Optimal selection of blended braking capacity for a hybrid electric vehicle

摘要

A hybrid powertrain system includes a transmission (10) operative to transfer power between an input member (12) and a torque machine (56,72) and an output member (64) coupled to a driveline (90) coupled to a wheel (93) including an actuable friction brake. The torque machine (56,72) is operative to react torque transferred from the wheel (93) through the driveline (90) to the output member (64) of the transmission (10). The torque machine (56,72) is connected to an energy storage device (74). A method for operating a hybrid powertrain system includes monitoring an operator torque request input to an accelerator pedal, determining a minimum available power output of the energy storage device (74), determining a preferred output torque reacted through the output member (64) to the driveline (90) based upon the minimum available power output of the energy storage device (74), determining a regenerative braking torque capacity comprising a torque range between the preferred output torque reacted through the output member (64) to the driveline (90) and the operator torque request input to the accelerator pedal, and controlling operation of the hybrid powertrain based upon the regenerative braking torque capacity.