Control device and method for operating an eddy current brake of a vehicle

Abstract

The present invention relates to a control device (10) and a method for operating an eddy current brake (12) of a vehicle (14) by setting a target current intensity with respect to a target current intensity to be conducted through at least one coil of the eddy current brake (12), at least taking into account at least one provided signal (34) with respect to a speed change of the vehicle (14) currently requested by a driver of the vehicle (14) or an automatic system of the vehicle (14), conducting an actual current intensity (I) corresponding to the target current intensity through the at least one coil of the eddy current brake (12), forecasting taking into account the at least one signal (34) and / or a provided environmental information item and / or reading out based on forecast information,whether a vehicle deceleration request for the vehicle (14) traveling without deceleration by the driver or the automatic system is likely within a predetermined future time interval, and, if appropriate, setting the target current intensity equal to a predetermined activation value or activation value curve such that an actual current intensity corresponding to the activation value or activation value curve is passed through the at least one coil of the eddy current brake (12).

Description

[0001] The present invention relates to a control device for at least one eddy current brake of a vehicle. The invention also relates to an eddy current brake for a vehicle. Furthermore, the invention relates to a method for operating an eddy current brake of a vehicle. State of the art

[0002] Eddy current brakes are known from the state of the art, such as DE 10 2021 214 867 A1, by means of which a vehicle equipped with them can be braked. Disclosure of the invention

[0003] The present invention provides a control device for at least one eddy current brake of a vehicle having the features of claim 1, an eddy current brake for a vehicle having the features of claim 9 and a method for operating an eddy current brake of a vehicle having the features of claim 10. Advantages of the invention

[0004] The present invention provides advantageous possibilities for predictively energizing an eddy-current brake used to brake a vehicle, thereby increasing the response dynamics of the respective eddy-current brake in a variety of situations in which braking of the vehicle is advantageous in the immediate future. The predictive energization of the respective eddy-current brake can also be referred to as setting an initial braking torque of the respective eddy-current brake, whereby an inductance of at least one coil / excitation coil of the respective eddy-current brake can be overcome even before a request for braking to be effected by the respective eddy-current brake.In addition, by predictively applying a slight braking torque to the respective eddy current brake, play in the drive train can be overcome and elasticities can be pre-tensioned in such a way that an improved / more direct transmission of the braking torque caused by the respective eddy current brake to at least one wheel of the vehicle to be braked is ensured.

[0005] The present invention thus provides advantageous possibilities for shortening the time required to apply a desired braking torque to the vehicle wheels to be braked by the respective eddy-current brake in a variety of situations. By means of the present invention, the predictive energization of the eddy-current brake makes it possible to shorten, in particular, a TTL (time-to-lock) time of the respective eddy-current brake, especially in emergency braking situations. In this way, the braking distance required to completely brake the respective vehicle (exclusively) by means of its eddy-current brake can also be shortened, particularly in emergency braking situations.

[0006] It is expressly pointed out here that the reduction in the required braking distance achieved by the present invention can be achieved purely through software measures. Therefore, the use of the present invention is associated with little or no additional costs.

[0007] In an advantageous embodiment of the control device, at least one signal from an accelerator or accelerator pedal sensor relating to an actuation of an accelerator or accelerator pedal of the vehicle by the driver can be read out by means of the electronic device as the at least one signal, wherein, if it is determined by means of the electronic device on the basis of the at least one signal from the accelerator or accelerator pedal sensor that an amount of a release speed of the accelerator or accelerator pedal of the vehicle traveling without deceleration is above a predetermined release speed threshold value, it is predicted by means of the electronic device that a vehicle deceleration request for the vehicle traveling without deceleration by the driver or the automatic system is likely within the future time interval.In particular, if the driver triggers a rapid and / or jerky release of the accelerator or gas pedal of the vehicle traveling without deceleration, it can be assumed with a high degree of probability that the driver assesses the current traffic situation in the vicinity of his vehicle as at least critical and will therefore request braking of his vehicle traveling without deceleration in the immediate future. In the embodiment of the control device described here, it may be ensured that by energizing at least one coil of the eddy-current brake with the actual current intensity corresponding to the activation value or activation value curve, the response dynamics of the eddy-current brake are optimized with regard to the driver's imminent braking request.

