Design and development of an active suspension system for T-2006 Pantograph

The authors of this paper have worked within a team formed by Trenitalia S.p.A., Italcertifer, and two Italian Universities (Università di Firenze and Politecnico di Milano) with the aim of developing a prototype of an innovative pantograph for Italian high speed lines. The focus of this paper is on innovative solutions proposed for the actuation system and on promising experimental results obtained during dynamic tests performed in various laboratories. The proposed control strategy is based on the theory of impedance control [1], i.e. the simulation of “desired” mechanical impedance by means of the active control of a mechanical device: the controlled pantograph is able to emulate, within certain limits, mainly related to the need for maintaining system stability, the desired dynamic response of a “virtual pantograph”. The advantages of the proposed solution are quite evident since force measurements or estimations are not necessary, improving reliability and reducing the costs of the active pantograph. Control design is also quite simple and robust against parameter uncertainties introduced by catenary modeling. Moreover, the proposed control-actuation strategy is quite general, since it is not constrained to a particular mechanical layout so, with very limited modification, it can be easily applied not only to the Trenitalia T-2006 prototype but also to other 2-stage pantographs.