Fca US LLC

Nathan J Saliga

Jeffrey E Ross

Dean M Baker

Brian P Young

Jacob Liberatore

Rahul Rangarajan

An automatic transmission system of a vehicle and a corresponding adaptation method utilize an automatic transmission comprising a hydraulic friction clutch and a controller configured to continuously perform a feedforward adaptation procedure that models wear of the clutch, the feedforward adaptation procedure comprising obtaining a set of operating parameters each indicative of wear of the clutch, model the wear of the clutch based on the set of operating parameters using a clutch wear model, and determine a clutch offset for controlling application of the clutch based on the modeled clutch wear, and control application of the clutch based on the determined clutch offset.

Energy based component wear model for clutch control offsets in an automatic transmission

Systems and methods for performing a garage shift of an automatic transmission of a vehicle comprise maintaining a clutch at a first holding pressure while the transmission is in a neutral gear and a brake input signal satisfies a threshold and maintaining the clutch at a lower second holding pressure while the transmission is in the neutral gear and the brake input signal satisfies the threshold to mitigate or eliminate causing drive torque to be transferred from a torque generating system of the vehicle to its driveline via the transmission. When the brake input signal satisfies the threshold and a shift from the neutral gear to a non-neutral gear is requested, the garage shift is then executed.

Brake-dependent clutch holding pressure while transmission is in neutral

A system for controlling transmission shifting includes a controller that receives a shift request signal and determines if a clutch has been unapplied for more than a predetermined time. With a yes determination, a maximum fill time value for hydraulic fluid to be applied to a clutch control circuit is determined, the maximum fill time value being a function of time the clutch has been unapplied and temperature. A signal indicative of an amount of engine RPM flare after the transmission executes the requested shift is received and a modified maximum fill time value is determined as a function of this flare. The modified maximum fill time value is stored as a replacement for the maximum fill time value for use with a subsequent transmission shifts using this clutch, and reduces an amount of air in the control circuit and an amount of flare with subsequent transmission shifts.

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Clarkston, MI, United States of America

Nathan J Saliga