Control unit for a motor vehicle control system, control system for a motor vehicle and method for operating a control system

Abstract

The present invention relates to a control unit (4) for a control system (2) of a motor vehicle, wherein the control unit (4) has at least one processing unit (12, 14, 16) for evaluating output signals of at least one sensor (6, 8) of the control system (2) and for controlling a power electronics unit (9) of an actuator (10) of the control system (2) by means of control signals depending on these output signals, wherein the control unit (4) has three processing units (12, 14, 16) and is designed and configured such that the output signals of the at least one sensor (6, 8) can be evaluated in parallel in all processing units (12, 14, 16) and the power electronics unit (9) of the actuator (10) can be controlled by means of control signals from each of the processing units (12, 14, 16), and wherein, in the event of a match of at least two corresponding control signals from two of the three processing units (12, 14,16) the power electronics (9) of the actuator (10) can be controlled by means of the control signals of at least one computing unit (12, 14; 12, 16; 14, 16) of these two computing units.

Description

[0001] The present invention relates to a control unit for a control system of a motor vehicle of the type mentioned in the preamble of claim 1, a control system for a motor vehicle of the type mentioned in the preamble of claim 7 and a method for operating a control system for a motor vehicle.

[0002] Such control units for a motor vehicle control system, control systems for motor vehicles and methods for their operation are already known in numerous design variants from the prior art.

[0003] The known control systems for motor vehicles for controlling a function of the motor vehicle are designed in such a way that at least one control unit of the control system has at least one computing unit for evaluating output signals of at least one sensor of the control system and for controlling a power electronics of an actuator of the control system by means of control signals depending on these output signals for the execution of this function of the motor vehicle.

[0004] This is where the present invention comes in.

[0005] The present invention is based on the objective of improving a control unit for a control system of a motor vehicle for controlling a function of the motor vehicle, a control system for a motor vehicle and a method for operating a control system for a motor vehicle.

[0006] This problem is solved by a control unit with the features of claim 1, characterized in that the control unit has three processing units, wherein the control unit is designed and configured such that the output signals of the at least one sensor can be evaluated in parallel in all processing units and the power electronics of the actuator can be controlled by means of control signals from each of the processing units, and wherein, if at least two corresponding control signals from two of the three processing units match, the power electronics of the actuator can be controlled by these two processing units by means of the control signals from at least one processing unit. Furthermore, this problem is solved by a control system for a motor vehicle with the features of claim 7 and a method for operating a control system for a motor vehicle with the features of claim 11.The subclaims relate to advantageous developments of the invention.

[0007] A significant advantage of the invention lies particularly in the fact that a control unit for a motor vehicle's control system for controlling a function of the motor vehicle, a control system for a motor vehicle, and a method for operating a control system for a motor vehicle are improved. Due to the inventive design of the control unit, the control system, and the method for operating the control system, sufficient redundancy for a so-called X-by-wire system or the like can be achieved in a simple and therefore cost-effective manner. Ensuring sufficient redundancy is particularly important for such systems and the motor vehicles equipped with them because the mechanical couplings that exist in conventional motor vehicles and are relevant for redundancy considerations are eliminated in such vehicles.This is easily understood, for example, in the case of a motor vehicle's steering system with a steer-by-wire system, where a so-called steer-by-wire system is used instead of the known mechanical connection between the vehicle's steering wheel and the wheels to be steered. The aforementioned mechanical connection is eliminated. However, the application of motor vehicle steering using steer-by-wire systems is merely an example here. The invention can also be advantageously applied to other functions of motor vehicles. For example, other by-wire systems, generally referred to as X-by-wire systems, should be mentioned. The basic design of such X-by-wire systems is well known to those skilled in the art. According to the invention, it is not necessary to provide a plurality of control units to achieve, for example, the aforementioned redundancy.Instead, it is possible to use only a single control unit to execute the respective function of the vehicle. Only the number of processing units is tripled; the number of other components of the control unit remains the same.

