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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
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(Saver)
SafeConnectorAPS 6-23-03
SafeConnector
AFCI ApplicationAFCI Application
AFCI AFCI Aircraft 2003Aircraft 2003--55
SSTDR:Patent Pending
Homes 2002Homes 2002
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Pending
(STDR / SSTDR)(STDR / SSTDR) Requires Requires
MiniaturizationMiniaturizationMiniaturizationMiniaturization
APS 6-23-03
The Tool Box : The Tool Box :
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Time DomainDigitalDigital
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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
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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
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APS 6-23-03
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APS 6-23-03
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APS 6-23-03
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APS 6-23-03
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APS 6-23-03
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APS 6-23-03
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APS 6-23-03
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APS 6-23-03
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APS 6-23-03
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APS 6-23-03
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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/[email protected]@ece.utah.edu
IEEE APS 6-20-03