Uniform robot relocation is hard in only two directions even without obstacles
Document Type
Article
Publication Date
3-2025
Abstract
Given n unit-sized robots contained within a square grid surrounded by four walls, we ask the question of whether it is possible to move a particular robot a to a specific grid location b by performing a sequence of global step operations in which all robots move one grid step in the same cardinal direction (if not blocked by a wall or other blocked robots). We show this problem is NP-complete when restricted to just two directions (south and west). This answers the simplest fundamental problem in uniform global unit tilt swarm robotics. We then consider a relaxed version of this problem called row relocation in which the goal is to move a robot a to a specific row regardless of its horizontal placement. We show that if asking about the first row of the square grid (bottom-most), then this version of the problem is solvable in polynomial time. Finally, we discuss several areas for future research and open problems.
Recommended Citation
Caballero, David, Angel A. Cantu, Timothy Gomez, Austin Luchsinger, Robert Schweller, and Tim Wylie. "Uniform robot relocation is hard in only two directions even without obstacles." Natural Computing 24, no. 1 (2025): 3-16. https://doi.org/10.1007/s11047-024-10007-4
Publication Title
Natural Computing
DOI
10.1007/s11047-024-10007-4
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