Technical Report No. 253 - Abstract

D. Sun, A. Kleiner, C. Schindelhauer
Decentralized Hash Tables For Mobile Robot Teams Solving Intra-Logistics Tasks

Although a remarkably high degree of automation has been reached in production and intra-logistics nowadays, human labor is still used for transportation using handcarts and forklifts. High labor cost and risk of injury are the unde- sirable consequences. Alternative approaches in automated warehouses are fixed installed conveyors installed either over- head or floor-based. The drawback of such solutions is the lack of flexibility, which is necessary when the production lines of the company change. Then, such an installation has to be re-built. In this paper, we propose a novel approach of decentral- ized teams of autonomous robots performing intra-logistics tasks using distributed algorithms. Centralized solutions suffer from limited scalability and have a single point of fail- ure. The task is to transport material between stations keep- ing the communication network structure intact and most importantly, to facilitate a fair distribution of robots among loading stations. Our approach is motivated by strategies from peer-to-peer-networks and mobile ad-hoc networks. In particular we use an adapted version of distributed hetero- geneous hash tables (DHHT) for distributing the tasks and localized communication. Experimental results presented in this paper show that our method reaches a fair distribution of robots over loading stations.