Abstract: This paper deals with the use of Petri nets in modelling metro railway network and designing appropriate control logic for it to avoid collision. Here, the whole metro network is presented as a combination of the elementary models blocks and signals within the track. We here model automatic train protection (ATP) and overlap to ensure safeness of the railway network. In this research work, we have actually introduced constraints at the signals in the metro track. These constraints ensure safe working of metro network.

Keywords: Petri nets, safeness constraints, ATP, asynchronous systems.