control unit 8 comprises an evaluation unit 11 for receiving and evaluating the actual vehicle data and the driving request, for determining a physical actual vehicle value, for comparing the determined actual vehicle value with the maximum vehicle value, and for transmitting an instruction for an action. Furthermore, the control unit 8 comprises a control unit 12 for executing an action. For this purpose, the control unit 12 transmits corresponding control commands via signal lines 10a, 10b, 10c, 10d, 10e to elements of the motor vehicle 1, such as a drive device 6a, 6b, 6c.

[0110] The control unit 8, the first sensor 9a and the second sensor 9b together form a drive control device 13 according to the third aspect of the invention. The drive control device 13 together with the wheel axle 3a, the wheel shaft 3b, the drive devices 6a, 6b, 6c and the gears 7a, 7b, 7c form a drive train according to the fourth aspect of the invention.

[0111] Figure 6 shows a motor vehicle that corresponds to motor vehicle 1 according to Figure 4 It essentially corresponds to the embodiment shown. It also has a wheel axle 3a with a first vehicle wheel 4a and a second vehicle wheel 4b, but unlike the wheel shaft 3b, it has a wheel axle 3c with a third vehicle wheel 4c and a fourth vehicle wheel 4d. A fourth drive device 6d and a fourth gearbox 7d are mounted on the wheel axle 3c, which drive the third vehicle wheel 4c as an individual wheel drive. Furthermore, a fifth drive device 6e and a fifth gearbox 7e are mounted on the wheel axle 3c, which drive the fourth vehicle wheel 4d as an individual wheel drive. In the embodiment shown, Figure 6 all vehicle wheels 4a, 4b, 4c, 4d are driven by individual wheel drive. Vehicle wheels: List of reference symbols used

[0112] 1 Motor vehicle 2 Body 3a Wheel axle 3b Wheel shaft 3c Wheel axle 4a First vehicle wheel 4b Second vehicle wheel 4c Third vehicle wheel 4d Fourth vehicle wheel 6a First drive device 6b Second drive device 6c Third drive device 6d Fourth drive device 6f Fifth drive device 7a First transmission 7b Second transmission 7c Third transmission 8 Control unit 9a First sensor 9b Second sensor 10a First signal line 10b Second signal line 10c Third signal line 10d Fourth signal line 10f Fifth signal line 11 Evaluation unit 12 Control unit 13 Drive control device

Claims

1. Method for controlling the drive of a motor vehicle (1) with individual wheel drive at two vehicle wheels (4a, 4b, 4c, 4d) and a first sensor (9a) by means of a control unit (8), wherein the control unit (8) has an evaluation unit (11) and a control unit (12), and wherein the method comprises the steps of: a. acquiring actual vehicle data by means of the first sensor (9a), in particular at vehicle wheels (4a, 4b, 4c, 4d), b. receiving and evaluating the actual vehicle data by means of the evaluation unit (11), wherein a maximum vehicle value, in particular a maximum slip, is stored on the evaluation unit (11), c. determining an actual vehicle value, in particular an actual slip, from the actual vehicle data using the evaluation unit (11), d. comparing the determined actual vehicle value with the maximum vehicle value, in particular the maximum slip, using the evaluation unit (11), e. transmitting an instruction for an action from the evaluation unit (11) to the control unit (12) if the actual vehicle value exceeds the maximum vehicle value, f. executing the action by the control unit (12), characterized in that the actual vehicle value, in particular the actual slip, is determined for each vehicle wheel (4a, 4b, 4c, 4d) driven by individual wheel drive and is respectively compared by means of the evaluation unit (11) with a maximum vehicle value, in particular maximum slip, assigned to this vehicle wheel (4a, 4b, 4c, 4d), and an action is a change in a torque at a vehicle wheel (4a, 4b, 4c, 4d), in particular at a vehicle wheel (4a, 4b, 4c, 4d) at which the actual vehicle value exceeds or is likely to exceed the maximum vehicle value, the change in torque being implemented by influencing an element assigned to the respective individual wheel drive, such as a drive device or a transmission.

2. Method for controlling the drive of a motor vehicle (1) with individual wheel drive at two vehicle wheels (4a, 4b, 4c, 4d), a first sensor (9a) and a second sensor (9b) by means of a control unit (8), wherein the control unit (8) has an evaluation unit (11) and a control unit (12), and wherein the method comprises the steps of: a. acquiring actual vehicle data by means of the first sensor (9a), in particular at vehicle wheels (4a, 4b, 4c, 4d), b. acquiring a driving request by means of the second sensor (9b), c. receiving and evaluating the actual vehicle data and the driving request by means of the evaluation unit (11), wherein a maximum vehicle value, in particular maximum slip, is stored on the evaluation unit (11), d. determining an actual physical vehicle value, in particular actual slip, using the evaluation unit (11), e. comparing the determined actual vehicle value with the maximum vehicle value, in particular the maximum slip, using the evaluation unit (11), f. transmitting an instruction for an action from the evaluation unit (11) to the control unit (12) if the actual vehicle value exceeds or, due to the driving request, is likely to exceed the maximum vehicle value, g. executing the action by the control unit (12), characterized in that the actual vehicle value, in particular the actual slip, is determined for each vehicle wheel (4a, 4b, 4c, 4d) driven by individual wheel drive and is respectively compared by means of the evaluation unit (11) with a maximum vehicle value, in particular maximum slip, assigned to this vehicle wheel (4a, 4b, 4c, 4d), and an action is a change in a torque at a vehicle wheel (4a, 4b, 4c, 4d), in particular at a vehicle wheel (4a, 4b, 4c, 4d) at which the actual vehicle value exceeds or is likely to exceed the maximum vehicle value, wherein the change in torque is implemented by influencing an element assigned to the respective individual wheel drive, such as a drive device or a transmission.

