Device and Method for Operating a Roll Stabilization System

Abstract

Please substitute the new Abstract submitted herewith for the original Abstract: A device for operating an active roll stabilization system of a vehicle is described, which active roll stabilization system has a roll stabilizer on at least one axle of the vehicle, which roll stabilizer is configured to adjust, by use of an electrically operated actuator, a degree of twist between lever arms of the roll stabilizer which act on different sides of the axle, in order to counteract a roll movement of the vehicle. The device is set up to determine which operating mode of a plurality of different operating modes of the roll stabilization system has been selected by a user of the vehicle. Further, the device is set up to operate the actuator as a generator, in order to recuperate electrical energy from a roll movement of the vehicle and/or from a roadway-induced movement of the vehicle, in a manner dependent on the selected operating mode.

Claims

1-11. (canceled)

12. A device for operating an active roll stabilization system of a vehicle, the active roll stabilization system having, on at least one axle of the vehicle, a roll stabilizer configured to adjust a rotation of lever arms of the roll stabilizer, comprising: an electrically operated actuator that actuates the lever arms on different sides of the axle in order to counteract a rolling movement of the vehicle, wherein the device is operatively configured to: determine which operating mode from a plurality of different operating modes of the roll stabilization system has been selected by a user of the vehicle; and depending on the selected operating mode, operate the actuator as a generator in order to recover electrical energy from a rolling movement of the vehicle and/or from a roadway-induced movement of the vehicle.

13. The device according to claim 12, wherein the plurality of different operating modes comprise at least one compensation mode and at least one recovery mode; and the actuator is operated actively as a motor more frequently, for a longer period of time, and/or more strongly, at least on average over time, in the compensation mode than in the recovery mode in order to counteract rolling movements of the vehicle; and/or the actuator is operated as a generator more frequently and/or for a longer period of time and/or more intensively, at least on average over time, in the recovery mode than in the compensation mode in order to recover electrical energy from rolling movements of the vehicle.

14. The device according to claim 13, wherein the recovery mode is designed in such a way that the actuator on average over time generates more electrical energy than the actuator consumes for roll stabilization of the vehicle and/or compensation of roadway unevennesses; and/or the compensation mode is designed in such a way that the actuator on average over time generates less electrical energy than the actuator consumes for roll stabilization of the vehicle and/or compensation of roadway unevennesses.

15. The device according to claim 12, wherein the plurality of a different operating modes each establish: one or more stabilization driving situations of the vehicle, in which the actuator is operated actively as a motor for roll stabilization of the vehicle; and/or one or more recovery driving situations of the vehicle, in which the actuator is operated as a generator for recovering electrical energy from rolling movements of the vehicle; and the operating modes differ at least in part with respect to establishment of the one or more stabilization driving situations and/or the one or more recovery driving situations.

16. The device according to claim 15, wherein the device is further operatively configured to: ascertain driving data relating to a current journey of the vehicle, wherein the driving data indicate a steering angle and/or a steering angle speed of a steering mechanism of the vehicle; on the basis of the driving data and on the basis of the selected operating mode, ascertain whether a stabilization driving situation or a recovery driving situation is present; and operate the actuator depending on whether the stabilization driving situation or the recovery driving situation is present.

17. The device according to claim 15, wherein the plurality of different operating modes comprises a compensation mode and a recovery mode; and at least one driving situation specified as stabilization driving situation in the compensation mode is specified as recovery driving situation in the recovery mode.

18. The device according to claim 17, wherein, in the recovery mode, straight-ahead travel of the vehicle, in which a steering angle and/or a steering angle speed is smaller in terms of magnitude than a predefined threshold value, is a recovery driving situation.

19. The device according to claim 12, wherein the vehicle comprises a user interface, by which the user of the vehicle makes one or more user inputs by actuating an operator control element; and the device is further operatively configured to determine, on the basis of a user input from the user, which operating mode was selected by the user of the vehicle.