[0008] Alternatively or additionally, at least one signal from the accelerator pedal sensor relating to the actuation of the accelerator pedal by the driver and at least one signal from a brake pedal sensor relating to an actuation of a brake pedal of the vehicle by the driver can be read out by means of the electronic device as the at least one signal, wherein, if it is determined by means of the electronic device on the basis of the signals from the accelerator pedal sensor and the brake pedal sensor that the accelerator pedal of the vehicle traveling without deceleration remains unactuated within a predetermined waiting time after the end of an actuation of the brake pedal by the driver, it is predicted by means of the electronic device that a vehicle deceleration request for the vehicle traveling without deceleration by the driver or the automatic transmission is likely within the future time interval.Even if the brake pedal is briefly released in the meantime, but the driver does not press the accelerator pedal of the now immediately moving vehicle, it can be assumed with a high degree of probability that the driver interprets the current traffic situation in the vicinity of his vehicle in such a way that (even if he is not yet aware of it at the time) he will soon request braking of his immediately moving vehicle again. Such situations occur relatively frequently during comfort braking. By means of the embodiment of the control device described here, it can be ensured that the braking of his immediately moving vehicle requested by the driver in the immediate future can be effected quickly and reliably by means of the "prepared" / "pre-activated" eddy current brake.

[0009] Likewise, if the electronic device determines on the basis of the environmental information that a current traffic situation in the current environment of the vehicle traveling without delay corresponds to a predetermined critical traffic situation and / or a predetermined emergency braking situation, the electronic device can predict that a vehicle deceleration request for the vehicle traveling without delay by the driver or the automatic system is likely within the future time interval.In particular, when an approaching obstacle is detected based on the environmental information provided, it can be assumed with relative reliability that the driver or the automatic system will request rapid braking of the vehicle moving without delay in the immediate future, whereby the embodiment of the control device described here can significantly shorten the braking distance required to bring the vehicle to a standstill by means of braking.

[0010] In a further advantageous embodiment of the control device, an activation value curve is stored on the electronic device such that the actual current intensity corresponding to the activation value curve has a first current intensity maximum during a first time interval and a second current intensity maximum during a subsequent second time interval, wherein the first current intensity maximum is greater than or equal to the second current intensity maximum by at least a factor of 1.3. As explained in more detail below, by means of the activation value curve described here, inductances of the at least one coil of the eddy current brake, which would otherwise counteract a rapid effect of the requested braking, can be overcome earlier. Therefore, the response dynamics of the controlled eddy current brake are also increased by means of the activation value curve described here.

[0011] As an advantageous further development, the electronic device can additionally be designed and / or programmed in such a way that, while the actual current intensity corresponding to the activation value or activation value curve is conducted through the at least one coil of the eddy current brake by means of the electronic device, at least one motor control signal can be output to at least one drive motor of the vehicle and / or to at least one controller of the at least one drive motor by means of the electronic device, so that the at least one drive motor can be controlled by means of the at least one motor control signal in order to increase an acceleration of the vehicle brought about by means of the at least one drive motor.By increasing the vehicle's acceleration in this way, unintentional deceleration of the vehicle during the predictive energization of the at least one coil of the eddy-current brake with the actual current corresponding to the activation value or activation value curve can be mitigated or avoided. Optionally, a drive torque realized by the increased vehicle acceleration can be less than or equal to a braking torque triggered by the predictive energization of the at least one coil of the eddy-current brake with the actual current corresponding to the activation value or activation value curve.

[0012] For example, the electronic device can be designed and / or programmed in such a way that, by means of the electronic device, taking into account the at least one signal, a target braking torque value can be determined with regard to a target braking torque to be applied to the vehicle by means of the eddy current brake, and the target current intensity value or an output value of the target current intensity value can be determined according to a predetermined function as a function of the determined target braking torque value.In this case, the output value of the target current intensity can preferably be determined by means of the electronic device according to the predetermined function as a function of the predetermined target braking torque value, wherein the electronic device is additionally designed and / or programmed such that during a predetermined initial time interval of a braking operation carried out by means of the eddy current brake on the previously undecelerated vehicle, the target current intensity can be determined by means of the electronic device as the product of the output value with a predetermined factor greater than 1, as the sum of the output value and a predetermined additional value greater than zero or as the maximum of the output value and a predetermined minimum value.As will become clear from the following description, by means of the embodiment of the control device / its electronic device described here, the inductance of the at least one coil of the eddy current brake, which conventionally counteracts a rapid execution of a requested braking by means of the eddy current brake, can be overcome earlier during the respective initial time interval.

