A lateral active suspension for conventional railway bogies

The present paper describes an active centring system for railway vehicles. The proposed solution is based on lateral pneumatic actuators placed between bogie and car body connected to the vertical secondary suspension air springs. The objective of the developed centring system is twofold: the improvement of the curving behaviour of the train and the decrease of the lateral acceleration perceived by the passenger in curve negotiation thanks to the reduction of the 'souplesse' coefficient. The system is described in detail in the paper. Results from simulations are included considering a bidimensional model of the vehicle, and a detailed model of the air spring and control valves. The performance in curve negotiation of a vehicle equipped with this system and a conventional one is compared. Specifically, lateral displacements of the secondary suspension, roll angle and lateral accelerations are analysed. The results show noticeable performance improvements in the vehicle curving behaviour. The proposed centring system can be implemented in a conventional bogie without special design requirements; and due to the low air consumption, additional pressurised reservoirs are not required.