Method for Controlling an Actuator of a Starting Clutch in the Automatic Transmission of a Vehicle

Abstract

A method for the control of an actuator of a starting clutch of a motor vehicle. The actuator is so regulated by a control apparatus that the starting clutch is closed upon the presence of a desire for starting, as well as closed by an adjusted, transmission ratio, and the clutch is opened upon the termination of the starting procedure. For the freeing of a vehicle from a roadway obstruction by way of a rocking process of the vehicle, it is proposed that the starting clutch, during a starting procedure and by way of control of the actuation actuator, is operated in a fully automatic manner in such a way, that the torque (M_K) periodically varies.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is a diagram in which the clutch torque M_K is plotted against the regulating distance S of a gas pedal, and

FIG. 2 is a diagram in which the pull moment M_Z of the vehicle, i.e., the vehicle's wheels, is plotted against the time t.

DETAILED DESCRIPTION OF THE INVENTION

Accordingly, FIG. 1 demonstrates that the starting clutch is operated over a wide portions of the gas pedal angle S during normal clutch control functions for vehicle starting or maneuvering in terminal yards.

As soon as a vehicle driver, using a manual operation of the invented control method, has engaged the gas pedal into a kick-down position with a deflection angle of 90% of the maximum regulated path then, by a corresponding activation of the clutch actuator, the starting clutch is forced into an alternative manner of opening and closing. As is indicated by the two vertical directive arrows in FIG. 1, this rocking process is maintained just as long as the gas pedal remains engaged in the kick-down position and the obstruction in the roadway is not overcome.

FIG. 2 presents the concept that the control apparatus can regulate the clutch actuator, for example, by an activation frequency F1, because of input vehicle and roadway specifics, as mentioned in the introductory comments, as well as by the surrounding circumstances as determined by appropriate sensors. The amplitude of this rocking process frequency can be the transmitted moment M_K from the clutch finally to the drive wheels of the vehicle or yet the pulling moment M_Z of the vehicle, which is necessary to escape an obstruction in the roadway.

Insofar as that during the rocking process, the surrounding circumstances, change themselves, which must be subject to consideration. This can also lead to an adjustment of the tuning of the frequency F1 at which frequency the starting clutch is obligated to function.

In this method of operation, it is possible that the vehicle driver can control the moment at which he would start and terminate the rocking process on his own.

Claims

1-12. (canceled)

13. A method for controlling an actuator of a starting clutch of an automatic transmission of a motor vehicle in which the actuator is so regulated by a control apparatus that a starting clutch engages, at an indication of a desire to start as well as engages by an adjustment activated by a given transmission ratio, and disengages at termination of a starting operation, the starting clutch is operated during a starting procedure by control of the actuator in such a way that a torque (M_K) transmitted therefrom periodically varies.

14. The method according to claim 13, further comprising the step conforming a periodicity of the actuator with characteristics of the vehicle and with those of an actual roadway obstruction so that the vehicle is able to overcome the roadway obstruction in a fully automatic manner.

15. The method according to claim 13, further comprising the step of taking into consideration, for a determination of a periodic actuation of the actuator, at least one of the following: a vehicle speed,a weight of the vehicle,a radius of vehicle wheels,ground contact of the vehicle wheels, andforces influenced by a roadway obstruction and arising from a rocking process of the vehicle, which forces act against progress of the vehicle in a current driving direction.

16. The method according to claim 13, further comprising the step of maintaining a constant transmission ratio during periodic operation of the actuator.

17. The method according to claim 13, further comprising the step of carrying out periodic operation only if the control apparatus previous confirms that (1) a driving speed is very small or is zero and (2) a slip of at least one of the vehicle driving wheels oversteps a predetermined threshold value.

18. The method according to claim 13, further comprising the step of carrying out a periodic operation only if (1) a driving speed is very small or is zero and (2) a prior determination is registered from the control apparatus that forces working against a drive moment (M_Z) of vehicle wheels exceed a predetermined threshold value.

19. The method according to claim 13, further comprising the step of carrying out a periodic operation only if the control apparatus has a previous confirmation that an actuation element for activation of the periodic operation is operated by a vehicle occupant.

20. The method according to claim 13, further comprising the step of selecting an activation frequency, for a periodic operation of the actuator, by adjustment of an actuation element.

21. The method according to claim 13, further comprising the step of calculating an actuation frequency by analysis of at least one of: a vehicle speed,a controlled direction,a controlled distance, anda speed of control of an activation element.

22. The method according to claim 13, further comprising the step of using a gas pedal of the vehicle as an actuation element.

23. The method according to claim 13, further comprising the step of discontinuing periodic operation only if a gas pedal for power control of a motor of the motor vehicle is engaged at a predetermined set angle.

24. The method according to claim 13, further comprising the step of employing the method for control of automated shifting of the automatic transmission of the motor vehicle

25. A method for controlling an actuator of a starting clutch of an automatic transmission of a motor vehicle for overcoming a roadway obstruction, the method comprising the steps of: regulating the actuator with a control apparatus so that the starting clutch engages, at an indication of a desire to start and engages and at a given transmission ratio, and disengages, at termination of a starting procedure; andoperating the starting clutch during the starting procedure by control of the actuator in such a way that a torque (M_K) transmitted therefrom varies periodically.