Zf Friedrichshafen Ag

Patrick Peter

Tobias Zollner

Anton Fritzer

Bernd Allgaier

Thomas Lemp

Holger Bacher

Clemens Kuhn

Alexander Pfau

Tobias Zöllner

Lorenz Fehrenbach

Stefan Gierer

A method of operating a drive-train of a hybrid vehicle which comprises at least a hybrid drive with an internal combustion engine and an electric machine, an automatic or automated change-speed transmission connected between the hybrid drive and a drive output, and a clutch connected between the internal combustion engine and the electric machine. When starting the internal combustion engine from a purely electric driving mode, the clutch is initially disengaged. To start the internal combustion engine, the clutch is at least partially engaged and the internal combustion engine is drag-started by the electric machine, and, in parallel with starting the internal combustion engine, a downshift in the transmission is initiated once a rotational speed of the internal combustion engine reaches or exceeds an applicable threshold value.

Method and control unit for operating a drive train of a hybrid vehicle

A method of operating a vehicle hybrid drive-train in which, depending on the operating situation, the engine and electric machine either operate individually or together. The engine and the electric machine can be coupled or separated by a clutch. The engine can be started by the electric machine or a separate starting device. To co-ordinate transmission shifts and required engine starts, during a transmission shifting process, if the engine needs to be started, then based on whether the shift is an upshift, a downshift, a traction shift or an overdrive shift and also depending on the type of engine start required, it is first determined whether the shift should be completed, at least partially completed or discontinued before carrying out the start and, based on this determination, measures for continuing, at least partially continuing or discontinuing the shift process are initiated.

Method for operating a hybrid drive train of a vehicle

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Kressbronn, Germany

Patrick Peter