The characterisation of driveability of CVT powertrains during acceleration transients

This paper describes work undertaken in a series of projects aimed at characterising the driveability of vehicles equipped with continuously variable transmissions (CVT) during acceleration transients. The aim of the work is to define driver requirements more clearly in order to design a control strategy that provides the framework to meet these requirements. Driveability assessment of seven vehicles with either a CVT or an automatic transmission (AT) was undertaken and the results are summarised in this paper. These were used as a guideline for the development of a transient controller strategy for a prototype powertrain controller. This was undertaken initially in a simulation environment prior to implementation on a prototype vehicle. The algorithms developed showed the necessary control authority to shape the vehicle responses in accordance with a driver demand