[0008] In principle, the inventive control system for motor vehicles, including the inventive control unit, can be freely selected within wide suitable limits with regard to type, function, material, and dimensions. See, for example, the multitude of different functions in modern motor vehicles, and the above discussion of the challenges of X-by-wire systems in general. The same applies to the inventive method for operating a control system for a motor vehicle.

[0009] An advantageous embodiment of the control unit according to the invention provides that the control unit is designed and configured such that a first processing unit of the three processing units is functionally connected to a first voltage source of the control system for supplying the actuator with electrical power for its operation, a second processing unit of the three processing units is functionally connected to a second voltage source of the control system for supplying the actuator with electrical power for its operation, and a third processing unit of the three processing units is functionally connected to the first and / or the second voltage source for supplying the actuator with electrical power for its operation. This enables the actuator to be operated with either a first and / or a second voltage source of the control system.For example, the actuator can have multiple electrical coils, with some of the coils connected to the first voltage source and the remainder to the second. Accordingly, even if one of the three processing units fails, two power supply paths for the actuator are always available.

[0010] A further advantageous embodiment of the control unit according to the invention provides that the control unit has only a single signal interface for all three processing units for transmitting sensor signals to a higher-level bus system of the motor vehicle. The output signals of at least one of the at least one sensor can be transmitted from this sensor to the processing units via the bus system and this signal interface. In this way, the sensor signal transmission connection of the three processing units to a higher-level bus system of the motor vehicle is significantly simplified. For example, output signals from at least one sensor that functionally interacts with a steering wheel of the motor vehicle to detect a steering wheel movement can be transmitted to the three processing units via the bus system.

[0011] Analogous to the aforementioned further development of the control unit according to the invention, another advantageous further development of the control unit according to the invention provides that the control unit has only a single signal interface for all three processing units for the sensor signal transmission connection of the three processing units to at least one sensor that functionally interacts with the actuator, wherein output signals from this sensor can be transmitted to the processing units via this signal interface. Accordingly, the signal transmission connection of the three processing units to the actuator, namely to the at least one sensor that functionally interacts with the actuator, is also significantly simplified.For example, analogous to the example above, output signals from at least one inductive and / or at least one magnetic and / or at least one capacitive sensor, which functionally interact with the actuator, can be transmitted to the three processing units via this signal interface. Using sensors based on different physical principles, i.e., through technological diversity in the sensors used, further improves reliability. Furthermore, to increase availability, analogous to the number of processing units, it is also conceivable to use more than one sensor per technology, for example, three inductive sensors and three magnetic sensors.

[0012] A further advantageous embodiment of the control unit according to the invention provides that the control unit has only a single control interface for all three processing units for the control signal transmission connection of at least one of the three processing units to the power electronics of the actuator. Control signals can preferably be transmitted to the power electronics of the actuator via this control interface in such a way that the actuator can be connected to at least one voltage source of the control system for supplying the actuator with the electrical power necessary for its operation. Analogous to the two aforementioned embodiments of the control unit according to the invention, this also significantly simplifies the control interface of the three processing units towards the actuator.

[0013] Accordingly, an advantageous further development of the method according to the invention provides that the power electronics of the actuator are controlled by means of control signals in such a way that the actuator is connected by means of these control signals to at least one voltage source of the control system to supply the actuator with the electrical power for operation of the actuator.

[0014] Furthermore, an advantageous embodiment of the control unit according to the invention provides that the control unit is designed as a single unit, preferably that all processing units of the control unit are functionally essentially identical to one another. In this way, the control unit is very compact and therefore easier to handle. The preferred embodiment of this embodiment also has the further advantage that the processing units can be sourced from different manufacturers. This achieves additional diversification of the processing units, thereby improving the operational reliability of the control unit. This is because, although the processing units are functionally essentially identical, their design can differ from manufacturer to manufacturer.Accordingly, the failure of two computing units from different manufacturers due to the same fault is practically very unlikely.

[0015] As already explained above, the control system according to the invention can be freely selected within wide suitable limits.

