Zhou YuanMiao Pan| University of Houston 1

Miao Pan

ECE, University of HoustonCourtesy to UH students, Debing Wei, Li Yan, Steban Soto, Chaoxian Qi, Drs. Jiefu Chen, Aijun Song, and Gangbing Song

Thanks to the support of NSF under grant CNS-1801925

Riding the Stress Wave:

Integrated Monitoring, Communications, and

Networking for Subsea Infrastructure

November 05, 2018

Zhou YuanMiao Pan| University of Houston 2

Outline

Background

Stress Wave Channel Capacity Estimation

Stress Wave Assisted Hybrid Subsea Networks

Stress Wave Platform Development

Conclusion

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Impact of Subsea Environments

Offshore Drilling

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BP’s “Deepwater horizon” oil spill

Fire boat response crews battle the blaze of the off shore oil rig Deepwater

Horizon, in the Gulf of Mexico, April 21, 2010.

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Stress Wave Assisted Communications

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Stress Wave Assisted Communications

Stress Wave Assisted Communications in Subsea Environments

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Stress Wave Channel Capacity

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Sound Propagation Schemes

• Spherical Spreading for

Deep Water

𝑷 = 𝟒𝝅𝒓𝟐𝑰P: transmit power

I: power density

r: transmission range

• Cylindrical Spreading for

Shallow Water

𝑷 = 𝟐𝝅𝒓𝑯𝑰H: height from seafloor to surface

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Sound Propagation Schemes

• Acoustic wave guide

Stress wave

Acoustic wave

PipeActuator

Spreading loss can be significantly reduced!

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Stress Wave Channel Capacity Estimation

• Path loss model

10log𝑇𝐿(𝑑, 𝑓) = 𝑘 · log(𝑑) + 𝑑 · 𝛼(𝑓) + 𝐴

𝑨𝒃𝒔𝒐𝒓𝒔𝒂𝒕𝒊𝒐𝒏 𝒍𝒐𝒔𝒔:𝟏𝟎𝐥𝐨𝐠𝑻𝑳(𝒅, 𝒇) = 𝟎. 𝟎𝟎𝟗𝒇𝟐𝒅

𝑪𝒉𝒂𝒏𝒏𝒆𝒍 𝑪𝒂𝒑𝒂𝒄𝒊𝒕𝒚

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Hybrid Subsea Networks

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Hybrid Subsea Netwok

One Hop

13

Multi-hop

14

Hybrid

15

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Stress Wave Testbed Development

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Testbed

Stress Wave Actuator

Acoustic Modem

MSP 432

USRP

Water Tank

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Dispersion analysis for pipe geometry

Group Velocity Dispersion Curves

Alleyne, D. N., and P. Cawley. "The excitation of Lamb waves in pipes using dry-coupled piezoelectric

transducers." Journal of Nondestructive Evaluation 15.1 (1996): 11-20

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PZT Transducer Design

First design Second Design

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Pulse Position Modulation (PPM)

Resonance Frequency: 17-21 kHz

Static Capacitance: 1000±20% pf

Resonance Frequency: 17-21 kHz

Electromechanical Coupling Coefficient: 0.52

Size (OD×ID×H): 53× 46×41

mm

For encoded pulses sending

For cyclical pulses sending

Eight piezoelectric ceramic

plates in parallel with

tangential polarization.

Coding format

Correlation analysis

Channel

𝑝(𝑡) ℎ(𝑡) 𝑦(𝑡)

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Experiment for PPM

1. Input ‘00’ to send

an impulse

2. Cyclically send

pulses

3. Input ‘01’ to send

an encoded pulse

sequence

Channel impulse

response

Received waveform

Received waveform

Correlation

analysis

Correlation

analysis

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Experiment setup

Transmitter

Receivers

Channel Response

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Channel Response

Linearity analysis

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Channel Response

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Conclusions

• The offshore infrastructures can be leveraged for stress wave communications.

• Combining different types of communication techniques can significantly enhance network performance in subsea environments.

THANK YOU