NN D t ti F lt L tiD t ti F lt L tiNonNon--Destructive Fault Location Destructive Fault Location on Aging Aircraft Wiring on Aging Aircraft Wiring g g gg g gNetworksNetworksPart 2Part 2 Live Wires in FlightLive Wires in FlightPart 2 Part 2 –– Live Wires in FlightLive Wires in Flight

Paul Smith, Alyssa Paul Smith, Alyssa MagelbyMagelby, , DeekshitDeekshitDosibhatlaDosibhatla, Chet Lo, Cynthia Furse, Jacob , Chet Lo, Cynthia Furse, Jacob

GuntherGuntherU i i f U hU i i f U hUniversity of UtahUniversity of Utah

Center of Excellence for Smart SensorsCenter of Excellence for Smart Sensors

IEEE Antennas and Propagation International Symposium, June 23,

2003, Columbus, OH

NonNon--Destructive Fault Location on Aging Aircraft Destructive Fault Location on Aging Aircraft Wiring NetworksWiring NetworksPart 2 Part 2 –– Live Wires in FlightLive Wires in Flight

By: Paul Smith**, Alyssa By: Paul Smith**, Alyssa MagelbyMagelby**, , DeekshitDeekshit DosibhatlaDosibhatla**, Chet Lo, Cynthia Furse**, Chet Lo, Cynthia Furse**, Jacob , Jacob GuntherGunther****

Center of Excellence for Smart SensorsCenter of Excellence for Smart SensorsUniversity of UtahUniversity of Utah** and Utah State University**and Utah State University**50 S. Campus Drive50 S. Campus Drive 4120 Old Main Hill4120 Old Main HillSalt Lake City, Utah 84112Salt Lake City, Utah 84112 Logan, Utah 84322Logan, Utah 84322--41204120

Aging aircraft wiring has been identified as an area of critical national concern. As the system ages, the wires become brittAging aircraft wiring has been identified as an area of critical national concern. As the system ages, the wires become brittle le and crack, break, or and crack, break, or develop short circuits. Short circuits, in particular, have been implicated in a variety of smoke incidents, indevelop short circuits. Short circuits, in particular, have been implicated in a variety of smoke incidents, in--flight fires, flight fires, and crashes. Some of and crashes. Some of these faults are intermittent, occurring only sporadically as the physical vibration, stresses, temperatures, electrical loadthese faults are intermittent, occurring only sporadically as the physical vibration, stresses, temperatures, electrical loads, s, moisture moisture condensation, etc. change throughout the flight. When the plane is on the ground, no fault can be found. These types of procondensation, etc. change throughout the flight. When the plane is on the ground, no fault can be found. These types of probleblems are among ms are among the most frustrating for aircraft maintainers, resulting in a typical “no fault found” incident taking tens or even hundreds the most frustrating for aircraft maintainers, resulting in a typical “no fault found” incident taking tens or even hundreds of of hours to locate. hours to locate. Some planes even remain grounded for extended periods of time until basic electrical systems can be fully replaced at great cSome planes even remain grounded for extended periods of time until basic electrical systems can be fully replaced at great costost and labor. and labor. One of the greatest hazards of these systems is that they may foreshadow a more serious in flight hazard as a small fault groOne of the greatest hazards of these systems is that they may foreshadow a more serious in flight hazard as a small fault grows,ws, yet for all yet for all intents and purposes, the system checks out OK. intents and purposes, the system checks out OK. p p , yp p , y

This paper describes two systems based on spread spectrum technology that are the first known sensors that can actively locatThis paper describes two systems based on spread spectrum technology that are the first known sensors that can actively locate fe faults on live aults on live wires in flight without disrupting or interfering with existing 400 Hz power or 1553 data bus signals. These systems are fouwires in flight without disrupting or interfering with existing 400 Hz power or 1553 data bus signals. These systems are found nd to be highly to be highly robust to inrobust to in--line noise, connection mismatches, etc. They provide measurements accurate to within inches or feet over several huline noise, connection mismatches, etc. They provide measurements accurate to within inches or feet over several hundred feet of ndred feet of both shielded and unshielded cables. They can function accurately within a realistic network environment, and can locate intboth shielded and unshielded cables. They can function accurately within a realistic network environment, and can locate intermermittent short ittent short ci c its ( et o d a c e ents) in flight The senso de elopment and testing fo ealistic sit ations algo ithms fo enhaci c its ( et o d a c e ents) in flight The senso de elopment and testing fo ealistic sit ations algo ithms fo enhancenced data p ocessingd data p ocessing

