Stand Up Indulgent Gathering

Quentin Bramas (1, 2, 3) , Anissa Lamani (1, 2, 3) , Sébastien Tixeuil (4)

1 ICube - Laboratoire des sciences de l'ingénieur, de l'informatique et de l'imagerie
2 UNISTRA - Université de Strasbourg
3 ICUBE-Réseaux - Equipe Réseaux du laboratoire ICUBE
4 NPA - Networks and Performance Analysis

We consider a swarm of mobile robots evolving in a bidimensional Euclidean space. We study a variant of the crash-tolerant gathering problem: if no robot crashes, robots have to meet at the same arbitrary location, not known beforehand, in finite time; if one or several robots crash at the same location, the remaining correct robots gather at the crash location to rescue them. Motivated by impossibility results in the semi-synchronous setting, we present the first solution to the problem for the fully synchronous setting that operates in the vanilla Look-Compute-Move model with no additional hypotheses: robots are oblivious, disoriented, have no multiplicity detection capacity, and may start from arbitrary positions (including those with multiplicity points). We furthermore show that robots gather in a time that is proportional to the initial maximum distance between robots.

Mots clés: Mobile robots; gathering; fault-tolerance

Domaines: Calcul parallèle, distribué et partagé [cs.DC]; Système multi-agents [cs.MA]

Quentin Bramas, Anissa Lamani, Sébastien Tixeuil. Stand Up Indulgent Gathering. Theoretical Computer Science, 2023, 939, pp.63-77. ⟨10.1016/j.tcs.2022.10.015⟩. ⟨hal-03975261⟩