A Supervisor of Traffic Light Systems Using Statecharts

In this paper, we propose a methodology to model a traffic light system with eight-phase. The modeling tool is called statechart. Statechart has been utilized as a visual formalism for the modeling of complex systems. It illuminates the features on describing properties of causality, concurrency, and synchronization. This paper focuses on the use of statecharts to model an eight-phase traffic lights control system. The advantage of the proposed approach is the clear presentation of traffic lights´ behaviors in terms of conditions and events that cause the phases alternations. Moreover, the paper also proposes a new modeling methodology, called concurrent state graphs, that allows us to present all the concurrent states in complex statecharts. The analysis of the control models is performed to demonstrate how the models enforce the lights´ transitions by reachability tree method. And then the reachability and reversibility properties of the control statecharts will be obtained.