Abstract-An Automated Storage and Retrieval System (AS/RS) consists of several aisles with storage racks, serviced by cranes. Each aisle is equipped with a storage and a retrieval conveyor and is serviced by rail guided vehicles. This paper focuses on operational control of AS/RSs and presents a management strategy taking decisions on resource allocations in order to avoid conflicts and deadlocks. A Colored Timed Petri Net models the system dynamics describing the system in a resource oriented and modular framework.

Abstract The industrial manufacturing environment is nowadays characterized by fierce global competition, rapid market changes and short product life cycles. Such a complex scenario originated a vast demand for sophisticated techniques guaranteeing adequate planning and control of warehouses. A widely used solution is to adopt Automated Storage and Retrieval Systems (AS/RSs). A typical AS/RS comprises a number of parallel aisles with storage racks, serviced by automated stacker cranes and rail guided vehicles.

Considers a modern warehousing system composed of a number of aisles, each one served by a crane and sided by a pair of racks, and a shuttle which moves along a 1D path placed orthogonally with respect to the aisles' axis. The main operations performed by the control system concern the optimization of the cranes and shuttle movements. Regarding the cranes, we propose an algorithm for optimizing the sequencing of dual command (storage and retrieval) cycles, so to maximize the throughput. As for the shuttle, an algorithm is proposed to optimize the scheduling of the shuttle operations; the performance of the algorithm is evaluated and compared with the case in which no optimization is considered. A further contribution of the paper is the derivation of the model of a real warehousing system, by means of a colored Petri net approach. Such a model is then used to show and validate the effectiveness of the proposed algorithms

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 modelling framework for heterogeneous automated storage and retrieval systems, comprising rail guided vehicles and narrow aisle cranes.

A system is a set of heterogeneous elements that work in direct relation with each other for a specific purpose;through its automation, it is possible to carry out productive processes with machines, without thedirect participation of a human operator. The Automated Integrated Logistics System (SALI by it’s acronymin Spanish) is a didactic environment that allows to emulate the activities and operation of a Logistic DistributionCenter (DC), developed at the New Granada Military University as a teaching and learning toolfor engineering. The current system programming in the software system allows a serial processing of apurchase order, from the moment in which the customer, passing through all the stations, until it is sent to adelivered point, requires the product. The present investigation presents a modeling of the system throughColored Petri Nets (CPN) it’s made, with the purpose of achieve a better understanding of the dynamics ofthe system, the relationships between the station...

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.

An analysis of the typical manufacturing/storage system, which represents a group of the discrete event systems, is introduced in the paper. For that system appropriate modelling tools are described where the main attention is devoted to the coloured Petri nets. They are used for the solution of the storage system modelling, which is one of the most important tasks on the DES higher level.