Engine start systems and technique for hybrid electric vehicles

摘要

An engine starting system and technique for transitioning from an electric drive mode to a hybrid drive made in a hybrid electric vehicle is disclosed. In an electric drive mode the torque demand of the hybrid electric vehicle is met by an electromechanical device. The starting technique includes slipping a clutch between the engine and electromechanical device with the vehicle in the electric drive mode to rotate the engine, disengaging the clutch so that the engine is fueled to obtain a speed that approximates a speed of the electromechanical device, and engaging the clutch to couple the engine and the electromechanical device to the drive shaft to meet driver torque demand.