Tandem Configurations for Automated Guided Vehicle Systems and the Analysis of Single Vehicle Loops

TLDR

Automated Guided Vehicle systems are widely used in low‑to‑medium flow manufacturing, offering inexpensive guidepaths and flexible routing, and have been proven viable since the 1990s, though traditionally all vehicles are assumed to visit any pick‑up or deposit point. This study proposes decomposing an AGV system into non‑overlapping, single‑vehicle loops operating in tandem and develops an analytical model to evaluate the throughput of such a loop. The authors model the system as independent single‑vehicle loops and derive a closed‑form throughput expression for a single vehicle under a specified dispatching rule in a stochastic environment. The derived expressions are the first closed‑form formulas that determine the throughput capacity of a single vehicle operating under a specific dispatching rule in a non‑deterministic setting. Funding: Dr.

Abstract

Abstract Automated Guided Vehicle (AGV) systems continue to play a significant role in many low to medium flow manufacturing operations, including Flexible Manufacturing Systems (FMS) and other applications. The relatively inexpensive guidepath, coupled with the high degree of flexibility and control offered in vehicle routing, has made AGV systems a proven and viable handling technology for the 90's. Traditionally, AGV systems have been implemented and analyzed assuming that every vehicle is allowed to visit any pick up/deposit point in the system. We introduce a conceptually simple and intuitive approach where the system is decomposed into non-overlapping, single-vehicle loops operating in tandem. In this paper, we also develop an analytical model to study the throughput performance of a single vehicle loop. The resulting expressions are the first closed form analytical expressions that have been obtained to determine the throughput capacity of a single vehicle operating under a specific dispatching rule in a non-deterministic environment. Notes Dr. Bozer is supported by a Presidential Young Investigator Award, NSF Grant DMC-8858562. Dr. Srinivasan is supported by Northern Telecom under Grant No. DRDA-883032. Handled by the Department of Facilities Design/Material Handling.