The Health of Our Infrastructure

Wireless Sensor Networks

Carl Freeman (Chairman)Jarred Hayes

Kanaan KanaanMohamed Nabolsi

Dr. Warsame Ali Dr. Penrose Cofie

Table of Contents • Problem Formulation

Problem Statement Objectives Limitations & Constraints

• Project Planning Work Breakdown Structure Gantt Chart

• Literature Review Updated Literature Review

• Calculations• Conceptual Designs

Preliminary Design Final Design Final Functional Design

• Design Analysis • Hardware/System Software • System Implementation • References

Problem Formulation Need

The collapse of the I-35W Highway Bridge has brought attention to the lack of data consumption about the status and health of infrastructures around the globe.

Objective The objective of the project is to design an electronic device

that will monitor the health and performance of the bridge and periodically send a diagnostics report to the command and control station.

Limitations & Constraints

• Inexpensive • Durable & Easy System Maintenance • High-speed data transmission • Excess weight and pressure detection • Real-time alerts

Objective Table

Gantt Chart

Literature Review Piezoresistors (Pressure sensor) • Resistors whose resistivity changes with applied strain.By applying pressure you get a voltage that will relate to the amount of pressure that has been applied which in turn can determine how much deformation has occurred to a bridge.

Bao, Minhang. "Piezoresistive Sensors." Piezoresistive Sensors. Lausanne: Elsevier-Sequoia, 1991. 207-44. Http://www.mech.northwestern.edu. Web.

Transmitter • It can easily fit into a breadboard and work well with microcontrollers to create

a very simple wireless data link.• Since these are only transmitters, they will only work communicating data one-

way. you would need two pairs (of different frequencies) to act as a transmitter/receiver pair.

• Transmitter generates a radio frequency.• The purpose of transmitters is to send information over a distance.

Transmission Systems for Communications, 3rd ed., Western Electric Co., Winston-Salem, NC, 1985, pp. 44–60.

Receiver• Device that receives radio waves and converts the information.• Extracts the desired information, as need ( Audio , images, digital)

B. Chappel, et. al. “Fast CMOS ECL Receivers With 100 mV Sensitivity”, IEEE Journal of Solid State Circuits, vol. 23, no. 1,Feb. 1988.

Updated Literature Review • Feltrin, G., J. Meyer, R. Bischoff, and M. Motavalli. Proc. of 4th

International Conference on Structural Health Monitoring of Intelligent Infrastructure, Zurich, Switzerland. N.p., July 2009. Web System Design: Wireless Sensor Network components

1. Sensing interface2. Computational core 3. Wireless transceiver 4. Actuation interface 5. Application Software

Testing & Node PlacementMultiple nodes will be placed at different locations. Commination between the nodes and sink node will send the raw data of the natural frequencies and can be cleaned by a filter for better readings

• Network architecture: this network is divided into groups sensors units. Each group has a Local Site Master, this network work as:

1. Lower Tier: groups of sensor units communicating with their corresponding LSM2. Upper Tier: LSM communicating with each other and the controller.

TWO-TIER WIRELESS SENSOR NETWORK

Wendi Rabiner Heinzelman, Anantha Chandrakasan, and Hari Balakrishnan, “Energy-efficient communication protocols for wireless microsensor networks,” Proceedings of the Hawaii International Conference on Systems Sciences, Jan. 2000.

Wireless Sensor Networks

•The WSN is built of "nodes” each node is connected to one sensors. Each such sensor network node has typically several parts: a radio transceiver with an internal antenna or connection to an external antenna, a microcontroller, an electronic circuit for interfacing with the sensors and an energy source.

•A wireless sensor network (wsn) consist of spatially distributed autonomous sensors to monitor physical or environmental conditions such as temperature, sound, pressure, strain, ect.

Kayiram Kavitha, 2012 Workload-Aware Tree Construction Algorithm for Wireless Sensor Networks, International Journal on Applications of Graph Theory In wireless Ad Hoc Networks And sensor Networks

Wireless Modular Monitoring System For Structures

Lynch, J. P. 2002 Decentralization of wireless monitoring and control technologies for smart civil structures.Technical Report No. 140, John A. Blume Earthquake Engineering Center. Stanford, CA: Stanford University.

•Computational coreThe computational core is primarily responsible for the

operation of the wireless sensing unit, including collection of data from the sensor interface, execution of embedded computing procedures and managing the flow of data through the wireless communication channel.

The flexibility of the wireless communication network of system sensors allows for system modularity as well as reduced dependence upon a centralized data acquisition unit to coordinate the activities of the system.

Circuit Diagram

Half Bridge Type II• Sensitive to bending Strain • Rejects Axial strain • Sensitivity ~ 1.0

per , for GF = 2.0

R1 and R2 – Half-Bridge completion resistors R3 – measuring compression from Poisson effectR4 – measuring tensile strain GF – Gage Factorv – Poisson’s ratio Vch – Measured voltage of the bridge VEX – Excitation Voltage Vr - Offset compensated ratiometric bridge output

Calculations

• Communication Standard IEEE 802.15.4

• Pressure Senor

Wheatstone Bridge

•

•

Preliminary Design

Tilt Sensor

Weather Transmitter

Microcontroller

Strain Gauge Data Logger

Pressure/Temp Logger

Microprocessor

Data Station

Strain Gauge

Data storage center

Add time stamp

Data

Acq

uisiti

on S

yste

m

Senspot 1(Humidity)

Senspot 2(Tilt)

Senspot 4(Tilt/Pressure)

Senspot 3(Crack)

via active RFCommunication

Computer Analysis with SenScope software

Warning Alert

Prime Lithion Battery

Yes NoParameter Breach?

