autowitness : locating and tracking stolen property while tolerating gps and radio outages
DESCRIPTION
AutoWitness : Locating and Tracking Stolen Property While Tolerating GPS and Radio Outages. Santanu Guha , Kurt Plarre , Daniel Lissner , Somnath Mitra , Bhagavathy Krishna, Prabal Dutta , Santosh Kumar ACM SenSys 2010 - Sowhat 2010.11.23. Outlines. Motivation - PowerPoint PPT PresentationTRANSCRIPT
AUTOWITNESS: LOCATING AND TRACKING STOLEN PROPERTY WHILE TOLERATING GPS AND RADIO OUTAGES
Santanu Guha, Kurt Plarre, Daniel Lissner, Somnath Mitra, Bhagavathy Krishna, Prabal Dutta, Santosh Kumar
ACM SenSys 2010- Sowhat 2010.11.23
OUTLINES Motivation Objectives & Challenges Related Works System Overview Hardware Design
Theft detection Estimating distance & Turns
Evaluation Conclusion
OUTLINES Motivation Objectives & Challenges Related Works System Overview Hardware Design
Theft detection Estimating distance & Turns
Evaluation Conclusion
Property crimes17.2 billion
Burglary, 22.7%$2079 / $4.6 billion
90% un-recovered
Larceny-theft, 67.5% $925 / $6.1 billion
90% un-recovered
Motor vehicle theft, 9.8%$6751 / $6.4 billion 80% recovered
MOTIVATION According to the FBI Uniform Crime Report,
2008an estimated losses resulted from…
OUTLINES Motivation Objectives & Challenges Related Works System Overview Hardware Design
Theft detection Estimating distance & Turns
Evaluation Conclusion
OBJECTIVES & CHALLENGES
Objectives Detection of theft Tracking of the stolen tag Pinpointing of the location
Challenges - Cost & Energy Hardware selection Theft classifier Tracking method
OUTLINES Motivation Objectives & Challenges Related Works System Overview Hardware Design
Theft detection Estimating distance & Turns
Evaluation Conclusion
RELATED WORKS Traditional home security systems
Deter or detect burglary only Unable to track or recover
Traditional asset tracking and vehicle recovery systems detected Not tolerate in-transit cloaking High power
LoJack, the most common stolen vehicle recovery systems A device to receive the activation signal needed High-power transmissions once actived Cost, $695
OUTLINES Motivation Objectives & Challenges Related Works System Overview Hardware Design
Theft detection Estimating distance & Turns
Evaluation Conclusion
SYSTEM OVERVIEW
SYSTEM OVERVIEWEmded tag
Dormant
Motion
Vehicular movement
Distance / turn estimate
(Accelerometer / Gyro)
Transfer to server(GSM / GPRS)
Path reconstruction
Motion detection(vibration dosimeter)
Sufficient time & RF power available
Classification(Accelerometer)
SYSTEM OVERVIEW
OUTLINES Motivation Objectives & Challenges Related Works System Overview Hardware Design
Theft detection Estimating distance & Turns
Evaluation Conclusion
HARDWARE Vibration dosimeter
– Motion detect 3-axis accelerometer
– Theft classification & Distance estimation 3-asix gyroscope
– Turns estimation GSM/GPRS modem
– Transfer Epic Core platform
OUTLINES Motivation Objectives & Challenges Related Works System Overview Hardware Design
Theft detection Estimating distance & Turns
Evaluation Conclusion
DESIGN – THEFT DETECTIONFLOW DIAGRAMDeep sleep Accelerometer sampling 1.05sec,
@200Hz
Accelerometer sampling 4.2 sec, @200Hz
Variance >
threshold
Compute variance ofmedians of every 15
samples
Partition 5.25 sec worth of data in 5 intervals
Decision tree classifier appliedMajority rule
vehicular movemen
t
Tracking
N
N
Y
Y
Collecting data in different scenarios Walking person car trolleys Rolling chair
Activity classification workUsing mobile phones to determine transportation modes[23]
Feature – energy & standard deviation
DESIGN – THEFT DETECTIONCLASSIFIER
Design - Estimating distance & TurnsAngle estimate Gyro rotation speed single integration
change in the attitude
Absolute value of 1st difference
Thresholds, Dh & Dl
Activation time
DESIGN - ESTIMATING DISTANCE & TURNSDISTANCE ESTIMATE 2nd order Butterworth Filter to remove noise
Median of 20 samples mean of 10 such medians
Accelerometer Double integration Distance
Curved roads – angular rotation info. From gyro
OUTLINES Motivation Objectives & Challenges Related Works System Overview Hardware Design
Theft detection Estimating distance & Turns
Evaluation Conclusion
EVALUATION – THEFT DETECTION 15000 samples (210 acc. readings/sample)
vehicle vs. person
EVALUATION – TURN ESTIMATION 120 turns for 6 values of angles
Ground truth – GPS on Android G1 phone
EVALUATION – DISTANCE ESTIMATION 300 different road segments (0.2 ~ 1.5miles)
Ground truth – GPS on Android G1 phone
OUTLINES Motivation Objectives & Challenges Related Works System Overview Hardware Design
Theft detection Estimating distance & Turns
Evaluation Conclusion
CONCLUSION Design & evaluation of the AutoWitness
systemDeter, detect, and track personal property theftLow-costUltra-low energy
Item PerformanceTheft detection No false negative / 1.45% false positiveTurn estimation Percentage error = 6.92 in averageDistance estimation >95% percentage of error < 10
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