A Coloured PETRI Net Based Solution for the Generalized Railway Crossing Problem

Abstract

The generalized railway crossing problem was defined as a benchmark problem for comparing different formal methods and methodologies developed for specifying and analysing mixed hardware/software systems. Various solutions of this problem were developed by the real-time researchers. The authors of this paper presents the model of a crossing controller specified in terms of coloured Petri nets. Important technical requirements of the controller are defined by means of temporal logics formulas. The problem had to be slightly redefined to omit the usage of time in the Petri net based model. Safety and liveness properties were verified during the design process. Such an attempt should shorten the design phase and could be a very efficient tool for co-verification of the integrated design methodology.