Design Concept 1

TracSenCorrosion SensorCrack Sensor

Strain GaugeTilt Sensor Temperature Transmitter

Alert

Is the operating temperature between -10 to 70°C (14 to 158°F)

Yes

User

Constant data transfer through RF

Clear Alert

Request Data

Storage

Data Logger

Receive Data

Daily data readings transferred through RF

Does pressure exceed limit?

Detected more than 0.1 degrees inclination?

Yes

System clear

No

Design Concept 2

NoYes No

Communication Standard IEEE 802.15.4

Economical Analysis Design Comparison

VS.

1. Strain Resolution: 1m Strain2. Acceleration & Vibration: resolution: 1mg, range adjustable

to ±2g, ±4g, ±8g, (g = acceleration due to gravity)3. Tilt & Inclination resolution: 12.9 arc second (0.003 degrees)4. Crack Width Accuracy 0.1mm5. Humidity & Moisture resolution: 1% RH6. Temperature resolution: 1°F

$150 - $200 per device

Easy-to-use software

Lithion Battery lifespan 30 years

Active RF Technology

$120 per device

Editable Software Package

Programmable Serial Ports

Programmable LEDs

Senspot XBOW Sensor Board

National Instruments NI WSN-3214

Programmable 4 Ch, Quarter-/Half-/Full-Bridge and Strain Gage Node

Qty: 1 $792.23

SGT-1LH/350-TY41

Half Bridge Uniaxial Strain Gage

Qty: 2Pack of 5

$42.80(2)=$85.60

TX4-100 Sensor and Transducer Wire and Multi-Conductor Cable

Qty: 1 $35.00

Equipment & Cost

Total: 912.83

Final Functional Design:Wireless Sensor Network Strain Gage/Bridge Completion Node

• support for hardware-timed waveform acquisition to the NI wireless sensor network (WSN) platform

• flexible analog front end, you can define sample rate, waveform size, and waveform interval

• high-speed and high-resolution analog input modes

• LabVIEW WSN Module, you can use graphical programming to customize the node’s behavior and add intelligence to perform local control, analysis, and data reduction

• support for logging, alarming, and web-based data visualization

National Instruments NI WSN-3214 Programmable 4 Ch, Quarter-/Half-/Full-Bridge and Strain Gage Node• four 1.5 V, AA alkaline or lithium battery

cells • 2.4 GHz, IEEE 802.15.4 radio that

provides up to 300 m outdoor range • -40 to 70 °C operating temperature and

50 g shock, 5 g vibration • Low-power operation with up to 3-year

battery life Advances: Single WSN Gateway Connection Star Topology – ability to connect 8 end

nodes Mesh Topology – connect up to 36

measurement nodes

4 Ch. Programmable Strain Gage

If Strain Approaching Max Strain

And Strain > Max Threshold

Trigger Alarm

Log Strain Readings in

Excel

Threshold Set Point

Trigger Warning

Flow Chart Based on LabView Code

Software: NI Labview Block Diagram

LabView Node Specifications Window

Software: Sensing Interface Front Panel

Data Frequency Captured with weight added

System Implementation

Aluminum Block

Strain Gauge

NI-3214Strain Node

Electronic Warning SystemRed Bulb: Max Strain Green Bulb: Operational Yellow Bulb: Approaching Max

Strain Gauge

Transducer Wire NI-9791Ethernet Gateway

References

1. Lynch, J. P. 2002 Decentralization of wireless monitoring and control technologies for smart civil structures.Technical Report No. 140, John A. Blume Earthquake Engineering Center. Stanford, CA: Stanford University.

2. Lynch J.P2005 Design of a wireless active sensing unit for localized structural health monitoring. J. Struct. Control Health Monit. 12, 405–423. doi:10.1002/stc.77.

3. Lynch, J. P., Law, K. H., Kiremidjian, A. S. & Carryer, E. 2002. Validation of a wireless modular monitoring system for structures. In Proc. of the 9th Annual Int. Symp. on Smart Structures and Materials, vol. 4696, pp. 124–135. San Diego, CA: SPIE—International Society for Optical Engi

4. Bao, Minhang. "Piezoresistive Sensors." Piezoresistive Sensors. Lausanne: Elsevier-Sequoia, 1991. 207-44. Http://www.mech.northwestern.edu. Web.

5. Held G. (2001). Data over wireless networks: Bluetooth, WAP, & wireless LANs. New York, New York :McGraw-Hill

6. Madisetti V.K., & willimas D.B. (Eds.). (1998). The digital signal processing handbook, Boca Raton,Florida: CRC Press.

7. Receiver. (n.d.). Retrieved from http://www.citrix.com/go/receiver.html8. Automation, Canberra, Australia. B. Elsener, H. Böhni, Potential Mapping and Corrosion of

Steel in Concrete, Corrosion Rates of Steel in Concrete, ASTM STP 1065 (1990) 143 – 156.9. Lynch, Jerome P., and Kenneth J. Loh. A Summary Review of Wireless Sensors and Sensor

Networks for Structural Health Monitoring. Rep. University of Michigan, Mar. 2006

References12. Wendi Rabiner Heinzelman, Anantha Chandrakasan, and Hari Balakrishnan, “Energy-efficient

communication protocols for wireless microsensor networks,” Proceedings of the Hawaii International Conference on Systems Sciences, Jan. 2000.

13. Feltrin, G., J. Meyer, R. Bischoff, and M. Motavalli. Proc. of 4th International Conference on Structural Health Monitoring of Intelligent Infrastructure, Zurich, Switzerland. N.p., July 2009. Web