Modelling and Simulation Process of Extended Petri Nets with PNML and Matlab/Simulink

Abstract

In this work, we introduce a modelling and simulation process based on Matlab/Simulink for Petri nets that considers inhibitor arcs and priorities of transitions, herein named eXtended Petri nets, for modelling deterministic complex systems. The presented process comprises the method for modelling the system, the functions for the import to Matlab of all the data structures that define a Petri net with inhibitory arcs and priorities in transitions, and the functions to perform the simulation of the Petri net behaviour as a Simulink block. We present an exploratory case study about Rate Monotonic Scheduling for tasks with harmonic periods to show the complete modelling and simulation process. First, the scheduling system is modelled with Renew editor and saved as a PNML file. Then, this file is read and transformed into a Matlab data type. The produced data structures are the inputs to the proposed Simulink block, which performs the dynamic of the eXtended Petri net. Finally, the outputs of the simulation help validate the logical and temporal correctness of the scheduler model used as a case study. The concluding remarks section provides a link for downloading and testing the simulation process.