[0013] The advantages described above are also guaranteed for an eddy current brake for a vehicle with such a control device.

[0014] Furthermore, implementing a corresponding method for operating an eddy current brake of a vehicle also provides the advantages explained above. It is expressly noted that the method for operating an eddy current brake can be further developed according to the above-described embodiments of the control device. Short description of the drawings

[0015] Further features and advantages of the present invention are explained below with reference to the figures. They show: Fig. 1a to 1c show a flowchart and coordinate systems for explaining an embodiment of the method for operating an eddy current brake of a vehicle; and Fig. 2 a schematic representation of a vehicle with an eddy current brake for explaining an embodiment of the control device. Embodiments of the invention

[0016] Fig. 1a to 1c show a flowchart and coordinate systems for explaining an embodiment of the method for operating an eddy current brake of a vehicle.

[0017] The feasibility of the method described below is not limited to any specific type of eddy current brake operated by it. Likewise, the feasibility of the method is not limited to any specific vehicle type / motor vehicle equipped with the eddy current brake.

[0018] The method comprises a method step S1 in which a target current intensity is determined with respect to a target current intensity to be conducted through at least one coil / excitation coil of the eddy current brake. The target current intensity is determined at least taking into account at least one provided signal with respect to a change in vehicle speed currently requested by a driver of the vehicle or an automatic system of the vehicle. The at least one signal that is evaluated / read out in method step S1 can, for example, be at least one signal from at least one actuating element sensor with respect to an actuation (or non-actuation) of at least one actuating element of the vehicle by the driver to request a change in vehicle speed. The at least one actuating element can, for example, be an accelerator pedal, an accelerator pedal and / or a brake pedal.Likewise, the at least one signal evaluated / read out in method step S1 can be a signal output by the vehicle's automatic system. The vehicle's automatic system can be understood, in particular, as a driver assistance system of the vehicle, such as, specifically, adaptive cruise control or an autonomous speed control system / autonomous driving system, and / or an emergency braking system of the vehicle.

[0019] For example, when executing method step S1, a target braking torque value can first be determined with respect to a target braking torque to be applied to the vehicle by means of the eddy current brake, taking into account the at least one signal. Subsequently, the target current intensity value or an initial value of the target current intensity value can be determined according to a predetermined function as a function of the predetermined target braking torque value. The predetermined function can be understood as a relationship that represents the target current intensity value or the initial value of the target current intensity value as a function of the predetermined target braking torque value.

[0020] It should also be noted here that the vehicle equipped with the eddy current brake can additionally have at least one electric motor that can be used in a recuperative mode as a generator for braking the vehicle and / or at least one wheel-specific service brake. The at least one wheel-specific service brake can be understood to mean, for example, at least one hydraulically actuated wheel brake cylinder, at least one electromechanical wheel brake cylinder and / or at least one parking brake. It is therefore not necessary, when executing method step S1, to specify the target braking torque value, the initial value of the target current value and / or the target current value in such a way that a vehicle deceleration specified by the driver or the automatic system as a requested change in vehicle speed is effected exclusively by means of the eddy current brake.Instead, the at least one electric motor of the vehicle, which can be operated in its recuperative mode, can also be used to at least partially effect the predetermined vehicle deceleration in order to convert the vehicle's kinetic energy into electrically storable energy. In particular, the target braking torque value, the initial value of the target current intensity and / or the target current intensity can only be set to be non-zero when, in the field weakening range, i.e. at a high vehicle speed, and / or in the fully charged state of at least one vehicle battery that can be charged by means of the at least one electric motor that can be operated in its recuperative mode, the at least one electric motor cannot or can hardly be used to effect the requested vehicle deceleration.Alternatively or additionally, at least one wheel-specific service brake of the vehicle can also be (co-)used to achieve the specified vehicle deceleration.

[0021] In a method step S2 executed after method step S1, an actual current corresponding to the target current is passed through at least one coil of the eddy current brake. In this way, an actual braking torque M brake the eddy current brake on the vehicle, by means of which the vehicle can be slowed down, in particular brought to a standstill.

