METHOD FOR OPERATING A VEHICLE DRIVE TRAIN

摘要

A method for operating a vehicle drive train (5) with a drive machine (2) and a transmission device (3) during a gear shift in the transmission device (3), wherein at least one positive-locking shifting element is deactivated and at least one friction-locking shifting element is activated. At the time of the shift request, a time monitoring for shifting is initiated as well as a monitoring for transmission input speed or an equivalent rotational speed. If the monitored speed deviates from a synchronous speed equivalent to the gear to be engaged in the transmission device, an opening of the positive-locking shifting element is recognized. If a closed operational state of the positive-locking shifting element to be deactivated is detected after the expiration of a predefined duration of time starting at the time of the shift request, an actual driving torque of the drive machine (2) is set to a torque value level during engine engagement, said level corresponding to a difference between the actual transmission input torque or a torque value equivalent thereof and a torque value which may be introduced via the friction-locking shifting element operating with slip to be activated plus a torque offset value.