Control device and method for operating at least one electric motor which can be used to brake a vehicle, an eddie-current brake, and at least one friction brake

Abstract

The invention relates to a control device (12) and to a method for operating at least one electric motor (14) which can be used to brake a vehicle (10), an eddie-current brake (16), and at least one friction brake (18) by ascertaining a first target variable relating to a first target braking torque to be applied to the vehicle (10) by means of the at least one electric motor (14), a second target variable relating to a second target braking torque to be applied to the vehicle (10) by means of the eddie-current brake (16), and a third target variable relating to a third target braking torque to be applied to the vehicle (10) by means of the at least one friction brake (18); and outputting at least one corresponding control signal (36a, 36b, 36c), wherein the first target variable is ascertained while taking into consideration first information (38a) relating to a first available braking torque, which can be maximally produced by means of the at least one electric motor (14), such that the first target braking torque equals a first minimum of a requested total braking torque and of the first available braking torque (M01).

Description

[0001] Description

[0002] title

[0003] Control device and method for operating at least one electric motor usable for braking a vehicle, an eddy current brake and at least one friction brake

[0004] The present invention relates to a control device for at least one electric motor usable for braking a vehicle, for an eddy-current brake, and for at least one friction brake. The invention also relates to a method for operating at least one electric motor usable for braking a vehicle, for an eddy-current brake, and for at least one friction brake.

[0005] State of the art

[0006] An axle module with an integrated eddy current brake is known from the state of the art, such as DE 10 2021 214 867 Al.

[0007] Disclosure of the invention

[0008] The present invention provides a control device for at least one electric motor usable for braking a vehicle, for an eddy current brake and for at least one friction brake having the features of claim 1 and a method for operating at least one electric motor usable for braking a vehicle, for an eddy current brake and at least one friction brake having the features of claim 7.

[0009] Advantages of the invention

[0010] The present invention provides advantageous possibilities for implementing an operating strategy for a vehicle equipped with at least one electric motor operable in a recuperative mode, an eddy current brake, and at least one friction brake, which optimally allocates a current braking request from a driver or an automatic speed control system of the vehicle to the brake actuators present in the vehicle. The created operating strategy takes into account, in particular, the special features of the individual brake actuators of the vehicle and makes extensive use of their advantages. Above all, the increased proportion of recuperative braking of the vehicle when using the operating strategy increases its energy efficiency. This allows a high proportion of the vehicle's kinetic energy to be recovered during braking, i.e.When the vehicle is decelerated or brought to a standstill, the energy is converted into electrically storable energy, which can significantly reduce the vehicle's energy consumption. If the vehicle in question is equipped with an internal combustion engine, an embodiment of the present invention also advantageously reduces its pollutant and carbon dioxide emissions. Particulate matter emissions from the vehicle can also be reduced by means of the present invention, since the increased proportion of recuperative braking reduces wear on the vehicle's brake pads.

[0011] As will become clear from the following description, the present invention can be easily implemented by means of a corresponding design / programming of at least one electronic device. Therefore, using the present invention involves little or no cost to the driver of the respective vehicle. The installation space required for the at least one electronic device used to implement the present invention is also little or no increased by the necessary design / programming.

[0012] In an advantageous embodiment of the control device, the at least one electronic device is additionally designed and / or programmed such that, if the specified first target braking torque is less than the requested total braking torque, the second target value can be set by means of the at least one electronic device, with additional consideration of a provided or self-set second item of information relating to a maximum second possible braking torque that can be effected by means of the eddy current brake, such that the second target braking torque is less than or equal to a second minimum of a first braking torque difference between the requested total braking torque and the specified first target braking torque and the second possible braking torque.If the requested total braking torque cannot be achieved exclusively by the at least one electric motor operating in its recuperative mode, the embodiment of the control device described here preferably uses the eddy-current brake. Due to the increased proportion of vehicle braking achieved by the eddy-current brake in this way, this option for wear-free braking of the vehicle is used comparatively frequently, thereby minimizing wear on the at least one friction brake. Likewise, the high torque setting accuracy of the eddy-current brake can be used comparatively frequently when braking the vehicle.