[0022] The method described here also has a method step S3 in which it is predicted whether a vehicle deceleration request (i.e. a deceleration of the vehicle other than zero) is likely for the vehicle traveling without deceleration by the driver or the automatic system within a predetermined future time interval. A vehicle traveling without deceleration is understood to mean that the vehicle is traveling at a current speed other than zero and only road friction and air resistance are braking the moving vehicle. Preferably, in the vehicle traveling without deceleration, the eddy current brake and possibly also the at least one electric motor of the vehicle that can be operated in its recuperative mode and / or the at least one wheel-specific service brake of the vehicle are in their respective inactive mode.Method step S3 is therefore preferably always carried out when the vehicle is traveling at a current speed other than zero and the eddy current brake and possibly also the at least one electric motor of the vehicle operable in its recuperative mode and / or the at least one wheel-specific service brake of the vehicle are not currently being used to brake the vehicle.

[0023] The prediction performed in method step S3 as to whether a deceleration request for the vehicle traveling without deceleration is likely within the specified future time interval by the driver or the automatic system can be made, for example, by reading out prediction information. The prediction information can be understood, for example, as information output by an on-board prediction device. Likewise, the prediction information can also be output by a vehicle-external traffic control system or retrieved via the Internet. Thus, vehicle-external traffic control systems can also be used to improve the operation of the eddy current brake.

[0024] Alternatively or additionally, the prediction performed in method step S3 as to whether a vehicle deceleration request for the vehicle traveling without deceleration is likely within the specified future time interval by the driver or the automatic system can also be carried out taking into account the at least one signal and / or provided environmental information. Advantageous examples for evaluating the at least one signal and / or the environmental information will be discussed below.

[0025] If, during the execution of method step S3, a probable vehicle deceleration request for the vehicle traveling without deceleration within the specified future time interval is predicted by the driver or the automatic system, the target current is set equal to a specified activation value or activation value curve during the subsequent execution of method step S1. The activation value or activation value curve is understood to mean at least one current value other than zero, so that by setting the target current equal to the activation value or activation value curve, a corresponding current supply to the at least one coil of the eddy current brake is triggered with an actual current other than zero.

[0026] Accordingly, during the subsequent execution of method step S2, an actual current corresponding to the activation value or activation value curve is passed through at least one coil of the eddy-current brake. This can also be described as a predictive energization of the eddy-current brake, by means of which the response dynamics of the eddy-current brake are prepared for the likely imminent vehicle deceleration request. Therefore, by predictively energizing the eddy-current brake, the time (TTL, Time-to-Lock) until the requested vehicle deceleration is effected is shortened, thereby reducing the vehicle's braking distance. The predictive energization of the eddy-current brake thus contributes significantly to improving the vehicle's safety standards and increasing driving comfort for its driver.

[0027] The predictive energization of the eddy current brake can be successfully used in particular in a variety of driving situations in which a reduction in the speed of the vehicle, in particular an emergency braking of the vehicle, is advantageous or necessary. For example, at least one signal from an accelerator or accelerator pedal sensor relating to an actuation of an accelerator or accelerator pedal of the vehicle by the driver can be read out / evaluated as the at least one signal. If it is determined / detected based on the at least one signal from the accelerator or accelerator pedal sensor of the vehicle traveling without deceleration that an absolute value of a release speed of the accelerator or accelerator pedal is above a predetermined release speed threshold, it can be reliably predicted that a vehicle deceleration request for the vehicle traveling without deceleration by the driver or the automatic system is likely within the future time interval.Particularly in the case of a rapid and jerky release of the accelerator or gas pedal of a vehicle traveling without deceleration, it can be reliably anticipated that the driver assesses the current traffic situation in the vicinity of his or her vehicle traveling without deceleration as critical, and therefore either the driver or the automatic system will, with a high probability, soon request actual deceleration / emergency braking of the vehicle. By predictively energizing the eddy-current brake, a conventional limitation of the dynamics of a braking torque buildup using the eddy-current brake, which is limited by the compliance of a drive train equipped with the eddy-current brake and the inductance of at least one coil of the eddy-current brake, can be overcome / cancelled. Therefore, the actually requested vehicle deceleration can be achieved more quickly in this case.

[0028] Likewise, at least one signal from the accelerator pedal sensor relating to the driver's actuation of the accelerator pedal and at least one signal from a brake pedal sensor relating to the driver's actuation of a vehicle's brake pedal can be read out / evaluated as the at least one signal. If it is determined / recognized based on the signals from the accelerator pedal sensor and the brake pedal sensor that the accelerator pedal of the vehicle traveling without deceleration remains unactuated within a predetermined waiting time after the driver has finished actuating the brake pedal, it can be predicted with good certainty that a vehicle deceleration request for the vehicle traveling without deceleration by the driver or the automatic system is likely within the future time interval.If the driver stops pressing the brake pedal without subsequently pressing the accelerator pedal of the vehicle moving without deceleration, it can be reliably concluded that the driver still considers the current traffic situation in the vicinity of his vehicle to be critical, and therefore, with a high probability, a further braking request from the driver or the automatic transmission can be expected soon. By predictively energizing the eddy current brake, the braking request actually indicated in the immediate future can be executed more quickly and conveniently.

