AN APPLICABLE TOPOLOGY-INDEPENDENT MODEL FOR RAILWAY INTERLOCKING SYSTEMS

In this article, two decision models for railway interlocking systems are presented. The first - for the case that the turnouts have spring switches-and the second - for the case that the turnouts should not be trailed through a switch set against-. Ln both cases, the algorithm i s independent of the topology of the station and is based on the calcu lation of accessibility in an oriented Ii graph. Both models are surpr isingly brief and easy to implement in Maple V.4. The package analyzes any change in the position of the switches and the clearances given b y the semaphores, and supervises if it is safe to authorize the change . Any turnout, that could be trailed through a switch set against, is also studied in the second model. In both cases, the fact that trains could occupy more than one section is considered. Some examples are in cluded. (C) 1998 IMACS/Elsevier Science B.V.