Gearshift control strategies for hybrid electric vehicles: A comparison of powertrains equipped with automated manual transmissions and dual-clutch transmissions

This article describes gearshift control strategies developed for a series-parallel hybrid electric vehicle architecture in which an electric machine is connected to the output of the transmission, thus obtaining torque filling capabilities during gearshifts. Two transmission systems are analyzed: hybrid automated manual transmission and hybrid dual-clutch transmission. The article focuses on the gearshift control strategies for the two transmission, splitting each gearshift into several phases. The objectives of each control phase, the equations for computing the set points for powertrain actuators, and the conditions that determine the passage from one shifting phase to the next are reported. Moreover, nonlinear dynamic models are described and used to verify through simulation the effectiveness of the controllers. Promising results, in terms of vehicle dynamic performance, are obtained for both transmission systems.