Method and Device for Operating an Electrically Driven Vehicle in Preparation for a Start-up Process

Abstract

A device for operating an electric drive machine of a vehicle in preparation for a start-up process of the vehicle is configured to determine that a preparation mode of the vehicle for preparing for the start-up process is active, and in response, operate the electric drive machine with a time-modulated target drive torque in a preparation phase for the start-up process in order to create vibrations of the vehicle by the drive machine as haptic feedback for a driver of the vehicle when the vehicle is stationary.

Claims

1-15. (canceled)

16. A device for operating an electric drive machine of a vehicle in preparation for a starting process of the vehicle, wherein the device is configured to; determine that a preparation mode of the vehicle in preparation for the starting process is active; and responsively operate the electric drive machine in a preparation phase for the starting process with a time-modulated target drive torque in order to, when at a standstill, bring about vibrations of the vehicle by the drive machine as haptic feedback for a driver of the vehicle.

17. The device according to claim 16, wherein the device is configured to: detect that, when the vehicle is at a standstill, a brake controller configured to control one or more brakes of the vehicle and a drive controller configured to control the drive machine are actuated simultaneously; and determine on a basis of this detection that the preparation mode of the vehicle is active.

18. The device according to claim 17, wherein the device is configured to: detect that a brake pedal and an accelerator pedal are actuated simultaneously.

19. The device according to claim 16, wherein the device is configured to: detect that it has been set by way of a user interface of the vehicle that the preparation mode is to be used in preparation for starting processes of the vehicle; and determine on a basis of this detection that the preparation mode of the vehicle is active.

20. The device according to claim 16, wherein the time-modulated target drive torque comprises; a DC component of the target drive torque; and an AC component of the target drive torque.

21. The device according to claim 20, wherein the device is configured to: change an amplitude of the AC component over time; change a frequency and/or a period duration of the AC component over time; and/or vary a speed at which the amplitude of the AC component is changed over time.

22. The device according to claim 16, wherein the device is configured to: determine braking information with respect to a brake torque brought about by one or more brakes of the vehicle; and determine the time-modulated target drive torque to be delivered by the drive machine in dependence on the braking information in such a way that the time-modulated target drive torque does not exceed the brake torque in the preparation phase.

23. The device according to claim 16, wherein the device is configured to: determine actuating information with respect to an extent of actuation of a brake pedal configured to control one or more brakes of the vehicle, wherein the actuating information indicates a brake torque requested by the driver; and determine a DC component of the time-modulated target drive torque to be delivered by the drive machine in dependence on the actuating information in such a way that the DC component of the time-modulated target drive torque increases as the requested brake torque increases.

24. The device according to claim 16, wherein the device is configured to: determine actuating information with respect to an extent of actuation of an accelerator pedal for controlling the drive machine, wherein the actuating information indicates a drive torque requested by the driver; and determine an AC component of the time-modulated target drive torque to be delivered by the drive machine in dependence on the actuating information in such a way that an extent of the vibrations of the vehicle brought about by the drive machine increases as the requested drive torque increases.

25. The device according to claim 16, wherein the vehicle comprises at least one active oscillation damper configured to damp a transmission of oscillations of the drive machine to a driver's position of the vehicle, and wherein the device is configured to: deactivate the active oscillation damper in the preparation phase; and/or operate the active oscillation damper in the preparation phase in such a way that transmission of oscillations of the drive machine to the driver's position of the vehicle is not damped and/or is intensified.

26. The device according to claim 16, wherein the vehicle comprises a steering wheel for steering the vehicle; and wherein the device is configured to make a steering wheel actuator bring about vibrations of the steering wheel as haptic feedback for the driver of the vehicle in the preparation mode.

27. The device according to claim 16, wherein the vehicle comprises a first electric drive machine for a first axle, and a second electric drive machine for a second axle of the vehicle; and wherein the device is configured to: operate the first drive machine with a first modulated target drive torque in the preparation phase; operate the second drive machine with a second modulated target drive torque in the preparation phase; and change the first modulated target drive torque and the second modulated target drive torque in relation to one another over time in such a way that the vibrations of the vehicle shift locationally over time.

28. The device according to claim 16, wherein the device is configured to: determine that the preparation phase has ended and/or the starting process is beginning; and responsively end the time-modulation of the target drive torque to be delivered by the electric drive machine and to operate the drive machine according to a drive torque predetermined by the driver by way of a drive controller.

