Method and apparatus for controlling a multi-mode powertrain system

A method for operating a powertrain system including a multi-mode transmission configured to transfer torque among an engine, torque machines, and a driveline, comprising:

• in response to an output torque request:
• executing a selection scheme to evaluate operating the powertrain system in a plurality of candidate powertrain states including in a pseudo-electric vehicle (pseudo-EV) range responsive to the output torque request, wherein operating the powertrain system in the pseudo-EV range comprises;
• operating the engine in a fuel cutoff state with the engine spinning and controlling the torque machines to transfer torque to the driveline responsive to the output torque request;
• and
• generating a plurality of engine torques associated with engine pumping, bearing friction, and valve spring resistance for each of the engine speeds over the engine speed range between 0 RPM and the engine idle speed;
• determining a respective minimum cost for operating the powertrain system in each of the candidate powertrain states including the pseudo-EV range;
• selecting a preferred powertrain state comprising one of the candidate powertrain states including the pseudo-EV range associated with a minimum of the respective minimum costs;
• and
• controlling the powertrain system in the preferred powertrain state responsive to the output torque request and operating the powertrain system in the preferred powertrain state.