Bus Structure Behaviour under Driving Manoeuvring and Evaluation of the Effect of an Active Roll System

One of the main causes of traffic accidents in which heavy vehicles are involved is lateral stability loss. It is well known that heavy vehicles have relatively high centres of gravity and narrow track widths and can lose roll stability at moderate levels of lateral acceleration. The influence of several parameters (i.e. height of the centre of gravity, weight distribution between axles, chassis torsional stiffness, etc.) on bus roll stability during a lane change manoeuvre, as well as the bus structure stress level has been analyzed by means of a six degrees of freedom beam finite element model. In addition, due to the use of active systems to prevent excessive roll motions in heavy vehicles, the effect of an active system based on anti-roll bars in a bus structure under a lane change manoeuvre is carried out by means of a bus dynamic finite element model. Results show that the fuzzy logic controller implemented in the anti-roll bar system significantly reduces both the vertical displacements at the corners of the bus structure and the stress level.