Modeling of an AS/RS Serviced by Rail-Guided Vehicles with Colored Petri Nets: a Control Perspective

An automated storage and retrieval system (AS/RS) automatically stores incoming material and retrieves stored parts with no direct human handling. This paper proposes a modular and unified modeling framework for heterogeneous automated storage and retrieval systems, comprising rail guided vehicles and narrow aisle cranes. We employ colored timed Petri nets, representing a concise and computationally efficient tool for modeling the system dynamic behavior, particularly suitable for real time control implementation. Indeed, the model can be utilized in a discrete event simulation to apply control policies in order to solve scheduling problems, as well as to avoid deadlock and collision occurrences.