lecture-7-cho_pte587_sensornet1-feb-24-2011

Ocean acousc tomography map the temperature and

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Unformatted text preview: –  Problem detec;on algorithm –  Calibra;on / training / learning of sensor •  Business –  Inexpensive, redundant, and spa;ally distributed sensors –  Quickly and easily installed, remote sensor monitoring –  Frequent data may lead to be|er understanding of injec;on 62 Many Inexpensive Sensor Nodes •  Intelligent Sensors –  Embedded System –  Low power embedded processor –  Integra;ng external sensors •  Advantages –  Exploit many inexpensive sensors –  Exploit local processing and computa;on •  The Sensor Node –  Berkeley Mica Z node –  Modified 3V Heliomote –  Temperature sensors 63 Interes;ng Detail: Steam Power •  Mo;va;on •  Embedded system needs “li|le” Power •  Steam ­flood pipes (500 degrees F) •  Con;nuous and “Free” energy •  No need for ba|eries or power outlet TEG Configuration •  Thermoelectric Generator (TEG) •  Seeback Effect •  Harvest electricity from temp. difference •  Steam pipe (hot) and ambient air (cool) 64 Seeback Effect Power Harvestor Heatsink TEG Insulation Aluminum block for thermal contact Hot plate (simulating steam pipe) •  Configura;on and Cost –  –  –  •  Harvested Energy –  65 260C rated, 40x40mm, lapped ceramic faces, w/ lead insulated wires (~$50) Aluminum Heat Sink and Parts (~$35) TEG pipe mount custom fabrica;on cost (~$200) Nearing 0.8W when delta T is 85 degree Celsius 2010 Field Test Thermoelectric Generator Wireless Sensor Node •  Experiment Result –  Con;nuous WSN overnight opera;on without failure –  Sufficient electricity to power WSN (~0.3W) 66 High Resolu;on Ground Eleva;on Monitor •  Con;nuously monitor surface eleva;on changes with differen;al GPS sensors –  Understand rela;onship between material balance and degree of subsidence/uplio –  Help understand water distribu;on in reservoir –  Satellite ­based InSAR system only takes a snapshot every 24 days –  Use a network of distributed GPS sensors for con;nuous monitoring •  More informa;on with downhole sensors –  But it is a very hard problem due to harsh environmental condi;on 02/28/2007 Sensor Networks, PTE587, USC 67 Underwater Sensor Networks •  Goal: extend sensornets to undersea applica;ons •  Poten;al applica;ons –  undersea 4 ­D seismic –  Remote equipment monitoring and opera;on Platform Supernode Buoy Robot Sensors Sensors 02/28/2007 Sensor Networks, PTE587, USC 68 Can We Use Current Land Sensor Nets? •  Radios Signals Do Not Transmit Well Underwater –  Water significantly absorbs radio waves •  Mica2’s Tx range is ~50cm in water (Sukhatme) •  Replace Radio with Acous;c Communica;on –  Long distances –  Large propaga;on delay •  Propaga;ng 200m needs 133ms(1500m/s) –  Need to work within the limita;ons •  Need New Networking Protocols 02/28/2007 Sensor Networks, PTE587, USC 69 Undersea Sensor Network Research •  Technical challenges –  Low ­power, sh...
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This note was uploaded on 05/31/2012 for the course PTE 587 taught by Professor Alejandrobugacov during the Fall '11 term at USC.

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