Gm Global Technolgoy Operations, Inc.

Amanda P Igel

Matthew D Whitton

Dara Monajemi

Nathaniel E Wilke

David Chris Webert

Timothy R Stockdale

Kristopher J Kokko

A system for a vehicle includes a desired pressure module, a valve actuation module, a filter module, and a capacity detection module. The desired pressure module selectively generates an increase in a desired pressure of hydraulic fluid for a clutch of an automatic transmission. The valve actuation module actuates a solenoid valve based on the desired pressure. The solenoid valve supplies hydraulic fluid to a regulator valve, and the regulator valve supplies hydraulic fluid to the clutch. The filter module filters an acceleration of a shaft of the automatic transmission to generate a filtered acceleration. The capacity detection module indicates whether the clutch reached torque carrying capacity based on the filtered acceleration.

Clutch capacity detection systems and methods

A vehicle transmission includes a plurality of oncoming clutches that are hydraulically-actuated. A controller is operatively connected to the plurality of oncoming clutches. An algorithm stored on and executable by the controller causes the controller to determine if at least one predefined coast condition is met and identify the plurality of oncoming clutches configured to be engageable during a downshift event from an initial gear ratio to respective other gear ratios. The initial gear ratio is greater than each of the respective other gear ratios. The algorithm causes the controller to generate a first pressure command to at least partially pressurize a first one of the oncoming clutches to a first staging pressure (P) if the at least one predefined coast condition is met prior to the downshift event. The first staging pressure (PS) is defined as a first return spring pressure (P) minus a first variable correction factor (CF).

Partial prefill of clutch for coast downshift conditions in a vehicle

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Howell, MI, United States of America

Amanda P Igel