An overview of modeling and control of a through-the-road hybrid electric vehicle

Abstract

Heavy reliance on fossil fuels poised a challenge in environment preservation as hazardous by-products from fuel-burning are dissipated irrepressibly to the atmosphere. The introduction of hybrid electric vehicles (HEV) in the transportation sector serves as a contemporary solution towards the realization of emission-free vehicles of the future. In this paper, a Through-the-Road (TtR) HEV configuration with in-wheel motors (IWM) fitted in the rear wheels is proposed and tested in simulation over standard drive cycles. Due to its simpler configuration, TtR HEV has a lower efficiency compared to other conventional HEVs but the architecture also grants several redeeming features such as enhanced acceleration and stability courtesy of its 4-wheel drive (4WD) setup. Further research is needed to improve the offering from TtR architecture to make them perform closer in efficiency to conventional HEVs. Modeling of the TtR HEV uses established mathematical equations in MATLAB® using Simulink. This is achieved through a modification of a power-split HEV model in Simulink into a TtR architecture through the elimination of the planetary gear system, the addition of IWM to the rear wheels and a slight modification of the EMS. The main objective of this exercise is to develop a robust simulation platform for future works such as drivetrain optimization and development of energy management strategy (EMS) controller. Simulation results have shown that the proposed TtR HEV is capable of satisfying the driver’s demand with acceptable fuel consumption.