---
_id: '56298'
abstract:
- lang: eng
  text: "In the general pattern formation (GPF) problem, a swarm of simple autonomous,\r\ndisoriented
    robots must form a given pattern. The robots' simplicity imply a\r\nstrong limitation:
    When the initial configuration is rotationally symmetric,\r\nonly patterns with
    a similar symmetry can be formed [Yamashita, Suzyuki; TCS\r\n2010]. The only known
    algorithm to form large patterns with limited visibility\r\nand without memory
    requires the robots to start in a near-gathering (a swarm of\r\nconstant diameter)
    [Hahn et al.; SAND 2024]. However, not only do we not know\r\nany near-gathering
    algorithm guaranteed to preserve symmetry but most natural\r\ngathering strategies
    trivially increase symmetries [Castenow et al.; OPODIS\r\n2022].\r\n  Thus, we
    study near-gathering without changing the swarm's rotational\r\nsymmetry for disoriented,
    oblivious robots with limited visibility (the\r\nOBLOT-model, see [Flocchini et
    al.; 2019]). We introduce a technique based on\r\nthe theory of dynamical systems
    to analyze how a given algorithm affects\r\nsymmetry and provide sufficient conditions
    for symmetry preservation. Until\r\nnow, it was unknown whether the considered
    OBLOT-model allows for any\r\nnon-trivial algorithm that always preserves symmetry.
    Our first result shows\r\nthat a variant of Go-to-the-Average always preserves
    symmetry but may sometimes\r\nlead to multiple, unconnected near-gathering clusters.
    Our second result is a\r\nsymmetry-preserving near-gathering algorithm that works
    on swarms with a convex\r\nboundary (the outer boundary of the unit disc graph)
    and without holes (circles\r\nof diameter 1 inside the boundary without any robots)."
author:
- first_name: Raphael
  full_name: Gerlach, Raphael
  id: '32655'
  last_name: Gerlach
  orcid: 0009-0002-4750-2051
- first_name: Sören
  full_name: von der Gracht, Sören
  id: '97359'
  last_name: von der Gracht
  orcid: 0000-0002-8054-2058
- first_name: Christopher
  full_name: Hahn, Christopher
  last_name: Hahn
- first_name: Jonas
  full_name: Harbig, Jonas
  id: '47213'
  last_name: Harbig
- first_name: Peter
  full_name: Kling, Peter
  last_name: Kling
citation:
  ama: 'Gerlach R, von der Gracht S, Hahn C, Harbig J, Kling P. Symmetry Preservation
    in Swarms of Oblivious Robots with Limited  Visibility. In: Bonomi S, Galletta
    L, Rivière  Etienne, Schiavoni  Valerio, eds. <i>28th International Conference
    on Principles of Distributed Systems (OPODIS 2024)</i>. Vol 324. Leibniz International
    Proceedings in Informatics (LIPIcs). Schloss Dagstuhl -- Leibniz-Zentrum für Informatik;
    2025. doi:<a href="https://doi.org/10.4230/LIPIcs.OPODIS.2024.13">10.4230/LIPIcs.OPODIS.2024.13</a>'
  apa: Gerlach, R., von der Gracht, S., Hahn, C., Harbig, J., &#38; Kling, P. (2025).
    Symmetry Preservation in Swarms of Oblivious Robots with Limited  Visibility.
    In S. Bonomi, L. Galletta,  Etienne Rivière, &#38;  Valerio Schiavoni (Eds.),
    <i>28th International Conference on Principles of Distributed Systems (OPODIS
    2024)</i> (Vol. 324). Schloss Dagstuhl -- Leibniz-Zentrum für Informatik. <a href="https://doi.org/10.4230/LIPIcs.OPODIS.2024.13">https://doi.org/10.4230/LIPIcs.OPODIS.2024.13</a>
  bibtex: '@inproceedings{Gerlach_von der Gracht_Hahn_Harbig_Kling_2025, series={Leibniz
    International Proceedings in Informatics (LIPIcs)}, title={Symmetry Preservation
    in Swarms of Oblivious Robots with Limited  Visibility}, volume={324}, DOI={<a
    href="https://doi.org/10.4230/LIPIcs.OPODIS.2024.13">10.4230/LIPIcs.OPODIS.2024.13</a>},
    booktitle={28th International Conference on Principles of Distributed Systems
    (OPODIS 2024)}, publisher={Schloss Dagstuhl -- Leibniz-Zentrum für Informatik},
    author={Gerlach, Raphael and von der Gracht, Sören and Hahn, Christopher and Harbig,
    Jonas and Kling, Peter}, editor={Bonomi, Silvia and Galletta, Letterio and Rivière,  Etienne
    and Schiavoni,  Valerio}, year={2025}, collection={Leibniz International Proceedings
    in Informatics (LIPIcs)} }'
  chicago: Gerlach, Raphael, Sören von der Gracht, Christopher Hahn, Jonas Harbig,
    and Peter Kling. “Symmetry Preservation in Swarms of Oblivious Robots with Limited 
    Visibility.” In <i>28th International Conference on Principles of Distributed
    Systems (OPODIS 2024)</i>, edited by Silvia Bonomi, Letterio Galletta,  Etienne
    Rivière, and  Valerio Schiavoni, Vol. 324. Leibniz International Proceedings in
    Informatics (LIPIcs). Schloss Dagstuhl -- Leibniz-Zentrum für Informatik, 2025.
