Linear and non-linear skyhook damping control laws for active railway suspensions

This paper presents and compares different control strategies for applying "skyhook" damping control laws 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 requirements, and then what can be achieved using non-linear methods based upon Kalman-filters is explored. The principles that are developed are general and can be applied to both vertical and lateral secondary suspensions, although the paper concentrates upon the vertical direction and quantifies the performance achievable for a particular combination of track characteristics. (C) 1999 Elsevier Science Ltd. All rights reserved.