Patent ID: 8347992

Claim:
A method for controlling operation of an internal combustion engine mechanically coupled via a planetary gear set to an accessory drive system and a torque machine, the method comprising: monitoring operator inputs; monitoring engine operation parameters; selecting a preferred operational state among a plurality of operational states in response to the operator inputs and the engine operation parameters for operating the engine, the torque machine and an accessory brake of the accessory drive system, the accessory brake comprising a potential energy conversion device configured to selectively accept torque from at least one of the engine and the torque machine transferred through the planetary gear set to control speed of the accessory drive system, and selectively transfer power to an energy storage device; and controlling the accessory drive system in the selected one of a plurality of operational states, the plurality of operational states comprising an engine autostop accessory control state including operating the torque machine in a torque generating state and transferring the generated torque to the accessory drive, an engine autostart state including operating the torque machine in the torque generating state and transferring the generated torque to the engine, an engine torque assist state including operating the torque machine in the torque generating state and transferring the generated torque to the engine, and an energy power generation state including operating the torque machine in a power generating state to react engine torque.