A Novel Modeling Design Method for Automated Storage and Retrieval System Based on Petri Nets

In nowadays, the materials handling level of a manufacturing enterprise reflects its whole production status. Driven by fierce global competition, a widely used logistics solution is to adopt auto warehouse with automated storage and retrieval system (AS/RS). This paper develops a novel modeling design method for AS/RS which can clearly denote its status, simulate its real time behaviors and easily design its control operations. This paper is distinguished by one key contribution, which introduces the concepts of resource, color, time and signal to the Petri Nets modeling technology for the description of various logistic movements and the sequence, subsequent, conflict relations among them in AS/RS. Moreover the model can be decomposed and reduced convenient for analysis and simulation. The other contribution of this work is that the Petri net model is intuitively applied to design the PLC control software.