29. The device according to claim 16, wherein a drive shaft of the electric drive machine does not rotate in the preparation phase; and/or a position of the drive shaft of the electric drive machine oscillates about an intermediate position on a basis of the modulated target drive torque to be delivered.

30. The device according to claim 16, wherein an AC component of the time-modulated target drive torque depends on a resonant frequency of a body of the vehicle.

31. A method for operating an electric drive machine of a vehicle comprising: determining that a preparation mode of the vehicle in preparation for a starting process is active; and responsively operating the electric drive machine in a preparation phase for the starting process with a time-modulated target drive torque in order to, when at a standstill, bring about vibrations of the vehicle by the drive machine as haptic feedback for a driver of the vehicle.

32. The method according to claim 31, comprising: detecting that a brake pedal configured to control one or more brakes of the vehicle and an accelerator pedal configured to control the drive machine are actuated simultaneously; and determining on a basis of this detection that the preparation mode of the vehicle is active.

33. The method according to claim 31, comprising: changing an amplitude of an AC component of the target drive torque over time; changing a frequency and/or a period duration of the AC component over time; and/or varying a speed at which the amplitude of the AC component is changed over time.

34. The method according to claim 31, comprising: determining actuating information with respect to an extent of actuation of a brake pedal configured to control one or more brakes of the vehicle, wherein the actuating information indicates a brake torque requested by the driver; and determining a DC component of the time-modulated target drive torque to be delivered by the drive machine in dependence on the actuating information in such a way that the DC component of the time-modulated target drive torque increases as the requested brake torque increases.

35. The method according to claim 31, comprising: determining actuating information with respect to an extent of actuation of an accelerator pedal for controlling the drive machine, wherein the actuating information indicates a drive torque requested by the driver; and determining an AC component of the time-modulated target drive torque to be delivered by the drive machine in dependence on the actuating information in such a way that an extent of the vibrations of the vehicle brought about by the drive machine increases as the requested drive torque increases.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIGS. 1a and 1b each show a vehicle, given by way of example, with electric drive machines;

[0042] FIG. 2 shows a variation over time, given by way of example, of the target drive torque to be provided by an electric machine during a preparation phase for a starting maneuver; and

[0043] FIG. 3 shows a flow diagram of a method, given by way of example, for operating an electric machine during a preparation phase for a starting maneuver.

DETAILED DESCRIPTION OF THE DRAWINGS

[0044] As explained at the beginning, the present document is concerned with the efficient provision of a preparation phase for a starting maneuver, by which an increased drive torque for the starting maneuver and/or an improved driving experience for the driver of the vehicle are made possible. In this connection, FIGS. 1a and 1b show different representations of an (if applicable exclusively) electrically driven vehicle 100, in particular a battery electric vehicle (BEV).

[0045] The vehicle 100 comprises at least one electric machine 114, which is operated by electrical energy from an electrical energy store (not shown) of the vehicle 100 and which is set up to drive the vehicle 100. The vehicle 100 may comprise a first electric machine 114 for a first axle (for example the rear axle) and a second electric machine 114 for a second axle (for example the front axle) of the vehicle 100, for example in order to provide an electrical all-wheel drive. The first and/or second machine 114 may each be a synchronous motor or an asynchronous motor.

[0046] The vehicle 100 also typically comprises brakes 113, in particular wheel brakes and/or friction brakes, which are set up to decelerate the vehicle 100. For this purpose, a brake 113 may act on a wheel 106 of the vehicle 100 in order to brake the wheel 106.

[0047] Furthermore, the vehicle 100 comprises a brake controller 103, for example a brake pedal, with which the one or more brakes 113 of the vehicle 100 can be actuated in order to brake the vehicle 100. In this case, the one or more brakes 113 may typically also be used to bring about the effect of keeping the vehicle 100 at a standstill even when a drive torque is acting on one or more wheels 106. In particular, the one or more brakes 113 may be used to bring about a brake torque, which can act against a drive torque of the vehicle 100. If applicable, the level of the brake torque may in this case be set by the driver by way of the brake controller 103, for example by way of a force exerted on the brake pedal and/or by way of the deflection of the brake pedal. The level of the brake torque typically increases the more strongly the driver actuates the brake pedal and/or the further the driver deflects the brake pedal.

