Method for operating a powertrain system to transition between engine states

摘要

A powertrain system includes a multi-cylinder engine (14) coupled to a hybrid transmission (10). The engine (14) is selectively operative in one of a plurality of main engine states to transfer engine torque to the hybrid transmission (10). A method for operating a powertrain system (10) includes monitoring an operator torque request, determining a preferred main engine state and a preferred engine torque associated with the preferred engine state, determining an engine state transition path from a present main engine state to the preferred main engine state including an engine transition state, and executing the engine state transition path between the present main engine state and the preferred main engine state and adjusting engine torque to the preferred engine torque.