Robot Sensor Networks

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Robot Sensor Networks
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Introduction

• For the current sensor network the topography and
  stability of the environment is uncertain and of
  course time is vitally important.
• Goals
• Map the space in 3D
• Identify targets within the space
• Long term goal is to deploy a physical system in
  a urban search and rescue test area.

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Challenge

• A challenge in working with the network is to
  reconfigure the network automatically but still
  focusing on the main goals.
• Network must possess reliability and complete
  full network connectivity
• Need to maintain consistent and reliable network
  communication amongst remote rescuers (human or
  robot)

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• Sensor networks may provide broader and more
  dynamic perspectives if placed strategically
  around an environment, delivering small snapshots
  over time.
• Later combine snapshots to create full image

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Non Mobile

• Traditional non mobile sensor networks possess
  potential yet face challenges
• Cant take an active role in manipulating and
  interacting with their environment
• Cant physically reconfigure themselves for more
  efficient area coverage, reliable wireless
  connectivity or protection against the elements

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Mobile Robots

• Mobile robots provide the ability to explore and
  interact with the environment in a dynamic and
  decentralized way.
• Robots with sensor capabilities offer new
  solutions to localization and navigation

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Problems

• Power management
• Communication
• Information fusion
• Message routing
• Decision making
• Role assignment
• System robustness
• System security

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Algorithmic questions

• Where should the network routing information be
  calculated and stored
• How should information regarding which sensors
  are detecting targets be distributed
• How should robots go about choosing a course of
  action
• What information should be exchanged between
  network components

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Robot Behavior

• Each robot to make a independent decision
• Avoid computational costs associated with
  sophisticated decison making
• Each robot has a hierarchy of behaviors
• Target has been detected
• Robot searches for the target until the robot
  finds the target, robot discovers another robot
  has gotten there or the robot knows the target
  signal

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• Target signal is present but some sensor is in
  range
• Robot will traverse the network towards a target
  some hops away
• Robot conducts a blind search looking first for
  target signals and for sensor signals

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• Once target is found and surroundings explored,
  sensors close enough to receive the target signal
  should be marked by the network
• Sensors may mark the passage of robots with a
  time stamp
• Doing so robots may decide to avoid sensors
  vistied often or recently
• Robots may leave trails in order to facilitate
  quick transference of information back to the
  base station

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Implementation

• The sensor robot systems perform badly when some
  of the targets have several sensors nearby while
  others have few or no nearby sensors