Symbolic techniques for model-based design of hybrid electric vehicles

The recent increase in oil prices and environmental concerns have attracted various research efforts on hybrid electric vehicles (HEVs) which provide promising alternatives to conventional engine-powered vehicles with better fuel economy and fewer emissions. To speed up the design and prototyping processes of new HEVs, a method that automatically generates mathematics equations governing the vehicle system response in an optimized symbolic form is desirable. To achieve this goal, we employed MapleSim^TM, a multi-domain physical modeling tool developed by Maplesoft, to develop the multi-domain model of a power-split HEV, utilizing the symbolic computing algorithms of Maple software package to generate an optimized set of governing equations. The HEV model consists of a mean-value internal combustion engine (ICE), an electrochemical Li-Ion battery pack, and a multibody vehicle chassis. Simulation results are then used to demonstrate the performance of the developed HEV system. Simulation results show the benefits of symbolic approach to HEV modeling, which allows the number of governing equations to be reduced significantly, resulting in a computationally efficient system.