[0013] As a possible further development, the at least one electronic device can additionally be designed and / or programmed in such a way that, if the specified first target braking torque is less than the requested total braking torque, the second target value can be specified by means of the at least one electronic device, with additional consideration of a specified limit value with regard to a maximum braking torque to be exerted on a common vehicle axle of the at least one electric motor and the eddy current brake, in such a way that the second target braking torque, if the requested total braking torque is less than or equal to the maximum braking torque, is equal to the second minimum, and, if the requested total braking torque is greater than the maximum braking torque, is equal to a third minimum of the second minimum and a second braking torque difference between the maximum braking torque and the specified first target braking torque.The embodiment of the control device described here thus takes into account the fact that a common force introduction path is often present for the at least one electric motor and the eddy-current brake. By programming the at least one electronic device described here, pitching movements of the vehicle, which conventionally occur when the regenerative brake and the dissipative brake are switched on, can be avoided. Therefore, the comfort losses of the prior art do not have to be accepted when using the embodiment of the control device described here.

[0014] In a further advantageous embodiment of the control device, the at least one electronic device is additionally designed and / or programmed such that, if the sum of the specified first target braking torque and the specified second target braking torque is less than the requested total braking torque, the third target value can be set by means of the at least one electronic device such that the third target braking torque is equal to a third braking torque difference between the requested total braking torque and the sum of the specified first target braking torque and the specified second target braking torque. This allows even comparatively strong decelerations of the vehicle to be achieved relatively quickly by utilizing its at least one friction brake. The vehicle described here therefore meets a high safety standard.

[0015] For example, the control device can be a central vehicle control unit or a driving dynamics control system. Alternatively, the control device can also comprise, as the at least one electronic device, a first electronic device designed as an electric motor controller, a second electronic device designed as an eddy-current brake controller, and a third electronic device designed as an ESP control device. The control device can therefore be designed in a variety of ways. In particular, implementation / realization of the control device as a one-piece / compact unit is not necessary. It is also pointed out that the exemplary embodiments listed here for the design of the control device as a one-piece / compact unit are not to be interpreted as exhaustive.

[0016] Furthermore, implementing a corresponding method for operating at least one electric motor usable for braking a vehicle, an eddy current brake, and at least one friction brake also provides the advantages explained above. It is expressly noted that the method can be further developed according to the above-described embodiments of the control device.

[0017] Short description of the drawings

[0018] Further features and advantages of the present invention are explained in more detail below with reference to the figures. They show:

[0019] Fig. 1 is a schematic representation of an embodiment of the

[0020] control device or a vehicle equipped with it; and

[0021] Fig. 2 is a flowchart explaining an embodiment of the method for operating at least one electric motor usable for braking a vehicle, an eddy current brake, and at least one friction brake. Embodiments of the invention

[0022] Fig. 1 shows a schematic representation of an embodiment of the control device or a vehicle equipped therewith.

[0023] The vehicle / motor vehicle 10 sketched in Fig. 1 can optionally be a hybrid or an electric vehicle. Although the vehicle 10 is depicted in Fig. 1 as a motor vehicle 10, the applicability of the control device 12 described below is not restricted to motor vehicles 10. Likewise, the applicability of the control device 12 is not limited to any specific vehicle type / motor vehicle type of the vehicle / motor vehicle 10. Instead, the control device 12 can be used for any vehicle type / motor vehicle type that is equipped with at least one electric motor 14 that can be used / is suitable for braking the vehicle 10, an eddy current brake 16, and at least one friction brake 18. Furthermore, the applicability of the control device 12 is not restricted to any specific design of the at least one electric motor 14, the eddy current brake 16, and the at least one friction brake 18 of the vehicle 10.

