Patent ID: 7637842

Claim:
Method to regenerate an electrical energy storage device using kinetic energy of a vehicle having an internal combustion engine operably coupled to an electrical machine and to a torque converter operably coupled to a transmission device wherein the vehicle kinetic energy is transmittable to the electrical machine electrically connected to the electrical energy storage device, comprising: monitoring an operator demand for power, an operating speed of the vehicle, and, an engine load; determining a first calibrated engine load based upon the operator demand for power and the vehicle operating speed; actuating a locking clutch for the torque converter when the monitored engine load is less than the first calibrated engine load; determining a second calibrated engine load based upon the operator demand for power and the vehicle operating speed; deactivating the actuated locking clutch for the torque converter when the monitored engine load is greater than the second calibrated engine load; and deactivating the actuated locking clutch for the torque converter at a vehicle speed less than a calibrated transmission shift vehicle speed when the operator demand for power is below a predetermined power threshold and the engine load is below the second calibrated engine load.