[0029] Environmental information can be understood as environmental information provided by at least one vehicle-specific sensor, as well as by a vehicle-external traffic monitoring system or retrieved via the Internet. The at least one vehicle-specific sensor can specifically be at least one radar sensor and / or a vehicle-specific camera and image analysis system. The environmental information can also be used to reliably determine / detect whether a current traffic situation in the current environment of the vehicle traveling without delay corresponds to a predefined critical traffic situation and / or a predefined emergency braking situation. If necessary, i.e.If the current traffic situation in the current environment corresponds to a predefined critical traffic situation and / or a predefined emergency braking situation, it is preferably predicted that a deceleration request for the vehicle traveling without deceleration by the driver or the automatic system is likely within the future time interval. By means of the subsequently executed predictive current application, even a strong deceleration of the vehicle can be achieved relatively quickly in this situation.

[0030] Instead of predictively energizing the eddy-current brake with the actual current corresponding to the temporally constant activation value, by setting the target current value according to the specified activation value curve, it is also possible to ensure that a current value of the actual current varies over time within the duration of the activation value curve. The activation value curve is therefore understood to be a temporal sequence of varying activation values.

[0031] If the driver or the automatic system requests vehicle acceleration during predictive energization of the eddy-current brake with the actual current corresponding to the activation value or activation value curve, the predictive energization can be terminated immediately and the eddy-current brake returned to its inactive mode. Even if the driver or the automatic system actually requests the predicted vehicle deceleration during predictive energization of the eddy-current brake with the actual current corresponding to the activation value or activation value curve, the system can immediately continue with a stronger energization of the eddy-current brake with a corresponding actual current instead of the predictive energization.

[0032] If, after predictive energization of the eddy current brake with the actual current corresponding to the activation value, no vehicle deceleration is requested by the driver or the automatic system within a predefined response waiting time interval, the predictive energization of at least one coil of the eddy current brake is terminated. Even if, after predictive energization of the eddy current brake with the actual current corresponding to the activation value curve, no vehicle deceleration is requested by the driver or the automatic system, the predictive energization of at least one coil of the eddy current brake is terminated. The eddy current brake then returns to its inactive mode, meaning that the eddy current brake does not counteract any acceleration request from the driver or the automatic system.

[0033] In an advantageous development of the method described here, an (optional) method step S4 is also carried out while the actual current intensity corresponding to the activation value or activation value curve is passed through the at least one coil of the eddy current brake as method step S2. When method step S4 is carried out, at least one drive motor of the vehicle, which can be, for example, the at least one electric motor operable in its recuperative mode and / or at least one internal combustion engine of the vehicle, is controlled by means of at least one motor control signal in such a way that an increase in the acceleration of the vehicle caused by the at least one drive motor is achieved.By carrying out method step S4, an actual braking torque M triggered by predictively energising the at least one coil of the eddy current brake with the actual current intensity corresponding to the activation value or activation value curve can be determined. brake the eddy current brake can be at least partially compensated. Optionally, an (additional) drive torque of the at least one drive motor of the vehicle, realized by executing method step S4, can be less than or equal to the actual braking torque M caused by the predictively energized eddy current brake. brake If the drive torque is smaller than the actual braking torque M brake is determined by the difference between the actual braking torque M brake and the drive torque already realizes a resulting braking effect not equal to zero of the eddy current brake in order to (slightly) preload a drive train formed with the eddy current brake.

[0034] Another advantageous development of the method is by means of the coordinate systems of the Fig. 1b and Fig. 1c is shown schematically. In the coordinate systems of the Fig. 1b and Fig. 1c, the abscissa is a time axis t (in seconds). Using the ordinate of the coordinate system of the Fig. 1b shows the gear ratio torque Φ of the eddy current brake (in Newton meters). The ordinate of the coordinate system of the Fig. 1c shows a resulting actual braking torque M brake of the eddy current brake (in Newton meters).

