Tight analysis of a collisionless robot gathering algorithm

Gokarna Sharma, Costas Busch, Supratik Mukhopadhyay, Charles Malveaux

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

1 Scopus citations


We consider the fundamental problem of gathering a set of n robots in the Euclidean plane which have a physical extent and hence they cannot share their positions with other robots. The objective is to determine a minimum time schedule to gather the robots as close together as possible around a predefined gathering point avoiding collisions. This problem has applications in many real world scenarios including fast autonomous coverage formation. Cord-Landwehr et al. (SOFSEM 2011) gave a local greedy algorithm in a synchronous setting and proved that, for the discrete version of the problem where robots movements are restricted to the positions on an integral grid, their algorithm solves this problem in O(nR) rounds, where R is the distance from the farthest initial robot position to the gathering point. In this paper, we improve significantly the round complexity of their algorithm to R + 2 · (n - 1) rounds. We also prove that there are initial configurations of n robots in this problem where at least R + (n - 1) over 2 rounds are needed by any local greedy algorithm. Furthermore, we improve the lower bound to R + (n - 1) rounds for the algorithm of Cord-Landwehr et al.. These results altogether provide a tight runtime analysis of their algorithm.

Original languageEnglish (US)
Title of host publicationIROS Hamburg 2015 - Conference Digest
Subtitle of host publicationIEEE/RSJ International Conference on Intelligent Robots and Systems
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages6
ISBN (Electronic)9781479999941
StatePublished - Dec 11 2015
Externally publishedYes
EventIEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2015 - Hamburg, Germany
Duration: Sep 28 2015Oct 2 2015

Publication series

NameIEEE International Conference on Intelligent Robots and Systems
ISSN (Print)2153-0858
ISSN (Electronic)2153-0866


ConferenceIEEE/RSJ International Conference on Intelligent Robots and Systems, IROS 2015

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Software
  • Computer Vision and Pattern Recognition
  • Computer Science Applications


Dive into the research topics of 'Tight analysis of a collisionless robot gathering algorithm'. Together they form a unique fingerprint.

Cite this