Fault-Tolerant Analysis for Active Steering Actuation System Applied on Conventional Bogie Vehicle

Active steering system can drastically improve dynamic behaviors of the railway vehicle but will also introduce safety-critical issues. The fault-tolerant analysis therefore is essential for the design and implementation of this technology. In this work, an approach based on Risk Priority Number from Failure Mode and Effect Analysis is established to present quantitative assessment for fault tolerance of actuation system. This method is adopted to compare proposed nine different active steering schemes where two different hydraulic actuators are considered, and additional passive spring or redundant structure is implemented as back-up to ensure the safety. In case studies, the impacts of typical failure modes are investigated through multi-body simulation and quantified by Severity factor. Finally, the fault tolerance of different actuation schemes is compared by RPN values.