0 0.5 1 1.5 2 2.5 3 3.5

0.16

0.18

0.2

0.22

0.24

0.26

0.28

Depth of the Notch (mm)

Am

plitu

de

of E

nve

lop

e C

urv

e (

V)

Sampling Rate = 2MHz

Next-Generation Wireless Bridge Weigh-in-Motion (WIM) System Integrated with

Nondestructive Evaluation (NDE) Capability for Transportation Infrastructure Safety

Yang Wang a, Laurence J. Jacobs a, Jin-Yeon Kim a, Nasim Uddin b a School of Civil and Environmental Engineering, Georgia Institute of Technology

b Department of Civil, Construction, and Environmental Engineering, University of Alabama Birmingham

Introduction

Motivation

Project Background Wireless Unit Development Bridge WIM

Wireless WIM+NDE Development

This project seeks to develop a low-cost wireless WIM (weigh-

in-motion) + NDE (nondestructive evaluation) system as a

solution to the transportation infrastructure safety problem in a

novel two-fold approach: control of overloaded trucks and

safety assessment and monitoring of transportation

infrastructure. The system contains individual wireless sensing

nodes that integrate state-of-the-art WIM technology and

ultrasonic NDE functionality. The result will be a transportation

infrastructure monitoring and protection system that is highly

portable, effective, and operation will require little manpower.

The main components of this system include: 1) a wireless

sensing system for real-time data acquisition and online

delivery; 2) tools for data analysis and interpretation; and 3) a

database for storage and archival.

Subject GPA Comments

Roads D ● Poor road conditions cost each US motorist

$324 per year in repairs and operating costs

Bridges C+ ● One in nine of nation’s bridges rated as

structurally deficient

Dams D ● More than 4,000 deficient dams, including

2000 deficient high-hazard dams

ASCE 2013 Ratings on America’s Infrastructure

I-35W Bridge Collapse, Minnesota

August 2007 (13 Casualties)

Teton Dam Collapse, Idaho

June 1976 (Damage: $2 billion)

Basket Lift Extensive Climbing Rigging

Current Practice for Bridge Inspection

Communication Network: from Wired to Wireless

Wireless

Sensor Units

Embedded

Sensors

Central Data

Server (CDS)

Coaxial Cables

Installation of wired system can take about 75% of total testing

time for large structures. (Straser and Kiremidjian, 1998)

$5,000 per sensor channel, half of the cost on cabling and labor.

(Celebi, 2002)

0.5mm

1.2mm 3.2mm

2.3mm

Steel specimen with

different notch depth

Diffuse ultrasonic NDE for

concrete specimen

Wedge ultrasonic transducer

Concrete bridge

component

Transmitter Receiver

Wireless

device

Surface crack

Ultrasonic NDE

BWIM shema SiWIM Bridge

Weigh-in-motion

system

Bridge Weigh-in-Motion

Wireless unit

Ultrasonic transducer

Excitation signal conditioning Output signal

conditioning

Laboratory Experiment

Excitation signal

conditioning

Transmitting ultrasonic transducer

Receivingultrasonic transducer

Output signal conditioning

Wireless unit

0 ~ 3.3V

-10 ~ 10V

-10 ~ 10mV1.65V ± 200mV

0 0.5 1 1.5 2 2.5 3 3.5 4

x 10-5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

Time (sec)

Am

plit

ude (

V)

Cabled system (250MHz)

WSU (2MHz)

Wireless Measurement Validated by Cabled system

Sensor Signal

Digitization

Analog-to-Digital

Conversion

Computational

Core Wireless

Communication

900MHz or

2.4GHz Wireless

Transceiver

Weigh-in-

motion (WIM)

sensors

External

Memory

Micro-

Processor

Sensor Signal

Conditioning

Amplification,

filtering, and

voltage-offsetting

Output Signal

Amplification

Amplification and

voltage-offsetting

Transmitting

ultrasonic transducer

Receiving

ultrasonic

transducer

Wireless Sensing Unit

Wireless NDE

Wireless NDE Result

Comparison of two algorithms -- run 5

A2+A3GVW

A1 A2 A3 A4 A5 Single A4+A5

-50

-40

-30

-20

-10

0

10

20

30

40

50

Pe

rce

nta

ge

err

or

(%)

SiWIM algorithm Proposed algorithm item

Future: Wireless Drive-By Inspection

Drive-by bridge

inspection system Portable bridge

weigh-in-motion

Bridge safety

management

Internet

Local

gateway

Office PC

AT&T

server

GPRS

Cell phone

tower

GSM/

GPRSWireless unitWireless unit

Wireless unit

Wireless unit