Zf Friedrichshafen Ag

Christoph Köhler

Frank Deprez

Thilo Schmidt

Anton Fritzer

Andreas Schmidt

Mario Hasel

Jonas Knör

Valentine Vincent

Jakob Mayer

Michael Miller

Pablo Ole Schmidt

Christian Hunger

Fabian Schöniger

A vehicle transmission includes a hydraulic circuit and a control unit. The control unit is configured to: obtain () a target pressure specification; convert () the target pressure specification into a target volume flow rate; determine () a valve volume flow rate as a function of the target volume flow rate and as a function of parameters that represent system properties of the hydraulic circuit; determine () a pressure drop at a valve due to flow forces as a function of the valve volume flow rate; determine () a compensated valve output pressure as a function of the valve volume flow rate and the pressure drop; determine () the electric control current as a function of the compensated valve output pressure; and activate a valve with the electric control current.

Method for the open-loop control of an electrically controllable valve in a vehicle transmission

A method for operating a motor vehicle includes, when a target differential speed is set for a separating clutch (), determining a power transmission factor depending on the target differential speed and an internal combustion engine-driven torque to be transmitted by the separating clutch (). The method also includes determining an actuating pressure for the separating clutch () depending on the power transmission factor, controlling the separating clutch () with the actuating pressure, ascertaining an actual differential speed forming at the separating clutch () depending on the actuating pressure, determining a corrected power transmission factor with a controller () depending on a deviation between the target differential speed and the actual differential speed, determining a corrected actuating pressure for the separating clutch () depending on the corrected power transmission factor and the internal combustion engine-driven torque to be transmitted, and controlling the separating clutch () with the corrected actuating pressure.

Control unit for a motor vehicle, and method to control the motor vehicle

A method for controlling torque transfer of a force-fitting shift element includes controlling a closing pressure at least temporarily upon presence of a closing request for the force-fitting shift element and when a prevailing system pressure of the hydraulic circuit is above a threshold value for the system pressure. The closing pressure is controlled in a manner that is different than upon the presence of the closing request for the force-fitting shift element and when the prevailing system pressure is below the threshold value for the system pressure.

Method for controlling the transfer of torque of a force-fitting shift element

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Bodolz, Germany

Christoph Köhler