[0048] The vehicle 100 also comprises a drive controller 103, for example an accelerator pedal or a gas pedal, with which the drive torque brought about by the one or more electric machines 114 can be set. In particular, the driver can increase the drive torque by the driver increasing the deflection of the accelerator pedal.

[0049] A (control) device 101 of the vehicle 100 may be set up to determine actuating information with respect to an actuation of the drive controller 104 and/or the brake controller 103 (for example on the basis of a respective sensor on the drive controller 104 or on the brake controller 103). Furthermore, the device 101 may be set up [0050] to determine a target drive torque on the basis of the actuating information of the drive controller 104; and/or [0051] to determine a target brake torque on the basis of the actuating information of the brake controller 103.

[0052] The device 101 may also be set up to operate the one or more electric machines 114 in dependence on the actuating information of the drive controller 104, in particular in dependence on the determined target drive torque, in particular in order to bring about the effect that the target drive torque is set by the one or more electric machines 114. In a corresponding way, the one or more brakes 103, in particular the one or more friction brakes, may be operated in dependence on the actuating information of the brake controller 103, in particular in dependence on the determined target brake torque, in particular in order to bring about the effect that the target brake torque is brought about by the one or more brakes 103.

[0053] The vehicle 100 may also comprise, as shown in FIG. 1b, at least one active oscillation damper 122 for reducing the vibrations brought about by the one or more electric machines 114 (in particular at the driver's position). The active oscillation damper 122 may in this case act on a mounting of an electric machine 114 on a bearer 121 of the vehicle 100.

[0054] As explained at the beginning, it may be desired by the driver of the vehicle 100, for example in preparation for starting in a vehicle race and/or for increasing the drive torque acting in a starting maneuver, to operate the vehicle 100 when at a standstill in a preparation mode in which the vehicle 100 is prepared for an imminent starting process. To prepare the vehicle 100 for the starting process, the driver 100 may simultaneously actuate the brake controller 103 in order to bring about the effect that a brake torque is brought about by the one or more brakes 113, and the vehicle 100 remains at a standstill. Furthermore, the drive controller 104 may be actuated by the driver 100 in order to bring about the effect that a drive torque is brought about by the one or more electric machines 114, but does not have the effect that the vehicle 100 starts to move on account of the brake torque acting. To initiate the actual starting process, the driver 100 may relinquish the actuation of the brake controller 103 such that the vehicle 100 is driven by the drive torque brought about by the one or more electric machines 114.

[0055] In the case of an electrically driven vehicle 100, the drive torque brought about by the one or more electric machines 114 typically does not lead to any noticeable haptic feedback for the driver of the vehicle 100, which makes it more difficult for the driver to set the desired drive torque already when at a standstill by actuating the drive controller 104.

[0056] The (control) device 101 of the vehicle 100 may be set up to operate the one or more electric machines 114 of the vehicle 100 in the preparation mode in such a way that haptic feedback is brought about at the driver's position of the vehicle 100 by the one or more electric machines 114. The haptic feedback brought about may in this case depend on the actuation, in particular on the actuating information, of the drive controller 104. In particular, the haptic feedback may be adapted in dependence on the target drive torque requested by the driver by way of the drive controller 104. Thus, it can be made possible for the driver of the vehicle 100 to prepare the vehicle 100 in a precise way for a starting process (with increased drive torque).

[0057] The (control) device 101 may be set up to modulate or vary the target drive torque requested by the one or more electric machines 114 in order to excite the one or more electric machines 114 to undergo oscillations which lead to noticeable haptic feedback at the driver's position.

[0058] The device 101 may also be set up to operate (or to deactivate) the one or more active oscillation dampers 122 for damping oscillations of the one or more electric machines 114 in order to bring about the effect that the oscillations of the one or more electric machines 114 are transmitted as well as possible to the driver's position of the vehicle 100.

[0059] The device 101 may consequently be set up to determine whether or not the vehicle 100 is to be operated in a preparation mode in preparation for a starting process. For this purpose, it may for example be checked [0060] whether the vehicle 100 is at a standstill; [0061] whether the preparation mode has been enabled by way of a user interface 102 of the vehicle 100; and/or [0062] whether the brake controller 103 and the drive controller 104 are being actuated simultaneously.

