Robot Sensor Networks

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.

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)

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

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

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

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

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

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

–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

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

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