Patent ID: 8775038

Claim:
A method for operating a powertrain system including a multi-mode transmission configured to transfer torque among an engine, torque machines, and a driveline, the method comprising: concurrently executing first and second searches in parallel, comprising: the first search to determine a first engine operating point within an all-cylinder operating state space and a corresponding operating cost for operating the powertrain system in response to an output torque request, the all-cylinder operating state space defined by an all-cylinder input speed range and an all-cylinder input torque range, wherein the all-cylinder input speed range traverses from an engine idle speed to a maximum achievable engine speed; and the second search to determine a second engine operating point within a cylinder deactivation state space and a corresponding operating cost for operating the powertrain system in response to the output torque request, the cylinder deactivation state space defined by a cylinder deactivation input speed range and a cylinder deactivation input torque range, wherein the cylinder deactivation input speed range traverses from a respective minimum engine speed that is greater than the engine idle speed to a threshold cylinder deactivation engine speed that is less than the maximum achievable engine speed; selecting one of the first and second engine operating points as a preferred engine operating point based upon said operating costs; and controlling the engine at the preferred engine operating point in the corresponding one of the all-cylinder state and the cylinder deactivation state.