APS 6-23-03

circuits (wet or dry arc events) in flight. The sensor development and testing for realistic situations, algorithms for enhacircuits (wet or dry arc events) in flight. The sensor development and testing for realistic situations, algorithms for enhancenced data processing, d data processing, and realand real--time analysis methods are described. time analysis methods are described.

Spread Spectrum Methods Spread Spectrum Methods

FDRSWR

•Many Signals•Noisy Channels

TDRSTDRSSTDR

•Noisy Channels•Interference Rejection•JammingL / Att ti

Timer•Loss / Attenuation•Multiple Channels•Multiple Paths•Stealth Communication•!! Communication PLUS Ranging

APS 6-23-03

SafeWire Commercialization PathSafeWire Commercialization PathSafeWire Commercialization PathSafeWire Commercialization Path

S f WiSafeWire

SafeConnector (Saver)

Handheld

SafeBreaker

(Saver)

SafeConnectorAPS 6-23-03

SafeConnector

AFCI ApplicationAFCI Application

AFCI AFCI Aircraft 2003Aircraft 2003--55

SSTDR:Patent Pending

Homes 2002Homes 2002

Spread SpectrumSpread Spectrum

Pending

(STDR / SSTDR)(STDR / SSTDR) Requires Requires

MiniaturizationMiniaturizationMiniaturizationMiniaturization

APS 6-23-03

The Tool Box : The Tool Box :

A l

Fault Location Methods Fault Location Methods Analog

Time DomainDigitalDigital

Capacitance

APS 6-23-03

Fault Location MethodsFault Location Methodsfrom the Utah Center of Excellence for from the Utah Center of Excellence for Smart SensorsSmart Sensors

Arc / Arc / LiveLive Cost NetwkCost Netwk In In

FDRSWR

//FrayFray SituSitu

TimerTimer No?No? No?No?

STDR / SSTDR STDR / SSTDR

FDRSWR

•Many Signals•Noisy Channels

TDRSTDRSSTDR

•Noisy Channels•Interference Rejection•JammingL / Att ti

Timer•Loss / Attenuation•Multiple Channels•Multiple Paths•Stealth Communication•!! Communication PLUS Ranging

APS 6-23-03

FDR / SWR for Fray DetectionFDR / SWR for Fray Detection

“Hard Fault” required“Hard Fault” required May run on live 400 Hz wires but haveMay run on live 400 Hz wires but have May run on live 400 Hz wires, but have May run on live 400 Hz wires, but have

poor noise immunitypoor noise immunity Cannot detect intermittent faultsCannot detect intermittent faults Cannot detect intermittent faultsCannot detect intermittent faults

APS 6-23-03

MilStd 1553 Plus SSTDR MilStd 1553 Plus SSTDR

APS 6-23-03

APS 6-23-03

DSSS CommunicationDSSS Communication� � � �

��������������

����� ��

����������������

��

� �

��������

���ω�τ)�

���������������

�������

������������

�������

�!�τ�"�

�#�

�$�

����%�

&����

����%�

APS 6-23-03

STDR/SSTDR CircuitSTDR/SSTDR Circuit

�(����)

!�����)����

�(����)�)�����)���

��*��

+����*��

����-�����������ω�

������!/���,������,�'�!�����)���

��������, .�

���-�������� � �

������!/

��&���'��� ���������

APS 6-23-03

"

#

!/

3�(��������)������4�����"#54�����'����������������������� 3�(��������)������4�����"#54�����'�����������������������

!/

0 10 "00 "10 #00 #10 $00 $10 200 0

0

#

�!

