smoke sentry 2_pdr_presentation
TRANSCRIPT
SMOKE SENTRY 2Preliminary Design Review
Senior Design Clinic
Team 10
Team Members and Roles Core Team:
Jeff Frank (EE) – Team LeadKelvin Kosbab (EE)Tim Nguyen (EE)Mike Masek (ME)
Advisor: Ramesh Rajagopalan Observers:
Chris Engelmann (Sponsor)Kevin Nicholson (Engineering Coordinator)
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Background
Smoke from fires and cigarettes differs greatlyCigarette smoke particles:
○ Considerably smaller○ Reduced particle concentration
Commercial smoke detectors are designed for fires○ Insensitive to cigarette smoke
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Problem Statement
Very challenging for hotels to enforce no smoking policies Some guests are sensitive to smoke residue
○ Discomfort○ Health issues○ Unpleasant odors
Smoke damage can result in thousands of dollars in repair costs
Customer needs system capable of notifying hotel staff of smoking violations
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Statement of Work
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Statement of Work
Deliverables:Research documentationDesign documentationPrototype of a cigarette smoke monitoring
systemTest specificationsData supporting a prototype functioning
within specifications
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Customer Requirements
Cost target: Detection Unit: < $50Monitoring Station: < $1,500
Size target: < twice fire smoke detectorssmaller than 8.5” x 8.5” x 3”
Improved sensitivity over existing detectors
Network capable of 100 room hotel Functional under US regulations
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Requirements Validation
Functional Requirement Validation
Capable of detecting cigarette smoke
Minimize false positives < 2 per hotel
Latency Network: < 20 seconds Detection: < 5 minutes
Establish controlled tests Record conditions
Run in controlled setting Count total false positives
Measure using timestamp
Testing in similar room
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What is Smoke? Gases
Carbon monoxide, nitrogen oxide
ChemicalsFormeldehyde, acrolene, benzene
ParticulatesNicotene, phenol, polyaromatic hydrocarbonsSize: 100 – 4,000 nm
http://www.engineeringtoolbox.com/particle-sizes-d_934.html
http://cancercontrol.cancer.gov/tcrb/monographs/7/m7_5.pdf 9
Work Breakdown Structure
Design choices have little effect on each other
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Smoke Detection
Cigarette smoke (average):
100 nm – 300 nm
Goal: optimize laser technique Increase sensitivity
○ Obscuration○ Particle size
Minimize false positives
Type of Detector
Obscuration Level(% obs/m)
Particle Sensitivity Range(nm)
Ionization 2.6 – 5.0 10 - 300
Photoelectric 6.5 – 13.0 300 – 10,000
Laser 0.06 – 6.41 N/A
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Ionization Method
Smoke Absent Smoke Present
http://www.epa.gov/radiation/sources/smoke_ion.html 15
Ionization Design Tweaks
Dual chamber sensorRejects fluctuations in humidity and
atmospheric pressure Increase current between plates
Larger voltageMinimize distance
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Implementation Difficulties
Measuring pico-Amps Design and construction of ionization
chamber Radioactive material
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Photoelectric Method
Smoke Absent Smoke Present18
Optimization Design Tweaks Laser Diode
Much brighter than LED
635 nm Photo-sensor array
Minimize ambient light
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Optimization Design Tweaks
Optical techniquesMirrorsLensFilters
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Optimization Design Tweaks Lock-in Amplifier
Laser sine wavePhotosensor sine wave
Noise rejectionAll frequencies components not equal to
sine wave attenuated○ Ambient light○ High frequency transients
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General Techniques
Optimize airflow into smoke chamber Concentrate airflow to one area
Laser beam path Algorithm rejects dust detection
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Flame Detection
UV and IR detection in combination
Used as a secondary sensorApplied as an aid for primary sensorIncrease sampling rate of Photoelectric
sensorSend notification to front desk
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Sensor Nodes: Microprocessor Requirements on microprocessor not
demandingChoose a PIC from Microchip
○ Many microprocessors availableChoose the smallest, cheapest one with
enough I/O and peripherals
Requires SPI, timer, sufficient I/O pins
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Wireless Network
Transmitted DataSmoke statusFlame statusRoom #Time Stamp
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Wireless Network Protocol IEEE 802.15.4
Low data rate, Personal Area Networks○ Zigbee○ MiWi
2.4 GHz – International○ 250 Kbit/s○ Shorter range
915 MHz – North America○ 40 Kbit/s○ Longer range
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MiWi Less complex implementation of ZigBee
Shorter development time○ MiWi Development Studio○ ZENA
MiWi standardizes…Network protocol
○ Software package
Transceivers
Hotel room capability: 8,128Mesh routing 28
Monitoring Station Application run on Windows 7 laptop
USB connected MiWi transceiver (ZENA)
Option 1: LabVIEWPros: Easiest to implement, most of the
programming already doneCons: License fee, not as flexible, limited
hardware options (NI hardware only)
http://labviewwiki.org/images/thumb/3/32/LabVIEW_Logo_Vertical_4c.jpg/200px-LabVIEW_Logo_Vertical_4c.jpg
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Monitoring Station Option 2: Java application
Communication with ZENA via C commands and system commands
Pros: Free, flexible, easy to implement, more control, experience in Java programming
Cons: more coding, more testing
http://www.digitaltrends.com/computing/most-vulnerable-browser-plugin-think-java-not-flash/
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Design Summary
Cigarette DetectionSmoke detection – Laser (Photoelectric)Flame detection – UV & IR
Wireless NetworkMiWi
Monitoring StationJavaZENA
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Project Schedule
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Budget
Total Allocated Budget = $2,500○ Cigarette Detection
$200
○ Wireless Network$500
○ PCB & Housing$400
○ Miscellaneous Prototyping$300
Estimated Cost: $1,400
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QUESTIONS?
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