[0016] An advantageous further development of the control system according to the invention provides that the control unit is designed as a single control unit. This significantly simplifies the control system according to the invention, since the required redundancy is ensured not by a plurality of control units, but merely by a plurality of computing units integrated in the single control unit.

[0017] As already explained in the introductory section, the invention, and thus the control system according to the invention, is very advantageously applicable to steering systems of motor vehicles. Accordingly, an advantageous further development of the control system according to the invention provides that the control system is designed as a control system for the steering of at least one wheel of the motor vehicle, wherein the power electronics of the actuator for the steering movement of the at least one wheel can be operated depending on output signals from at least one sensor of the control system that functionally interacts with a steering wheel of the motor vehicle to determine a steering movement of the steering wheel, and depending on output signals from at least one sensor of the control system that functionally interacts with the actuator of the control system to determine a steering position of the wheel; preferably, the control system is designed solely as a steer-by-wire control system.By means of the control system according to the preferred embodiment of the present further development, sufficient redundancy is also ensured in steering systems of motor vehicles where, for example, there is no longer any mechanical connection between the steering wheel on one side and the at least one wheel on the other side.

[0018] Accordingly, an advantageous further development of the method according to the invention provides that the actuator, which is connected to at least one wheel of the motor vehicle in a force-transmitting manner, is operated depending on output signals of at least one sensor of the control system that functionally cooperates with a steering wheel of the motor vehicle to determine a steering movement of the steering wheel and depending on output signals of at least one sensor of the control system that functionally cooperates with the actuator of the control system to determine a steering position of the wheel; preferably, that the control system is operated only as a steer-by-wire control system.

[0019] Another advantageous embodiment of the control system according to the invention provides that the control unit comprises at least two of the following components of the control system, preferably all of the following components, particularly preferably as a single unit: the three processing units, a signal interface for transmitting sensor signals from the three processing units to a bus system superior to the control unit, a signal interface for transmitting sensor signals from the three processing units to at least one sensor cooperating with the actuator, a control interface for transmitting control signals from the three processing units to the power electronics of the actuator, the power electronics for the actuator,A voltage source switch for connecting at least one of at least two voltage sources of the control system to the actuator via the control interface, in order to supply the actuator with the electrical power for its operation. In this way, a high to very high degree of structural and circuit integration of the control system according to the invention is enabled.

[0020] The invention is explained in more detail below with reference to the attached, roughly schematic drawing. The sole figure shows: Fig. 1 An embodiment of the control system according to the invention with the control unit according to the invention for carrying out the method according to the invention in a partial process circuit diagram.

[0021] In the Fig. Figure 1 is an embodiment of the control system according to the invention with the control unit according to the invention for carrying out the method according to the invention, shown purely by way of example.

[0022] In the present embodiment, the control system 2 of a motor vehicle (not shown in detail) is configured to control a steering function of the motor vehicle and comprises a control unit 4. The control unit 4 of the control system 2 has at least one processing unit for evaluating output signals from at least one sensor 6, 8 of the control system 2 and for controlling a power electronics unit 9 of an actuator 10 of the control system 2 by means of control signals depending on these output signals to execute the steering function of the motor vehicle. According to the invention, the control unit 4 comprises three processing units 12, 14, 16 for evaluating output signals from the sensors 6, 8 and for controlling the power electronics unit 9 of the actuator 10 by means of control signals depending on these output signals.For this purpose, the control unit 4 is designed and configured such that the output signals of the sensors 6, 8 can be evaluated in parallel in all processing units 12, 14, 16, and the power electronics 9 of the actuator 10 can be controlled by means of control signals from each of the processing units 12, 14, 16, wherein, if at least two corresponding control signals from two of the three processing units 12, 14, 16 match, the power electronics 9 of the actuator 10 can be controlled by these two processing units 12, 14, 16 by means of the control signals from at least one of these two processing units. In the present embodiment, the power electronics 9 of the actuator 10 is controlled in normal operation by two of the three processing units 12, 14, 16, as will be explained in more detail below. In the... Fig. The sensors 6 and 8 shown in Figure 1 consist of three magnetic sensors 6 functionally connected to the actuator 10 and three inductive sensors 8 functionally connected to the actuator 10. This results in improved reliability, firstly due to the technological diversity of sensors 6 and 8 already explained above, and secondly due to the aforementioned triple sensor configuration of both sensors 6 and sensors 8. In addition, the control system 2 includes at least one steering wheel sensor (not shown) that functionally interacts with the steering wheel of the vehicle.

