Dynamics of Gear Shifting Processes of Dual-Clutch Automatic Transmissions in Integrated Powertrains of Battery Electric Vehicles

Abstract

In connection with the beginning transition of mass-produced battery electric vehicle (BEV) powertrains from single-gear gearboxes to specially configured automatic transmissions (AT), the number of publications devoted to justification and research of their architecture, as well as optimization of applied design solutions, is rapidly increasing. A large number of publications focus on dual-clutch AT (i. e. DCT) with two clutches (or frictions) in the first stage application. A clear recent trend in their subject matter is a shift of interest in DCT control, especially in transient automatic gear shifting with joint control of the motorgenerator (MG) and frictions in an integrated powertrain. It is shown that smoothness of shifting here is of no less importance than in classical AT, not only because of shift shocks, which deteriorate comfort, but also because of the possibility of excitation of oscillating modes in the electric drive. The paper analyzes several published variants of a strategy for controlling such shifting processes and their computer and physical implementation. We believe that, given the lack of Russian-language materials on this subject, this information is published for the first time.

Keywords

• battery electric vehicles
• integrated powertrains
• automatic transmissions
• dual-clutch transmissions