Modelling and simulation of gear synchronisation and shifting in dual-clutch transmission equipped powertrains

Abstract

Dual-clutch transmissions have increased in prevalence through the combination of high efficiency and shift quality. This is achieved through the automation of conventional manual transmission synchronisers for gear selection with automated clutch-to-clutch shift control, minimising loss of traction to the road. This article derives a suitably detailed model of a dual-clutch transmission equipped powertrain for the transient simulation and analysis of combined synchroniser engagement and gear shifts. Models are derived for a powertrain equipped with a wet dual-clutch transmission with particular focus on a detailed synchroniser mechanism model, including speed synchronisation, ring unblocking and indexing stages of engagement. To demonstrate the combination of synchroniser engagement with clutch-to-clutch shifting, several simulations are conducted to study the variation of chamfer alignment, vehicle speed and synchroniser engagement timing on powertrain response. Results indicate that vehicle speed and chamfer alignment have only limited impact on the quality of shifting. Synchroniser timing can have a more significant influence on shift quality, stressing the need for independence of these processes.