[0024] As illustrated in Fig. 1, the at least one electric motor 14 can also be used as a drive motor for driving at least two wheels 20a and 20b of a first vehicle axle 22a of the vehicle 10, in that the respective electric motor 14 is coupled to the wheels 20a and 20b via a transmission 24, a differential 26, and drive shafts 28. Preferably, the eddy current brake 16 is also integrated into the drive train together with the at least one electric motor 14 usable as a drive motor, so that the eddy current brake 16 can also act on the wheels 20a and 20b of the first vehicle axle 22a via the transmission 24, the differential 26, and the drive shafts 28. This can also be described as meaning that the braking torques of the at least one electric motor 14 and the eddy current brake 16 can be / are exerted on the “common” first vehicle axle 22a equipped with the wheels 20a and 20b.

[0025] If the vehicle 10 has at least two additional wheels 20c and 20d of a second vehicle axle 22b in addition to the wheels 20a and 20b of the first vehicle axle 22a, the at least two additional wheels 20c and 20d can preferably be braked by means of the at least one friction brake 18. The at least one friction brake 18 can be understood as a "conventional" brake that can be actuated hydraulically, electrohydraulically, or electromechanically. The at least one friction brake 18 can thus be an electromechanical friction brake, a hydraulic friction brake, and / or a parking brake.

[0026] The at least one electric motor 14, the eddy current brake 16, and the at least one friction brake 18 thus implement various actuators, each of which can be used to brake the vehicle 10. To brake the vehicle 10, i.e., to slow down / decelerate the vehicle 10 and / or to bring the vehicle 10 to a standstill, all three actuators can in principle be used together. However, it is often not necessary to fully utilize the power of all three actuators. Optionally, at least one parking brake 30 can also be arranged on at least one differential output of the differential 26 of the drive train, by means of which the wheels 20a and 20b of the first vehicle axle 22a can be additionally braked.

[0027] In order to optimally distribute a braking request from a driver of the vehicle 10 or from an automatic speed control system (not shown) of the vehicle 10 among the three different actuators with regard to energy efficiency, driving comfort, and wear, the control device 12 has at least one electronic device 32. The at least one electronic device 32 is designed and / or programmed such that, by means of the at least one electronic device 32, a first target variable relating to a first target braking torque to be applied to the vehicle 10 by means of the at least one electric motor 14, a second target variable relating to a second target braking torque to be applied to the vehicle 10 by means of the eddy current brake 16, and a third target variable relating to a third target braking torque to be applied to the vehicle 10 by means of the at least one friction brake 18 can be / are defined.The first target value, the second target value, and the third target value are determined by means of the at least one electronic device 32, at least taking into account at least one default value 34 relating to a total braking torque requested by the driver or the automatic cruise control system. The driver of the vehicle 10 can request the total braking torque, for example, by actuating a brake actuation element (not shown), such as specifically a brake pedal. The automatic cruise control system can be understood, in particular, as a driver assistance system of the vehicle 10. After the first target value, the second target value, and the third target value have been determined, at least one control signal 36a to 36c can be output to the at least one electric motor 14, to the eddy current brake 16, and / or to the at least one friction brake 18 by means of the at least one electronic device 32.For example, the at least one electronic device 32 can be designed to output at least one first control signal 36a corresponding to the first target value to the at least one electric motor 14, at least one second control signal 36b corresponding to the second target value to the eddy current brake 16 and at least one third control signal 36c corresponding to the third target value to the at least one friction brake 18.

[0028] Furthermore, the at least one electronic device 32 is designed and / or programmed such that the first target value can be / is determined by the at least one electronic device 32, additionally taking into account a first piece of information 38a regarding a maximum possible first braking torque that can be achieved by the at least one electric motor 14. The first piece of information 38a can be information provided (externally) to the at least one electronic device 32.Alternatively, however, the at least one electronic device 32 can also be designed / programmed to determine the first information 38a based on at least one provided (not sketched) sensor signal, specifically based on at least one sensor signal relating to a temperature of at least one battery (not shown) of the vehicle 10 that can be charged by means of the at least one electric motor 14, relating to a respective state of charge (SoC) of the at least one battery and / or relating to a current rotational speed of the wheels 20a to 20d of the vehicle 10.