0 10 "00 "10 #00 #10 $00 $10 200 �#

0 /

"000

�

�!/

0 10 "00 "10 #00 #10 $00 $10 200 �100

0

100 �

��

��

�����

APS 6-23-03

STDR with Open Circuited CableSTDR with Open Circuited Cable

0.6

0.2

0.3

0.4

0.5

0.6

plitu

de (

V) &�67�

��)���

����7����8

"�

�/�'�7

����7����8

#���/

�'�7

����7����8

-0.1

0

0.1

0.2

-50 0 50 100 150 200 250 300 350

Cor

rela

tion

Am

pl

-50 0 50 100 150 200 250 300 350

Co

Distance (feet)

APS 6-23-03

SSTDR with Open Circuited cableSSTDR with Open Circuited cable

0.4

��)���

��8

�7/�'�7

���8

0.1

0.2

0.3

mpl

itude

(V

)

&�67���)

����7����8

"�

7�

����7���

#���/

�'�7

����7����8

-0.2

-0.1

0

-50 0 50 100 150 200 250 300 350 400

Cor

rela

tion

Am

p

-50 0 50 100 150 200 250 300 350 400

Distance (feet)

Sampled Data Sampled Data Minus Peaks

APS 6-23-03

SSTDR with Short Circuited CableSSTDR with Short Circuited Cable

0.3

0

0.1

0.2

0.3

plitu

de (

V) &�67�

��)���

����7����8 #�

��/�'�7

����7����8

-0.3

-0.2

-0.1

0

-50 0 50 100 150 200 250 300 350 400

Cor

rela

tion

Am

pl

"�

�/�'�7

����7����8

-50 0 50 100 150 200 250 300 350 400

Co

Distance (feet)

APS 6-23-03

75 ohm Coax with 28 V 60 Hz75 ohm Coax with 28 V 60 Hz

APS 6-23-03

Unshielded 22g with 28V 60 HzUnshielded 22g with 28V 60 Hz

APS 6-23-03

MilMil--Std 1553 Test DataStd 1553 Test Data

APS 6-23-03

STDR/SSTDR: “Dry” ArcSTDR/SSTDR: “Dry” ArcControlled Impedance CableControlled Impedance Cable

STDR

0.2

0.25

0.3

0.35

0.4

plitu

de (V

)

%����������

0

0.05

0.1

0.15

0.2

-10 0 10 20 30 40 50 60 70

Corre

lation

Am

plit

Distance (feet)

Baseline Sample 1 Sample 2 Sample 3

.��

Baseline Sample 1 Sample 2 Sample 3

0.05

0.1

0.15

itude

(V)

%����������SSTDR 32.5’ cableRG59 Coax

-0.15

-0.1

-0.05

0

-10 0 10 20 30 40 50 60 70

Corre

lation

Amp

litud

Distance (feet)

Baseline Sample 1 Sample 2 Sample 3

.��

(75-ohm controlled Z)60 Hz 28V

APS 6-23-03

Baseline Sample 1 Sample 2 Sample 3

STDR: “Dry” ArcSTDR: “Dry” ArcNonNon--Controlled Impedance CableControlled Impedance Cable

0.45

Original Data

00.05

0.10.15

0.20.25

0.3

0.350.4

rela

tion

Ampl

itude

(V)

.��

%����������

-0.050

-10 0 10 20 30 40 50

Corre

Distance (feet)

Baseline Sample 1 Sample 2 Sample 3

0.4

0.6 32.5’ cableDifference Data

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

-10 0 10 20 30 40 50Cor

rela

tion

Ampl

itude

(V)

.�� %����������

32.5 cableMultistrand Cable(non-controlled Z)60 Hz 28V

APS 6-23-03

-1-10 0 10 20 30 40 50C

o

Distance (feet)

Baseline10x(Sample 1 - Baseline)

10x(Sample 2 - Baseline)10x(Sample 3 - Baseline)

