Distributed Collision-free Protocol for AGVs in Industrial Environments

TL;DR

This paper introduces a decentralized protocol for collision-free coordination of AGVs in industrial settings, ensuring safety and efficiency without centralized control or synchronized clocks.

Contribution

A novel distributed coordination algorithm using shared resources and replanning, guaranteeing collision avoidance, deadlock prevention, and livelock conditions in dynamic environments.

Findings

Guarantees ordered traffic flow avoiding collisions

Proves mutual access and deadlock prevention under certain conditions

Defines local livelock verification criteria

Abstract

In this paper, we propose a decentralized coordina- tion algorithm for safe and efficient management of a group of mobile robots following predefined paths in a dynamic industrial environment. The proposed algorithm is based on a shared resources protocol and a replanning strategy. It is proved to guarantee ordered traffic flows avoiding collisions, deadlocks (stall situations) and livelock (agents move without reaching final destinations). Mutual access to resources has been proved for the proposed approach while condition on the maximum number of AGVs is given to ensure the absence of deadlocks during system evolutions. Finally conditions to verify a local livelocks will also be proposed. In consistency with the model of distributed robotic systems (DRS), no centralized mechanism, synchronized clock, shared memory or ground support is needed. A local inter-robot communication, based on sign-boards, is considered among a small number of spatially adjacent robotic units.