Shift control device for hybrid vehicle

摘要

A shift control device includes a controller and a differential mechanism including four rotating elements. Each of the elements is connected to an engine, two motor/generators and an output. The controller is programmed to calculate a target driving power; make a judgment as to whether the target driving power is less than or equal to a driving power wherein the engine is driven under optimum fuel efficiency; when the judgment shows that the target driving power is larger than the driving power, calculate an engine's speed and torque wherein the target driving power is realized such that the engine is driven for maximum load; and control the engine under the engine's speed and torque.