Patent ID: 7603219

Claim:
A method for controlling clutch engagement of a friction clutch system in a vehicle powertrain, the powertrain having an engine and a power transmission, the clutch system including a clutch actuator under the control of a vehicle operator, the actuator being movable between a clutch open position and a clutch closed position in accordance with a clutch position variable to establish and disestablish a power flow path from the engine to a powertrain power output element through the transmission, the method comprising the steps of: developing a dynamic model of the driveline under conditions that cause clutch slipping; developing an initial functional relationship of the clutch position variable and clutch torque defined by algebraic equations with known parameters that determine an initial clutch engagement characteristic as the clutch position variable changes between an initial clutch slip state value and a clutch engaged state value; determining an engine torque request in response to vehicle speed requests by the vehicle operator; using the initial clutch engagement characteristic to determine the clutch position variable; determining the quality of clutch engagement using the initial clutch engagement characteristic; and determining a target clutch torque; and computing a new estimated clutch engagement characteristic following clutch wear during a clutch operating time history using estimated parameters for the dynamic model whereby optimal clutch engagement quality is achieved.