[0063] If the aforementioned (in particular all of the aforementioned) conditions are satisfied, it can be determined that the vehicle 100 is being operated in the preparation mode. On the other hand, it can be determined, if applicable, that the vehicle 100 is not being operated in the preparation mode.

[0064] If it is determined that the vehicle 100 is not being operated in the preparation mode, it can for example be brought about by the device 101 that no drive torque and/or no haptic feedback for the driver of the vehicle 100 are brought about by the one or more electric machines 114 when the brake controller 103 is actuated (if applicable, also when the drive controller 104 is simultaneously actuated).

[0065] On the other hand, if it is determined that the vehicle 100 is being operated in the preparation mode, the one or more electric machines 114 can be activated to provide a specific target drive torque 201 (see FIG. 2). The target drive torque 201 may in this case be made up of an average target drive torque 202 or a DC component 202 and a modulation component for the modulation of the target drive torque 201.

[0066] The average target drive torque 202 (i.e. the DC component of the target drive torque 201) may depend on [0067] the actuating information with respect to the actuation of the drive controller 104, in particular on the deflection of the drive controller 104; [0068] the actuating information with respect to the actuation of the brake controller 103, in particular on the deflection of the brake controller 103 and/or on the force acting on the brake controller 103; and/or [0069] the brake torque brought about by the one or more brakes 103.

[0070] The average target drive torque 202 may be such that, even with a modulation about the average target drive torque 202, the effective target drive torque 201 does not exceed the brake torque. Thus, unintentional starting of the vehicle 100 can be prevented in a reliable way.

[0071] In FIG. 2, a variation 200 over time, given by way of example, of the requested target drive torque 201 is shown. At the point in time 222, it is determined that the vehicle 100 is to be operated in the preparation mode. In a first phase 231 before that point in time 222, typically no target drive torque 202 is requested by the one or more electric machines 114. As from the point in time 222, a time-modulated target drive torque 201, which oscillates and/or varies about the average target drive torque 202, is requested in a preparation phase 232. The modulation of the target drive torque 201 serves in this case for exciting oscillations of the one or more electric machines 114 that lead to haptic feedback at the driver's position of the vehicle 100.

[0072] The modulation of the requested target drive torque 201 may comprise an amplitude modulation of the amplitude 203 of the variation or the oscillation about the average target drive torque 202 (i.e. the AC component of the target drive torque 201). The amplitude 203 may in this case be changed with time. The changing of the amplitude 203 may take place continuously or step by step (for example periodically). In the example shown in FIG. 2, the third period of the requested target drive torque 201 has a smaller amplitude 203 than the first and second periods.

[0073] Alternatively or additionally, the modulation of the requested target drive torque 201 may comprise a frequency modulation, in which the period duration 204 of a period of the modulated target drive torque 201 is changed with time. The changing of the period duration 204 may take place continuously or step by step (for example periodically).

[0074] Alternatively or additionally, the frequency and/or the speed at which the amplitude 203 of the modulated target drive torque 201 is changed may be changed.

[0075] During the preparation phase 232, a modulation of the requested target drive torque 201, by which the one or more electric machines 114 (the drive shafts of which typically do not rotate) are excited to undergo oscillations, may consequently take place, the oscillations in turn leading to noticeable haptic feedback at the driver's position of the vehicle 100.

[0076] The modulation of the requested target drive torque 201 may take place in such a way that the haptic feedback brought about depends on the actuating information with respect to the actuation of the drive controller 104, in particular on the deflection of the drive controller 104, in particular in such a way that the extent of the vibrations noticeable for the driver increases as the deflection of the drive controller 104 increases. Haptic feedback brought about in such a way can make it possible for the driver of the vehicle 100 to set in a precise way the drive torque desired for the subsequent starting process. Such haptic feedback can also intensify the driving experience for the driver of the vehicle 100.

[0077] The starting process may be started by the driver in particular by the driver ending the actuation of the brake controller 103. As a consequence of this, the vehicle 100 is started with the target drive torque 201 requested by way of the drive controller 104. The modulation of the target drive torque 201 is in this case ended (abruptly or smoothly).

