패트리넷 분할 알고리즘 기반의 유연 생산 시스템 스케쥴러 설계
- 원문 URL
Petri Net is classified very diversely. Since it is applied and operated to fit the characteristics of systems, it is one of the appropriate modeling analysis methods. To date, various research on the division of Petri Net have been conducted. In particular, Natomi, et., al., conducted a study that seeks to minimize state explosion. Said research on module division is more efficient than the composition method, mathematical method, and reachability analysis method. Since a system is divided according to the arbitrary criteria of the writer, however, formulating diverse modeling is difficult. A structural parallel mathematical expression was therefore created and efficient methods explored using this expression, in order to determine the divisible structure. Since structural parallelism has invariant status, a transitive matrix was used whereby the relation between place and transition was expressed. An Algorithm was then proposed, which was aimed at dividing system models. This division algorithm can resolve difficulties in analysis caused by the state explosion of Petri Net models. Thus, equally applying this method and the proposed division algorithm to any system modeling is expected to significantly enhance efficiency. The division algorithm was applied to the scheduling problem, with the division- scheduling algorithm constructed for verification. The division-scheduling algorithm was able to calculate the divided subnet table. And it is able to reduce the analysis complexity. In addition, the propose division algorithm and division-scheduling algorithm were applied to flexible manufacturing system models. A good schedule was obtained, the efficiency of the division-scheduling algorithm compared with the Hillion algorithm, Korbaa algorithm, and Unfolding algorithm proposed in previous research, and results analyzed. On the other hand, a transitive matrix was used in order to propose an algorithm designed to confirm and analyze the deadlock status of the Petri Net. The algorithm determines the deadlock status and consequently facilitates the analysis and verification of the system validity. Ultimately, this research aimed to use the transitive matrix and propose an algorithm designed to divide the Petri Net model. To verify the efficiency of the proposed division algorithm, the division-scheduling algorithm was applied to the flexible manufacturing system model. Finally, an algorithm was proposed to determine the deadlock status and consequently evaluate the validity of the system. The flexible manufacturing system uses the system of producing multi-item and small-quantity production and plays an increasing role in today's industries. Efficient scheduling of flexible manufacturing system production enables speedy response to continuous calls for improving productivity at less costs, reducing the period required for long-term flexible manufacturing system, and promoting technological innovations and development at the front lines of the industry. Thus, there is a need to develop an algorithm designed to complement shortcomings in memory and an algorithm designed to determine the status of more than one marking. The proposed division algorithm should be applied to other systems to further its generalization. Likewise, further research on the automation of scheduling analysis, system properties analysis of discrete types, and model status analysis in the flexible manufacturing system through the division-scheduling algorithm is recommended to expand usage.