[0029] It is expressly pointed out here that the first target value can be / is set by means of the at least one electronic device 32 in such a way that the first target braking torque (corresponding to the first target value), which is to be applied to the vehicle 10 by means of the at least one electric motor 14, is equal to a first minimum of the requested total braking torque and the first possible braking torque. Thus, a comparatively high proportion of braking operations of the vehicle 10 are effected (almost) exclusively by means of the at least one electric motor 14 operating in its recuperative mode. This maximizes the recuperative braking of the vehicle 10, thereby significantly increasing its recuperation efficiency. The energy consumption of the vehicle 10 is thus significantly reduced.In addition, the advantageous design / programming of the at least one electronic device 32 prevents unnecessary brake wear of the at least one friction brake 18, which also reduces particulate matter emissions from the vehicle 10.

[0030] The design / programming of the at least one electronic device 32 described here thus results in an optimal distribution of the total braking torque requested by the driver or the cruise control system to the actuators / brake actuators of the vehicle 10. At the same time, the design / programming of the at least one electronic device 32 takes into account that it cannot always be assumed that the at least one electric motor 14 of the vehicle 10 can currently be used for regenerative braking of the vehicle 10 (as the only actuator). In particular, at a high temperature of the at least one battery of the vehicle 10, at a high charge level of the at least one battery and / or in the field weakening range, ieat a high speed of the wheels 20a to 20d, the braking request of the driver or the cruise control system typically cannot be effected exclusively by means of the at least one electric motor 14.

[0031] However, if the specified first target braking torque is less than the requested total braking torque, the at least one electronic device 32 can ensure, by appropriately specifying the second target value and the third target value, that a first braking torque difference between the requested total braking torque and the specified first target braking torque is applied to the vehicle 10 by means of the eddy current brake 16 and / or the at least one friction brake 18. The vehicle 10 equipped with the control device 12 therefore has a high safety standard, which also enables the execution of sudden / surprise emergency braking.

[0032] As illustrated in Fig. 1, the control device 12 can be understood as a compact / integral unit, such as specifically a central vehicle control unit or a driving dynamics control system. Alternatively, however, the control device 12 can also consist of units that can be mounted / are mounted separately on the vehicle 10. For example, the control device 12 can comprise, as its at least one electronic device 32, a first electronic device designed as an electric motor controller, a second electronic device designed as an eddy-current brake controller, and a third electronic device designed as an ESP control device. This allows for a multitude of different design options for advantageous, in particular space-saving, design of the control device 12.

[0033] It should also be noted here that the vehicle topology depicted in Fig. 1 is only intended as an example. In principle, the proposed blending strategy can also be applied to other brake types. It is not necessary for the braking torque of the eddy-current brake 16 to be introduced into the wheels 20a and 20b of the first vehicle axle 22a via the same force introduction path as the braking torque or drive torque of the at least one electric motor 14. In particular, the eddy-current brake 16 can also be arranged at the wheel level, although this would require a larger and heavier design of the eddy-current brake 16.

[0034] The control device 12 / its at least one electronic device 32 can also be designed and / or programmed to carry out at least one of the method steps described below.

[0035] Fig. 2 shows a flow chart for explaining an embodiment of the method for operating at least one electric motor that can be used to brake a vehicle, an eddy current brake and at least one friction brake.

[0036] The executability of the method described below is not limited to any specific vehicle type / motor vehicle type. Likewise, the executability of the method is not limited to a specific type of the at least one electric motor, the eddy current brake, and the at least one friction brake of the respective vehicle.

[0037] By means of the method steps S1 to S3 of the method described below, a first target variable is determined with respect to a first target braking torque Mi to be applied to the vehicle by means of the at least one electric motor, a second target variable is determined with respect to a second target braking torque M2 to be applied to the vehicle by means of the eddy current brake, and a third target variable is determined with respect to a third target braking torque M3 to be applied to the vehicle by means of the at least one friction brake. The first target variable, the second target variable, and the third target variable are determined at least taking into account at least one default variable with respect to a total braking torque Mtotal requested by a driver or an automatic speed control system of the vehicle.

