Collisions avoidance and deadlocks prevention, for dynamic routing of trains in a railway node

This paper presents a collisions avoidance and a deadlocks prevention method for automatic trains routing in railway nodes. This method allows controlling train routing which depends on the position of other trains in the node. This control is based firstly on the construction of a Petri Net Controller that corresponds to a specific class of Petri Net called System of Simple Sequential Process with Resource (S3PR), which guarantees the system safety. Thus, the behavior of the S3PR is restricted to non-blocking states by the application of a supervisory control synthesis method, in order to guaranty the liveness of the control.