[0023] The control unit 4 is designed and configured such that a first computing unit 12 of the three computing units 12, 14, 16 is functionally connected to a first voltage source 18 of the control system 2 to supply the actuator 10 with electrical power for operating the actuator 10, a second computing unit 14 of the three computing units 12, 14, 16 is functionally connected to a second voltage source 20 of the control system 2 to supply the actuator 10 with electrical power for operating the actuator 10, and a third computing unit 16 of the three computing units 12, 14, 16 is functionally connected to the first and the second voltage sources 18, 20 to supply the actuator 10 with electrical power for operating the actuator 10.

[0024] Furthermore, the control unit 4 has only a single signal interface 22 for all three processing units 12, 14, 16 for transmitting sensor signals to a bus system 24 of the vehicle that is superior to the control unit 4. The output signals of the at least one sensor (not shown) can be transmitted from this sensor to the processing units 12, 14, 16 via the bus system 24 and this signal interface 22. The aforementioned at least one sensor is the steering wheel sensor (not shown) mentioned above, which detects a steering movement of the steering wheel (also not shown) of the vehicle. Analogous to sensors 6 and 8, the aforementioned at least one steering wheel sensor can be implemented using different technologies and, alternatively or additionally, redundantly.

[0025] Furthermore, the control unit 4 has only one signal interface 26 for all three computing units 12, 14, 16 for the sensor signal transmission connection of the three computing units 12, 14, 16 with the sensors 6, 8 which functionally interact with the actuator 10, whereby output signals of the sensors 6, 8 can be transmitted to the computing units 12, 14, 16 by means of this signal interface 26.On the other hand, the control unit 4 has only a single control interface 28 for all three computing units 12, 14, 16 for the control signal transmission connection of at least one of the three computing units 12, 14, 16 with the power electronics 9 of the actuator 10, whereby control signals can be transmitted to the power electronics 9 of the actuator 10 by means of this control interface 28 in such a way that the actuator 10 can be connected to the two voltage sources 18, 20 of the control system 2 by means of these control signals to supply the actuator 10 with the electrical power for the operation of the actuator 10.

[0026] Furthermore, the control system 2 here comprises only a single control unit 4, which in the present embodiment is designed as a single unit. The processing units 12, 14, 16 of the control unit 4 are also functionally essentially identical to one another.

[0027] As already outlined above, the control system 2 is designed as a control system for the steering of at least one wheel 30 of the motor vehicle, wherein the actuator 10 can be operated for the steering movement of the at least one wheel 30 depending on output signals from the at least one sensor of the control system 2, which functionally interacts with the steering wheel of the motor vehicle (not shown), to determine a steering movement of the steering wheel, and depending on output signals from the sensors 6, 8 of the control system 2, which functionally interact with the actuator 10 of the control system 2, to determine the steering position of the wheel 30. In the motor vehicle (not shown in detail), the control system 2 is designed solely as a steer-by-wire control system.As already explained in the introductory description, the steering system of a motor vehicle with steer-by-wire is designed without a mechanical connection between the vehicle's steering wheel (not shown) and the at least one wheel of the vehicle, which can be steered by means of a steering wheel movement. In addition to the control system 2 mentioned above, which is designed as a steer-by-wire control system, there is therefore no functionally parallel mechanical connection between the steering wheel and the at least one wheel 30.