[0038] In a method step S1, the first target value is first determined. The first target value is determined in method step S1 taking into account the at least one specified value and additionally taking into account first information 38a regarding a maximum first possible braking torque Moi that can be achieved by the at least one electric motor. The first information 38a regarding the first possible braking torque Moi can be understood as provided information. Alternatively, the first information 38a / the first possible braking torque Moi can also be determined in an (optional) method step S4. To determine the first information 38a / the first possible braking torque Moi, all factors that influence the availability of the at least one electric motor for braking the vehicle can be taken into account in method step S4.In particular, a respective temperature of at least one battery of the vehicle that can be charged by means of the at least one electric motor, a respective state of charge (SoC) of the at least one battery and / or a current rotational speed of wheels of the vehicle can be evaluated in method step S4 to determine the first information 38a / the first possible braking torque Moi.

[0039] In addition, when executing method step S1, the first target value is set such that the first target braking torque Mi (corresponding to the first target value) is equal to a first minimum Mini of the requested total braking torque M to tai and the first braking torque Moi. This can also be expressed by equation (Eq. 1):

[0040] (Eq. 1) Mi = Mim {Mtotai, Moi}

[0041] The braking strategy achieved by the method described here enables the requested total braking torque Mto tai is preferably effected (almost) exclusively by means of the at least one electric motor operated in its recuperative mode in order to maximize recuperation. If possible, the maximum executable first possible braking torque Moi is fully utilized. Furthermore, in the embodiment of the method described here, at least one first control signal 36a corresponding to the first target value is output to the at least one electric motor. As explained below, a first braking torque difference AMi = Mtotai - Mi (AMi is always greater than or equal to zero) between the requested total braking torque Mtotai and the specified first target braking torque Mi can be effected on the vehicle 10 by means of the eddy current brake 16 and / or the at least one friction brake 18.

[0042] If the specified first target braking torque Mi is (essentially) equal to the requested total braking torque M totai (i.e. AMi = 0), when method step S2 is carried out, the second target variable is set such that the second target braking torque M2 is equal to zero. If the set first target braking torque Mi is less than the requested total braking torque Mtotai (i.e. AMi > 0), in method step S2 the second target variable is set with additional consideration of second information 38b relating to a maximum second possible braking torque M02 that can be achieved by means of the eddy current brake. The second information 38b can also be understood as provided information. Alternatively, the second information 38b / the second possible braking torque M02 can also be set in an (optional) method step S5. To set the second information 38b / the second possible braking torque M02, all factors that influence the availability of the eddy current brake for braking the vehicle can be taken into account in method step S5.

[0043] The availability of the eddy-current brake to decelerate the vehicle depends primarily on the current speed of the eddy-current brake and the current temperature of the eddy-current brake. At a comparatively low speed of the eddy-current brake, the eddy-current brake can only achieve a relatively small second braking torque M02. Furthermore, the current temperature of the eddy-current brake should not exceed a specified maximum temperature, such as a specified maximum temperature of 180 °C, to ensure the availability of the eddy-current brake in the event of unforeseen emergency braking.Determining the second information 38b / the second possible braking torque M02 at least taking into account the current temperature of the eddy-current brake therefore ensures that the eddy-current brake can always absorb a relatively large amount of energy during at least one further emergency braking operation without fear of overheating of the eddy-current brake. Therefore, in method step S5, the second information 38b / the second possible braking torque M02 is preferably determined taking into account the current speed of the eddy-current brake and / or the current temperature of the eddy-current brake.

