Rollover stabilities of three-wheeled vehicles including road configuration effects

Abstract

This study investigates the rollover stabilities of three-wheeled vehicles including the effects of road configurations. Tripped and untripped rollovers on flat and sloped roads are studied, and a new rollover index is introduced. To explore the unique dynamic behaviours of three-wheeled vehicles, the rollover stability is investigated on the basis of the lateral load transfer ratio, and the proposed rollover index is expressed in terms of measurable vehicle parameters and state variables. In addition to the effects of the lateral acceleration and the roll angle, the proposed rollover index takes the effects of the longitudinal acceleration and the pitch angle into account as well as the effects of banked roads and graded roads. Lateral and vertical road inputs are also considered since they can represent the effects of kerbs, soft soil and road bumps as the main causes of tripped rollovers. Sensitivity analysis is also provided in order to evaluate and compare the effects of different vehicle parameters and different state variables on the rollover stabilities of three-wheeled vehicles. To evaluate the proposed rollover index, simulations are also conducted using a high-fidelity CarSim model for a three-wheeled vehicle.