Abstract
Continuously variable transmissions (CVTs) in automotive powertrains permit an optimization of the engine operating point resulting in significant fuel economy. A wide ratio spread and a fast shifting response are prerequisites to achieving both the system efficiency and the required driveability. The full toroidal variator fulfills these requirements along with offering the highest torque capacity of all CVTs. Moreover, this variator is torque controlled, enabling the operation of an IVT (Infinitely Variable Transmission) in geared neutral. The ability of shuttling a vehicle without slipping a clutch extends the application range to off-highway vehicles. The motivation of using this transmission is therefore not only concerned with improving the fuel efficiency, but also in enhancing the maneuverability. This paper explores various control configurations that can be applied to a powertrain. Different vehicle applications and their control objectives are reviewed with the most appropriate control.
