Vehicle Modeling and Evaluation of the Engine Options in Conventional and Mild-Hybrid Powertrain

The focus of this paper is on developing, modeling and simulation framework for a bias free comparison of different engine concepts in a conventional and hybrid configuration. The first unique contribution of this paper is in the development of a shift logic algorithm that allows tailoring the shift schedule to unique engine characteristics in a consistent manner. The shift schedule is intentionally generated in a generic manner by using identical set of rules for all engines. Therefore, the methodology allows a fair comparison of different engine concepts, while taking into account the individual features of the engine i.e. speed range, efficiency and maximum performance. The latter establishes a baseline for the subsequent study of hybrid configurations. The second unique contribution is the hybrid strategy optimization algorithm, also tailored to a particular engine configuration. The strategy is developed using a dynamic programming algorithm, followed by rule extraction to develop an implementable strategy. Ultimately, the proposed approach enables a consistent evaluation process, where different engines and hybrid hardware are treated in a unified simulation-based framework.