Zf Friedrichshafen Ag

Thea Schlueter

Mario Steinborn

Martin Fajfr

Frieder Norrenberg

Werner Wolfgang

Maik Würthner

Karel Veisheipl

Otakar Šprdlík

Richard Malínský

A method for operating a motor vehicle drive train having a drive aggregate, an automated group transmission connected between the drive aggregate and a drive output, and a disconnect clutch connected between the drive aggregate and the group transmission. The group transmission has a plurality of sub-transmissions, including a main transmission, a splitter group upstream from the main transmission, and a range group downstream from the main transmission. When the disconnect clutch cannot be shifted to carry out a shifting operation in the group transmission, an emergency shifting program is activated. Shifting from a current gear to a target gear is carried out automatically, as a function of input rotation speed of the group transmission or as a function of rotation speed of the drive aggregate, while the disconnect clutch is closed and where the main transmission and/or the range group participate exclusively, but not the splitter group.

Method and control device for operating a drive train

A method for operating a drive train of a motor vehicle, where the drive train includes a drive aggregate, a group transmission connected between the drive aggregate and a drive output, and a separating cutch connected between the drive aggregate and the group transmission. If a speed is lower than a limit value, the separating clutch is opened and for transmission preselection one or all the other sub-transmission(s) is/are changed to a friction-force-locking condition. The separating clutch is then at least partially closed and the drive aggregate is brought to a defined rotation speed. When a friction-force-locking group transmission is required, it is checked whether a starting gearshift or a driver-desired shift for the group transmission is called for and the target rotation speed of the drive aggregate is checked. Depending on the results, the sub-transmission can be synchronized by a transmission brake or by the drive aggregate.

A control device for a hybrid vehicle having a drive-train with a hybrid drive unit including an internal combustion engine and an electric machine. A clutch is connected between the internal combustion engine and the electric machine. An automatic or automated transmission is connected between the hybrid drive unit and a drive output. When the hybrid vehicle has been driving and comes to a standstill with its internal combustion engine stopped, the control device automatically determines, on the one hand, a starting mode for the subsequent re-starting of the internal combustion engine when the hybrid vehicle is at rest, and the control device, on the other hand, automatically changes at least the transmission and the clutch connected between the internal combustion engine and the electric machine of the hybrid drive unit to a condition appropriate for the starting mode determined by emitting appropriate control signals.

Control device of a hybrid vehicle and method for operating same

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Friedrichshafen, Germany

Thea Schlueter