A modular simulation tool for fixed block and moving block railway signalling systems
This paper presents a time-based modular simulation tool implemented in MATLAB® and Simulink® for evaluating fixed block (FB) and moving block (MB) railway signalling systems. The simulator integrates the Radio Block Centre (RBC), On-Board Unit (OBU), vehicle longitudinal dynamics, and a driver behavioural model to replicate realistic train operations. Two case studies are conducted on a main railway line with twelve stations, involving a leading and a trailing train with identical mechanical characteristics. An unexpected departure delay of the leading train at the fifth station reduces the headway, forcing the signalling system to intervene. Simulation A employs identical driver parameters for both trains, while simulation B assigns an aggressive and less responsive driver to the trailing train, resulting in a more pronounced signalling action. Results indicate that MB signalling reduces the trailing train's travel time by 70 s (2.5% of total time) compared to FB, albeit with a more jagged speed profile due to frequent activations. The authors caution that these findings are limited to the two case studies and that a comprehensive parametric investigation is necessary for generalised conclusions. The tool aims to reduce on-site testing of railway signalling systems by providing a flexible platform for scenario analysis.