Linear and non-linear methods to analyse the drivability of a through-the-road parallel hybrid electric vehicle

This paper deals with the simulation of the low frequency drivability of through-the-road parallel (TTRP) hybrid electric vehicles (HEVs). The current literature relating to HEVs is predominantly focused on energy efficiency optimisation. However, the drivability of this HEV typology can be particularly critical, due to the interaction of the front and rear axle dynamics. The article presents an experimentally validated non-linear model of a TTRP HEV, consisting of a front axle driven by an internal combustion engine (ICE) with a six-speed transmission, and a rear axle powered by an electric motor with a prototype two-speed transmission. The simulated TTRP HEV is then considered with both driven axles, and drivability manoeuvres in conditions of constant gear are carried out. The results are analysed to study acceleration and jerk profiles, and understand the anti-jerk control system fundamentals through linearisation methods.