A full-scale roller-rig for railway vehicles: multibody modelling and Hardware In the Loop architecture

In this paper an innovative Hardware In the Loop (HIL) architecture to test braking onboard subsystems on full-scale roller-rigs is described. The new approach allows reproducing on the roller-rig a generic wheel–rail adhesion pattern (especially degraded adhesion conditions) without sliding and, consequently, wear between the roller and wheel surfaces. The presented strategy is also adopted by the innovative full-scale roller-rig of the Railway Research and Approval Center of Firenze-Osmannoro (Italy); the new roller-rig has been built by Trenitalia S.p.A. and is owned by SIMPRO S.p.A. At this initial phase of the research activity, to effectively validate the proposed approach, a complete multibody model of the HIL system has been developed. The numerical model is based on the real characteristics of the components provided by Trenitalia and makes use of an innovative wheel–roller contact model. The results coming from the simulation model have been compared to the experimental data provided by Trenitalia and relative to on-track tests performed in Velim, Czech Republic, with a UIC-Z1 coach equipped with a fully-working WSP system. The preliminary validation performed with the HIL model highlights the good performance of the HIL strategy in reproducing on the roller-rig the complex interaction between degraded adhesion conditions and railway vehicle dynamics during the braking manoeuvre.