unmanned mobile sensor net - ben snively
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Unmanned Mobile Sensor Net- Ben Snively
Unmanned Underwater Gliders
Survey and extensions to work from:COOPERATIVE CONTROL OF COLLECTIVE MOTION FOR OCEAN SAMPLING WITH AUTONOMOUS VEHICLES; Derek A. Paley
University of Central Florida
Manual Ocean Sampling labor, resource, and time intensive.
Objectives/Sensing Gradient Climbing Feature Tracking Boundary Monitoring Perimeter Surveillance Mapping
Autonomous Distributed Agents both reduce over costs, improve accuracy, and reduce latency for critical data.
Problem / Motivation
University of Central Florida
Marine Sensing Equipment
NOAA Manual Ocean Survey Ships with complex survey equipment Performs in both shallow and deep
water collections.
AUV – Autonomous Underwater Vehicle Shallow water survey using GPS and
Satellite communication
University of Central Florida
Sensor Network Details
Sink Satellite Communication
Agents/Sensors Mobile Gliders Every Glider in Range of Sink / GPS
Satellite only communicate with satellite when at surface
Cannot control movement at surface (just floats) – has control only when submerged.
GCCS – Glider Coordinated Control System GCCS steers groups/sets of gliders Gliders controlled remotely No Agenda/Beliefs/Planning
GCCS
University of Central Florida
Overview
“Apply a cooperative control methodology to control a fleet of autonomous underwater gliders. Underwater gliders soar through the water on a pair of fixed wings, collecting valuable oceanographic data for weeks at a time. We describe the Glider Coordinated Control System (GCCS), which steers multiple gliders to a set of coordinated trajectories. The GCCS automatically controlled up to six gliders continuously for over three weeks in a 800 km2 region in California’s Monterey Bay in August 2006. The GCCS enables oceanographers to specify and adapt glider sampling patterns with minimal human intervention.”(Paley)
University of Central Florida
Mobile Sensors and Sink
University of Central Florida
Domain Definition
Domain:Outer Search Area
University of Central Florida
Domain Example<domain>
<rectangle><x>
<units>deg</units><value>-122.3817</value>
</x><y>
<units>deg</units><value>36.9765</value>
</y><a>
<units>met</units><value>20000</value>
</a><b>
<units>met</units><value>10000</value>
</b><ori>
<units>deg</units><value>137</value>
</ori>
</rectangle></domain>
Center Point Longitude
Center Point Longitude
Width
Height
Angle
University of Central Florida
Search Paths
Tracks Search Paths
University of Central Florida
Tracks Example<tracks>
<superellipse><name>track1</name><x>
<units>deg</units><value>-122.2713</value>
</x><y>
<units>deg</units><value>36.8950</value>
</y><a>
<units>met</units><value>10000</value>
</a><b>
<units>met</units><value>6667</value>
</b><ori>
<units>deg</units><value>47</value>
</ori><p>
<value>3</value></p>
</superellipse></tracks>
Shape/Name
Center Point
Width
Height
University of Central Florida
Glider Groups
Glider Tree:Entities, which paths to use,Comm model.
University of Central Florida
Glider Groups Example
<group><group>
<phase> <value>0</value> <units>pct</units>
</phase><glider>
<mnf>w</mnf> <!-- Manufacturer --><sn>7</sn> <!-- Serian Number --><model>e</model><track>track1</track><direction>1</direction><phase> <!-- Curve Phase -->
<value>0</value><units>pct</units>
</phase><control> sellipse control </control>
</glider><glider> . . . </glider>
</group></group>
University of Central Florida
YAES Simulations
Simulations Performed
1. 4 Boundary Gliders rotating same direction
2. 4 Boundary and 6 Interior Sensors, All positioned in ideal/planned position.
3. 4 Boundary and 6 Interior Gliders, all starting from hub location
Actual software from research done in Matlab. Software allows for both simulated and real tests
University of Central Florida
Background Information on Simulation
XML Configurations drive simulation setup and context. Much like the Real system, xml configuration files define gliders,
tracks, and other system configuration. (The XML Schema was slightly modified in order to simplify configuration)
Main Simulation class allows for selection of which simulation to perform.
JAXB used to parse XML Input / Java 1.6 SDK/Runtime(JAXB = Java API for XML Binding)
University of Central Florida
Simulation 1: Boundary Test
Sink Communication at surface4 Boundary Gliders
University of Central Florida
Simulation 2 : Interior Gliders
6 Interior Gliders covering Area3 Groups, 2 Gliders in each.(Gliders communicate w/ Sink at Surface)
University of Central Florida
Simulation 3 : Boundary and Interior Gliders
Sink Communication at surface4 Boundary Gliders6 Interior Gliders
Flow adds error (off track) when Glider is at surface
University of Central Florida
Extending Network
Current Limitations Central control/Planning Planning communication only done at surface
(when gliders are floating and have no control – drift) Limited Inter-glider communication.
Extending Sensor network principals to the system Gliders become agents with beliefs, agendas, and planning Sensor communication models and MDP principals
(Specifically Partially Observable - MDP) This is critical due to the fluxations and inconsistencies in the robot
control.
University of Central Florida
Glider Agents
Key Difference Glider has Agenda, Goal, and isn’t pure input/sensing device.
Glider communicate with each other Goal:
Cover area (and plan) that hasnot been covered by other agents.
Inform others plan/area covered.
Single Sink transmitter could be at surface, to bridge under-water to satellite gap.
University of Central Florida
Planning / Decision Process
PO-MDP (Partially Observable Mark-ov Decision Process. Outcome from Glider commands uncertain.
Policy mapping between States / Actions Perceived new State.
Routing issues isn’t applicable due to every glider having access to the sink (via satellite). Routing issues could be introduced in a more complex system where
messages between gliders and to sink are transmitted.
University of Central Florida
Questions?
Questions / Comments?
Thank you.
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