Research On Petri Net Modeling And Output/Input Optimization Management In AS/RS

Automated Storage and Retrieval System (AS/RS) is an integrated system which involves logistics information management, automated equipment control, goods location optimization, etc. The real-time performance and flexibility are the main development trends.Choosing an appropriate mathematical modeling technology to build a proper model for Automated Storage System is very crucial for its analysis and optimization. The theory of Variable-imparted Petri Net was introduced based on the basic Petri Net, which divides the material flow into protomer flow and information flow. In order to solve the deadlock problem caused by conflict in actual system, the Variable-imparted Petri Net logistics model of the AS/RS was established. The analysis results showed that the model could support the scheduling strategies.For a given AS/RS, its operating efficiency is closely related to the rationality of goods location assignment and the condition of input/output optimization maneuver. The optimization of goods location and scheduling of Storage and Retrieval Machine (SRM) in AS/RS was analyzed in this thesis, the design principles and theories of system optimization were put forward. And special emphasis was placed on the research of using Dynamic Programming method to optimize SRM's task route. The pre-handling which mates task sequences before using Dynamic Programming method reduces the steps of decision-making and decision variables, simplifies the mathematical model and the calculation.The prototype system of automated warehouse was designed on the basis of AS/RS architecture research. The mechanical structure and control system design work for SRM which is the most important equipment of AS/RS were introduced. Besides, the Warehouse Management System (WMS) was developed, whose task management module verified optimization method for the SRM.