A Petri net model for analysis, optimisation, and control of railway networks and train schedules

Petri nets and railway networks are considered in this paper with the aim of providing a comprehensive model to be used for analysis, optimisation, and control purposes. The overall model consists of two interconnected Petri nets that represent, respectively, the physical part of the network (stations, blocks, crossovers, tracks, and so on, as well as trains travelling on the network) and the logical part of it (train schedule over the available lines). The former Petri net has a fixed structure whereas the second one changes in accordance with the number of trains, lines, and timetable. In the paper, the main elements of the two Petri nets are described in detail, making use of an example of network which is representative of real-word railways. Moreover, some applications of the proposed model are discussed in order to highlight the effectiveness in employing Petri nets to analyse, optimise, and control railway networks and train schedules.