An Improved Optimization Algorithm for Timed Petri Net Based on Genetic Algorithm

Abstract

Abstract.A variety of theoretical and practical work exists on Petri-net-based optimization algorithm. However, the efficiency of optimization is still the bottleneck of its application, especial for NP problem (e.g., Flexible Manufacturing System (FMS) scheduling problem). In order to improve the optimization efficiency, an optimization approach for the Timed Petri Net (TPN) model is proposed in this paper. Firstly, definition of Simplified Timed Petri Net (Simplified TPN) and method of simplifying traditional model are proposed. Based on this Simplified TPN, the concepts of mutual exclusion contracts and order contracts are defined, and the optimization mathematical model is obtained. Then, a reachability checking method is introduced to ensure the feasibility of solutions. Finally, this paper proposes a new crossover operator and mutation operator of Genetic Algorithm (GA) and describes the steps of optimization approach. This proposed approach is evaluated on FMS scheduling.