[0078] In the example shown in FIG. 2, the driver of the vehicle 100 initiates the starting process at the point in time 223 (for example by letting go the brake pedal). The preparation phase 232 is thereby ended, and a starting phase 233 follows. In the starting phase 233, in particular at the point in time 223, the modulation of the target drive torque 201 is ended. It is also brought about that the target drive torque 201 requested by the driver by way of the drive controller 104 is provided by the one or more electric machines 114.

[0079] During the preparation phase 232 and/or during the operation of the vehicle 100 in the preparation mode, an actuator on the steering wheel (generally on the steering device) of the vehicle 100 may be additionally activated in order to bring about vibrations on the steering wheel as part of the haptic feedback. Thus, the driving experience for the driver can be improved further.

[0080] Alternatively or additionally, the user interface 102 of the vehicle 100 may be adapted when the vehicle 100 is in the preparation mode and/or in the preparation phase 232. For example, the user interface 102 may be adapted in color in order to indicate to the driver that the vehicle 100 is in the preparation mode and/or in the preparation phase 232. Alternatively or additionally, a specific symbol may be displayed by way of the user interface 102 in order to indicate to the driver that the vehicle 100 is in the preparation mode and/or in the preparation phase 232. Thus, the comfort and driving experience for the driver can be improved further.

[0081] A description is consequently given of measures by which relatively strong vibrations of the vehicle 100 are produced during a preparation phase 232 (in particular during so-called launch control preparation) in order to improve the driving experience for the driver and/or in order to make it possible for the driver to perceive the provided drive torque already when the vehicle 100 is at a standstill. A steering-wheel vibration function may be coupled with the launch control sequence in order to intensify the haptic feedback.

[0082] During the preparation phase 232, one or more further measures for initiating the starting process may be alternatively or additionally carried out. The vehicle 100 may comprise an audio system for producing acoustic signals. The audio system may be made to produce during the preparation phase 232 acoustic signals (for example special sound effects) that further improve the driving experience for the driver of the vehicle 100. Alternatively or additionally, seat heating of the driver's seat may be selectively operated during the preparation phase 232, in particular in order to give the driver of the vehicle 100 the impression of heat being generated by the drive of the vehicle 100.

[0083] During the preparation phase 232, the drive train may be preloaded by the one or more electric machines 114 when the vehicle 100 is at a standstill such that the drivetrain of the vehicle 100 oscillates in amplitude and frequency, thereby bringing about a corresponding vibration of the vehicle 100, which is perceived by the driver of the vehicle 100 as haptic feedback.

[0084] FIG. 3 shows a flow diagram of an (if applicable computer-implemented) method 300, given by way of example, for operating an electric drive machine 114 of a vehicle 100 in preparation for a starting process of the vehicle 100. The vehicle 100 may be a vehicle that is exclusively electrically driven. In particular, the vehicle 100 may be designed in such a way that the vehicle 100 does not have an internal combustion engine.

[0085] The method 300 comprises determining 301 that the preparation mode of the vehicle 100 in preparation for the starting process is active. To activate the preparation mode, the driver of the vehicle 100 may set that the preparation mode is to be used in preparation for a starting process, if applicable by way of the user interface 102 of the vehicle 100. When the vehicle 100 is at a standstill, the driver may also actuate the brake controller 103 (in particular the brake pedal) and the drive controller 104 (in particular the accelerator pedal) simultaneously in order to activate the preparation mode of the vehicle 100.

[0086] The method 300 also comprises operating 302 the electric drive machine 114 in a preparation phase 232 for the starting process with a time-modulated target drive torque 201 in response to it having been detected that the preparation mode is active. In other words, a target drive torque 201 can be requested by the drive machine 114, with the target drive torque 201 being time-modulated. In particular, the requested target drive torque 201 may oscillate about a DC component 202.

[0087] The modulation of the requested target drive torque 201 may in this case take place in such a way that, when the vehicle 100 is at a standstill, vibrations of the vehicle 100 (in particular vibrations at the driver's position of the vehicle 100) are brought about by the drive machine 114 as haptic feedback for the driver of the vehicle 100. Thus, the driving experience for the driver can be enhanced. It can in this way also be made possible for the driver to set in a precise way the drive torque to be delivered at the beginning of the starting process.

[0088] The present invention is not restricted to the exemplary embodiments shown. In particular, it should be noted that the description and the figures are only intended to illustrate the principle of the proposed methods, devices, and systems by way of example.