Patent ID: 8285432

Claim:
A method for controlling a powertrain system including a transmission mechanically coupled to an engine and an electric machine to transfer power to an output member, said transmission selectively operative in one of a plurality of operating range states, said method comprising: monitoring operator inputs to an accelerator pedal; determining a preferred operating point of said powertrain based upon said operator inputs, wherein said determining a preferred operating point of said powertrain comprises utilizing a strategic optimization control scheme; determining a preferred operating range state of said transmission based upon said preferred operating point, wherein said determining a preferred operating range state of said transmission comprises selecting one of said plurality of operating range states according to inputs from vehicle sensors and a lookup table; determining lead control signals for said engine and said transmission based upon said preferred operating point and said preferred operating range state of said transmission; determining immediate control signals for said electric machine and said transmission, wherein said immediate control signals are based upon said preferred operating point, said preferred operating range state of said transmission, and a lead period calibrated to a difference in control signal reaction times of said engine and said electric machine in order to effect changes to an actual electric machine output simultaneously with changes to an actual engine output; and coordinating parallel control of said engine and said electric machine, comprising: simultaneously providing power from said engine and said electric machine to said output member, comprising: controlling operation of said engine based upon said lead control signals for said engine and said transmission; and controlling operation of said electric machine based upon said immediate control signals for said electric machine and said transmission; wherein said parallel control of said engine and said electric machine synchronizes torque transfer from said engine and said electric machine to said output member to preserve vehicle drivability.