[0035] For all graphs g b+ , g b0 , g c+ and g c0 the coordinate systems of the Fig. 1b and Fig. 1c, in method step S1, the initial value of the target current is first determined according to the specified function as a function of the specified target braking torque. In the case of the function g b+ , and gc+ the coordinate systems of the Fig. 1b and Fig. 1c, the target current intensity is then newly determined during a predetermined initial time interval of a braking operation carried out by means of the eddy current brake on the previously undecelerated vehicle, whereby the target current intensity during the initial time interval is optionally determined as the product of the initial value with a predetermined factor greater than 1, as the sum of the initial value and a predetermined additional value greater than zero, or as the maximum of the initial value and a predetermined minimum value (new). In addition, in the case of the braking operation carried out by means of the graphs g b+ , and g c+ the coordinate systems of the Fig. 1b and Fig. 1c, the target current value is set equal to the initial value after the initial time interval has elapsed. In contrast, in the case of the current value calculated using the graph g b0 and g c0the coordinate systems of the Fig. 1b and Fig. 1c, the target current intensity is set equal to the initial value during the entire braking operation carried out by the eddy current brake on the previously undecelerated vehicle.

[0036] In the example of the coordinate systems of the Fig. 1b and Fig. 1c, a strong deceleration of the vehicle is requested at time 15s. As can be seen from a comparison of the graphs g b+ , g b0 , g c+ and g c0 the coordinate systems of the Fig. 1b and Fig. 1c, a requested braking torque M requestedThis is possible because, by increasing the actual current supplied by the at least one coil during the initial time interval, the inductance of the at least one coil of the eddy-current brake can be overcome earlier. The increase in the actual current during the initial time interval can also be described as a brief increase in the excitation current of the eddy-current brake above a nominal maximum current. Emergency braking, in particular, can be effected (even) faster in this way.

[0037] Optionally, the activation value curve can also be specified such that the actual current intensity corresponding to the activation value curve has a first current intensity maximum during a first time interval and a second current intensity maximum during a subsequent second time interval, wherein the first current intensity maximum is greater than or equal to the second current intensity maximum by at least a factor of 1.3. For example, the first current intensity maximum can be greater than or equal to the second current intensity maximum by at least a factor of 1.5, in particular by at least a factor of 1.8, especially by at least a factor of 2.

[0038] Thus, by setting the target current according to the specified activation value curve, a very high actual current, in particular equal to a maximum excitation current, can be passed through the at least one coil of the eddy-current brake during the first time interval, thereby overcoming the inductance of the at least one coil at an early stage. At the same time, by using the lower actual current, which is smaller than the nominal maximum current of the coils, it can be ensured that the coils of the eddy-current brake are not thermally overloaded during the second time interval.

[0039] Fig. 2 shows a schematic representation of a vehicle with an eddy current brake for explaining an embodiment of the control device.

[0040] It is expressly pointed out that the usability of the control device 10 described below is not limited to any specific vehicle type / motor vehicle type of the vehicle / motor vehicle 14 equipped therewith and with the cooperating eddy current brake 12. Furthermore, the vehicle 14 merely has, by way of example, a vehicle topology in which the eddy current brake 12 (eddy current brake module, ECB) is integrated into a drive train of an electric motor 16, which acts on wheels 26a and 26b of the driven vehicle axle 24 via a reduction gear 18, a differential 20 and drive shafts 22 of a driven vehicle axle 24 of the vehicle 14. This can also be described as an integration of the eddy current brake 12 into an e-axle of the vehicle 14. The driven vehicle axle 24 is also merely an example of a rear axle of the vehicle 14. The control device 10 is particularly suitable for the Fig.2, but can also be used with other vehicle topologies, for example if the eddy current brake 12 is integrated into wheel-individual drives and / or also acts via a transmission on at least one of the wheels 26a to 26d of the vehicle 14.

[0041] Only as an optional further development, a parking brake 28a and 28b can be attached to an associated differential output of the differential 20 for each wheel 26a and 26b of the driven vehicle axle 24. The equipping of a further vehicle axle 30 of the vehicle 14 with a wheel-specific electromechanical wheel brake cylinder 32 for each wheel 26c and 26d of the further vehicle axle 30 is also to be interpreted only as an example.

