Zf Friedrichshafen Ag

Ruben Cueppers

Max Trautwein

Andreas Schmidt

Markus Maurer

Georg Mihatsch

Martina Jehle

Christoph Hess

Philipp Kölbl

Thorsten Schaetzle

A method for operating an automatic transmission includes shifting the automatic transmission to a substitute gear if, after adjusting a first one of at least one positive-locking shift element towards a closed configuration, the first one of the at least one positive-locking shift element occupies an intermediate position. The first one of the at least one positive-locking shift element does not participate in the transmission of power in the substitute gear. A related transmission control device for an automatic transmission is also provided.

Method and control device for operating an automatic transmission

A method for operating an automatic transmission includes determining at least one of an elapsed time from adjusting a first one of at least one positive-locking shift element towards a closed configuration or a differential speed rotation of the first one of the at least one positive-locking shift element and shifting the automatic transmission to a substitute gear if the elapsed time from adjusting the first one of the at least one positive-locking shift element towards the closed configuration reaches or exceeds a time limit and/or the differential speed rotation of the first one of the at least one positive-locking shift element reaches or exceeds a rotational speed limit. A related transmission control device for an automatic transmission is also provided.

A method for operating an automatic transmission is provided. The method includes initiating a synchronization of a positive shifting element of the automatic transmission. The method also includes closing a first non-positive shifting element of the automatic transmission and positioning a second non-positive shifting element of the automatic transmission at an engaged configuration of the second non-positive shifting element during the synchronization of the first positive shifting element in order to synchronize the first positive shifting element.

Method for operating an automatic transmission

A method for operating an automatic transmission is provided. The method includes initiating a synchronization of a positive shifting element of the automatic transmission while the automatic transmission is operating at less than a threshold output speed. The method also includes closing a first non-positive shifting element of the automatic transmission and positioning a second non-positive shifting element of the automatic transmission at an engaged configuration of the second non-positive shifting element during the synchronization of the first positive shifting element in order to synchronize the first positive shifting element.

A method for operating an automatic transmission is provided. The method includes disengaging a shifting element of the automatic transmission and measuring an input speed of the automatic transmission while the shifting element is disengaging. A command pressure of the shifting element is adjusted to a target command pressure based at least in part on the input speed of the automatic transmission while the shifting element is disengaging.

A method for operating an automatic transmission is provided. The method includes synchronizing a positive shifting element of the automatic transmission, braking the automatic transmission with a first non-positive shifting element of the automatic transmission, establishing a position of the positive shifting element, and increasing a pressure of fluid supplied to a second non-positive shifting element of the automatic transmission if the position of the positive shifting element is an intermediate position.

The present subject matter provides a method for operating an automatic transmission in a limp mode. The method includes actuating a first non-positive shifting element to an engaged configuration and actuating a second non-positive shifting element to the engaged configuration. A positive shifting element is substantially synchronized after actuating the second non-positive shifting element. The method also includes commanding the positive shifting element to actuate from a disengaged configuration to the engaged configuration.

Method for operating an automatic transmission in a limp mode

A method for operating an automatic transmission is provided. The method includes commanding a positive shifting element to actuate to a disengaged configuration or an engaged configuration and opening at least one non-positive shifting element if the positive shifting element does not properly actuate. Opening the at least one non-positive shifting element may terminate power flow from the automatic transmission in order to protect the automatic transmission.

A method for operating an automatic transmission is provided. The method includes synchronizing a first positive shifting element of the at least one positive shifting element with a first process, a second process or a third process depending upon an input speed and/or an output speed of the automatic transmission. The first process, the second process and the third process can provide smooth and/or satisfactory shifting of the first positive shifting element at various input speeds and output speeds of the automatic transmission.

Growing community of inventors

Wangen, Germany

Ruben Cueppers