In: Proc. IFAC Conf. on Control Systems Design (CSD'2000), 18-20 June 2000, Bratislava, Slovak Republic, pages 299-304. 2000.
Abstract: Control system usually have high security requirements. Petri nets play an important role in the modeling of control systems because they provide various means for analysis as well as for verification. Verification is an important issue for ensuring the required security issues. Safety properties of a Petri net model constitute a main class of security constraints. This paper describes the stepwise development of a colored Petri net model for a train control system. It proposes a rule-based approach that allows the preservation of safety properties. Rules that preserve or even introduce safety properties are applied to current Petri net model. The resulting transformation refines the net model and preserves or even introduces the safety property.
Keywords: colored Petri nets, rule-based refinements, train control systems.