Transitioning Between Electric-Drive and Parallel-Drive in a Hybrid-Electric Vehicle Powertrain

摘要

A method for operating a vehicle powertrain includes driving first wheels using an electric machine, starting an engine, using a second electric machine driven by the engine to produce synchronous speed at a input of a transmission having a desired gear engaged, engaging a clutch that connects said input and the engine, and using the engine and the transmission to drive second wheels.