[0028] To further increase the level of integration of control system 2, all of the following components of control system 2 are integrated as a single unit in the control unit 4 of control system 2: the three processing units 12, 14, 16; the signal interface 22 for transmitting sensor signals from the three processing units 12, 14, 16 to the bus system 24; the signal interface 26 for transmitting sensor signals from the three processing units 12, 14, 16 to the sensors 6, 8 that interact functionally with the actuator 10; the control interface 28 for transmitting control signals from the three processing units 12, 14, 16 to the power electronics 9 of the actuator 10; the power electronics 9 for the actuator 10; and a voltage source switch 32 for connecting at least one of the two voltage sources 18 via the control interface 28.20 of the control system 2 with the actuator 10 for supplying the actuator 10 with the electrical power for operating the actuator 10 and the actuator 10. In the , Fig. 1 is a system boundary of the control unit 4, represented by a continuous, thick line.

[0029] The following describes the functioning of the control system according to the invention with the control unit according to the invention and the method according to the present embodiment with reference to the Fig. 1 explained in more detail.

[0030] If the steering wheel of the motor vehicle (not shown) is turned manually, this steering movement is detected in a known manner by means of the at least one sensor functionally connected to the steering wheel, namely the at least one steering wheel sensor (not shown), and the output signals from this at least one sensor are transmitted to the control unit 4 of the control system 2 via the bus system 24. These output signals are supplied in parallel to all three processing units 12, 14, 16 for evaluation via the signal interface 22 of the control unit 4. In order to properly control the power electronics 9 of the actuator 10 of the control unit 4, it is additionally necessary that the current steering position of the at least one wheel 30 of the motor vehicle is known.This current steering position is detected by the sensors 6 and 8 of the control unit 4, which functionally interact with the actuator 10, in a manner known to those skilled in the art. The output signals from the sensors 6 and 8 are then transmitted via the signal interface 26 of the control unit 2, analogous to the output signals mentioned above, in parallel to the three processing units 12, 14, and 16 for evaluation. After the parallel evaluation of all output signals in all three processing units 12, 14, and 16, each of the three processing units 12, 14, and 16 generates a control signal corresponding to these output signals, which can be used to control the power electronics 9 of the actuator 10. Thus, a total of three corresponding control signals are present in parallel at the control interface 28. If all three processing units 12, 14, and 16 are functioning correctly, the aforementioned control signals should be identical.

[0031] If at least two corresponding control signals from two of the three processing units 12, 14, 16 match, the actuator 10 is controlled by these two processing units using the control signals from at least one of them. Provided all three processing units 12, 14, 16 are functioning correctly, the voltage source switch 32 of the control unit 2 is controlled by the first and second processing units 12, 14 such that, for normal operation of the actuator 10, three electrical coils of the actuator 10 are energized by the first processing unit 12 via the first voltage source 18, and, for the aforementioned normal operation of the actuator 10, a further three electrical coils of the actuator 10 are energized by the second processing unit 14 via the second voltage source 20.

[0032] Should one of the two processing units 12, 14 malfunction, i.e., should the aforementioned control signal of the faulty processing unit 12 or 14 deviate from the control signal of the properly functioning processing unit 14 or 12, the corresponding control signal of the properly functioning third processing unit 16 is present in parallel at the control interface 28. Accordingly, the actuator 10 is controlled by means of this control signal from the third processing unit 16 such that the voltage source 18 or 20 corresponding to the faulty processing unit 12 or 14 is electrically connected to the corresponding three electrical coils of the actuator 10 by means of the third processing unit 16.Thus, the above-described regular operation of the actuator 10 can always be maintained by means of two properly functioning computing units, namely 12, 14 or 12, 16 or 14, 16, even in the case of a faulty computing unit 12, 14, 16 of the control unit 4, using the aforementioned two-out-of-three control.

[0033] Due to the inventive design of the control unit 4, the control system 2, and the method for operating the control system 2, sufficient redundancy for a motor vehicle or the like can be achieved with X-by-wire in a simple and therefore cost-effective manner. This is easily understood, for example, using the present embodiment, namely the steering of the motor vehicle. In the motor vehicle of the embodiment, instead of the known mechanical connection between the steering wheel of the motor vehicle and the at least one wheel to be steered, only the so-called steer-by-wire system is used, in which the aforementioned mechanical connection is eliminated. According to the present embodiment, it is not necessary to provide a plurality of control units to achieve, for example, the aforementioned redundancy.Instead, only control unit 4 is used as the sole control unit for executing the vehicle's steering function. Thus, only the number of processing units is tripled; the number of other components of control unit 4 remains the same.

