METHOD FOR CONTROLLING A DRIVE TRAIN AND DRIVE TRAIN

Abstract

A method is provided for controlling a drive train (12) of a motor vehicle (10) having an electric drive motor (16, 17), a wheel (26, 27) driven by the electric drive motor (16), and an anti-lock braking system (30) for preventing the wheel from locking (26, 27). The method includes detecting an impending control intervention of the anti-lock braking system (30) and disconnecting a torque-transmitting connection from the electric drive motor (16) to the wheel (26, 27) when an impending control intervention of the anti-lock braking system (30) is detected. Also disclosed are a control device (60), a drive train (12), and a motor vehicle (10) configured to carry out such a method.

Claims

1. A method for controlling a drivetrain (12) of a motor vehicle (10) with an electric drive motor (16, 17), a wheel (26, 27) driven by the electric drive motor (16, 17), and an anti-lock braking system (30) for preventing the wheel from locking (26, 27), comprising the following steps: detecting an impending control intervention of the anti-lock braking system (30), disconnecting a torque-transmitting connection from the electric drive motor (16, 17) to the wheel (26, 27) when an impending control intervention of the anti-lock braking system (30) is detected.

2. The method according to claim 1, wherein detecting the impending control intervention of the anti-lock braking system (30) includes detecting position of a brake actuating element (34).

3. The method according to claim 1, wherein detecting the impending control intervention of the anti-lock braking system (30) includes detecting a speed of change in the position of the brake actuating element (34).

4. The method according to claim 1, wherein detecting the impending control intervention of the anti-lock braking system (30) includes detecting a speed at which brake pressure is built up and/or when a threshold value for the brake pressure is exceeded.

5. The method according to claim 1, wherein disconnecting the torque-transmitting connection is includes shifting a gearbox (18, 19) located in the drivetrain (12) between the electric drive motor (16, 17) and the driven wheel (26, 27) to a neutral position (48).

6. The method according to claim 5, comprising delaying a build-up of brake pressure at a driven axle (22, 25) of the drivetrain (12) until the gearbox (18) is transferred to the neutral position (48) in order to prevent gearbox components and/or the drivetrain (12) from becoming jammed.

7. The method according to claim 6, wherein the motor vehicle (10) has a plurality of driven axles (22, 25), each of the driven axles (22, 25) being connected in a torque-transmitting manner via a gearbox (18, 19) to an electric drive motor (16, 17), wherein delaying the build-up of the brake pressure at the driven axles (22, 25) is performed sequentially.

8. The method according to claim 1, wherein disconnecting the torque-transmitting connection includes opening a clutch (50) arranged in the drivetrain (12) between the electric drive motor (16, 17) and the driven wheel (26, 27).

9. A control unit (60) for controlling a drivetrain (12) in a motor vehicle (10), wherein the control unit (40) is in operative connection with an anti-lock braking system (30) and a torque-transmitting connection of the drivetrain (12) and is configured to carry out the method according to claim 1.

10. A drivetrain (12) for a motor vehicle (10), comprising: an electric drive motor (16, 17); a driven wheel (26, 27); a torque-transmitting connection between the electric drive motor (16, 17) and the driven wheel (26, 27); an anti-lock braking system; and a control unit (60) for controlling the drivetrain and configured to carry out the method according to claim 1, wherein the control unit (40) is in operative connection with the anti-lock braking system (30) and with the torque-transmitting connection of the drivetrain (12)

11. The drivetrain (12) according to claim 10, wherein the anti-lock braking system (20) is pneumatically operated.

12. A motor vehicle (10) with a drivetrain (12) comprising: an electric drive motor (16. 17); a driven wheel (26, 27); a torque-transmitting connection between the electric drive motor (16, 17) and the driven wheel (26, 27); an anti-lock braking system; and a control unit (60) for controlling the drivetrain and configured to carry out the method according to claim 1, wherein the control unit (40) is in operative connection with the anti-lock braking system (30) and with the torque-transmitting connection of the drivetrain (12).

13. The motor vehicle (10) according to claim 12, comprising multiple drive axles (22, 25).

14-15. (canceled)

16. A computer-readable medium comprising executable code that, when executed by a computer, carries out the method according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The invention is briefly explained below with reference to drawings. The following is shown in the figures:

[0039] FIG. 1: a schematic view of a preferred exemplary embodiment of a drivetrain for a motor vehicle, which is controlled by a method according to the invention for controlling the drivetrain during emergency braking of the motor vehicle,

[0040] FIG. 2: another preferred exemplary embodiment of a drivetrain according to the invention for a motor vehicle, and

[0041] FIG. 3: a flow chart for carrying out a method according to the invention for controlling a drivetrain of a motor vehicle.

DETAILED DESCRIPTION

[0042] FIG. 1 shows a schematic view of a drivetrain 12 for a motor vehicle 10. The drivetrain 12 comprises a power supply unit 14, an electric drive motor 16 connected to the power supply unit 14, and a brake system 20. The drivetrain 12 comprises a first, driven axle 22 and a second, preferably non-driven axle 24. The drivetrain 12 further comprises a gearbox 18, which is arranged between the electric drive motor 16 and a driven axle 22. A first driven wheel 26 and a second driven wheel 27 are provided on the driven first axle 22, which are connected to the gearbox 18 via a differential 42, so that an output torque of the gearbox 18 is transmitted to the driven wheels 26, 27 via the differential 42.

[0043] In a first shift position 46, the gearbox 18 is connected to a differential 42 on the drive axle 22 in a torque-transmitting manner. The gearbox 18 has a second shift position 48 in which torque transmission from the gearbox 18 to the wheels 26, 27 is interrupted. This second shift position 48 is also referred to as the neutral position. Alternatively, or additionally, the drivetrain 12 may also have a clutch 50 which can disconnect or connect a torque-transmitting connection between the electric drive motor 16 and the wheels 26, 27.

