Abstract
If the power needed for vehicle propulsion is determined, the most fuelefficient operating point during steady-state driving operation can be determined with complete certainty and in using a continuously variable transmission (CVT), the optimal operating point can be obtained over a wide operating range. During the on-road operation, however, power requirements continuously fluctuate, meaning that the power control system must continuously track and accommodate the changes. Further the power settings matched to the road environment and to the driver´s acceleration demands are needed. In setting of the target operating point for the optimal fuel efficiency, the CVT´s transmission efficiency is considered in addition to the engine´s fuel consumption rate. And since the target operating point varies greatly within short periods of time, dynamic torque and gear ratio trajectory generation that take torque-generation response and shift response into account is also performed. The concept of the reserve power was adopted, and an algorithm was created for changing the operating point from the point of optimal fuel efficiency in accordance with changes in the road environment and to accommodate any preference for sporty driving on the part of the user. By means of the created algorithm, it became possible to consolidate fuelefficiency enhancement with acceleration enhancement matched to driver behaviour.
KEYWORDS - CVT, Gear Shift Strategy, Dynamic Scheduling, Fuel Efficiency, Driving Style Classification