U ndergraduate S tudent’s T opology(H) C ourse An Introduction
CS H ONORS U NDERGRADUATE R ESEARCH P ROGRAM - F INAL P ROJECT T ALK Tingyu Thomas Lin Advisor:...
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CS HONORS UNDERGRADUATE RESEARCH PROGRAM - FINAL PROJECT TALK Tingyu Thomas Lin Advisor: Professor Deborah Estrin Date of Presentation: Thursday, June 7, 2007
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O UTLINE Overview of system Design Simulation Experimentation and Results
Transcript of CS H ONORS U NDERGRADUATE R ESEARCH P ROGRAM - F INAL P ROJECT T ALK Tingyu Thomas Lin Advisor:...
CS HONORS UNDERGRADUATE RESEARCH PROGRAM - FINAL PROJECT TALKTingyu Thomas LinAdvisor: Professor Deborah EstrinDate of Presentation: Thursday, June 7, 2007
AN INVESTIGATION OF ACOUSTIC SOURCE LOCALIZATION IN A HETEROGENEOUS NETWORK
OUTLINE Overview of system Design Simulation Experimentation and Results
OUTLINE Overview of system Design Simulation Experimentation and Results
OVERVIEW OF SYSTEM Two tiered distributed sensing network:
ENSBox + Lots of resources, precise - Expensive in cost, resources, to deploy in large
numbers Mica2 Mote
+ Cheap to deploy in large numbers - Resource constraints, poor resolution in measurements
Why? To leverage the advantages respective
advantages General context of acoustic source localization
OUTLINE Overview of system Design Simulation Experimentation and Results
SYSTEM GOALS Functionality to support acoustic localization:
Wireless Communication Time synchronization Self-calibration
ENSBox Already have functionality
Mica2 Mote Extend functionality to motes
WIRELESS COMMUNICATION & TIME SYNC Mote-Mote communication
Mica2 motes - onboard 433 MHz radio BMAC Transport/Routing Protocols
Mote-ENSBox communication ENSBox – tethered mote
Time Synchronization Flooding Time Synchronization Protocol (FTSP) Time translation between ENSBox & Motes
SELF-CALIBRATION How to determine positions of motes w/o any
prior knowledge of location? ENSBox acoustic source localization facilities
Equip motes with speakers
Process: Schedule the motes to emit a signal ENSBoxes localize signal Localization results => mote locations
DOA-BASED LOCALIZATION Determine Direction of Arrival (DOA)
Combine DOAs
DOA LIKELIHOOD PLOTS
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FUSING DOAS:PSEUDO-LIKELIHOOD MAPS
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LOCALIZATION, CONT’D The Mica2 Motes now support:
Wireless Communication Time synchronization Self-calibration
OUTLINE Overview of system Design Simulation Experimentation and Results
GOALS OF SIMULATION Modeling System
Rapid Simulation Controllable
Self-Calibration Accuracy of localizing Motes w/ ENSBoxes
SIMULATING LOCALIZATION Field
60x60 m, no obstructions
ENSBox placement and self-calibration Errors in self-calibration
Gaussian errors: 4 cm for position, .96 degrees in orientation
Mote Localization Sound wave DOA and pseudo-likelihood maps
SIMULATING LOCALIZATION
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OUTLINE Overview of system Design Simulation Experimentation and Results
EXPERIMENT #1 Questions:
Frequency of call? More ENSBoxes = better?
Scenario: 20 motes randomly but uniformly generated in
field Initially: 5 ENSBoxes Localize motes using different frequency calls
1 KHz, 4 KHz, 10 KHz
Increase ENSBox count up to 8
EXPERIMEN
T #1, CO
NT’D
Squares = ENSBoxes
Blue = Motes
Red = Estimated mote positions
Call: 1 KHz
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EXPERIMENT #1 RESULTS Table of mean errors ± standard deviation,
units in cm In this particular simulation setting:
Frequency of call, no effect Increasing ENSBox count, no effect
Frequency of Call 1 KHz 4 KHz 10 KHz
5 47±23 47±23 47±24Number
of 6 38±23 38±23 39±22ENSBoxes 7 40±35 39±35 36±31
8 39±25 40±25 38±23
EXPERIMENT #1 EXTENSION For 1 KHz call
localization results for 9 and 10 ENSBoxes Indicates > 5 ENSBoxes != >accuracy
Frequency of Call 1 KHz 4 KHz 10 KHz
5 47±23 47±23 47±24Number of 6 38±23 38±23 39±22ENSBoxes 7 40±35 39±35 36±31
8 39±25 40±25 38±239 44±19 - -
10 35±30 - -
EXPERIMENT #2 Question:
Least amount of ENSBoxes w/o losing accuracy?
Scenario: Same 20 motes 5 ENSBoxes to start from, 1 KHz calls from motes ENSBoxes removed, motes localized with
remaining boxes
EXPERIMEN
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NT’D
Same 5 ENSBoxes, 20 motes.
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EXPERIMENT #2 RESULTS1 ENSBox Removed,
4 left Error in Measurement
ID Mean Std. dev
1 46 18
2 32 15
3 52 24
4 50 24
5 51 32
2 ENSBox Removed, 3
left Error in Measurement
IDs Mean Std. dev
1,2 52 33
1,3 77 71
1,4 60 22
1,5 86 73
2,3 40 19
2,4 46 40
2,5 33 21
3,4 68 42
3,5 63 32
4,5 62 33
3 ENSBox Removed, 2
left Error in Measurement
IDs Mean Std. dev
1,2,3 138 114
1,2,4 87 84
1,2,5 73 50
1,3,4 148 157
1,3,5 160 152
1,4,5 133 170
2,3,4 106 257
2,3,5 40 21
2,4,5 88 104
3,4,5 173 242
EXPERIMENT #2 RESULTS, CONT’D In simulation framework:
< 5 ENSBoxes = < accuracy
Suggests: At least 5 ENSBoxes in the 60x60 m yields most
accuracy w/ errors about 40±25 cm Comparable to other mote acoustic localization
schemes
