In this thesis, a variety of different approaches are proposed to study the energy restoration problem in wireless sensor networks by one or more robots.
First, we introduce an on-demand decentralized strategy performed by a robot that
visits the sensors in a predefined circular order. We study it both analytically and experimentally analyzing the impact of various network parameters on network coverage,
disconnection time, and time sensors have to wait to be served. We then introduce an optimal centralized approach as a benchmark to assess how close to optimal our on-demand
strategy is, and we discover that, for sufficiently large networks, the on-demand strategy
is indeed optimal. We then propose an even simpler mechanism where the robot simply
moves blindly along the circular order, which is experimentally shown to be as efficient as
the other two. The results above apply to arbitrary sensor network; we then consider a
common special topology: a linear arrangement of sensors, were we propose three restoring
mechanisms. We compare them experimentally discovering, once again, that the simplest
approach is also the best, in most cases. We finally consider the case of multiple robots.
We propose two strategies where the network is portioned among the robots and each
robot takes care of a portion, and we compare those with a collaborative strategy where
all robots work on the global network.
The main general result of this study is that simple solutions are often as good as more
sophisticated ones. In fact, a totally blind strategy where a robot simply moves around
restoring energy on its way turns out to be as efficient as the best possible centralized
solution for most networks.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/39226 |
| Date | 23 May 2019 |
| Creators | Omar, Eman |
| Contributors | Flocchini, Paola, Santoro, Nicola |
| Publisher | Université d'Ottawa / University of Ottawa |
| Source Sets | Université d’Ottawa |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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