Research On The Modeling Of Urban Mass Transit Emergency Based On Petri Nets

The urban rail transit emergency response system is an integrated function system which will ensure public safety, system facility safety and stability and also has the capability of "early warning, defense, disposal" in all types of unexpected events in urban rail traffic. An early warning system is the "outpost" of various types of emergencies in urban rail transit system. It is also the equipment function and behaviour order system of "monitoring, measurement, report" of various types of risk factors in unexpected events.Nowadays, there is a new peak of rail transit development all over the country. Because of the complicated structure of rail transit, great traffic density and space layout constraints, etc, we need to find the suitable urban rail transit emergency system for China's society to reduce the threat and pressure of emergent event.Based on the current situation of urban rail transit development, this article first made the urban rail transit emergency system analysis, divided the system into four parts, namely, early warning systems, defense systems, plan systems and organizational system and then made detailed description of the four parts and their inner relations. Establish system model with Petri nets and the urban rail transit emergency rescue system of a certain event. Add the time factor to this system to assess the rescue its time and as a result, have quantitative understanding of the system.