Gathering asynchronous mobile robots with inaccurate compasses

Samia Souissi, Xavier Défago, Masafumi Yamashita

Research output: Chapter in Book/Report/Conference proceedingConference contribution

54 Citations (Scopus)


This paper considers a system of asynchronous autonomous mobile robots that can move freely in a two-dimensional plane with no agreement on a common coordinate system. Starting from any initial configuration, the robots are required to eventually gather at a single point, not fixed in advance (gathering problem). Prior work has shown that gathering oblivious (i.e., stateless) robots cannot be achieved deterministically without additional assumptions. In particular, if robots can detect multiplicity (i.e., count robots that share the same location) gathering is possible for three or more robots. Similarly, gathering of any number of robots is possible if they share a common direction, as given by compasses, with no errors. Our work is motivated by the pragmatic standpoint that (1) compasses are error-prone devices in reality, and (2) multiplicity detection, while being easy to achieve, allows for gathering in situations with more than two robots. Consequently, this paper focusses on gathering two asynchronous mobile robots equipped with inaccurate compasses. In particular, we provide a self-stabilizing algorithm to gather, in a finite time, two oblivious robots equipped with compasses that can differ by as much as π/4.

Original languageEnglish
Title of host publicationPrinciples of Distributed Systems - 10th International Conference, OPODIS 2006, Proceedings
PublisherSpringer Verlag
Number of pages17
ISBN (Print)9783540499909
Publication statusPublished - 2006
Event10th International Conference on Principles of Distributed Systems, OPODIS 2006 - Bordeaux, France
Duration: Dec 12 2006Dec 15 2006

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume4305 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other10th International Conference on Principles of Distributed Systems, OPODIS 2006

All Science Journal Classification (ASJC) codes

  • Theoretical Computer Science
  • General Computer Science


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