20. The device according to claim 12, further comprising: an electrical on-board power system of the vehicle that comprises a first electrical subsystem with a first system voltage and a second electrical subsystem with a second system voltage; wherein the actuator is arranged in the first subsystem; and the device is further operatively configured to: detect the recovery of electrical energy by the actuator; and, in response thereto, transfer electrical energy from the first subsystem to the second subsystem, by operating a DC voltage converter between the first subsystem and the second subsystem.

21. The device according to claim 20, wherein the first subsystem comprises an energy store for storing electrical energy for the operation of the actuator; and the device is further operatively configured to: determine an inability of the energy store to fully take up the electrical energy recovered by the actuator due to a delimited charging power and/or a delimited storage capacity of the energy store; and, in response thereto, operate the DC voltage converter between the first subsystem and the second subsystem in order to transfer electrical energy from the first subsystem to the second subsystem.

22. A method for operating an active roll stabilization system of a vehicle, which, on at least one axle of the vehicle, comprises a roll stabilizer designed to adjust a rotation between lever arms of the roll stabilizer, which act on different sides of the axle, via an electrically operated actuator in order to counteract a rolling movement of the vehicle, the method comprising: determining which operating mode from a plurality of different operating modes of the roll stabilization system was selected by a user of the vehicle; and operating the actuator depending on the selected operating mode as a generator, in order to recover electrical energy from a rolling movement of the vehicle and/or from a roadway-induced movement of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1a shows exemplary components of a vehicle having a roll stabilization system;

[0034] FIG. 1b shows an exemplary effect of roadway unevenness on a stabilizer of a vehicle;

[0035] FIG. 2 shows an exemplary multi-voltage on-board power system; and

[0036] FIG. 3 shows a flow diagram of an exemplary method for operating a stabilization system.

DETAILED DESCRIPTION OF THE DRAWINGS

[0037] As set out in the introduction, the present document is concerned with increasing the energy efficiency of a vehicle having a roll stabilization system. In this context, Figure la shows exemplary components of a vehicle 100. The vehicle 100 comprises a drive motor 101 (e.g. an internal combustion engine and/or an electric machine) which is designed to drive at least one axle 121 (e.g. the rear axle) of the vehicle 100. The vehicle 100 typically comprises a further axle 122 (e.g. the front axle). Wheels 109 are arranged on the axles 121, 122 of the vehicle 100.

[0038] The (two-track) vehicle 100 illustrated in FIG. 1 comprises an active (roll) stabilizer 130 for each axle 121, 122. The lever arms 132 of a stabilizer 130 are each attached to the chassis of the vehicle 100 via a bearing 131. In this context, the lever arms 132 each act (indirectly) on the wheel carriers 105 of a wheel 109. A lever arm 132 may act indirectly on the wheel carrier 105 of a wheel 109, e.g. via a damper or a connecting rod.

[0039] In particular, a stabilizer 130 comprises a right-hand lever arm 132 for the right-hand wheel 109 and a left-hand lever arm 132 for the left-hand wheel 109 of an axle 121, 122. The two lever arms 132 of the stabilizer 130 may be rotated in opposite directions via an actuator 133, which typically comprises an electric machine, in order to make forces that counteract a rolling movement act on the wheels 109 of an axle 121, 122.

[0040] The electrical energy for the operation of the actuator 133 of a stabilizer 133 can be drawn from an electrical energy store 106. The operation of the actuator 133 can be controlled by at least one control unit (or by a triggering device) 111, for instance by a central control unit and/or by multiple decentralized control units. In particular, regulation may be carried out in order to bring about a determined setpoint behavior of the vehicle 100 with respect to rolling movements.

[0041] FIG. 1b illustrates how a rolling movement of the vehicle 100 can be brought about owing to unevenness of the roadway 150 on which the vehicle 100 is traveling and/or owing to a cornering maneuver. The stabilizer 130 can make forces that counteract such a rolling movement act on the lever arms 132 by triggering the actuator 133.

