A method and apparatus for selecting an operating condition of an engine for a multi-mode powertrain system

摘要

A powertrain system includes a multi-mode transmission configured to transfer torque among an engine, torque machines, and a driveline. One method of controlling the operation of the powertrain system includes determining a preload engine speed based on an engine speed. A search is performed which includes determining respective candidate power costs for operating the powertrain system in response to an output torque request and determining respective candidate drivability costs for the candidate engine speed based on the preload engine speed. The search also selects one of the candidate engine speeds and one of the candidate engine torques that meet a minimum of a combination of the respective candidate drivability costs and the respective candidate performance costs as a preferred engine speed. Speed and a preferred engine torque. Operation of the powertrain system is controlled based on the preferred engine speed and torque.