System constraints method of determining minimum and maximum torque limits for an electro-mechanical powertain system

摘要

A powertrain including an electro-mechanical transmission (10) mechanically-operatively coupled to an internal combustion engine (14) and first (56) and second (72) electric machines to transmit power to an output member (64) is disclosed. A method for controlling the electro-mechanical transmission (10) includes determining minimum and maximum motor torque constraints for the first (56) and second (74) electric machines, and determining available battery power in terms of battery power constraints. One of a first, a second and a third case is determined based upon the motor torque constraints and the battery power constraints. A preferred output torque is determined for transmitting to the output member (64) of the electro-mechanical transmission (10).