[0042] The control device 10 has an electronic device 10a, which is designed and / or programmed such that a target current intensity can be / is determined by means of the electronic device 10a with respect to a target current intensity to be conducted through at least one coil of the eddy current brake 12. The target current intensity is determined by means of the electronic device 10a, at least taking into account at least one provided signal 34 with respect to a speed change of the vehicle 14 currently requested by a driver of the vehicle 14 or an automatic system (not shown) of the vehicle 14. Examples of the at least one provided signal 34 and the automatic system have already been listed above. By means of the electronic device 10a, an actual current intensity I corresponding to the target current intensity can be / is conducted through the at least one coil of the eddy current brake 12.As a rule, the eddy current brake 12 has a linear, but speed-dependent, relationship between the actual current I conducted through the at least one coil of the eddy current brake 12 and the resulting braking torque of the eddy current brake 12. To conduct the actual current I through the at least one coil, a voltage can be applied, for example, to an RL element of the eddy current brake 12.

[0043] The electronic device 10a is additionally designed and / or programmed in such a way that it is also possible to predict / predict and / or read out based on provided (not sketched) forecast information whether a vehicle deceleration request for the vehicle 14 traveling without deceleration is likely within a predetermined future time interval by the driver or the automatic system. For the prediction, for example, the at least one signal 34 and / or a provided (not shown) environmental information can be evaluated. What can be understood by the forecast information and the environmental information has already been explained above. If necessary, i.e.If it is determined that a vehicle deceleration request for the vehicle 14 traveling without deceleration by the driver or the automatic system is likely within the future time interval, the target current intensity value can be set by means of the electronic device 10a to be equal to a predetermined activation value or activation value curve in such a way that an actual current intensity I corresponding to the activation value or activation value curve can be conducted through the at least one coil of the eddy current brake 12 by means of the electronic device 10a.

[0044] By means of the design / programming of the control device 10 / its electronic device 10a described here, not only can the low time constant of the eddy-current brake 12 (generally between 10 and 20 msec) be utilized for the highly dynamic buildup of a braking torque, but also voltage reserves that increase the actual current intensity I in the inductance of the coil, and compliance (play / elasticity) of the drive train, through which the braking torque generated by the eddy-current brake 12 is transmitted to the wheels 26a and 26b of the driven vehicle axle 24, can be overcome earlier. Likewise, sudden load changes that can lead to vibrations in the drive train, such as so-called longitudinal jerking in a frequency range of 4 to 10 Hertz, can be avoided.

[0045] As an advantageous further development, the control device 10 / its electronic device 10a can also be designed / programmed to carry out further method steps of the method explained above.

[0046] The control device 10 can, for example, be a central vehicle control unit of the vehicle 14. The advantageous design / programming of the control device 10 / its electronic device 10a can thus be integrated with a multitude of additional control functions into a device frequently used on the vehicle 14. Alternatively, the control device 10 can also be a separate control electronics unit for the eddy current brake 12. However, the possible designs for the control device 10 listed here are not to be interpreted as exhaustive. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 214 867 A1

[0002]