SSTDR: “Dry” ArcSSTDR: “Dry” ArcNonNon--Controlled Impedance CableControlled Impedance Cable

Original Data

0.1

0.15

0.2

de (V

)

%����������

g

-0.15

-0.1

-0.05

0

0.05

-10 0 10 20 30 40 50

Corre

latio

n Am

plitu

de

.��

-10 0 10 20 30 40 50

Distance (feet)

Baseline Sample 1 Sample 2 Sample 3

0.150.2

0.25

Difference Data

32.5’ cable

-0.25-0.2

-0.15-0.1

-0.050

0.050.1

0.15

Corre

latio

n Am

plitu

de (V

)

.�� %����������

32.5 cableMultistrand Cable(non-controlled Z)60 Hz 28V

APS 6-23-03

-0.25-10 0 10 20 30 40 50C

o

Distance (feet)

Baseline10x(Sample 1 - Baseline)

10x(Sample 2 - Baseline)10x(Sample 3 - Baseline)

STDR: “Wet” ArcSTDR: “Wet” ArcNonNon--Controlled Impedance CableControlled Impedance Cable

0.3

0.350.4

0.45

(V)

%����������

Original Data

-0.050

0.050.1

0.150.2

0.250.3

-10 0 10 20 30 40 50

Corre

lation

Am

plitu

de (V

.��

-0.05-10 0 10 20 30 40 50

C

Distance (feet)

Baseline Sample 1 Sample 2 Sample 3

0.30.40.5

)

Difference Data

32.5’ cable

-0.6-0.5-0.4-0.3-0.2-0.1

00.10.20.3

-10 0 10 20 30 40 50Cor

relat

ion A

mpli

tude

(V)

.�� %����������

32.5 cableMultistrand Cable(non-controlled Z)60 Hz 28V

APS 6-23-03

-10 0 10 20 30 40 50

Distance (feet)

Baseline10x(Sample 1 - Baseline)

10x(Sample 2 - Baseline)10x(Sample 3 - Baseline)

SSTDR: “Wet” ArcSSTDR: “Wet” ArcNonNon--Controlled Impedance CableControlled Impedance Cable

0.2

Original Data

-0.1

-0.05

0

0.05

0.1

0.15

0.2

orrela

tion A

mplitu

de (V

)

.��

%����������

-0.15-10 0 10 20 30 40 50

Corr

Distance (feet)

Baseline Sample 1 Sample 2 Sample 3

0.1

0.15

0.2

(V)

Difference Data

32.5’ cable

-0.15

-0.1

-0.05

0

0.05

0.1

-10 0 10 20 30 40 50Corr

elatio

n Amp

litude

(V

Distance (feet)

.�� %����������

32.5 cableMultistrand Cable(non-controlled Z)60 Hz 28V

APS 6-23-03

Baseline10x(Sample 1 - Baseline)

10x(Sample 2 - Baseline)10x(Sample 3 - Baseline)

Fault Location MethodsFault Location Methodsfrom the Utah Center of Excellence for from the Utah Center of Excellence for Smart SensorsSmart Sensors

Arc / Arc / LiveLive Cost NetwkCost Netwk In In

FDRSWR

//FrayFray SituSitu

TimerTimer No?No? No?No?

Application of Spread Spectrum to Application of Spread Spectrum to Wire TestingWire TestingWire TestingWire Testing

S t WiSmart Wire

Smart Connector (Saver)

Handheld

Smart Breaker

(Saver)

Smart ConnectorAPS 6-23-03

Smart Connector

© All rights reserved. No part of this © All rights reserved. No part of this presentation may be copied or reused presentation may be copied or reused p y pp y pwithout express written permission of without express written permission of the authors. Contact:the authors. Contact:Dr. Cynthia FurseDr. Cynthia Furse

www ece utah edu/~cfursewww ece utah edu/~cfursewww.ece.utah.edu/~cfursewww.ece.utah.edu/~cfursecfurse@ece.utah.educfurse@ece.utah.edu

IEEE APS 6-20-03