[0042] FIG. 2 shows an exemplary electrical on-board power system 200 of a vehicle 100. The on-board power system 200 may comprise multiple subsystems 210, 220 with different system voltages 211, 221. In particular, a first subsystem 210 (e.g. a 48 V system) may have a first system voltage 211 (e.g. 48 V), and a second subsystem 220 (e.g. a 12 V system) may have a second system voltage 221 (e.g. 12 V). The subsystems 210, 220 may be connected to one another via a DC voltage converter 201 in order to enable the transfer of electrical energy between the subsystems 210, 220.

[0043] In an alternative scenario, both subsystems 210, 220 may have the same system voltage 211, 221 (e.g. 12 V). The subsystems 210, 220 may be arranged in series. In this case, if appropriate, no DC voltage converter 201 is required between the subsystems 210, 220.

[0044] The one or more stabilizers 130 of the vehicle 100 may be arranged in the first subsystem 210 as electrical consumers 212. An energy store of the first subsystem 210 may be used as energy store 106 for the one or more stabilizers 130 (e.g. a lithium-ion-based energy store). The second subsystem 220 may correspondingly comprise one or more electrical consumers 222 and/or an electrical energy store 223.

[0045] The vehicle 100 may comprise a user interface (not illustrated) for a user, in particular for a driver, of the vehicle 100. The user interface may comprise e.g. at least one operator control element enabling the user to select an operating mode 135 of the stabilization system of the vehicle 100 having the one or more stabilizers 130. Exemplary operating modes 135 are a compensation mode, in which rolling movements of the vehicle 100 are compensated as comprehensively as possible by active engagement of the actuators 133 of the one or more stabilizers 130; and a recovery mode, in which rolling movements of the vehicle 100 are compensated only to a reduced extent (compared to the compensation mode), but in which the actuators 133 of the one or more stabilizers 130 are operated at least temporarily as electrical generators, in order to generate electrical energy on the basis of the rolling movements of the vehicle 100. In the process, the electrical energy recovered can be stored in the energy store 106 of the first subsystem 210.

[0046] If appropriate, a multiplicity of different operating modes that enable e.g. (virtually) stepless adjustment between a compensation mode (with stabilization which is as comprehensive as possible) and a recovery mode (with recovery which is as comprehensive as possible) can be enabled and/or selected and/or adjusted.

[0047] The control unit 111 may be configured to determine in which operating mode the (roll) stabilization system of the vehicle 100 is operated. The actuators 133 of the one or more stabilizers 130 may then be operated depending on the operating mode selected. In particular, the actuators 133 can be made to generate electrical energy on the basis of the rolling movement of the vehicle 100 when a determination has been made that the stabilization system should be operated in the recovery mode.

[0048] Furthermore, the control unit 111 may be configured (when the stabilization system is operated in the recovery mode) to operate the DC voltage converter 201 in such a way that electrical energy is transferred from the first subsystem 210 to the second subsystem 220. Expressed generally, the at least one control unit 111 may be configured to bring about the transfer of electrical energy from the first subsystem 210 to the second subsystem 220 (when the stabilization system is operated in the recovery mode and/or when there is a voltage difference between the subsystems 210, 220).

[0049] This can be effected in particular when it is ascertained that the energy store 106 of the first subsystem 210 has a relatively high state of charge (e.g. a state of charge above a determined state-of-charge threshold value). In this way, the effect can reliably be brought about that excessive recovered electrical energy can be utilized for operating one or more electrical consumers 222 in the second subsystem 220 and/or for storage in the energy store 223 of the second subsystem 220. This therefore brings about an increase in the energy efficiency of the vehicle 100.

[0050] It is consequently possible to provide a recovery mode of the stabilization system of the vehicle 100 that has a positive energy balance (with the result that, on average over time, more electrical energy is generated by the actuators 133 of the one or more stabilizers 130 than is consumed by the actuators 133 for the purpose of roll stabilization). In this respect, the stabilization system may be operated e.g. in the 48 V on-board power system 210 of the vehicle 100.