Claims

[1] Control device (10) for at least one eddy current brake (12) of a vehicle (14) with: an electronic device (10a) which is designed and / or programmed in such a way that, by means of the electronic device (10a), at least taking into account at least one provided signal (34) relating to a change in speed of the vehicle (14) currently requested by a driver of the vehicle (14) or an automatic system of the vehicle (14), a target current intensity can be determined with regard to a target current intensity to be conducted through at least one coil of the eddy current brake (12), and by means of the electronic device (10a), an actual current intensity (I) corresponding to the target current intensity can be conducted through the at least one coil of the eddy current brake (12); characterized by , that the electronic device (10a) is additionally designed and / or programmed such that, by means of the electronic device (10a), taking into account the at least one signal (34) and / or a provided environmental information item, it is possible to predict and / or read out on the basis of a provided forecast information whether a vehicle deceleration request for the vehicle (14) traveling without deceleration by the driver or the automatic system is likely within a predetermined future time interval; and, if necessary, the target current intensity can be set equal to a predetermined activation value or activation value curve by means of the electronic device (10a) in such a way that an actual current intensity (I) corresponding to the activation value or activation value curve can be conducted through the at least one coil of the eddy current brake (12) by means of the electronic device (10a). [2] Control device (10) according to claim 1, wherein at least one signal from an accelerator or accelerator pedal sensor relating to an actuation of an accelerator or accelerator pedal of the vehicle (14) by the driver can be read out by means of the electronic device (10a) as the at least one signal (34), and wherein, if it is determined by means of the electronic device (10a) on the basis of the at least one signal from the accelerator or accelerator pedal sensor that an amount of a release speed of the accelerator or accelerator pedal of the vehicle (14) traveling without deceleration is above a predetermined release speed threshold value, it is predicted by means of the electronic device (10a) that a vehicle deceleration request for the vehicle (14) traveling without deceleration by the driver or the automatic system is likely within the future time interval. [3] Control device (10) according to claim 1 or 2, wherein at least one signal from the accelerator pedal sensor relating to the actuation of the accelerator pedal by the driver and at least one signal from a brake pedal sensor relating to an actuation of a brake pedal of the vehicle (14) by the driver can be read out as the at least one signal (34) by means of the electronic device (10a), and wherein, if it is determined by means of the electronic device (10a) on the basis of the signals from the accelerator pedal sensor and the brake pedal sensor that the accelerator pedal of the vehicle (14) traveling without deceleration remains unactuated within a predetermined waiting time after the end of an actuation of the brake pedal by the driver, it is predicted by means of the electronic device (10a) that a vehicle deceleration request for the vehicle (14) traveling without deceleration by the driver or the automatic system is likely within the future time interval. [4] Control device (10) according to one of the preceding claims, wherein, if it is determined by means of the electronic device (10a) on the basis of the environmental information that a current traffic situation in a current environment of the vehicle (14) traveling without deceleration corresponds to a predetermined critical traffic situation and / or a predetermined emergency braking situation, it is predicted by means of the electronic device (10a) that a vehicle deceleration request for the vehicle (14) traveling without deceleration by the driver or the automatic system is likely within the future time interval. [5] Control device (10) according to one of the preceding claims, wherein an activation value curve is stored on the electronic device (10a) such that the actual current intensity (I) corresponding to the activation value curve has a first current intensity maximum during a first time interval and a second current intensity maximum during a subsequent second time interval, wherein the first current intensity maximum is greater than or equal to the second current intensity maximum by at least a factor of 1.

3. [6] Control device (10) according to one of the preceding claims, wherein the electronic device (10a) is additionally designed and / or programmed such that, while the actual current intensity (I) corresponding to the activation value or activation value curve is conducted through the at least one coil of the eddy current brake (12) by means of the electronic device (10a), at least one motor control signal can be output to at least one drive motor of the vehicle (14) and / or to at least one controller of the at least one drive motor by means of the electronic device (10a), so that the at least one drive motor can be controlled by means of the at least one motor control signal in order to increase an acceleration of the vehicle (14) brought about by means of the at least one drive motor. [7] Control device (10) according to one of the preceding claims, wherein the electronic device (10a) is designed and / or programmed such that by means of the electronic device (10a), taking into account the at least one signal (34), a desired braking torque value can be determined with regard to a desired braking torque to be applied to the vehicle by means of the eddy current brake (12), and the desired current intensity value or an output value of the desired current intensity value can be determined according to a predetermined function as a function of the determined desired braking torque value. [8] Control device (10) according to claim 7, wherein the output value of the desired current intensity can be determined by means of the electronic device (10a) according to the predetermined function as a function of the determined desired braking torque value, and wherein the electronic device (10a) is additionally designed and / or programmed such that during a predetermined initial time interval of a braking operation carried out by means of the eddy current brake (12) on the previously undecelerated vehicle (14), the desired current intensity can be determined by means of the electronic device (10a) as the product of the output value with a predetermined factor greater than 1, as the sum of the output value and a predetermined additional value greater than zero, or as the maximum of the output value and a predetermined minimum value. [9] Eddy current brake (12) for a vehicle (14) with a control device (10) according to one of the preceding claims. [10] Method for operating an eddy current brake (12) of a vehicle (14) comprising the steps: Setting a target current intensity with respect to a target current intensity to be conducted through at least one coil of the eddy current brake (12), at least taking into account at least one provided signal (34) with respect to a speed change of the vehicle (14)(S1) currently requested by a driver of the vehicle (14) or an automatic system of the vehicle (14); and Conducting an actual current (I) corresponding to the target current through the at least one coil of the eddy current brake (12)(S2); characterized by the steps: Predicting, taking into account the at least one signal (34) and / or a provided environmental information item and / or reading out based on a forecast information item, whether a vehicle deceleration request for the vehicle (14) traveling without deceleration by the driver or the automatic system is likely within a predetermined future time interval (S3); and, if necessary, setting the target current intensity equal to a predetermined activation value or activation value curve such that an actual current intensity (I) corresponding to the activation value or activation value curve is passed through the at least one coil of the eddy current brake (12).

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