Development of a Dual Clutch Transmission Model for Real-Time Applications

The paper presents the main features of a control-oriented model of a Dual Clutch Transmission (DCT) system that has been designed to support model-based development of the DCT controller. The model represents an innovative attempt to reproduce the fast dynamics of the hydraulic circuit while maintaining a simulation step size large enough for real time application. The model includes a detailed physical description of clutches, synchronizers and gears, and a simplified model of the vehicle and of the internal combustion engine, in order to simulate the behavior of the entire system. As the oil circulating in the system has a large bulk modulus, the pressure dynamics are very fast, possibly causing instability in a real time simulation; the same challenge involves the servo valves dynamics, due to the very small masses of the moving elements. Therefore, the hydraulic circuit model has been modified and simplified without losing physical validity, in order to adapt it to the real time simulation requirements. The results of offline simulations are compared to on board measurements to verify the validity of the developed model for real time Hardware In the Loop (HIL) applications.