,
Marc van Kreveld
,
Othon Michail
,
Andreas Padalkin
Creative Commons Attribution 4.0 International license
We consider geometric collision-detection problems for modular reconfigurable robots. Assuming the nodes (modules) are connected squares on a grid, we investigate the complexity of deciding whether collisions may occur, or can be avoided, if a set of expansion and contraction operations is executed. We study both discrete- and continuous-time models, and allow operations to be coupled into a single parallel group. Our algorithms to decide if a collision may occur run in O(n²log² n) time, O(n²) time, or O(nlog² n) time, depending on the presence and type of coupled operations, in a continuous-time model for a modular robot with n nodes. To decide if collisions can be avoided, we show that a very restricted version is already NP-complete in the discrete-time model, while the same problem is polynomial in the continuous-time model. A less restricted version is NP-hard in the continuous-time model.
@InProceedings{gupta_et_al:LIPIcs.SAND.2024.26,
author = {Gupta, Siddharth and van Kreveld, Marc and Michail, Othon and Padalkin, Andreas},
title = {{Brief Announcement: Collision Detection for Modular Robots - It Is Easy to Cause Collisions and Hard to Avoid Them}},
booktitle = {3rd Symposium on Algorithmic Foundations of Dynamic Networks (SAND 2024)},
pages = {26:1--26:5},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-315-7},
ISSN = {1868-8969},
year = {2024},
volume = {292},
editor = {Casteigts, Arnaud and Kuhn, Fabian},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.SAND.2024.26},
URN = {urn:nbn:de:0030-drops-199044},
doi = {10.4230/LIPIcs.SAND.2024.26},
annote = {Keywords: Modular robots, Collision detection, Computational Geometry, Complexity}
}