Patent Document ID: 20090076672
Application ID: 11858105
Patent Flag: 0

Claim One:
1. A method to operate a powertrain, the powertrain comprising an internal combustion engine and an electric machine mechanically-operatively coupled to an electro-mechanical transmission to transmit mechanical power to a driveline and the electric machine electrically-operatively coupled to an energy storage system for electric power flow therebetween, the method comprising: determining occurrence of a pre-defined trip; monitoring an operator torque request, an operator braking request, and a state of charge of the energy storage system; determining a projected gain in the state of charge of the energy storage system for a braking event occurring during the pre-defined trip; determining a torque output from the electric machine based upon the projected gain in the state of charge of the energy storage system for the braking event; and controlling torque outputs from the electric machine and the engine based upon the torque output from the electric machine and the operator torque request.