Supervisory control of timed-place marked graph based on Marking Exclusion Constraint

Abstract

This paper presents a control synthesis approach for Discrete Event Systems (DES) modeled by Timed Place Marked Graphs TPMG where the time is associated with places. It solves a forbidden state problems characterized by Marking Exclusion Constraint (MEC). A computationally efficient technique to build the supervisor is proposed, which we take in consideration the uncontrollable and/or unobservable nature of some events. The time makes our control policies more permissive by allowing the system to reach more states (marking) which were considered as dangerous marking in partially controllable Marked Graph. We depend on the initial marking as known marking to build time-tables that show us the timeline of marking distribution over the system. These time-tables help to build a Control Law Table (CLT), through analysis the information in this table the supervisor may determine the moment of its intervention.