A Prediction of Wheel/Rail Lateral Force Induced by Actively Controlled Suspension for High Speed Railway Vehicles. Comparison between the Truck with Side Bearers and the Bolsterless Truck.

Abstract

Instead of good effects on the ride comfort, the active suspension may have unfavorable effects on the wheel/rail interaction such as the increase of lateral force on the wheel. This paper deals with an analytical study about the lateral dynamics of two types of railway vehicles, in which an active suspension mechanism controls the running vibration. One vehicle type has the trucks with a bolster and side bearers, and the other type the bolsterless trucks with yaw dampers. The analytical models for the vehicles consider non-linear characteristics such as creep forces and wheel flange/rail side collision. In this study the active suspension has a controller based on the optimal control theory and assumes ideal actuators to be available. Their operations on the track with alignment irregularities are simulated up to the speed of 350km/h. The results show that the active suspension can improve the ride quality without any increase of the wheel lateral force and that the bolsterless truck has better ride quality and occurs smaller wheel lateral force than the other type truck in the higher running speed range.