3. Method according to claim 2, characterized in that an instruction for an action is transmitted from the evaluation unit (11) to the control unit (12) if there is a risk of the actual vehicle value exceeding the maximum vehicle value due to an imminent change in the driving situation of the motor vehicle.

4. Method according to one of the preceding claims, characterized in that the method is repeated, in particular several times per second, and is executed again without performing an action if the actual vehicle value falls sufficiently below the maximum vehicle value.

5. Method according to one of the preceding claims, characterized in that, after executing an action over a defined period of time a. if the actual vehicle value continues to exceed or continues to be likely to exceed the maximum vehicle value, an instruction for a further action is transmitted from the evaluation unit (11) to the control unit (12), and b. the control unit (12) executes the further action.

6. Method according to one of the preceding claims, characterized in that in the action a. a torque at one vehicle wheel (4a, 4b, 4c, 4d) is reduced and at the same time b. a torque at another vehicle wheel (4a, 4b, 4c, 4d) is increased.

7. Method according to one of the preceding claims, characterized in that an action is a braking intervention at a vehicle wheel (4a, 4b, 4c, 4d), in particular at a vehicle wheel (4a, 4b, 4c, 4d) at which the actual vehicle value exceeds or is likely to exceed the maximum vehicle value.

8. Method according to claim 7, characterized in that a. in a first step, a change in a torque is performed at a vehicle wheel (4a, 4b, 4c, 4d) and b. in a second step, a braking intervention at a vehicle wheel (4a, 4b, 4c, 4d) is executed as an action only if, after the first step, in particular after a first defined period of time during which the first step was performed, the actual vehicle value continues to exceed the maximum vehicle value or continues to be likely to exceed the maximum vehicle value.

9. Method according to one of the preceding claims, characterized in that an action is the activation of a drive device (6a, 6b, 6c), preferably the activated drive device (6a, 6b, 6c) drives a vehicle wheel (4a, 4b, 4c, 4d) that was not driven before the drive device (6a, 6b, 6c) was activated, and further preferably a. before the drive device (6a, 6b, 6c) is activated, the actual vehicle value is acquired at the previously driven vehicle wheels (4a, 4b, 4c, 4d) and b. after the drive device (6a, 6b, 6c) is activated, the actual vehicle value is determined at the vehicle wheels (4a, 4b, 4c, 4d) that were driven before the drive device (6a, 6b, 6c) was activated and at the vehicle wheels (4a, 4b, 4c, 4d) driven by the activated drive device (6a, 6b, 6c).

10. Method according to claim 9, characterized in that the activated drive device (6a, 6b, 6c) acts on a wheel shaft and drives a front wheel (4a, 4b, 4c, 4d) of the vehicle, in particular both front wheels (4a, 4b, 4c, 4d) of the vehicle, and / or a. in a first step, a change in a torque and / or a braking intervention is performed at a vehicle wheel (4a, 4b, 4c, 4d) and b. in a second step, the activation of the drive device (6a, 6b, 6c) is only performed as an action if, after the first step, in particular after a second defined period of time during which the first step was carried out, the actual vehicle value continues to exceed the maximum vehicle value or continues to be likely to exceed it.

11. Method according to one of the preceding claims, characterized in that the actual vehicle data comprise: a. a rotational speed of a vehicle wheel (4a, 4b, 4c, 4d) and / or b. a rotational speed of a component of a drive train and / or c. a speed of the motor vehicle (1) and / or d. a yaw rate and / or e. a roll rate and / or f. a torque and / or g. an acceleration and / or braking deceleration.

12. Method according to one of claims 2 to 11, characterized in that an action is a manipulation of the driving request, in particular a. a reduction in an acceleration request and / or b. an angular change in a steering request and / or c. a time delay or refusal of a gear change request or a request to change a driving mode.

13. Drive control device (13) for controlling the drive of a motor vehicle (1) with individual wheel drive at two vehicle wheels (4a, 4b, 4c, 4d) according to a method according to one of the preceding claims, comprising a. a first sensor (9a) for acquiring actual vehicle data, in particular at vehicle wheels (4a, 4b, 4c, 4d), b. a control unit (8) having an evaluation unit (11) and a control unit (12), i. the evaluation unit (11) for receiving and evaluating the actual vehicle data, for determining a respective physical actual vehicle value from the actual vehicle data, for comparing the respectively determined actual vehicle value with a maximum vehicle value, and for transmitting an instruction to the control unit (12), and ii. the control unit (12) for executing an action based on a transmitted instruction from the evaluation unit (11).

14. Drive train for a motor vehicle (1), comprising a. two drive devices (6a, 6b), each of which drives exactly one vehicle wheel (4a, 4b, 4, 4d), b. a drive control device (13) according to claim 13.