[0044] If the specified first target braking torque Mi is less than the requested total braking torque Mtotai (i.e., AMi > 0), then when executing process step S2, the second target value is set such that the second braking torque M2 (corresponding to the second target value) is less than or equal to a second minimum Mm2 of the first braking torque difference AMi and the second possible braking torque M02. According to equation (Eq. 2), the following applies (for the case where AMi > 0):

[0045] (Eq. 2) M2< Min2{AMi, M 02}

[0046] Thereafter, in the embodiment described here, at least one second control signal 36b is output to the eddy current brake taking into account the specified second target value.

[0047] In particular, if the specified first target braking torque Mi is smaller than the requested total braking torque Mtotai (i.e., AMi > 0), the second target value can be determined during the execution of method step S2 such that the second target braking torque M2 is equal to the second minimum Mim of the first braking torque difference AMi and the second possible braking torque M02. Equation (Eq. 2) then becomes (in the case where AMi > 0) equation (Eq. 3) with:

[0048] (Eq. 3) M2= Min2{AMi, M 02}

[0049] Thus, if the first possible braking torque M01 is sufficient to meet the requested total braking torque M totai is not sufficient (almost) exclusively by means of the at least one electric motor, the first braking torque difference AMi is initially effected via the second target braking torque M2 of the eddy current brake. The eddy current brake generally has a higher availability than the at least one electric motor. Compared to the at least one friction brake, the eddy current brake, when interacting with the at least one electric motor, also has the advantage that cross-fading between the at least one electric motor and the eddy current brake can take place very dynamically and without any loss of comfort. Since the eddy current brake acts on the assigned wheels of the vehicle via the same force introduction path as the at least one electric motor, no unwanted "pitching" or "braking pitching" of the vehicle occurs when cross-fading between the at least one electric motor and the eddy current brake.This is not the case when there is a cross-fade between the at least one electric motor and the at least one friction brake.

[0050] Furthermore, the use or joint use of at least one friction brake to decelerate the vehicle is subject to comparatively high uncertainty, as the friction values ​​of the at least one friction brake can vary considerably. In contrast, the eddy-current brake can be adjusted relatively precisely, so that a high degree of accuracy in maintaining the second target braking torque M2 is generally guaranteed using the eddy-current brake.

[0051] A further advantage of more frequent and / or intensive use of the eddy current brake compared to the use of at least one friction brake is that less frequent use of the at least one friction brake slows its wear. Unlike the at least one friction brake, the eddy current brake operates wear-free.

[0052] Optionally, however, when carrying out method step S2 for determining the second target value, a predetermined limit value can also be set with regard to a maximum braking torque M to be exerted on a common vehicle axle of the at least one electric motor and the eddy current brake. ma x must be taken into account. (The common vehicle axle of the at least one electric motor and the eddy-current brake is understood to be the vehicle axle of the vehicle on which, or on whose wheels, the braking torques caused by the at least one electric motor and the eddy-current brake are applied.)

[0053] If necessary, ie if it is desired not to exceed the maximum braking torque Mmax to be applied (and if AMi > 0), the second target value is set in such a way that the second target braking torque M2 is only applied if the requested total braking torque M to tai less than or equal to the maximum braking torque Mma x is equal to the second minimum Mm2. Equation (Eq. 3) is therefore only valid if: Mtotai < However, if the requested total braking torque M to tai is greater than the maximum braking torque Mmax (and if AMi > 0), the second target braking torque M2 (by means of the definition of the second target value) is equal to a third minimum Mim of the second minimum Mim and a second braking torque difference AM2 = Mtotai - M ma x between the maximum braking torque M ma x and the specified first target braking torque Mi. Equation (Eq. 2) then becomes equation (Eq. 4) with:

[0054] (Eq. 4) M2= Mim {Mim {AMi, M 02}, AM2}

[0055] By not exceeding the maximum braking torque Mmax to be applied, tire slip on the common vehicle axle can be prevented, which conventionally always occurs when a sum E1+2 = MI + M2 of the specified first target braking torque Mi and the specified second target braking torque M2 exceeds the adhesion potential of the corresponding vehicle axle, or the maximum braking torque M ma x exceeds.

