Patent ID: 8062174
Filing Date: 2011-11-22
Classification: B60K,F16D,Y02T,Y10T

Abstract:
1. Method for controlling a powertrain comprising an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member via selective application of a plurality of hydraulically actuated torque transfer clutches, said method comprising: filling one of said hydraulic clutches to a reference fill volume expected to create a touching state in said clutch, wherein said filling is accomplished through control of a pressure control solenoid; monitoring an actual fill time of said hydraulic clutch; monitoring a flow utilized in said filling; determining a measured fill volume based upon said actual fill time and said flow; calculating a fill volume error based upon said measured fill volume and said reference fill volume; adjusting said reference fill volume based upon said fill volume error; and utilizing said adjusted reference fill volume in subsequent operation of said clutch.