Patent ID: 8121766

Claim:
A method for operating an internal combustion engine mechanically coupled to an electro-mechanical transmission to transmit power to a driveline in response to an operator torque request, the method comprising: defining a two-dimensional search region based upon an input power transmittable between the internal combustion engine and the electro-mechanical transmission; iteratively dividing the two-dimensional search region into a plurality of subregions based upon one of the input power and an input speed transmittable from the internal combustion engine to the electro-mechanical transmission, determining an engine operating point within each of the subregions, calculating an operating cost to operate the internal combustion engine and the electro-mechanical transmission to meet the operator torque request for each engine operating point within each of the subregions, identifying the subregion having a minimum operating cost to meet the operator torque request; and determining a preferred engine operating point based upon the engine operating point within the identified subregion having the minimum operating cost to meet the operator torque request.