    <a href="https://doi.org/10.4230/LIPIcs.OPODIS.2024.13">https://doi.org/10.4230/LIPIcs.OPODIS.2024.13</a>.
  ieee: 'R. Gerlach, S. von der Gracht, C. Hahn, J. Harbig, and P. Kling, “Symmetry
    Preservation in Swarms of Oblivious Robots with Limited  Visibility,” in <i>28th
    International Conference on Principles of Distributed Systems (OPODIS 2024)</i>,
    Lucca, Italy, 2025, vol. 324, doi: <a href="https://doi.org/10.4230/LIPIcs.OPODIS.2024.13">10.4230/LIPIcs.OPODIS.2024.13</a>.'
  mla: Gerlach, Raphael, et al. “Symmetry Preservation in Swarms of Oblivious Robots
    with Limited  Visibility.” <i>28th International Conference on Principles of Distributed
    Systems (OPODIS 2024)</i>, edited by Silvia Bonomi et al., vol. 324, Schloss Dagstuhl
    -- Leibniz-Zentrum für Informatik, 2025, doi:<a href="https://doi.org/10.4230/LIPIcs.OPODIS.2024.13">10.4230/LIPIcs.OPODIS.2024.13</a>.
  short: 'R. Gerlach, S. von der Gracht, C. Hahn, J. Harbig, P. Kling, in: S. Bonomi,
    L. Galletta,  Etienne Rivière,  Valerio Schiavoni (Eds.), 28th International Conference
    on Principles of Distributed Systems (OPODIS 2024), Schloss Dagstuhl -- Leibniz-Zentrum
    für Informatik, 2025.'
conference:
  end_date: 2024-12-13
  location: Lucca, Italy
  name: 28th International Conference on Principles of Distributed Systems (OPODIS
    2024)
  start_date: 2024-12-11
date_created: 2024-10-01T13:29:43Z
date_updated: 2025-01-09T11:39:19Z
department:
- _id: '101'
doi: 10.4230/LIPIcs.OPODIS.2024.13
editor:
- first_name: Silvia
  full_name: Bonomi, Silvia
  last_name: Bonomi
- first_name: Letterio
  full_name: Galletta, Letterio
  last_name: Galletta
- first_name: ' Etienne'
  full_name: Rivière,  Etienne
  last_name: Rivière
- first_name: ' Valerio'
  full_name: Schiavoni,  Valerio
  last_name: Schiavoni
external_id:
  arxiv:
  - '2409.19277'
intvolume: '       324'
keyword:
- Swarm Algorithm
- Swarm Robots
- Distributed Algorithm
- Pattern Formation
- Limited Visibility
- Oblivious
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/2409.19277
oa: '1'
project:
- _id: '106'
  grant_number: '453112019'
  name: 'Algorithmen für Schwarmrobotik: Verteiltes Rechnen trifft Dynamische Systeme'
publication: 28th International Conference on Principles of Distributed Systems (OPODIS
  2024)
publication_identifier:
  isbn:
  - 978-3-95977-360-7
  issn:
  - 1868-8969
publication_status: published
publisher: Schloss Dagstuhl -- Leibniz-Zentrum für Informatik
series_title: Leibniz International Proceedings in Informatics (LIPIcs)
status: public
title: Symmetry Preservation in Swarms of Oblivious Robots with Limited  Visibility
type: conference
user_id: '97359'
volume: 324
year: '2025'
...
