Powertrain driveability is considered as one of the most important customer requirements of a vehicle. In fact, in a more and more competitive market, each car manufacturer tries to distinguish himself by improving the driving pleasure felt by its customer. However, the consideration of the powertrain driveability during the vehicle design cycle is not easy because this customer requirement is a consequence of the optimization of the entire vehicle and not only of each sub-system (motor, gearbox, …). The aim of this article concerns the use of dynamical modeling, analysis and simplification tools in order to help vehicle conception engineering departments to optimize the powertrain driveability.
Based on a bibliographical study concerning representations of the various sub-systems influencing the powertrain driveability, a complete vehicle model is built. For every studied aspect of driveability (tip-in or tip-out, takeoff, and gearshift), various proper models are proposed. The use of modeling and analysis tools like activity index of each energetic element of the system (inertia, stiffness, dissipation) permits selection of the suitable model complexity level to simulate the studied phenomena. Generated models are able not only to reproduce vehicle behaviors but also to analyze global dynamic behaviors of the vehicle.
Finally, this study improves the competitiveness of engineering departments by bringing better understanding of the global vehicle behavior in upstream phase of vehicle design cycle.