Data Collection Storage, and Retrieval with an Underwater Sensor Network SENSYS 2005

Data Collection Storage, and Data Collection Storage, and Retrieval with an Underwater Retrieval with an Underwater

Sensor NetworkSensor NetworkSENSYS 2005SENSYS 2005

I. I. VasilescuVasilescu  K. Kotay  D. Rus    K. Kotay  D. Rus  MIT CSAIL, Cambridge, MA MIT CSAIL, Cambridge, MA

M. Dunbabin  P. Corke  M. Dunbabin  P. Corke  CSIRO ICT Centre, Brisbane, CSIRO ICT Centre, Brisbane,

Australia Australia Speaker: Steven

OutlineOutline

• IntroductionIntroduction

• Hardware architectureHardware architecture

• ExperimentExperiment

• ConclusionConclusion

• Concluded my own wayConcluded my own way

IntroductionIntroduction

• A platform for long-term monitoring A platform for long-term monitoring of coral reefs and fisheriesof coral reefs and fisheries

• Consists of both static and mobile Consists of both static and mobile nodesnodes– Cameras, water temperature, and Cameras, water temperature, and

pressurepressure

• Optical and acoustic communication Optical and acoustic communication modelmodel

Introduction-problemsIntroduction-problems

• Power efficiency, deployment and repair Power efficiency, deployment and repair are harder in the underwater environmentare harder in the underwater environment– Mobile nodeMobile node

• Radio communication is no longer Radio communication is no longer practicalpractical– Radio waves are attenuated strongly in salt Radio waves are attenuated strongly in salt

waterwater– Optical and acoustic communication insteadOptical and acoustic communication instead

Introduction-optical and Introduction-optical and ultrasonicultrasonic

• OpticalOptical– Capable of higher data transmission rates Capable of higher data transmission rates – Propagation speed is closer to the speed Propagation speed is closer to the speed

of the lightof the light– Essentially directionalEssentially directional

• UltrasonicUltrasonic– A shared media that supports A shared media that supports

broadcastingbroadcasting– Low propagation rate poses a challenge Low propagation rate poses a challenge

for carrier-sense transmission strategiesfor carrier-sense transmission strategies

Hybrid communication Hybrid communication approach-optical and acousticapproach-optical and acoustic

• Optical system Optical system – shot-range line-of-sight data transfer shot-range line-of-sight data transfer – communication between a sensor node communication between a sensor node

and an AUVand an AUV

• Acoustic system Acoustic system – signal eventssignal events

•Notify the AUV about the exception situationNotify the AUV about the exception situation

– transmit small amounts of datatransmit small amounts of data

Optical transmitterOptical transmitter

• Luxeon 5 LXHL-PM02, Luxeon 5 LXHL-PM02, a 532nm green LED a 532nm green LED with approximately with approximately 700mW radiated 700mW radiated power while power while consuming 6W of consuming 6W of input powerinput power

• The choice of the light The choice of the light frequency is based the frequency is based the sensitivity of the sensitivity of the photodiode and the photodiode and the attenuation of light attenuation of light

Acoustic communication Acoustic communication systemsystem

• They build their own system to fit the They build their own system to fit the demanddemand– Shorter communication range, 25mShorter communication range, 25m

• Panasonic EFR-RQB40K5(receiver) Panasonic EFR-RQB40K5(receiver) and EFR-TQB40K5(transmitter)and EFR-TQB40K5(transmitter)

Introduction-static and mobile Introduction-static and mobile nodesnodes

• The advantage of mobile nodesThe advantage of mobile nodes– Provides means for deploying, Provides means for deploying,

reconfiguring, and retrieving the nodes reconfiguring, and retrieving the nodes in the networkin the network

– Permits large area coverage with sparse Permits large area coverage with sparse networksnetworks

– Can act as data mules to collect dataCan act as data mules to collect data

OutlineOutline

• IntroductionIntroduction

• Hardware architectureHardware architecture

• ExperimentExperiment

• ConclusionConclusion

• Concluded my own wayConcluded my own way

Hardware infrastructureHardware infrastructure

• Static underwater sensor nodeStatic underwater sensor node– AquaflecksAquaflecks

• Mobile underwater sensor nodeMobile underwater sensor node– Also known as Autonomous Underwater Also known as Autonomous Underwater

Vehicles (AUV)Vehicles (AUV)•AmourAmour

•StarbugStarbug

Hardware infrastructure-Hardware infrastructure-AquafleckAquafleck• ATmega128 processor, 128kbyte ATmega128 processor, 128kbyte

programming flash memory, 4kbyte programming flash memory, 4kbyte RAM,512kbyte flash memory for data RAM,512kbyte flash memory for data logginglogging

• Contained in a 170x100x90 mm watertight Contained in a 170x100x90 mm watertight yellow box up to 30myellow box up to 30m

