Dynamic and kinematic model of a dual clutch transmission

In the last years Dual Clutch Transmissions (DCT) have spread worldwide in the automotive industry due to their capability to change the actual gear ratio, between engine and driving wheels, without interrupting vehicle traction by means of an efficient mechanical layout. Dynamic performance of DCT and the relating driver perceptions strongly depend on the control system whose main task is to generate the reference signals both for synchronisers and clutches. Detailed mechanical models of DCT system, considering also the synchronisers dynamics, are required to tune these control algorithms. This paper investigates the transmission kinematics and dynamics of a DCT, considering all the possible configurations that can take place in relation to the various power flow paths. A detailed analysis of the system with different degrees of freedom (1 to 3) is proposed and the resulting sets of equations are written in an indexed form that can be easily integrated in a vehicle model, thus allowing the description of both gear shift transients and operation with a specific gear. Finally, some simulation results are presented aiming at comparing the effect of different synchroniser models on transmission and vehicle dynamics.