[0044] The drivetrain 12 can be divided into a first drivetrain component 52 and a second drivetrain component 54. The first drivetrain component 52 comprises the electric drive motor 16, while the second drivetrain component 54 comprises the driven wheels 26, 27. Between the first drivetrain component 52 and the second drivetrain component 54, an element 18, 50 is provided for disconnecting a torque-transmitting connection between the electric drive motor 16 and the wheels 26, 27.

[0045] The drivetrain 12 also comprises a brake system 20, which includes an anti-lock braking system 30, a rotational speed sensor 32 for detecting the rotational speed of one of the wheels 26, 27, 28, 29, a brake actuator 34, in particular a brake pedal 36 or a brake lever, and a wheel brake 38. A brake actuator sensor 44, in particular a brake pedal sensor, is provided on the brake actuator element 34 in order to detect a position of the brake actuating element 34 and/or a change in the position of the brake actuating element 34. The brake system 20 may also include a compressed air reservoir 58 for pneumatic activation of one of the wheel brakes 38.

[0046] The motor vehicle 10 further comprises a non-driven second axle 24 with wheels 28, 29, on each of which a wheel brake 38 is arranged for braking the wheels 28, 29, which are also operatively connected to the anti-lock braking system 30.

[0047] The drivetrain 12 also comprises a control unit 60 for controlling the anti-lock braking system 30 and the torque-transmitting connection between the electric drive motor 16 and the driven wheels 26, 27. The control device 60 has a memory unit 62 and a processing unit 64. The memory unit 62 stores a computer program code 66 for executing a method according to the invention for controlling the drivetrain 12, which executes such a method when the computer program code 66 is executed by the processing unit 64.

[0048] FIG. 2 shows another preferred exemplary embodiment of such a drivetrain 12 for a motor vehicle 10. The drivetrain 12 comprises a power supply unit 14, which is designed as a high-voltage battery 40. Such a high-voltage battery 40 may be, in particular, but not exclusively, of the lithium-ion accumulator, lithium iron phosphate accumulator, solid electrolyte accumulator, or sodium-ion accumulator type.

[0049] With essentially the same structure as described in FIG. 1, the motor vehicle 10 in this exemplary embodiment has a drivetrain 12 with two electric drive motors 16, 17 and two driven axles 22, 25, each of the electric drive motors 16, 17 is connected to one of the driven axles 22, 25 via a gearbox 18.

[0050] FIG. 3 shows a flow chart for carrying out a method according to the invention for controlling a drivetrain 12 of a motor vehicle 10 with an electric drive motor 16, 17, a wheel 26, 27 driven by the electric drive motor 16, 17, and an anti-lock braking system 30 for preventing the wheel 26, 27 from locking.

[0051] In a method step <100>, the anti-lock braking system 30 is monitored and an impending control intervention by the anti-lock braking system 30 is detected. Such an impending control intervention can be effected in particular by detecting a position of a brake actuating element 34, in particular a brake pedal 36, relative to a threshold value for a position of the brake actuating element 34 which is known to be associated with probable locking. As an alternative to an absolute position of the brake actuating element 34, an impending control intervention of the anti-lock braking system 30 can also be detected by detecting the change in the position of the brake actuating element 34, in particular by comparing a rate of change relative to a threshold value for such a rate of change, wherein a rate of change above the threshold value represents a typical reaction of a driver during emergency braking and an associated impending control intervention of the anti-lock braking system 30. If no value is available for a brake actuating element 34, an impending control intervention by the anti-lock braking system 30 can also be derived from an absolute brake pressure or a rate of change of the brake pressure. In a method step <110>, a torque-transmitting connection between the electric drive motor 16, 17 and a driven wheel 26, 27 of the drivetrain is interrupted when an impending or actual control intervention of the anti-lock braking system 30 is detected. This can be achieved in particular by shifting the gearbox 18 from a torque-transmitting first shift position 46 to a second, non-torque-transmitting neutral position 48. Alternatively, the torque-transmitting connection can also be interrupted by opening a clutch 50 in the drivetrain 12 between the electric drive motor 16, 17 and the wheels 26, 27. In a method step <120>, the brake pressure is then regulated as part of the control intervention, wherein the torque-transmitting connection between the electric drive motor 16, 17 and the wheel 26, 27 remains interrupted.

[0052] The invention is not limited to the exemplary embodiments described. The scope of protection is defined by the patent claims.

[0053] In principle, all methods described in the description or in the claims can be carried out by devices comprising means for carrying out the respective method steps of these methods.

REFERENCE NUMBERS

[0054] 10 motor vehicle [0055] 12 drivetrain [0056] 14 power supply [0057] 16 electric drive motor [0058] 17 second electric drive motor [0059] 18 gearbox [0060] 19 second gearbox [0061] 20 braking system [0062] 22 first axle/drive axle [0063] 24 second axle [0064] 25 third axis/additional drive axle [0065] 26 first wheel [0066] 27 second wheel [0067] 28 third wheel [0068] 29 fourth wheel [0069] 30 anti-lock braking system [0070] 32 rotational speed sensor [0071] 34 brake actuating element [0072] 36 brake pedal [0073] 38 wheel brake [0074] 40 high-voltage battery [0075] 42 differential [0076] 44 brake actuator sensor [0077] 46 first gearbox shift position/torque-transmitting shift position [0078] 48 second gearbox shift position/neutral position [0079] 50 clutch [0080] 52 first drivetrain component [0081] 54 second drivetrain component [0082] 56 pneumatic activator [0083] 58 compressed air reservoir [0084] 60 control unit [0085] 62 memory unit [0086] 64 processing unit [0087] 66 computer program code