Fms Simulation Platform Based On Eopn And Heuristic Search Algorithm

Flexible Manufacturing System is a typical real-time dynamic discrete event system composed of a number of computer-controlled machines, automated material handling and storage equipments. These physical entities operate as an integrated system under the control of the computer software system. The growing demand for higher performance and flexibility and the interlocking factors of concurrency, event-driven activities, real-time decision-making poses a significant challenge to FMS design, especially in terms of control and scheduling.The combination of Petri nets as an analysis tool for discrete-event dynamic systems and artificial intelligence heuristic search has been shown to be a promising way to solve FMS scheduling problems. However, the NP hard nature of the problem obscures the Petri net capability of reasoning about the behavior of the systems.In this paper, Extended Object-oriented Petri net is developed for modeling FMS. After FMS modeling phase, heuristic search formulates the scheduling problem based on Petri net model. Then, it generates and searches a partial reachability graph to find an optimal or near optimal feasible schedule in terms of the fire sequence of the transitions of the Petri net model. Some heuristic functions for efficient search are explored and the experimental results are presented. At the end of this paper, an integrated FMS simulation platform is presented. This platform integrates the whole sequence of modeling and simulation procedure. The schedule algorithm based on heuristic search and Petri net is tested in this simulation platform.