Usage-based optimisation of characteristic maps for conceptual powertrain design

Abstract

With an increasing number of vehicles having alternative powertrains, the choice of the most appropriate powertrain for a vehicle class or load cycle is more challenging. This paper introduces a method for usage-based optimisation of powertrains. Based on a longitudinal dynamic simulation, the characteristic maps of the traction machines are optimised for different user cycles and these characteristic maps form the objective function of a minimisation problem. The goal of optimisation is to minimise well-to-wheel carbon dioxide emissions. Besides the conventional powertrain provided with petrol or diesel engine, battery electric, parallel-, serial- and power-split hybrid powertrains with assisting or dominating petrol and diesel engines are investigated. The results show that the proposed method delivers the optimal powertrain for a specific usage by applying an optimisation with reasonable restrictions.