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How to Gather Asynchronous Oblivious Robots on Anonymous Rings

  • Gianlorenzo D’Angelo
  • Gabriele Di Stefano
  • Alfredo Navarra
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7611)

Abstract

A set of robots arbitrarily placed on different nodes of an anonymous ring have to meet at one common node and remain in there. This problem is known in the literature as the gathering. Anonymous and oblivious robots operate in Look-Compute-Move cycles; in one cycle, a robot takes a snapshot of the current configuration (Look), decides whether to stay idle or to move to one of its neighbors (Compute), and in the latter case makes the computed move instantaneously (Move). Cycles are asynchronous among robots. Moreover, each robot is empowered by the so called multiplicity detection capability, that is, it is able to detect during its Look operation whether a node is empty, or occupied by one robot, or occupied by an undefined number of robots greater than one.

The described problem has been extensively studied during the last years. However, the known solutions work only for specific initial configurations and leave some open cases. In this paper, we provide an algorithm which solves the general problem, and is able to detect all the ungatherable configurations. It is worth noting that our new algorithm makes use of a unified and general strategy for any initial configuration, even those left open by previous works.

Keywords

Mobile Robot Common Node Single Robot Axis Passing Mobile Entity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Gianlorenzo D’Angelo
    • 1
  • Gabriele Di Stefano
    • 2
  • Alfredo Navarra
    • 3
  1. 1.MASCOTTE ProjectINRIA/I3S(CNRS/UNSA)France
  2. 2.Dipartimento di Ingegneria e Sceinze dell’Informazione e MatematicaUniversità degli Studi dell’AquilaItaly
  3. 3.Dipartimento di Matematica e InformaticaUniversità degli Studi di PerugiaItaly

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