Post on 25-Dec-2015
transcript
Underwater Network Localization
Patrick Lazar, Tausif Shaikh, Johanna Thomas, Kaleel Mahmood
University of Connecticut Department of Electrical Engineering
OutlineBackgroundObjectiveHardware/SoftwareMethods
SynchronousAsynchronous
Range TestNoise TestBudgetFuture WorkDivision of RolesTimeline
BackgroundCannot use GPS because electromagnetic
signals cannot propagate well through waterUse acoustic signals
Signal strength independent of conductivity of medium
Currently four commercial underwater localization techniques
Two research methodsSynchronousAsynchronous
ObjectiveDesign a highly accurate localization system
capable of being used on underwater vehicles.
Implement localization algorithms for real time testing.
Provide the AUV senior design group with an effective localization schematic that can be integrated into the AUV for underwater tracking.
Hardware/SoftwareSix digital processing boardsFour anchor nodesOne tracking nodeSix hydrophonesSix transducersFour GPS tracking devicesWaterproof housingSoftware : Code Composer Studio 5.1
DSP boards in waterproof housing.
Synchronous LocalizationAdvantages of synchronous localization:
Able to service multiple AUV at onceDoes not require continuous GPS signal to
synchronize surface nodes Disadvantages of synchronous localization:
Nodes must be on the surface initially to receive a GPS signal initially.
Any missed node signal means position can not be computed if working with the minimum node schematic.
Synchronous Code Flow DiagramStart
(nodes)
Init Modem
Send Call
Wait for other nodes
Start(AUV)
Init Modem
Listen for node
calls
when 4 calls
received
Position algorithm
Asynchronous LocalizationAdvantages of Asynchronous Localization:
Node clocks do not require synchronization with each other.
Extra timing measurements sent from other nodes can be factored into to calculations to provide better position accuracy.
Disadvantages of Asynchronous Localization:The initiator signal must send out a delay factor
long enough so no nodes send out signals at the same time.
Never field tested so actually accuracy improvement is unknown.
Asynchronous Code Flow DiagramStart
(nodes)
Init Modem
Wait for AUV call
Record time
Send Respons
e
Start(AUV)
Init Modem
Call N1
Call N2
Call N3
Call N4
Record N1
response
Record N2
response
Record N3
response
Record N4
response
Localize
Position algorithm
Range TestThe speed of sound travels at a faster rate in
water than air.It depends on water properties of
temperature, salinity, and pressure.As temperature of water increases, the speed
of sound increases.On average, the speed of sound travels at
approximately 1500 m/s under water.
Noise TestThe range of the signal can be affected by the
ambient noises and man made noises.The variance calculated from the noise test is
used to calculate the Time of Arrival (TOA) of the signal.
Swimming Pool
BudgetCurrently all our hardware needs are handled
by the Underwater Sensor Network Lab.In terms of software the version of Code
Composer studio we use is a free license version provided by the company.
At this time we have no plans to use the $1000 budget but in the future we may consider using funding to buy additional digital signal processing boards from Spectrum Digital if necessary.
Future WorkAnalyze the modem code supplied by UWSN LabCreate algorithm code for both Asynchronous and
Synchronous methods in C.Implement tracking algorithms for localization of
moving objects (if needed)Conduct pool testing:
Range test of equipmentDetermine delay time for more accurate
calculationsDetermine pool interference
Project RolesTausif Shaikh (EE)
Synchronous and
Asynchronous algorithm
implementation in C
Analysis of pool test results
Website maintenance and updates
Johanna Thomas
(EE)Synchronous
and Asynchronous
algorithm implementation
in C
Analysis of pool test results
Coordinator of data and
results collected by
each part of the team
Patrick Lazar (EE)
DSP Board Programming
Hardware setup
Website maintenance and updates
Kaleel Mahmood (EE)
DSP Board programming
Hardware setup
Main communication
between design group and advisor
September
• Project Statement.
•Background research in existing Localization methods.
October
•Project specifications.
•Additional localization research.
•Coding DSP C
November
•Code composer studio setup and completion of tutorial on coding in DSP C.
•Finalize implementation plans.
December
•Ranging and noise pool tests using two nodes.
•Coding DSP C algorithms.
Timeline
January
•Ranging and pool tests using two nodes.
•Hardware setup of remaining nodes.
•Field testing of algorithms .
February
•Field testing of algorithms.
•Algorithm comparison analysis.
March
•Field testing of algorithms.
•Algorithm comparison analysis.
April
•Integration of localization with other groups.
•Algorithm comparison analysis.
May
•Complete integration of localization with an AUV.