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Bibliographic Details
Main Authors: Amir, Michael, Rabinovich, Dmitry, Bruckstein, Alfred M.
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2307.09214
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author Amir, Michael
Rabinovich, Dmitry
Bruckstein, Alfred M.
author_facet Amir, Michael
Rabinovich, Dmitry
Bruckstein, Alfred M.
contents This work addresses the challenge of patrolling regular grid graphs of any dimension using a single mobile agent with minimal memory and limited sensing range. We show that it is impossible to patrol some grid graphs with $0$ bits of memory, regardless of sensing range, and give an exact characterization of those grid graphs that can be patrolled with $0$ bits of memory and sensing range $V$. On the other hand, we show that an algorithm exists using $1$ bit of memory and $V=1$ that patrols any $d$-dimensional grid graph. This result is surprising given that the agent must be able to move in $2d$ distinct directions to patrol, while $1$ bit of memory allows specifying only two directions per sensory input. Our $1$-bit patrolling algorithm handles this by carefully exploiting a small state-space to access all the needed directions while avoiding getting stuck. Overall, our results give concrete evidence that extremely little memory is needed for patrolling highly regular environments like grid graphs compared to arbitrary graphs. The techniques we use, such as partitioning the environment into sensing regions and exploiting distinct coordinates resulting from higher-dimensionality, may be applicable to analyzing the space complexity of patrolling in other types of regular environments as well.
format Preprint
id arxiv_https___arxiv_org_abs_2307_09214
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Patrolling Grids with a Bit of Memory
Amir, Michael
Rabinovich, Dmitry
Bruckstein, Alfred M.
Robotics
Computational Geometry
Discrete Mathematics
Multiagent Systems
Combinatorics
05A99
F.2.2; G.2.1
This work addresses the challenge of patrolling regular grid graphs of any dimension using a single mobile agent with minimal memory and limited sensing range. We show that it is impossible to patrol some grid graphs with $0$ bits of memory, regardless of sensing range, and give an exact characterization of those grid graphs that can be patrolled with $0$ bits of memory and sensing range $V$. On the other hand, we show that an algorithm exists using $1$ bit of memory and $V=1$ that patrols any $d$-dimensional grid graph. This result is surprising given that the agent must be able to move in $2d$ distinct directions to patrol, while $1$ bit of memory allows specifying only two directions per sensory input. Our $1$-bit patrolling algorithm handles this by carefully exploiting a small state-space to access all the needed directions while avoiding getting stuck. Overall, our results give concrete evidence that extremely little memory is needed for patrolling highly regular environments like grid graphs compared to arbitrary graphs. The techniques we use, such as partitioning the environment into sensing regions and exploiting distinct coordinates resulting from higher-dimensionality, may be applicable to analyzing the space complexity of patrolling in other types of regular environments as well.
title Patrolling Grids with a Bit of Memory
topic Robotics
Computational Geometry
Discrete Mathematics
Multiagent Systems
Combinatorics
05A99
F.2.2; G.2.1
url https://arxiv.org/abs/2307.09214