Method and apparatus to determine a preferred output torque for operating a hybrid transmission in a fixed gear operating range state

摘要

A hybrid transmission (10) includes a torque machine (56,72) and an energy storage device (74) connected thereto. The hybrid transmission (10) is operative to transfer power between an input member (12) and an output member (64) and the torque machines (56,72) in a fixed gear operating range state. A method for controlling the hybrid transmission (10) includes determining a preferred output torque, determining a relationship between power from the energy storage device (74) and an output torque of the transmission (10), determining power constraints from the energy storage device (74), determining motor torque constraints for the torque machine (56,72), determining linear torque constraints to the output torque based upon the motor torque constraints for the torque machine (56,72), determining quadratic output torque constraints based upon the power constraints from the energy storage device (74) and the relationship between the power from the energy storage device (74) and the output torque of the transmission device (10), and determining an output torque to the output member (64) responsive to the preferred output torque and achievable based upon the linear output torque constraints and the quadratic output torque constraints.