METHOD FOR PREVENTING UNCONTROLLED ROLLBACK

• US 20090127012A1
• Filed: 10/30/2008
• Published: 05/21/2009
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Getrag Ford Transmissions GmbH
• Original Assignee: Getrag Ford Transmissions GmbH
• Inventors: Leibbrandt, Martin, Schmitz, Harald
• Granted Patent: US 8,123,659 B2
• Time in Patent Office: Days
• US Class Current: 180/170
• CPC Class Codes: B60W 30/18118 Hill holding
• CPC Class Codes: F16D 2500/3108 Vehicle speed
• CPC Class Codes: F16D 2500/3144 Accelerator pedal position
• CPC Class Codes: F16D 2500/31466 Gear lever
• CPC Class Codes: F16D 2500/50841 Hill hold
• CPC Class Codes: F16D 2500/7044 Output shaft torque
• CPC Class Codes: F16D 2500/7061 Feed-back
• CPC Class Codes: F16D 48/06 Control by electric or electronic means, e.g. of fluid pressure

Abstract

A method and a motor vehicle applying that method for preventing an uncontrolled rollback of a motor vehicle is suggested, said method comprising means for influencing the torque transmission by a drive train. In case a rollback action is detected, namely a movement in opposite direction as the predetermined direction of movement, the transmission of torque is influenced such that a torque is transmitted via the drive train acting against the rollback direction and the torque does not exceed a defined maximum value. The control allows a controlled rollback by making the intervention by the system to be perceived little disturbing, but at the same time in particular in case of strong incline of the road does not render the driver non-informed about the actual incline.

Claims

1. Method for preventing an uncontrolled rollback of a motor vehicle, said motor vehicle having means for influencing the torque transmission by a drive train;

said method comprising the method steps;

influencing the torque such that in case a rollback is detected, said rollback being a movement in opposite direction as the predetermined direction of movement of the motor vehicle having disengaged brakes, a torque is transmitted via the drive train acting against the rollback direction; and

limiting the torque to a defined maximum torque.

2. Method for preventing an uncontrolled rollback according to claim 1, comprising the further method step of controlling at least the engagement of one clutch for influencing the torque transmission.

3. Method for preventing an uncontrolled rollback according to claim 1, further comprising the method step of increasing the torque up to a maximum value with increasing rollback speed at least over a controlled partial range.

4. Method for preventing an uncontrolled rollback according to claim 1, further comprising the method step of transmitting a constant reduced torque in comparison to the maximum value via the drive train over a partial range that comprises the rollback speed zero.

5. Method for preventing an uncontrolled rollback according to claim 4, further comprising the method step of regulating down the reduced torque such that a predetermined creeping speed in the predetermined direction of movement is not exceeded as long as no starting mode has been chosen.

6. Method for preventing an uncontrolled rollback according to claim 4, further comprising the method step of applying a further reduced torque in the breaking mode.

7. Method for preventing an uncontrolled rollback according to claim 4, further comprising the method step of controlling a further reduced torque in the breaking mode by the braking pressure.

8. Method for preventing an uncontrolled rollback according to claim 1, further comprising the method step of varying the rotational speed of the motor in a predetermined range for influencing the torque.

9. Method for preventing an uncontrolled rollback according to claim 1, further comprising the method step of increasing the rotational speed of the motor if a releasing of the brake is detected.

10. Method for preventing an uncontrolled rollback according to claim 1, further comprising the method step of increasing the rotational speed of the motor if a rollback action is detected.

11. Method for preventing an uncontrolled rollback according to claim 1, further comprising the method step of increasing the rotational speed of the motor if a releasing of the brake and a rollback action are detected.

12. Motor vehicle comprising a transmission;

means for influencing the torque transmission of a drive train;

means for detecting the rollback condition; and

a control configured to conduct the method according to claim 1.

13. A motor vehicle comprising:

a transmission;

means for influencing a torque transmitted by a drive train;

means for detecting the rollback condition; and

a control configured such that the torque is influenced so that in case a rollback is detected, said rollback being a movement in opposite direction as the predetermined direction of movement of the motor vehicle having disengaged brakes, an additional torque is transmitted via the drive train acting against the rollback direction and the torque is limited to a defined maximum torque.

14. The motor vehicle according to claim 13, wherein at least one controllable clutch is provided in the drive train between a motor and at least one driven wheel as a means for influencing a torque transmitted by a drive train.

15. Motor vehicle according to claim 13, wherein at least one device for increasing the idle rotational speed is provided.

16. Motor vehicle according to claim 13, wherein the means for detecting the rollback action comprise a rotational direction sensor provided at an input shaft of the transmission.

17. Motor vehicle according to claim 13, wherein the transmission is an automated shift transmission, an automatic transmission or a dual clutch transmission.