[0056] In the embodiment of the method described here, at least one friction brake is activated to decelerate the vehicle as desired only if the sum E1+2 of the specified first target braking torque Mi and the specified second target braking torque M2 is insufficient to meet the requested total braking torque Mtotai. (The sum E1+2 is smaller than the requested total braking torque Mtotai if the sum of the maximum achievable first braking torque M01 and the maximum achievable second braking torque M02 is smaller than the requested total braking torque M to tai and / or if the requested total braking torque M to tai the maximum braking torque M ma x.)

[0057] Is the sum V ? of the specified first target braking torque Mi and the specified second target braking torque M2 equal to the requested total braking torque M totai, e.g., because the specified first target braking torque Mi is equal to the requested total braking torque Mtotai, when executing process step S3, the third target value is set such that the third target braking torque M3 (corresponding to the third target value) is equal to zero. However, if the sum E1+2 of the specified first target braking torque Mi and the specified second target braking torque Mi is smaller than the requested total braking torque M to tai, the third target value is set such that the third target braking torque M3 (corresponding to the third target value) is equal to a third braking torque difference AM; between the requested total braking torque Mtotai and the sum E1+2 of the specified first target braking torque Mi and the specified second target braking torque M2. This can also be expressed by equation (Eq. 5):

[0058] (Eq. 5)

[0059] Subsequently, in the embodiment of the method described here, at least one third control signal 36c corresponding to the third target value is output to the at least one friction brake.

[0060] Thus, equation (Eq. 6) is always reliably observed in the procedure described here with:

[0061] (Eq. 6)

[0062] The procedure described here therefore meets a high safety standard.

Claims

Claims 1. A control device (12) for at least one electric motor (14) usable for braking a vehicle (10), for an eddy current brake (16), and for at least one friction brake (18), comprising: at least one electronic device (32), wherein, by means of the at least one electronic device (32), at least taking into account at least one preset variable (34) relating to a total braking torque (Mtotai) requested by a driver or an automatic speed control system of the vehicle (10), a first setpoint variable relating to a first setpoint braking torque (Mi) to be applied to the vehicle (10) by means of the at least one electric motor (14), a second setpoint variable relating to a second setpoint braking torque (M2) to be applied to the vehicle (10) by means of the eddy current brake (16), and a third setpoint variable relating to a third setpoint braking torque (M3) to be applied to the vehicle (10) by means of the at least one friction brake (18),and taking into account the specified first, second and third target values, at least one control signal (36a, 36b, 36c) can be output to the at least one electric motor (14), to the eddy current brake (16) and / or to the at least one friction brake (18); characterized in that the at least one electronic device (32) is designed and / or programmed such that, by means of the at least one electronic device (32), with additional consideration of a provided or self-defined first item of information (38a) regarding a maximum possible first braking torque (M0i) that can be effected by means of the at least one electric motor (14), the first target value can be set such that the first target braking torque (Mi) is equal to a first minimum (Mini) of the requested total braking torque (M, to tai) and the first possible braking torque (M01).

2. Control device (12) according to claim 1, wherein the at least one electronic device (32) is additionally designed and / or programmed such that, if the specified first target braking torque (Mi) is smaller than the requested total braking torque (M to tai), by means of the at least one electronic device (32) with additional consideration of a provided or self-determined second information (38b) relating to a maximum second possible braking torque (M02) that can be effected by means of the eddy current brake (16), the second desired value can be determined in such a way that the second desired braking torque (M2) is less than or equal to a second minimum (Mm2) of a first braking torque difference (AMi) between the requested total braking torque (Mtotai) and the determined first desired braking torque (Mi) and the second possible braking torque (M02).

3. Control device (12) according to claim 2, wherein the at least one electronic device (32) is additionally designed and / or programmed such that, if the specified first target braking torque (Mi) is smaller than the requested total braking torque (M to tai) is, by means of the at least one electronic device (32) with additional consideration of a predetermined limit value with respect to a maximum braking torque (M ma x) the second target value can be set in such a way that the second target braking torque (M2), provided that the requested total braking torque (Mtotai) is less than or equal to the maximum braking torque (M ma x) is equal to the second minimum (Mm2), and, if the total braking torque requested (Mtotai) is greater than the maximum braking torque (M max) is equal to a third minimum (Mim) of the second minimum (Mim) and a second braking torque difference (AM2) between the maximum braking torque (M ma x) and the specified first target braking torque (Mi).

