Zf Friedrichshafen Ag

Rosenberger Hochfrequeńztechnik Gmbh & Co. Kg

Günther Maier

Harald Stehle

Peter Schiele

Christian Villing

A gearbox () includes an input shaft () and a first and a second proportionally controllable shift element (A to F). The shift elements (A to F) are configured to control, by way of an open-loop system, engagement or disengagement of a gear ratio in the gearbox (). A method () for the open-loop control of the gearbox () includes: determining a specified differential speed profile that is a profile of a difference between a rotational speed of the input shaft () and a synchronous speed of a gear ratio to be engaged; and determining a torque demand of a drive source connected to the input shaft () or determining a control profile for the one of the first and second shift elements (A to F) to be engaged in the gear ratio on the basis of the specified differential speed profile.

Transmission control system

A method () for the open-loop control of a gearbox () that includes a first and a second proportionally controllable shift element (A-F) is provided. The method includes disengaging () the first shift element (A-F) according to a first control profile and engaging () the second shift element (A-F) of the gearbox () according to a second control profile. The first control profile includes a first variable portion which is determined as a function of a temperature of the gearbox ().

Transmission control

A gearbox () includes an input shaft (), which is connected to a drive source, and a first and a second proportionally controllable shift element (A-F). A method () for open-loop control of the gearbox () includes: determining () an absolute torque demand () on the drive source on the basis of a profile controlled by way of an open-loop system () and a profile controlled by way of a closed-loop system (); determining () whether the absolute torque demand () threatens to exceed a predetermined threshold value (); and, in response, reducing () the portion controlled by way of the closed-loop system ().

A method () for the open-loop control of a gearbox () that comprises an input shaft () and a first and a second proportionally controllable shift element (A-F) is provided. The method includes disengaging () the first shift element (A-F) according to a first control profile and engaging () the second shift element (A-F) according to a second control profile. The method also includes cyclically performing the following during the disengagement and the engagement: determining () a difference between the rotational speed of the input shaft () and a rotational speed which the input shaft () assumes when the second shift element (A-F) has been completely engaged; determining () a gradient of the difference; and adapting () the first control profile on the basis of the gradient.

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Meckenbeuren, Germany

Günther Maier