Methods and systems for engine cranking

摘要

Systems and methods for improving operation of a hybrid vehicle are presented. In one example, an engine may be started in one of two ways depending on operating conditions. In particular, the engine may be started via a lower power output electric machine or a higher power output electric machine.

主权项

1. A method of starting an engine, comprising:
starting the engine via a first electrical machine when a desired torque demand is less than a first threshold amount; starting the engine via a second electrical machine when the desired torque demand is greater than the first threshold amount; supplying torque sufficient to rotate vehicle wheels solely via the first electrical machine during selected operating conditions; and decoupling the second electrical machine from the engine when engine speed reaches a threshold speed.