Analytical and Experimental Handling Performance of Ultra-Efficient Lightweight Vehicles

The rising environmental awareness has led to a growing interest in electric and lightweight vehicles. Four-wheeled Ultra-Efficient Lightweight Vehicles (UELVs) have the potential to improve the quality of urban life, reduce environmental impact and make efficient use of land. However, the safety of these vehicles in terms of dynamic behaviour needs to be better understood. This paper aims to provide a quantitative assessment of the handling behaviour of UELVs. An analytical single-track model and a numerical simulation by VI-CarRealTime are analysed to evaluate the dynamic performance of a UELV compared to a city car. This analysis shows that the lightweight vehicle has a higher readiness (i.e. lower reaction time to yaw rate) for step steering and lower steering effort (i.e. higher steady-state value). Experimental analysis through real-time driving sessions on the Dynamic Driving Simulator assesses vehicle responses and subjective perception for different manoeuvres. The driving performance results are in line with the analytical and numerical simulation. Drivers perceive a quicker response to steering input from the UELV compared to the city car for curves, slalom and lane changes. This performance is subjectively perceived as positive for short sharp manoeuvres and negative for long slalom manoeuvres, where the vehicle behaviour is perceived as nervous and abrupt. Such aggressive driving can be reduced through safe driving training, especially for young drivers.