Simulation model for the analysis of road vehicles global efficiency

Abstract

Along with the rapid growth of energy shortage and environmental pollution, the improvement of road vehicles' overall efficiency becomes a topical research argument in automotive areas. A significant contribution towards this goal, apart from modifying the powertrain layout and optimizing engine and mechanical components, could be provided by the development of computer-aided energy management systems. Vehicular powertrain is a nonlinear dynamic integrated system of electrical, mechanical, chemical and thermodynamic devices, whose primary objective is providing the power needed for motion. In order to analyze such a complex system, a simulation platform for a generic vehicle powertrain has been developed in the Matlab/Simulink environment, on the basis of vehicle characteristics (mass, front area,...) and loads (friction, route,...). The aim of this study is the development of a validated powertrain simulation model, able to test different on-board power and energy management strategies. The paper identifies a series of key parameters useful for the study of the overall vehicle efficiency, highlighting the energy losses associated to each powertrain component and plotting energy flows balance diagram. The models of the different powertrain components have been characterized and cascade-connected. The powertrain operational logics has been implemented in a control system including power distribution and advanced energy management strategies (e.g. overdrive, Stop&Start system, regenerative braking). The simulation model has been validated with New European Driving Cycle literature data and experimental road tests. © 2011 WIT Press.