• 532nm light, capable of a range of 532nm light, capable of a range of 2.2m/8m2.2m/8m3, 3, within a cone of 30 degrees, within a cone of 30 degrees, maximum data rate of 320kbits/smaximum data rate of 320kbits/s

• 30kHz FSK modulation with a range of 20m 30kHz FSK modulation with a range of 20m omnidirectional, data rate of 50bits/somnidirectional, data rate of 50bits/s

• 4 days of continuous operation with all 4 days of continuous operation with all hardware fully poweredhardware fully powered

Hardware infrastructure-Amour Hardware infrastructure-Amour AUVAUV• Used to dock and transport the Aquafleck Used to dock and transport the Aquafleck

nodes, and data mulingnodes, and data muling• 4 external thrusters4 external thrusters• Pressure sensor as depth feedback, Pressure sensor as depth feedback,

magnetic compass as orientation feedbackmagnetic compass as orientation feedback• 8bits microcontroller with 64kbyte of 8bits microcontroller with 64kbyte of

program memory and 2kbyte of RAMprogram memory and 2kbyte of RAM• Can dock with any mate whose docking Can dock with any mate whose docking

element is a 15.24 cm long rod of 1 cm element is a 15.24 cm long rod of 1 cm diameterdiameter

• Optical communication Optical communication

Hardware infrastructure-Hardware infrastructure-Starbug AUVStarbug AUV

• Used to locate the aquafleck nodes Used to locate the aquafleck nodes by vision, data muling and to dock by vision, data muling and to dock with Amour in order to provide visual with Amour in order to provide visual control feedbackcontrol feedback

• 2 stereo vision heads, downward for 2 stereo vision heads, downward for sea-floor altitude and speed sea-floor altitude and speed estimation, forward for obstacle estimation, forward for obstacle avoidanceavoidance

• Acoustic communicationAcoustic communication

OutlineOutline

• IntroductionIntroduction

• Hardware architectureHardware architecture

• ExperimentExperiment

• ConclusionConclusion

• Concluded my own wayConcluded my own way

Experiment of data Experiment of data collectioncollection

• Long term collection of temperature Long term collection of temperature and pressure data (Tingalpa Creek)and pressure data (Tingalpa Creek)

• Sensor nodes were deployed Sensor nodes were deployed approximately 1 km for a period of 3 approximately 1 km for a period of 3 daysdays

• Log data every 150 secLog data every 150 sec

Data retrieval using mobilityData retrieval using mobility

• A relative position of the network can A relative position of the network can be preloaded in the mobile node to be preloaded in the mobile node to locate the static nodelocate the static node

• Starbug located the next node using Starbug located the next node using visual odometry while Amour locates visual odometry while Amour locates the node using the magnetic the node using the magnetic compasscompass

Data retrieval using mobilityData retrieval using mobility

• Mobile node sends a request for data Mobile node sends a request for data • The data is transmitted either packet by packet or The data is transmitted either packet by packet or

in a groups of packets in a groups of packets – Depends on the quality of communication linkDepends on the quality of communication link

• If any packet is lost If any packet is lost – Time out and request againTime out and request again

• Transmission is completedTransmission is completed– Reset and erase the dataReset and erase the data

• Adjust the clock of a static node to the clock of a Adjust the clock of a static node to the clock of a mobile nodemobile node– For long term monitoring, clock need to be synchronuzedFor long term monitoring, clock need to be synchronuzed

OutlineOutline

• IntroductionIntroduction

• Hardware architectureHardware architecture

• ExperimentExperiment

• ConclusionConclusion

• Concluded my own wayConcluded my own way

ConclusionConclusion

• The first prototype for an underwater The first prototype for an underwater sensor network sensor network

• Still many technical challenges to be Still many technical challenges to be solvedsolved– How to control the mobile node in the How to control the mobile node in the

presence of currentspresence of currents

• Mobile node helps a lotMobile node helps a lot

OutlineOutline

• IntroductionIntroduction

• Hardware architectureHardware architecture

• ExperimentExperiment

• ConclusionConclusion

• Concluded my own wayConcluded my own way

Concluded my own wayConcluded my own way

• Just an application use the idea of sensor Just an application use the idea of sensor network yet it’s the first onenetwork yet it’s the first one

• Relatively new compared to e-home, Relatively new compared to e-home, military purpose, etcmilitary purpose, etc

• It continuously collect data for several It continuously collect data for several days nevertheless I think the transfer in days nevertheless I think the transfer in underwater environment is gradually, not underwater environment is gradually, not in a suddenin a sudden

• I can not believe that Aoyama will put her I can not believe that Aoyama will put her hand in Densha Otoko’shand in Densha Otoko’s

Thank youThank you