Effects of road pavement profiles on driver behaviour in the TEST driving simulator

The road pavement surface is not a perfect plane but it includes irregularities that can be singular or distributed. The latter are always present in every pavement surface. They can be ascribed to the unavoidable defects in the road construction process and to the progressive degradation of the materials and of the structural capacity of the pavements. Vehicles moving onto the road surface are dynamically excited by the variations of the elevations of road profile and, as a result of this, vibrations are transmitted by vehicle body to car occupants. The discomfort drivers fell due to these vibrations is one of the key factor in the speed perception and choice. It is therefore believed that, speed profiles derived from driving simulators may be higher than those reached in real driving scenarios A dynamic driving simulator (DDS) employing a real car fixed on a 6 degrees of freedom motion platform is currently operating at the TEST Laboratory. The DDS system is able to reproduce most of the accelerations the occupants feel, in particular those arising from turning and braking manoeuvres and from dynamic interaction with pavement surface singular irregularities such as trenches, potholes, road humps and so on. A team of researchers from University of Naples “Federico II”, Second University of Naples, University of Cassino and the Oktal Company have improved the system allowing the implementation of a module simulating vehicle vibrations induced by distributed irregularities. In this paper, the development of the vibration simulation module and the results from preliminary experimental calibration procedures are briefly reported. The initial outcomes of the performed tests seem to highlight that road roughness level has a remarkable influence of on driving behaviour in DDS.