Gm Global Technolgoy Operations, Inc.

Morgan Postic

David W Wright

Nathaniel E Wilke

Marc Rambert

Emmanuel Hoff

Eric Dalais

Philippe Ramet

At least a method is provided learning a characteristic filling volume of a hydraulic clutch. The method includes, but is not limited to applying a pressure pulse to the hydraulic clutch when the clutch is in a disengaged state and determining an inflection event at an input or at an output of a torque path in which the hydraulic clutch is situated. A characteristic filling volume of the hydraulic clutch is derived from the determined inflection event. Furthermore, a method is provided for learning a characteristic return spring pressure of the hydraulic clutch, for engaging the hydraulic clutch and corresponding devices for carrying out these methods.

Hydraulic clutch and method for determining an adaptive clutch fill volume of the hydraulic clutch

A method is provided for improving shift quality in an automatic transmission. In many automatic transmissions, the shift quality during lift foot upshifts is unsatisfying. Generally, two types of complaints concerning shift quality are known: harsh feel right after the shift order and bump at the synchronization of the shift. In order to provide an automatic transmission which overcomes these two problems, a first and a second positive torque requests are initiated on upshift coasts. This measure improves the global shift feel by controlling the engine toque level at shift order and at synchronization: the engine torque level at the beginning of the gear shift is smoothly decreased to reduce the initial bump and is controlled at the synchronization to reduce the amplitude of underlap when the clutch capacity is rising.

Method for improving shift quality in an automatic transmission

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Osthouse, France

Morgan Postic