[0051] Excess energy from the recovery of the stabilization system can be transferred from the 48 V store 106 to the 12 V on-board power system 220. The energy transferred can be utilized for 12 V consumers 222. This means that less energy needs to be taken from a HV (high-voltage) on-board power system of the vehicle 100 and/or from a generator, thereby resulting in an increased range of the vehicle 100 and/or in a reduction of the (possibly electrical) energy consumption or CO2 emissions of the vehicle 100.

[0052] During operation of the stabilization system, for example, the vehicle 100 can travel in the recovery mode along a roadway 150 with relatively large and/or a relatively large number of unevennesses. During the journey, electrical energy can be recovered by the one or more actuators 133 and stored in the (optional) 48 V store 106. Excess energy can be transferred from the 48 V store 106, e.g. via the (bidirectional) DC voltage converter 201, to the 12 V on-board power system 220. If appropriate, given a corresponding design of the converter 201 (with sufficiently high power dynamics), operation without a store 106 is enabled.

[0053] FIG. 3 shows a flow diagram of an exemplary (optionally computer-implemented) method 300 for operating an active roll stabilization system of a (motor) vehicle 100. The method 300 can be carried out by a device or by a control unit 111 of the vehicle 100.

[0054] On at least one axle 121, 122 of the vehicle 100, the roll stabilization system comprises a roll stabilizer 130 designed to rotate lever arms 132 of the roll stabilizer 130, which act on different sides of the axle 121, 122, in different directions by means of an electrically operated actuator 133 (in particular by means of an electric machine or by means of an electric motor), in order to counteract a rolling movement of the vehicle 100. The roll stabilization system may comprise a first roll stabilizer 130 for a first axle 121, e.g. the rear axle, and a second roll stabilizer 130 for a second axle 122, e.g. the front axle, of the vehicle 100.

[0055] The method 300 comprises determining 301 which operating mode 135 from a plurality of different operating modes 135 of the roll stabilization system was selected by a user of the vehicle 100. The operating mode 135 may have been selected e.g. via a user interface of the vehicle 100. The roll stabilization system may be operated e.g. (as standard practice) in a compensation mode. Furthermore, the roll stabilization system can be operated in a recovery mode. In this respect, the recovery mode may be designed in such a way that, in this mode, the amount of electrical energy that can be recovered by the roll stabilization system can be increased (compared to the compensation mode). By contrast, the compensation mode may optionally have higher comfort with respect to the roll stabilization than the recovery mode. If appropriate, in the compensation mode there is no recovery at all of electrical energy by the roll stabilization system.

[0056] The method 300 also comprises operating 302 the actuator 133 of the at least one roll stabilizer 130 (as a motor and/or as a generator) depending on the selected operating mode 135. In the process, the actuator 133 of the at least one roll stabilizer 130 can be utilized to recover electrical energy from a rolling movement of the vehicle 100 and/or from roadway-induced wheel movements. If appropriate, the actuator 133 (in a determined driving situation) can be operated in the compensation mode in such a way that no electrical energy is recovered by the actuator 133 (but, if appropriate, the actuator 133 is actively triggered for roll stabilization of the vehicle 100). By contrast, the actuator 133 (in the determined driving situation) can be operated in the recovery mode in such a way that electrical energy is recovered by the actuator 133 (and the actuator 133 is not actively triggered, or is actively triggered only to a reduced extent compared to the compensation mode, for roll stabilization of the vehicle 100).

[0057] The selective use of a roll stabilizer 130 for recovering electrical energy makes it possible to provide an optimized compromise between comfort and energy efficiency of a vehicle 100.

[0058] The present invention is not restricted to the exemplary embodiments shown. In particular, it should be noted that the description and the figures are intended only to illustrate the principle of the proposed methods, devices and systems.