Patent ID: 7774109

Claim:
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 operation of which is controlled by a control module, the method comprising: utilizing the control module for determining occurrence of a pre-defined trip; utilizing the control module for monitoring an operator torque request, an operator braking request, and a state of charge of the energy storage system; utilizing the control module for determining a projected gain in the state of charge of the energy storage system as a result of regenerative braking for a braking event occurring during the pre-defined trip; utilizing the control module for determining a requested torque output from the electric machine based upon the projected gain in the state of charge of the energy storage system as a result of regenerative braking for the braking event; and utilizing the control module for controlling torque outputs from the electric machine and the engine based upon the requested torque output from the electric machine and the operator torque request.