[0034] However, the application of steer-by-wire systems for the steering of motor vehicles is mentioned here only as an example. The invention can also be advantageously used in other functions of motor vehicles. For example, other by-wire systems, also commonly referred to as X-by-wire systems, should be mentioned here. Accordingly, the invention is not limited to the present embodiment. See, for example, the relevant explanations in the introduction and in the description of the specific embodiment. The basic design of such X-by-wire systems is well known to those skilled in the art. Reference symbol list 2 Control system 4 Control unit 6 Magnetic Sensors 8 inductive sensors 9 Power Electronics 10 Actuator 12 First computing unit 14 Second computing unit 16 Third unit of calculation 18 First voltage source 20 Second voltage source 22 Signal interface 24 bus system 26 Signal interface 28 Control interface 30 wheel 32 Power source switch

Claims

[1] Control unit (4) for a control system (2) of a motor vehicle for controlling a function of the motor vehicle, wherein the control unit (4) has at least one computing unit (12, 14, 16) for evaluating output signals of at least one sensor (6, 8) of the control system (2) and for controlling a power electronics unit (9) of an actuator (10) of the control system (2) by means of control signals depending on these output signals for executing this function of the motor vehicle, characterized byin that the control unit (4) has three computing units (12, 14, 16), wherein the control unit (4) is designed and configured such that the output signals of the at least one sensor (6, 8) can be evaluated in parallel in all computing units (12, 14, 16) and the power electronics (9) of the actuator (10) can be controlled by means of control signals from each of the computing units (12, 14, 16), and wherein, if at least two control signals corresponding to one another from two of the three computing units (12, 14, 16) match, the power electronics (9) of the actuator (10) can be controlled by means of the control signals from at least one computing unit (12, 14; 12, 16; 14, 16) of these two computing units (12, 14; 12, 16; 14, 16). [2] Control device (4) according to claim 1, characterized byin that the control device (4) is designed and configured such that a first computing unit (12) of the three computing units (12, 14, 16) is functionally connectable to a first voltage source (18) of the control system (2) for supplying the actuator (10) with electrical power for operating the actuator (10), a second computing unit (14) of the three computing units (12, 14, 16) is functionally connectable to a second voltage source (20) of the control system (2) for supplying the actuator (10) with the electrical power for operating the actuator (10), and a third computing unit (16) of the three computing units (12, 14, 16) is functionally connectable to the first and / or the second voltage source (18, 20) for supplying the actuator (10) with the electrical power for operating the actuator (10). [3] Control device (4) according to claim 1 or 2, characterized bythat the control unit (4) has only a single signal interface (22) for all three computing units (12, 14, 16) for the sensor signal-transmitting connection of the three computing units (12, 14, 16) to a bus system (24) of the motor vehicle that is superordinate to the control unit (4), wherein output signals of at least one of the at least one sensor can be transmitted from this sensor to the computing units (12, 14, 16) by means of the bus system (24) and this signal interface (22). [4] Control device (4) according to one of claims 1 to 3, characterized by that the control unit (4) has only a single signal interface (26) for all three computing units (12, 14, 16) for the sensor signal-transmitting connection of the three computing units (12, 14, 16) to at least one sensor (6, 8) functionally interacting with the actuator (10), wherein output signals from this sensor (6, 8) can be transmitted to the computing units (12, 14, 16) by means of this signal interface (26). [5] Control device (4) according to one of claims 1 to 4, characterized by that the control unit (4) has only a single control interface (28) for all three computing units (12, 14, 16) for the control signal-transmitting connection of at least one of the three computing units (12, 14, 16) to the power electronics (9) of the actuator (10), wherein by means of this control interface (28) control signals can preferably be transmitted to the power electronics (9) of the actuator (10) in such a way that the actuator (10) can be connected by means of these control signals to at least one voltage source (18, 20) of the control system (2) for supplying the actuator (10) with the electrical power for operating the actuator (10). [6] Control device (4) according to one of claims 1 to 5, characterized bythat the control unit (4) is designed as a structural unit, preferably that all computing units (12, 14, 16) of the control unit (4) are designed to be essentially identical to one another in functional terms. [7] Control system (2) of a motor vehicle for controlling a function of the motor vehicle, with at least one control unit (4), wherein the control unit (4) has at least one computing unit (12, 14, 16) for evaluating output signals of at least one sensor (6, 8) of the control system (2) and for controlling a power electronics unit (9) of an actuator (10) of the control system (2) by means of control signals depending on these output signals for executing this function of the motor vehicle, characterized by that the control device (4) is designed as a control device (4) according to one of claims 1 to 6. [8] Control system (2) according to claim 7, characterized by that the control unit (4) is designed as only a single control unit (4). [9] Control system (2) according to claim 7 or 8, characterized by that the control system (2) is designed as a control system (2) for steering at least one wheel (30) of the motor vehicle, wherein the actuator (10) for steering the at least one wheel (30) is operable as a function of output signals from at least one sensor of the control system (2) that functionally interacts with a steering wheel of the motor vehicle for determining a steering movement of the steering wheel and as a function of output signals from at least one sensor (6, 8) of the control system (2) that functionally interacts with the actuator (10) of the control system (2) for determining a steering position of the wheel (30), preferably that the control system (2) is designed merely as a steer-by-wire control system. [10] Control system (2) according to one of claims 7 to 9, characterized bythat the control unit (4) comprises at least two of the following components of the control system (2), preferably all of the following components, particularly preferably as one structural unit: the three processing units (12, 14, 16), a signal interface (22) for the sensor signal-transmitting connection of the three processing units (12, 14, 16) to a bus system (24) superordinate to the control unit (4), a signal interface (26) for the sensor signal-transmitting connection of the three processing units (12, 14, 16) to at least one sensor (6, 8) functionally interacting with the actuator (10), a control interface (28) for the control signal-transmitting connection of the three processing units (12, 14, 16) to the power electronics (9) of the actuator (10), the power electronics (9) for the actuator (10), a voltage source switch (32) for the controlled connection of at least one of at least two voltage sources by means of the control interface (28) (18,20) of the control system (2) with the actuator (10) for supplying the actuator (10) with the electrical power for operating the actuator (10), the actuator (10)., [11] Method for operating a control system (2) of a motor vehicle according to one of claims 7 to 10, according to which the output signals of the at least one sensor (6, 8) are evaluated in parallel in all computing units (12, 14, 16) and the power electronics (9) of the actuator (10) can be controlled by means of control signals from each of the computing units (12, 14, 16), wherein if at least two corresponding control signals from two of the three computing units (12, 14, 16) match, the power electronics (9) of the actuator (10) is controlled by means of the control signals from at least one computing unit (12, 14; 12, 16; 14, 16) of these two computing units (12, 14; 12, 16; 14, 16). [12] Method according to claim 11, characterized bythat the power electronics (9) of the actuator (10) are controlled by means of control signals in such a way that the actuator (10) is connected by means of these control signals to at least one voltage source (18, 20) of the control system (2) for supplying the actuator (10) with the electrical power for operating the actuator (10). [13] Method according to claim 11 or 12, characterized bythat the actuator (10) connected to at least one wheel (30) of the motor vehicle in a force-transmitting manner is operated as a function of output signals from at least one sensor of the control system (2) that functionally interacts with a steering wheel of the motor vehicle for determining a steering movement of the steering wheel and as a function of output signals from at least one sensor (6, 8) of the control system (2) that functionally interacts with the actuator (10) of the control system (2) for determining a steering position of the wheel (30), preferably that the control system (2) is operated only as a steer-by-wire control system.

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