Distinguishing Between Random and Deterministic Track Inputs for Active Railway Suspensions

This paper presents and compares different control strategies for applying absolute or "skyhook" damping in active suspension systems for railway vehicles. It first examines a number of linear approaches for filtering the absolute velocity signal in order to optimise the trade-off between the random and deterministic track input requirement, and then what can be achieved using non-linear Kalman-Filter methods is explored. Studies in this paper show that an improvement of nearly 20% in ride quality can be achieved with a linear complementary filter control and over 50% by using non-linear Kalman filter methods.