4. Control device (12) according to claim 2 or 3, wherein the at least one electronic device (32) is additionally designed and / or programmed such that, if a sum (S1+2) of the specified first target braking torque (Mi) and the specified second target braking torque (M2) is less than the requested total braking torque (M to tai), by means of the at least one electronic device (32) the third target value can be determined in such a way that the third Target braking torque (M3) equal to a third braking torque difference (AM3) between the requested total braking torque (M to tai) and the sum of the specified first target braking torque (Mi) and the specified second target braking torque (M2).

5. Control device (12) according to one of the preceding claims, wherein the control device (12) is a central vehicle control unit or a driving dynamics control system.

6. Control device (12) according to one of claims 1 to 4, wherein the control device (12) comprises, as the at least one electronic device, a first electronic device designed as an electric motor control, a second electronic device designed as an eddy current brake control and a third electronic device designed as an ESP control device.

7. Method for operating at least one electric motor (14) which can be used to brake a vehicle (10), an eddy current brake (16') and at least one friction brake (18), comprising the steps: Determining a first target value with respect to a first target braking torque (Mi) to be applied to the vehicle (10) by means of the at least one electric motor (14), a second target value with respect to a second target braking torque (M2) to be applied to the vehicle (10) by means of the eddy current brake (16), and a third target value with respect to a third target braking torque (M3) to be applied to the vehicle (10) by means of the at least one friction brake (18), at least taking into account at least one preset value (34) with respect to a total braking torque requested by a driver or an automatic speed control system of the vehicle (10). and Outputting at least one control signal (36a, 36b, 36c) to the at least one electric motor (14), to the eddy current brake (16) and / or to the at least one friction brake (18) taking into account the specified first, second and third target values; characterized by the step that the first target value is set with additional consideration of a provided or defined first information (38a) regarding a maximum possible first braking torque (Moi) that can be achieved by means of the at least one electric motor (14) such that the first target braking torque (Mi) is equal to a first minimum (Mini) of the requested total braking torque (M to tai) and the first possible braking torque (Moi).

8. The method according to claim 7, wherein, if the specified first target braking torque (Mi) is less than the requested total braking torque (M totai), the second target value is set with additional consideration of a provided or defined second information (38b) regarding a maximum possible second braking torque (M02) that can be effected by means of the eddy current brake (16) such that the second target braking torque (M2) is less than or equal to a second minimum (Mm2) of a first braking torque difference (AMi) between the requested total braking torque (M to tai) and the specified first target braking torque (Mi) and the second possible braking torque (M02).

9. The method according to claim 8, wherein, if the specified first target braking torque (Mi) is less than the requested total braking torque (M to tai), the second target value is determined taking into account a predetermined limit value with respect to a maximum braking torque (M max) is set in such a way that the second target braking torque (M2), provided that the requested total braking torque (M to tai) less than or equal to the maximum braking torque (M ma x) is equal to the second minimum (Mim), and, if the total braking torque requested (Mtotai) is greater than the maximum braking torque (M max ) is equal to a third minimum (Mini) of the second minimum (Mm2) and a second braking torque difference (AM2) between the maximum braking torque (M max ) and the specified first target braking torque (Mi).

10. The method according to claim 8 or 9, wherein, if a sum (S1+2) of the specified first target braking torque (Mi) and the specified second target braking torque (M2) is smaller than the requested total braking torque (Mtotai), the third target value is set such that the third target braking torque (M3) equal to a third braking torque difference (AMs) between the requested total braking torque (M totai) and the sum (S1+2) of the specified first target braking torque (Mi) and the specified second target braking torque (M2).

Images